Fast355

iTrader: (2)

I recently ported a pair of TBI 350 193 swirl ports as an experiment. I went into it knowing that they are swirl ports and can only have so much potential. Thing is when I got done and had a buddy flow bench them, the flow #s suprised the hell out of me. Not bad for 8 hrs with a air grinder.

Valve Lift------Intake Flow---------Exhaust Flow
.050--------------35.6----------------------31.0
.100--------------72.4----------------------60.5
.150-------------105.8---------------------87.3
.200-------------133.4--------------------124.2
.250-------------154.1--------------------147.3
.300-------------180.6--------------------171.5
.350-------------195.5--------------------184.7
.400-------------209.3--------------------196.3
.450-------------217.4--------------------203.7
.500-------------224.3--------------------215.6

All I did was knock the casting flash off the intake, reworked the intake bowl area and swirl ramp (swirl ram is still in place), then reworked the exhaust like you would any small block head. I also unshrouded and opened up the chambers slightly around the intake and exhaust valves. The heads still exhibit very strong swirl. While cleaning them I sprayed water into the intake port and recieved an unexpected shower. The swirl port literally threw water out in about a 6' diameter area. The heads were flow benched at 28 in/h20 just like any other head.

Notice how much better the exhaust flow is than the intake considering the intake is through a 1.94" valve and the exhaust a 1.5"

These heads are going onto a 350 TBI with either a vortec cam or LT1 cam. Probably the vortec since it only has a mild performance spring and considering that over camming won't help performance much.

I wish that someone knew what these things flowed stock??? Should have thought to check one before I reworked it.

kdrolt

Hah !!!

It's too soon for 1 April, so assuming that your post is no joke, then IMO you confirmed Dyno Don's previous work (at least the head-flow portion) and posts on porting the swirl port (193 casting) heads. DD did measure his heads before he ported them. Let me see if I can find the post:

https://www.thirdgen.org/techbb2/sho...hreadid=177465

Peak numbers, stock heads:
178 cfm intake
146 cfm exhaust

I don't think he ever posted the full set of number before porting, but he did for the after-porting results.

This data lends more credence to JPrevost's comment that a single pattern cam might be a better choice when using these heads, mostly due to the superior exhaust flow. Of course, this also blows a major hole in the tiresome hearsay comment that swirl port heads are junk, just because they don't "look" right.

I know you retained the stock-sized valves -- but did you back-cut them? That would improve the numbers at low-lift.

Last questions: are you an experienced porter of heads and did you spend TONS of time porting them?, because I'm expecting comments to that effect next.

Thanks for posting.

Formula4Speed

Port shape and size means more than flow #s. The cross-sectional area of the port is more critical than anything. There are 2 areas of the port that need to be a certain size for a cylinder head to support so much horsepower in a desired rpm range. Velocity is key. Not to say those aren't good flow numbers, but numbers can be deceiving.

Fast355

iTrader: (2)

I know the final say will be the chassis dyno and track.

The air velocity around the outer edge of the swirl ramp and bowl is very high. Used a hair dryer set on low to blow into the port and a mist of water to see what kind of velocity and swirl the port made.

I used stock sized valves from Precision engine parts their pro series. They were cheap when I bought them a year ago, are under cut, swirl polished, stainless and of a very high quality. I got them from a local engine builder. When I was learning how to port (had an expert friend help me through the first set (my 601 305 heads) the precision engine parts valves in those heads were worth almost 15 cfm on the intake and 8 cfm on the exhaust with no changes other than changing the valve.

The valves were done with a 5 angle valve job. (Buddy had the tools so all it took was a little extra time)

I also spoke with three professional porters and they told me that the swirl ports are GMs sleeper heads. One told me that he is consistently able to make them perform up to vortec horsepower levels on an engine dyno. He also commented that the low to mid range torque was much greater on the TBI heads. When you get to thinking about it if it cost $400-600$ to get a set of TBI heads rebuilt and ported to vortec levels it would be very worthwhile. All you have to do is increase the velocity and open up the port slightly below and around the swirl ramp. I also ground the swirl ramp into a U shap to help it flow better. You want to keep the swirl ramp because it greatly adds to the flow through the valve at low lifts by litterally spiraling it out in 360* around the vavle.

I wouldn't really call myself an experienced porter although I have ported about 5 sets of heads and have about 200 hours on my air grinder. Total time for these heads including research and valve job cam to just under 20 hours. I only spent about 8 hours with the air grinder in my hand.

My first set of 305 HO heads flow about 15 cfm more on the intake and 20 cfm less on the exhaust.

All of the ports flowed within a few CFM of each other so I must have done something right.

I am glad that in my moment of indecisiveness last night I stuck the 1993 F-Body LT1 cam I have laying around my garage into the engine. I believe that that cam is a single pattern. The heads are on the shortblock, the cam is in it, all the lifters are in, pushrods set, valve covers are on and finally the edelbrock performer manifold is back on. The engine is back in, all the accessories are installed and the engine was test run for 15 minutes.

I am topping this engine with a TBI w/ ultimate tbi mods, 65 lb/hr injectors, and 15.5 psi fuel pressure. I know I am going to have to do some chip work but that isn't a problem. I have played with burning chips and have had a 454 TBI sytem running on a 307 olds with good results.

Fast355

iTrader: (2)

This site is of a truck that is still using swirl ports and inspired me for doing the same.
http://www.elmnet.net/~lange_c/c1500.html

It is running low 15s with the crummy edelbrock 3702 cam. That cam only has like 194* & 214* duration @ .050 and .398" of lift intake and .442" exhaust. Imagine how much more power would be had by running a LT1 roller cam and the proper chip(not a mail order one). I bet that truck would be in the low 14s or high 13s with a little more cam, a little more stall, and a better tune.

kdrolt

The port size on the 193 heads is in the 170 cc range (Dyno Don posted the size once); he got 168 cc unported and 175 cc after porting. I doubt Fast355 removed enough material to make a dent in the port volume.... so the flow numbers aren't deceiving, especially given the use of the 1.94 and 1.50 valves. It's a math exercise to determine the flow velocity once you have the cfm values and the port & valve areas. Since the port volume is small (compared to other heads), and since the 193 uses small-ish 1.94/1.50 valves, then it stands to reason that the flow velocity has to be very good to make the flow numbers measured.

Using either the curtain-area of the intake valve, or using the facial area of the intake valve (the numbers are very close), the average flow speed at max lift (and max flow) is:

2182.5 in/sec, or
181.9 ft/sec, or
Mach index 0.165

which is well below Taylor's Mach index threshold of 0.5.

If we want the peak flow (rather than the average flow) then the numbers will roughly double to 364 ft/sec, and 0.33 Mach index which is still under 0.5, so there is room for more improvement -- probably by removing the swirl ramp, but that would defeat the swirl, and less swirl means more ignition advance.

I've said it before --- advance is needed to make optimum power because the combustion event inside the chamber is so slow --- but this also has the disadvantage of increasing pressure in the cylinder when the piston is still climbing twds TDC. It's a necessary tradeoff: give up some work done on the piston while the piston is still climbing in order to get more complete combustion so that optimum power can be made on the piston downstroke.

If you could reduce the need for lots of ignition advance, by making the flame/combustion event occur faster (via intaker swirl), then more work could be done on the piston during the downstroke. That's one reason for adding swirl, either via the ramp in the 193 casting, or via the inlet port and combustion chamber shape in newer heads (LT1, LS1 etc).

Fast355's heads are flowing as good as stock iron L31/LT1 heads on the intake, and much better than L31 LT1 heads on the exhaust. The combustion chamber shapes are basically the same on all three heads (193 L05, LT1, L31) so it's not a stretch to think that the LO5 heads still have better swirl among all three.

If Fast355 dynos the heads (on an engine) then it will be interesting to see how little ignition advance he needs to make optimum power.

kdrolt

LT1 cams are dual pattern:

Bcar LT1: 191/196 deg i/e
F & Ycar LT1: approx 202/207 deg i/e

Fear not.... because the exhaust system you use on the Fcar won't flow as well as it would in a larger car (Caprice/Impala) or C/K truck simply because each of those has more room to run a full set of duals.

So you'll lose some of the exhaust port flow due to the exh restriction downstream. The LT1 cam ought to make it fairly easy to tune the combo.

Thx for the info on the valves (already backcut) and seats (5 angle). Also interesting what your bud said about the heads in relation to the LT1/L31s. It dovetails with my own (unproven) comments.

Fast355

iTrader: (2)

Port volume ccd to around 180 so the volume went up about 10 cc which is really no big deal in past experiences.

My buddy uses about 32* advance on his carbed TBI head engines to make max power. I watched him dyno a carbed early 80s truck. Any more timing and he looses power but audible ping does not occur until about 38* where the engine is already down almost 25 RWHP.

The engine isn't going into a F-car it went into a G-van in place of the one that currently has a broken piston.(That engine is eventuall going to be rebuilt and find its way into a F-car) It has headers and 2 1/2 duals into 40 series flowmasters so exhaust flow is not a problem or a restriction.

The old combination with 10.3:1 compression was just a little much for towing in hot weather with the A/C on as it started to detonate (broke a piston)

A already broke the engine in and it idles pretty smooth with only a little surging due to the commanded 500 rpm idle. When the engine was running at speed for the initial break in the engine actually ran real smooth and sound real good. I will take it out this afternoon after I finish up everything to do some data loging and to seat the rings. While breaking the engine in I saw between a 124 and 118 blm which isn't bad. I am using a factory TBI computer, 15.5 psi fuel pressure, and 4* initial advance. That is what seems to make the engine happiest.

kdrolt

I've looked at that one before. I think the big problem is the lack of good tuning. The cam isn't great, but it's still warmer and higher-lift than the LT1 Bcar cam (191/196 deg i/e; 0.418/0.430 lift i/e). The Bcar LT1 is 260 fwhp and 330 fw ftlbs stock, and will run a 4200 lb Caprice to 15.0 to 15.3 @ 89-91 mph depending on conditions. With air cleaner and muffler mods, the car will run mid 14s and gain 20+ fwhp.

A C/K truck weighs similarly, but isn't as aerodynamic. So his cam should make up for the aero difference --- yet he runs only mid 15s @ 87+. IMO his problem is ECM tuning, as you said; he shouldn't be using a mail-order chip.

Fast355

iTrader: (2)

I helped a friend do the ultimate TBI mods, put headers, edelbrock TBI intake and a melling MTC1 cam into a 1994 chevy truck with a 350 (don't like the edelbrock TBI cam as it isn't much hotter than stock). The mellings cam ran good with the factory TBI injection and about 15 psi fuel pressure and 4* advanced. The thing pulled great from about 1,200 to the 4,500 rpm shift poit. Those 3 mods really woke the 350 TBI engine up. Truck dyno'd 230 rwhp an 290 ft/lbs at the rear wheels through a 4L60E. Probalby would have run better with a better tune.

The Mellings cam specs out at 204* intake and 214* exhaust at .050", .422" Intake lift and .444" exhaust lift and 114 lobe center.

Idle was a little different from stock but still made 20 in/hg of vacuum and had great throttle response. Not to mention the mods were made when the timing chain needed to be changed and only cost about $500 total.

BronYrAur

iTrader: (1)

Very impressive numbers Fast355. kdrolt, you must be proud, you've been talking about how you knew they'd flow well for a while now.

ShiftyCapone

iTrader: (7)

If it is okay with you guys I will like to merge this thread into the one JP started on swirl ports. The info in here is too good to let it slide down the page.

25THRSS

How do the 305 TBI heads differ from the 193's as far as port volume, combustion chamber, etc? I know the 193's have larger combustion chambers than the 58 CC chambers of the 305 TBI heads, but are they identical otherwise?

Fast355

iTrader: (2)

They have smaller intake valves but a similar chamber and intake ports. The exhaust ports are common amoung pretty much every SBC.

25THRSS

So the intake and exhaust port cc's are identical?

Fast355

iTrader: (2)

I am pretty sure the exhaust are but the intake is anyones guess. I haven't messed much with the 305 swirl ports other than have done valve jobs on them etc.

Fast355

iTrader: (2)

Worked on it some more this evening and have a funny story.

Actually datalogged and used a wide band on the engine today. It doesn't even need much if any more tuning after the first two chips. All I did was adjust the injector constant, change the PE and open loop air fuel mixtures, and eliminated the PE timing and added what was needed to the main fuel table. Wide band says that I am at 12.7: 1 all the way across the board while in PE. I can live with that. VE tables seem pretty close because I am sitting at 124-127 BLM across the whole table.

The engine runs like a rapped ape even pulling all that weight and those gears. Had a friend with me when I was datalogging. He was running the laptop and the wideband while I was driving. A civic with a wing and fart can pulled up next to me at a light. Keep in mind that I am datalogging and using moderate acceleration out of lights, up this hill that is about 1 1/2 miles long. On top of the hill is a flat, straight section of road that is divided by a concrete dividing wall for several miles. Nothing out past this light as it is between two cities. Figured it would be a good place to populate the 80-100 KPA sections while under moderate loads and at speed as the limit is 70 on this particular road. Start off from the light at about 1/3 throttle partially due to the fact it is a new engine, and I wanted to check AE. Only problem is the tires screech a little due to the instant torque rise and the fact that I am sitting on a hill. Also my 40s are kicking out their mean growl. Civic kid thinks that it means I am trying to race him, so he nails the pedal. Well once I get traction I hit it to 2/3 throttle, transmission shifts into 2nd @ about 2,800, goes through 2nd, shifts 2-3 at 2,800. It then goes into OD at about 75 and the converter locks up. All this time I hear this little engine screaming beside me. All I do is keep it about 2/3 of the way down and I started leaving him like he was sitting still (his engine screaming, mine just loafing along at Part Throttle, in OD up this hill).

My laptop recorded 108 mph on the dataloging while in OD at 1/2 throttle with 3.08 gears in closed loop with STOICH set at 15.4:1!. Talk about some mid-range torque.

Didn't actually think that I had it much over 85 (needle was pegged but you don't pay much attention to it at that speed) but apparently the VSS and WinALDL think that I did.

Basically I beat a civic in a 5,300 lbs brick, with a 355 TBI, 3.08 gears, at part throttle, while driving up a large hill.

stew'86MCSS396

Interesting thread...I have a LO5 and been contemplating to slap on 081s (I think) but am thinking that with those numbers, it'll support my goals. The LO5 might end up in my bro's truck after I'm done playing with it so I'm not in a horsepower war with anyone. Only thing...I've never done any head porting except grind out that little hump in the exhaust of some smog heads of yesteryear. I'd appreciate any comments and pointers. Oh and in case anyone has ideas like go buy some AFRs and be done with it, I'm on a free budget...like free heads, free LT1 cam, free... Let's keep the topic "193" heads! stew

kdrolt

I just came across these articles. They're quite old, but relevant to the discussion.

This one is recent (1999), but it refers to a review of the original work:

http://www.theoldone.com/articles/Th...5FHead%5F1999/


From 1986:
http://www.theoldone.com/articles/Ci...Commentary.jpg

Here are the earlier articles, circa 1985:

http://www.theoldone.com/articles/Ci...rl_Power_1.jpg
http://www.theoldone.com/articles/Ci...rl_Power_2.jpg
http://www.theoldone.com/articles/Ci...rl_Power_3.jpg
http://www.theoldone.com/articles/Ci...rl_Power_4.jpg
http://www.theoldone.com/articles/Ci...rl_Power_5.jpg

http://www.theoldone.com/articles/Ho...ng_Heads_1.jpg
http://www.theoldone.com/articles/Ho...ng_Heads_2.jpg
http://www.theoldone.com/articles/Ho...ng_Heads_3.jpg
http://www.theoldone.com/articles/Ho...ng_Heads_4.jpg
http://www.theoldone.com/articles/Ho...ng_Heads_5.jpg
http://www.theoldone.com/articles/Ho...ng_Heads_6.jpg
http://www.theoldone.com/articles/Ho...ng_Heads_7.jpg

http://www.theoldone.com/articles/Ho...oft_Head_1.jpg
http://www.theoldone.com/articles/Ho...oft_Head_2.jpg
http://www.theoldone.com/articles/Ho...oft_Head_3.jpg

All of these were found here:
http://www.theoldone.com/articles/

There's a lot of other good reading starting at Endyn's main page:

http://www.theoldone.com/

FWIW, HTH.

JPrevost

Wow, how did I let this topic slip through my gaze?
Awesome work on the heads. The swirl ports are junk and I'm not the only one speaking this. First off, the intake flow numbers aren't good compared to other ported heads and even some stockers.
The reason you can get decent power out of these heads is for two reasons. First is the relatively low RPM and second is the inherent design flaw of the SBC being it's poor exhaust port design. Fix the exhaust port on just about any SBC head and it'll perform remarkably better than stock!
Want more proof that I'm not the only guy that thinks these heads are still junk, well check this out.
http://www.theoldone.com/articles/Ho...ng_Heads_3.jpg
Read Kent Ford's interview and you'll see what I've been trying to preach for that past few years.
Swirling at high engine speeds actually is detromental to keeping the AFR in the cylinder Homogonous. Like that test with spraying water and watching it fling out from the chamber, again proof that swirl in the intake track is BAD. Believe in what works and the direction that the rest of the automotive world has taken too... quench and tumble. Swirl is done during quench but to make peak horsepower don't swirl the intake air flow.
Also, if you want REAL flow numbers with heads you need a better test bench than a "superflow". They're really useless when comparing heads to one another. They're only good for back to back comparisons of the same head before and after porting. Install a LONG cylinder between the head and flow bench and you'll see again why swirl on the intake is a bad idea, then spray in some water and see what happens to the mix.

edit- Yes I'm slightly biased but remember that I too still own a swirl port headed vehicle AND vortec. Vortec heads are lean mix fast burns, the 193 heads are not, they're like revision 1 compared to revision 10 with the vortecs being that much better. The only reason I wouldn't recommend vortec or fastburn heads to somebody is if they are on a REAL tight budget or they don't want to deal with a different intake manifold (which is stupid if you ask me).

Fast355

iTrader: (2)

I'm not running 6,000+ rpm and chances are most of this board is not. 5,000 rpm is a very reasonable rpm limit for a STREET driven vehicle. Come on we are not talking about making 7,000 rpm TBI 305s or 350s for that matter.

For power under 4,000-4,500 rpm the swirl ports are very hard to beat. I doubt the vortecs could lay down the low speed torque that these 193s can. It turned out to be a great combination for me. The engine is still pulling at the 5,000 rpm shift point that I adjusted my 700r4 for.

On a street engine how often are you going to turn it to 4,000+ anyways? I would rather have an engine that is capable of as much acceleration at 1/2 throttle and 3,000 rpm as WOT and 5,000. But then again that is just me.

JPrevost

Simply put... I think anybody looking to keep their "low end" in their street f-body's is living too old school. Live and learn, we're driving sports cars and have v8's. You'd really have to try HARD to get rid of the low end grunt of any v8. If you're happy that's all that matters.

NorcalZ71

Fast355, how did your build turn out? Did you get Dyno numbers? Im looking at just porting my stock 350 TBI heads such as you did and throwing in a mild cam (LT1, 2030, something along those lines) and then tuning, just to get my feet wet in chip burning and for a little more power this summer.

Fast355

iTrader: (2)

Double

Fast355

iTrader: (2)

JPrevost-You forget that not all TBI board users are third-gen specific!!!! Many TBI applications need to retain low-speed torque. This is really one of the best TBI boards I have found. The users have caprices, trucks, S10s, etc.

On to my engine now. The thing runs awesome and is still getting 17-19 mpg on the highway on my 40 mile commute. I took it to the 1/8 this last weekend and ran a 10.32 @ 70 with a 2.55s 60", which isn't bad considering it is a two barrel 350 pulling a 5,000 lbs brick with 3.08 gears and an automatic. I left the line at idle and let the transmission shift 1-2 automatically at 5,000 rpm and trapped the 1/8 at about 3,800 rpm in 2nd. Even with 255/70/r15s and a posi, traction is still an issue. I am also very gear challenged. I have not dynoed mine yet as I am still dialing everything in. By my 1/8 mile run I would say that I am atleast making decent HP and TQ.

NorcalZ71- In an above post I mentioned the specs of a friends 94 350 TBI truck that I helped modify. The cam was a basic, cheap RV cam that ended up with good results even on the stock tune. All that was done is advance the timing some and add fuel pressure. Car Craft got like 185 RWHP out of a bolt-on 350 TBI truck engine without going into it. On the otherhand this truck was 234 RWHP and 295 ft/lbs to be exact. Very little was done to this truck, RV cam, raised fuel pressure, headers, ultimate TBI mods, open element, and an Edelbrock intake (might as well since it is off for the cam swap). The truck runs great despite the mods and the factory ECM tuning, in fact he gained about 1-2 m.p.g. over stock.

NorcalZ71

Fast355: thanks bro, definitely have to look into it all. A guy over on another of my forums (fullsizechevy.com) has a 212/348 rear wheels 350. He used the 2030 cam, new springs and lifters i believe, bored out TBI w/ injector spacers and 55lbs/hour injectors, port matched stock intake w/ a 3" single exhaust through a high flow cat and then tuning. I am thinking I would do similar to him, as 212/348 at the rears is pretty impressive i think, but also do some head porting such as you did.

Fast355

iTrader: (2)

The mellings MTC-1 cam that is in that truck is almost the same if not the same as the crane 2030 cam. I ran it in my 305 headed 350 before switching to the LT1 cam. It made nearly identical numbers to my friends truck on the stock 1992 van prom and tbi setup.

What gear was the torque dynoed in 2nd? 348 ft/lbs is roughly 425 ft/lbs at the crank!!!! I thought the 295 (360 flywheel tq) out of my friends truck was good.

My 10.3:1 compression 305 HO headed 350 TBI with mellings MTC-1 cam made 225 RWHP @ 3,800 rpm and 315 ft/lbs @ 2,300 which was the lowest the transmission would stay in 3rd gear(with a 6.2 diesel 3,800 rpm governor in it). I wanted to see what the torque was like and had the governor sitting around so, I got my numbers.

kdrolt

Using Cartest as the math tool (on a computer), I mimiced your parameters closely but conservatively: 4900 lb vehicle weight, 700R4/4L60 gearing, 3.08 rear, 255/60R15 tires, and (guess) 70" tall by 75" wide frontal area and a Cd=0.40 (brick aero).

I needed 255 fwhp and 330 fwftlbs to run 10.35 @ 69.9 mph at 660 feet (1/8th mile). The quarter mile was 15.7 @ 85.3 mph. BTW the code gave a 2.0 sec 60' time, so the code assumes ideal traction and you don't have that (as your said).

So that means you are making more torque than 330 ftlbs, and at least 255 fwhp (though the hp estimate is probably close). Those numbers are exactly equal to the stock L31 "Vortec" 5.7 engine output. And I agree with you that the torque/hp you are making are decent, and probably excellent given that you aren't a professional head porter, and that the heads are junk, and that you didn't make your flow measurements on a good flow bench.

I also can't be sure how close my estimates for the van (frontal area, actual weight with fuel+driver) are to what you had when you ran at the track. Still, it does confirm what the approximate engine output is.

Again, using the computer and just for fun I "yanked" your engine out of the van and put it into a 3rdGen Fcar using 3500 lb weight, 3.42, same trans: 9.39 @ 79.1 mph in the 1/8th mile and 14.2 @ 96.9 mph for the quarter mile. i.e. similar to a L98 Fcar.... which is reasonable given than the L98 had 240 fwhp and 350 fwftlbs.

Given that the heads breathe so well now, I wonder if you are running too lean. With the heads flowing equal to LT1/L31 on the intake side, and much better than either on the exhaust, with an Fcar LT1 cam installed, you should be making more like 280+ fwhp, so that makes me think you are running too lean at the high end.

FWIW, swirl port heads are fast-burn. That's why the swirl ramp was put there, and why the chamber shape of the 187/193 heads is shaped the way it is -- both to promote fast burning and low emissions from very little ignition advance. The GM literature of the day calls them fast-burn too. The LT1 and L31 heads also have the same chamber shape, to promote swirl from the chamber shape. What we don't have is the factory (or factory-sponsored) flow, swirl and tumble test data on the 187/193 and LT1/L31 heads. Obviously the factory eliminated the ramp and gained higher flow as a result --- we just don't know how much of a change in the swirl it made and we don't know what the optimum amount of flow/swirl/tumble should be.

Fast355

iTrader: (2)

It actually weighs more like 5,300 lbs with a full tank of gas, me, and my tools in it. The van is 80" tall, 79.5" wide and 8" ground clearance. I have read somewhere that the CD is around .380. I have a 700r4 with a 2,000 rpm stall, shifting at 5,000. The rear is 3.08 as you stated and I mentioned before. You have my tire size wrong (don't know how much it would affect it), I have 255/70/r15s. That means I am actually geared taller than you have in your setup now, because the tire is taller

I know that I am lean even with the 65 lb/hr injectors at 17 psi and my chip burning. I still need to get the PE right. I am about to change to 454 injectors and change the BPW in the chip. Maybe this weekend I can run again.

Looks like I am well below the power estimates of DD2000.

RPM------HP-----TQ
2000----145----381
2500----181----379
3000----216----378
3500----249----373
4000----271----355
4500----279----326
5000----268----281
5500----239----228
6000----198----173

Also looks like I am over-reving the engine for the best time? Maybe my shift points should be about 4,500?
9's should be close enough to taste!!!! Don't forget that I also launched at idle (650 rpm), by just mashing the gas. I think it is time for traction bars, LOL.

My friend ran his 1993 civic hatchback 5 speed with about 2K in mods(Header, Cold Air intake, Del Sol ECM, Cat-back, High Flow Cat, Pulleys, Adjustable Timing Gear, Cam, raised compression, ported head) and only ran a 10.3 so I don't feel too bad.

I have 1K in my whole engine which makes me feel good.

kdrolt

I altered the params to all the ones you just mentioned (but I kept the Cd = 0.400). This required more output from the engine <grin> to run the following:

0-60 mph in 7.5 sec
1/8th mile: 10.36 sec @ 70.0 mph
1/4 mile: 15.7 sec @ 86.0 mph
top speed <grin> = 119 mph

Which pretty much still agrees with your track data.

To do this I needed 282 fwhp @ 5100 rpm and 377 fw ftlbs @ 3700 rpm. I suspect that the torque is correct but the actual rpm for the peak is higher on the real engine than it is in the simulation. So the real engine, with the ported 193 heads and the Fcar LT1 cam is a lot closer to what it should make given that the Fcar LT1 engine was 275-285 fwhp depending on the model year.



fwhp = 2*65*sqrt(17/10.5)*0.90*0.80/0.42 = 283.5 fwhp

for two (2) injectors, each at 65 lb/hr then increased by the sqrt(17 psi/ 10.5 psi), and using a 90% duty cycle and an 80% VE, with an assumed high efficiency BSFC of 0.42 lb fuel per hr per hp. The BSFC is reasonable given your comment about the increase in fuel economy, and the rest of it is an engineering estimate. IOW the simple math is on-par with the above. So it jives with the track data and the hp/torque data backed out of it using Newton's laws (via Cartest). IIRC Dyno Don measured 250 hp at the rear wheels during his 193-casting porting exercise, so that's in the 295 fwhp range... which is again in the same basic neighborhood of what you seem to have.



Interesting. DD usually over estimates performance but in this case it's very close to what I got. The torque is spot-on, though I can't imagine that DD would predict a torque peak at 2000 rpm, especially with an Fcar LT1 cam. And the hp peak also occurs at the wrong rpm (it should be above 5000 rpm for an Fcar LT1 engine with decent flowing heads). Are you sure you used the LT1 Fcar cam parameters in DD? And correct me if I had it wrong, but you previously said you actually installed the Fcar LT1 cam -- right?



I don't think so. Even with a really mild cam like the peanut cam (which you don't have), you would be shifting at 4500 rpm. The Bcar LT1s shift above 5000 rpm so I would think you would want to shift above 5000.



My old 94 9C1 (with LT1) had to be launched the same way -- I had to roll onto the throttle from idle otherwise I'd vaporize the tires (255/60VR15, 3.08 GU4 rear end).

If you could break down that $1k into the actual components it might be helpful to anyone that wants to go this route.

EDIT: I dumped the above-revised engine into the 3rd gen Fcar again (via computer sim). This time it ran 13.9 @ 99.8 mph. IIRC the 4th gen Fcars ran mid 13s optimally so I'm sure that the simulation I'm running isn't the best. But it does help put your modified engine into the performance context of having it in a 3500 lb 3rdgen Fcar instead of a 5300 lb Gvan. BTW if you can get more out of the engine after tuning & injector swap, you might be at the point where the Rochester 220 TBI (TBI used on sbc's) is getting too small to flow enough air. It might be helpful to run a differential pressure guage across the TB and note how much of a difference there is during WOT.

NorcalZ71

yea, the $1000 breakdown would be really helpful if you could post it

Fast355

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If you notice the torque curve from DD2000 is almost flat from 2,000-3,500. That is basically what it feels like when you are running it. By the way the stock F-body LT1 has its peak torque at 2,400 rpm. With a small port dual plane intake it is possible that the peak torque is 2,000 rpm.

My 65 lb/hr injectors are maxed out right now.

The $1,000 breakdown is as follows.

Bought a complete 1992 Chevy Van with a 20,000 mile rebuilt 355 TBI and a bad 4L60(non E) for $400.00. That provided the long-block and the TBI setup. I sold the remainder as junk to a local wrecking yard for $200.00. I bought a set of Clevite Rod and Main Bearings for $35.00 and Hastings Chromemoly Rings for about $50.00 I used loaner tools from my work for the rebuild (Hone, Ring Compressor, Valve Spring compressor, Balancer installer and remover, and torque wrench) I bought a pair of Flowtech Headers from Autozone with my employees discount for $85.00. The exhaust shop across the street from my work did the work to connect my exhaust to my headers for $80.00. The engine was already roller cam equiped, so it had the lifters, pushrods, spider, link bars, etc. All I did was change the timing set, $15.00 at City Motor Supply( Local engine rebuilder and supply). The Felpro gasket set cost me $35.00 at City Motor Supply. The 60,000 mile 1993 Camaro LT1 roller camshaft cost me $25.00 at a local Speed shop (Speed Tech) as it was a leftover from a cam swap. Then their was the Edelbrock TBI performer intake off ebay for $100.00 shipped to my door. I also used a set of Z/28 replacement valve springs made by Precision Engine Parts from City Motor Supply for $26.99. Add another $150.00 for the small stuff, parts cleaner, hoses, belts, gromets, A/C o-rings, oil, filters, transmission fluid, etc. Finally add $200.00 for a prom burner, eraser, and TunerCat program w/747 ecu file that I don't have yet. The total comes to about $1,002

Fast355

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Fast355

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Fast355

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Fast355

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Fast355

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Fast355

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Apparently my computer flipped yesterday!

kevm14

Wow this is all very interesting. Is my 9C1 equipped with these 193 castings? I'd like to see what those heads could do with a better intake manifold, a real cam, and a 2" TBI.

kdrolt

Yes. Your '93 has the 193 castings.

badone07

Fast355 did you happen to take any pics? Just curious for comparison. I did a set for my pickup about a little more than a year ago. cut the ramp down and opened it up to 1/2". removed all the casting flash. backcut valves, all casting flash removed , etc. have done a few more sets, just regret not getting them flowed.

kdrolt

The unported stock 083 iron heads (used on the Fcar L98 TPI engine) flow similarly to the unported stock 193 heads (swirl port, or SP), contrary to prior comments made by many of the TGO "experts".

Stock (unported) peak cfm's summarized L to R by: casting number suffix (last 3 digits), material, RPO code, cfm peaks for int & exh and owner. The owner/thread posters: ME Leigh, smithtc, rhuarc30 and Dyno Don are all from TGO threads. All the heads listed have small-volume intake ports so there really is no issue of poor velocity due to oversize.

The SP heads are the LB4 (casting #?), 187 and 193 castings.

262 v6 head, ?"/?"
iron LB4 head: 165 intake; 119 exh (? source)
iron LB4 head: 138 intake; 116 exh (HRM, 1.94"/1.50")

305 heads, 1.84"/1.50"
187 iron LO3 head: 165 intake; 140 exh (Fast355)
081 iron head: 195 intake; 110 exh (ME Leigh)

350 heads, 1.94"/1.50" unless otherwise specified
083 iron L98 head: 185 intake; 106 exh (smithtc)
083 iron L98 head: 194 intake; 118 exh (rhuarc30)
083 iron L98 head: 202 intake; 141 exh (source unknown, but reposted by F-BIRD)
113 alum L98 head: 199 intake; 149 exh (Chevy High Performance)
113 alum L98 head: 182 intake; 145 exh (Vizard book, p124,127)
113 alum L98 head: 193 intake; 162 exh (GMHTP, 1.94/1.50)
193 iron LO5 head: 178 intake; 146 exh (Dyno Don)

Also see http://www.fullsizechevy.com/forums/...d.php?t=178604 for newer stock data from Fast305 (nee Fast355 on TGO).
193 head: 0.500----178.9----146.8 1995 Tahoe
083 head: 0.500----192.3----116.9

The relevant TGO threads and web sources for these:

https://www.thirdgen.org/techbb2/sho...hreadid=198595

https://www.thirdgen.org/techbb2/sho...hreadid=177465
https://www.thirdgen.org/techbb2/sho...&highlight=LO5

https://www.thirdgen.org/techbb2/sho...hreadid=268064

https://www.thirdgen.org/techbb2/sho...threadid=97882

https://www.thirdgen.org/techbb2/sho...416+heads+flow

https://www.thirdgen.org/techbb2/sho...+head+flow+cfm

http://www.chevyhiperformance.com/te...98/index4.html

http://herning.crosswinds.net/projects/350heads.html

http://www.hotrod.com/techarticles/e...v6/index1.html


L98 iron vs L98 alum (083 vs 113 castings):
http://www.chevyhiperformance.com/te...359/index.html
http://www.chevyhiperformance.com/te...59/index2.html
http://www.chevyhiperformance.com/te...59/index3.html

The 187 casting data came from a Fast355 PM, and some came from Vizard's book Build & Modify Chevrolet SB Cylinder Heads. They confirm other tests on L98 heads.

The 081 head (305 v8) was added because 081 (and 416) are often mentioned as being decent factory heads. The 081s are apparently the same as the 416s, except that one is used with centerbolt valve covers, and the other uses perimeter bolts. I also included the 4.3 liter v6 LB4 data from the Hot Rod mag data on SP LB4 heads ( swirl ramp based on the pix from their article). The other LB4 data appears on the web in several places but w/no source listed.

I also added Fast355's data on stock 187 casting SP 305 LO3 heads. Like the 193 SP heads, they don't flow as well on the int side but they flow better on the exh. It's not obvious that the stock 081 heads are better than the 187 LO3 heads due to the flow imbalance -- you can't fully use the int if the exh can't flush the cylinder. That's not to say that the LO3 heads are better. Both LO3 and 081 heads have their flaws in stock form. But you should be able to figure that out by looking over the numbers above.

The iron L98 heads are all better in the int side (they should be -- no swirl ramp) but they are not as good on the exh as compared to the 193 casting.

The aluminum L98 heads (113 casting) are equal to the iron L98 heads on the int, and much better on the exh side, and slightly better than the 193 exh as well. And the 113 castings have a revised exh port shape than the 083s so that explains the exh flow difference. Note: 88+ L98 aluminum heads got the higher-flow D-port, while pre-88 aluminum heads did not.

Now for the ported comparisons, and again I'm showing the peak values for cfm, along with valve data if available in the same script format as above:

305 heads
416 iron head: 220 intake; 161 exh (Kitch, 14014416)
081 iron head: 221 intake; ??? exh (ME Leigh, stock 1.84" diam int valve)
081 iron head: 230 intake; ??? exh (ME Leigh, 1.90" diam int valve)
601 iron heads: 224 intake; 157 exh (Fast305, 1.84/1.50, 14022601, medium duty truck heads)

350 heads
083 iron L98 head: 209 int; 137 exh (dj haf, stock valves) radiused int inlet, open no pipe exh
083 iron L98 head: 200 int; 139 exh (smithtc, stock valves)
083 iron L98 head: 206 int; 144 exh (smithtc, stock valves)
083 iron L98 head: 203 int; 171 exh (smithtc, 2.02/1.60 Manley)
083 iron L98 head: 229 int; 171 exh (rhuarc30, 2.02/1.60)
083 iron L98 head: 241 int; 180 exh (rhuarc30, 2.02/1.60)
083 iron L98 head: 265+ int; 192+ exh (rhuarc31, 2.02/1.60) final version, 271/195 cfm on 190-195 cc runner volume, Manley Proflo

083 iron L98 head: 197 int; 160 exh (CHP)
083 iron L98 head: 248 int; 181 exh (Insomniac92z28, 2.02/1.60)

113 alum L98 head: 210 int; 172 exh (Vizard stock valves, backcut)
113 alum L98 head: 224 int; 177 exh (Vizard, 2.00/1.55 valves)
113 alum L98 head: 220 int; 191 exh (CHP) revised & upgraded casting
113 alum L98 head: 263 int; 206 exh (Lingenfelter CNC ported, big valves)
113 alum L98 head: 243 intake; 192 exh (slightly ported by owner, GMPP pn 12556463)

SP heads
v6 LB4 iron head: 208 intake; 190 exh (HRM) (2.02"/1.60")
193 iron L05 head: 196 int; 183 exh (Dyno Don, stock valves)
193 iron L05 head: 224 int; 216 exh (Fast355, stock size valves, backcut)

The HRM data on the v6 SP heads shows the same trend observed by Dyno Don and Fast355: the exh flows really well after porting (190 cfm up from 116), and the int flows well too (208 cfm up from 138) showing again that the e/i ratio favors the exh. The 270 cid v6 (overbored from 262) engine made 301 fwhp, which would be 388 fwhp on an equal-spec ported 350.

EDIT: This post describes just how good the factory L98 head castings are now, after 10+ years of tweaking to the casting (backcut valves, smooth radii etc). So you could say that the newest versions of the 113 casting have nearly no room for porting... although keep in mind that the owner did use some sanding rolls before he got them flowed.

FYI, Dyno Don's 3rd gen Fcar car ran 13.7 @ 101 mph with the ported 193 heads listed above, 1.6 rockers and LT1 cam. It dyno'd at 250 rwhp and 335 rw ftlbs. Prior to the swap, using the unported stock 193 heads, it dynod at 210 rwhp and 330 rw ftlbs, and ran 14.1 at the track (edit: not sure if it had the Fcar Lt1 cam during that run or the factory L31 cam which =s the Bcar LT1 cam). All per this thread, and this thread.

Fast355's 1/8th mile runs in his heavy Gvan with his ported 193 heads, extrapolated to a 3500 lb Fcar in a previous post in this thread, show an equivalent run in the mid to low 13s. He also measured 279 rwhp. When Fast355 as known as Fast305, he ported some 601 heads for a 305 so I added those in the above.

Among all the info collected here I don't know:

- which heads had back cut valves
- the port volumes
- flow values vs lift

though all are GM factory heads for production vehicles so they all have relatively small port volumes. None have large valves (except as noted after porting & head work). The exhaust flow seems to be really good on the 193s even with a 1.50" exh valve. And of course all the above data were taken by different people at different times, locations etc. so there is some scatter in the data but the trend is pretty clear. FWIW.

Relevant edits: Stock SP performance and Mopar SP

Fast writes on FSC:

http://www.fullsizechevy.com/forums/...=183103&page=2

From Lo-tec post here, probably using a carb given the intake manifold choice. The carb+manifold solves the breathing/fuel on the induction side (improved over TPI), so the decent ET & trap shows that the heads, even swirl port heads, can't be the problem they were claimed to be. 13.6 @ 101+ (below) is on par with one TGO critic's Vortec-head custom-ECM 3rdgen, similarly modified. It's not a stretch to think that any head porting done on the LO5 Cad long block would have dropped the ET and raised the trap speed:

Dewey316's post on dyno and track data on his LO3 TBI car with cam + intake mod, that ran 14.5 @ 94.6 mph and dyno'd 208 rwhp @ 4700 rpm and 272 rw ftlbs @ 3000 rpm :

https://www.thirdgen.org/techbb2/sho...ighlight=swirl

His detailed mod list is:

stock bottom end, stock (unported) heads, stock TB, stock injectors, UltraDyne Cam (206/216 .447 .447 112 on a 106 centerline), Weiand 7525 intake, thru a centerforce clutch, lightweight flywheel, LS1 driveshaft, and 3.42's. Hooker headers, flowmast 3" catback, with a cut-out.

The recurring theme in both above is that, if the LO3 (Dewey) and LO5 (Lo-tec) heads were as bad as many on TGO have said, then the cam+intake+exh swap would not have been able to overcome the lack of adequate flow through the heads. For Dewey, the int + exh fixed the factory restriction to allow the (swapped) cam to make more power than the stock "peanut" cam. The new cam is only slightly warmer than LT1 cam, and 208 rwhp is approx 236 fwhp (12% loss) or 245 fwhp (15% loss) depending on the choice manual trans loss. An Fcar LT1 (350) is 15% larger than a 305, so if you scale Dewey's numbers up by 1.15 you get 239 rwhp which is slightly better rwhp than the stock LT1 Fcars measured, and the torque is close.

Mopar SP

CDP (Chrysler Dodge Plymouth) had swirl port heads, with intake ramp AND heart-shaped combustion chambers, in the '85+ 318 v8. So they had the GM swirl intake port ramp plus the chamber of the later LT1/LT4/L31 heads. Here's HRM's article:

http://www.hotrod.com/howto/113_0304_junk/index1.html

FWIW a 318 that made over 400 fwhp and 408 fw ftlbs using a Comp 268 cam (.480" lift; 224/230 deg duration i/e) stamped factory rockers and the usual exh mods. The heads flowed 215 cfm @ 0.500" lift (intake), up from 135 cfm stock (nearly the same flow #s by HRM on the LB4 v6 test above). The exh #s were not posted. Scaling the Mopar 318's 400 hp result back to same-mods + unported-heads, 400*(135/215), and scaling from 318 to 305 cid (305/318), you get 241 fwhp.... which is on-par with Dewey316's 305 (above) using a milder cam.

See also:

http://www.geocities.com/alwest_83/318

JPrevost

I'd like to see these ported swirl ports put through a dyno test. Contact a truck magazine or Hot Rod magazine and tell them you've got some swirl ports heads you'd like to see tested against a slew of other GM heads. That would make one GREAT article .
Again, as for flow bench one head vs another, never shows actual horsepower, it's only good for comparing before and after on the SAME head. Unless you've got one of those 100hp air flow research labs which gets contracted out to everybody from F1 to the Big 3.

kevm14

Are we sure there is no difference among L05 heads? Like truck (VIN K) vs car (VIN 7)?

kdrolt

They both use the 193 castings Kevin, which doesn't guarantee that they're identical but it does suggest the same base casting.

Fast355

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I haven't had much time for an update, so here it goes. Last week I added a set of 454 injectors, an open element air cleaner (unshrouded the TBI compared to a factory TBI van air cleaner), a K&N filter, and reworked the chip a little. While I was under the engine cover I found the #6 plug wire wasn't even on the spark plug as it was just dangling. One other thing was I changed the plugs to a set of AC Delco Rapidfires. I took it back to the 1/8 on Friday night. After letting it cool for about 30 minutes, my first run of the night felt real strong and netted a 79 mph trap speed but only a 9.95s with a 2.65s 60'. The next pass was my new best with 9.86 @ 76 with a 2.18s 60'.

Tuesday it was on the Mustang Dyno at school where it kicked out 267 rwhp @ 4,600 rpm and 335 ft/lbs @ 3,200 rpm. That was with a killer 11.6:1 air/fuel mixture due to a bad CTS(need to get a new one and change it). It could have been almost a full point leaner. We were checking emissions before my smog test this month and couldn't resist reprograming the dyno for a HP pull. By the way even without a cat it is very clean for a 1983 (could probably meet 1992 standards with a cat).

As a side note it is time for traction bars if I can only find some that will work with my rear end setup. My springs are over my axles and the only ones I can seem to find are for the springs that go under the axles.

NorcalZ71

Sounds like it has been a pretty worthwhile build. How much do you have into the heads aside from the porting you did? I'm looking to do a set of 193's from my truck this summer

Fast355

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IMO it is a very worthwhile build. More power and better gas mileage too.

About $150.00 considering they came on the engine and all I had to buy was the valves, valve seals, springs, retainers, and keepers off ebay that includes the stones and cutters too.

Fast355

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IMO it is a very worthwhile build.

About $150.00 considering they came on the engine and all I had to buy was the valves, valve seals, springs, retainers, and keepers off ebay that includes the stones and cutters too.

Oh I also forgot to mention that I had to pull the edelbrock off and go to a standard TBI intake due to oil being pulled into the intake ports.

NorcalZ71

sounds perfect, just what I need. It will be in my truck, so if it works for your van i imagine its about the same for a heavy truck. I'm looking at porting the stock heads, boring the TBI, K&N, headers, 2030, LT1 or LT4 cam, new springs and what not, e-fans and tuning.