adm030

Which would we be best for l03 with crane 2031 cam, 1.6 roller rockers, stock heads, full exhaust, pullies, tbi and injector spacer?

thomas1976

Couldent find the cam you mention.

The TBI performer requires only minor modifications to fit everithing on it. Just bore the bores to at least 4.6mm, after that chamfer the cutting edges as on the inside of the bores as good as possible, ruffen the bores with 80 sandpaper, and do a gasket mach "porting".

ownor

iTrader: (5)

thomas, are you referring to the performer tbi or performer rpm?

adm030

This is the cam specs, which would give me more power in the everyday driving range like 1500-5000 rpm. I just want to have the right combination I dont want to put together a bunch of mixed matched parts and not see a gain in performance and lose drivability also thanks.

Brand: Crane Cams
Product Line: Crane CompuCam Camshafts
Part Type: Camshafts
Part Number: CRN-104225
Cam Style: Hydraulic roller tappet
Basic Operating RPM Range: 1,500-5,000
Intake Duration at 050 inch Lift: 208
Exhaust Duration at 050 inch Lift: 214
Duration at 050 inch Lift: 208 int./214 exh.
Advertised Intake Duration: 264
Advertised Exhaust Duration: 270
Advertised Duration: 264 int./270 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.438 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.452 in.
Valve Lift with Factory Rocker Arm Ratio: 0.438 int./0.452 exh. lift
Lobe Separation (degrees): 112
Intake Valve Lash: 0.000 in.
Exhaust Valve Lash: 0.000 in.
Computer Controlled Compatible: Yes
Grind Number: 2031
CARB EO Number: D-225-22
Quantity: Sold individually.

Camshaft, Hydraulic Roller Tappet, Advertised Duration 264/270, Lift .438/.452, Chevy, Small Block, Each

Check to make sure this part fits your application More power for your computer-controlled vehicle.
Crane CompuCam camshafts have special profiles designed to improve engine performance. And they do so without sending the computer into fits, or causing the stalling, surging, or drivability problems some "computer-compatible" cams are known for. They're 50-state legal for the applications listed.

RBob

iTrader: (1)

These are really two completely different intakes. The Performer TBI is basically a stock replacement. Maybe a slight step up in performance.

The Performer RPM is designed for a high performance street engine. It also doesn't support EGR (if that matters). If you want room to grow then the RPM manifold is the way to go (don't get the air-gap version).

RBob.

robert1

iTrader: (3)

If you're going to stick with TBI, get the matching manifold. There's no way I'd get a Performer RPM for a TBI.

Fast355

iTrader: (2)

Thats a pretty goofy thing to say. Unless you are after torque from idle-2,500 rpm, stock look, and emissions compliance, stay away from the 3704 Performer TBI. The Performer RPM has a very slight torque loss down low, but will twist to 6,500 rpm in a heartbeat on top of the correct engine. I even used one on the TBI 350 in my fullsize van. Plenty of low-midrange torque for that application.

dctrumpet

iTrader: (10)

I have a 350 TBI bored .040. I just had my Edelbrock Performer TBI #3704 bored to 50mm (2") to match the 7.4L TBI base that I am installing on her with the 65-68# caprice injectors and high vol fuel pump with afpr. My cam is 8-304-8 from Comp Cams and RHS heads with 2.02/1.60 valves.

If you're doing the 305 I would go with the Edelbrock 3704 with a modified TBI unit. Stock units are 42mm and stock manifolds (#3704 as well) are 42mm. I would suggest a 46mm TBI from CFM-tech and have your manifold bored to match it. Having it bored to 46mm should cost about $50 at your local machine shop. The 3704 is limited to about 5500 rpm. CFM-Tech also has a nice TBI powerplate that is modified to allow fuel flow from injectors.

Also, make sure your heads can handle the lift with this cam along with those 1.6 rockers. Most stock 350 heads can handle up to .470-.475 lift.

You will definitely be limited with your stock heads. NO reason to go with the rpm series unless you are going to change your heads in the near future, but Fast355 does know his stuff.

You will need to do some data logging and mods to your chip. Talk to Brian Harris @ tbichips.com or Craig Moates.

RBob

iTrader: (1)

Maybe I don't know. However, the Performer RPM with a TBI on top runs darn good with the 331 under it. Only mod is a cut down plenum divider, which adds to the top end.

I've seen more then my fair share of performance street engines choked down by using the Performer TBI intake.

RBob.

dctrumpet

iTrader: (10)

Probably true! I am hoping that the 50mm bores might give me a bit more overall. I am going to give it a shot and see what happens. My setup will be about 375hp when done. I just might test the 3704 for a bit and get some dyno readings then change her out and update the dyno results.

I will let you know what happens.

I am doing dyno testing now on the stock 350 with all the ultimate TBI mods, headers, chip burning, 3" Magnaflow exhaust, etc.

Then I am going to install the Comp Cams 8-304-8 cam, 1.6 roller rockers, bored 3704 intake, 454 tbi with 68# injectors, 255lph fuel pump and the RHS heads with 2.02/1.60 valves with 76cc chambers (225cfm rating). Then doing a few more pulls on the dyno.

I will see how she runs and I just might swap out the intakes and change nothing else.

the_target

Do they make a rerformer RPM for the 93 heads with the center angled intake bolts ?

dctrumpet

iTrader: (10)

Here's a link to Summit's site with the RPM intakes.

http://store.summitracing.com/egnsea...=KeywordSearch

adm030

I believe im going t go with the perforemer rpm. It's cheaper and the hp and tq readings are higher compared to the tbi thanks.

Fast where you saying that for my app. it would have plenty of torque or yours thanks.

thomas1976

Are you going to grind the inside edges of the bores and gasket match the TBI performer?

Would also be interesting to see if the 3704 casting allows an opening to be bored between the bores like the stock one.

dctrumpet

iTrader: (10)

I am installing a 7.4L TBI base on the 3704. So, the bores of the intake and TBI unit will match exactly as well as the gasket. I have a 1/2" adapter plate due to the fact that the 7.4L base has a larger footprint than the standard 7.4L base. It has larger passages for the IAC valve thus it's base is larger than the mounting surface on the 3704.

dctrumpet

iTrader: (10)

Here's a pic that shows a passage/opening in the left bore. I assume you can open a passage between both bores

ownor

iTrader: (5)

nice job on the grinding. those flappers on the 7.4L look huge

anyway, i think thomas was referring to the runner passages when talking about the gasket matching.. so kind of a porting job there.

this thread is interesting. i also have a performer tbi lying around here but plan to go with the stock TB or get one of the CFM-tech ported ones. when boring a passage between the two bores i assume that does the same thing as the CFM power plate, helping to balance max flow?

oh and could anyone please post the different bore sizes again? stock, cfm-tech, 7.4l, edelbrock, ..?

Ronny

iTrader: (1)

Dont overlook the Holley Projection TBI. Already sized for the 2.000 7.4L TB. Rated to 6500 RPMs. Not aware of any flow numbers but the port size and Felpro gasket is listed on the Holley site.

Edit: Port size 1.89 inch height
1.15 width
How does that compare with Performer RPM?

the_target

SO how are you going to bolt on the Performer RPM on the tbi heads the 4 center intake bolts are sitting at 72 degrees not 90 like the pre 87 heads. you may have a sealing issue on ytour hands.

Ronny

iTrader: (1)

Another reason to consider the Holley TBI unit as they offer 87 later cast iron heads as well

adm030

You have to modify the intake by drilling them to the correct angle from what I've read, someone please elaborate on this thanks, has anybody used the holley projection, I'm just trying to go with the intake that going to give me the most power, I plan on swapping in a rebuilt 350 next year so I knew the rpm would be good for both the 305 and the 350, it would be good if the holley made close to the same as the rpm because it lets you keep the egr and looks like you don't have to modify it to work.

thomas1976

Stick the finger down in the 3704 bores and feel the lower edges. The cutting edges, I belive should be chamfered as much as possible.

Yea, the passage from one bore to the other shoul be below the vacuum bore.

thomas1976

Seems the performer rpm has no place to put the brake boster line.

JohnBlazeLTZ

This was actually a really interesting read.

Does anyone know of any other 4 barrel manifolds w/ EGR that will work with Centerbolt heads?

I have seen people try to use an intake that didn't work with centerbolt heads and the result was not good.

Also...what would someone be looking for when they are trying to get an intake for a 383?

Thanks,

JB

titchener

I don't have much hope for the Performer TBI intake. If you want to get depressed, take a look at their supplied dyno curves.

http://www.edelbrock.com/automotive_.../ds//3704.html

Its not a curve on the manifold alone, it shows a combined package including heads, cam, the TBI manifold and headers. Compared to the stock engine it only makes around 40 HP more (248 versus 206 for the stocker).

That's not much gain for all that expensive hardware, including aluminum heads. The other thing about the curves is the peak HP RPM point is hardly moved up at all, so the combination doesn't seem to have added hardly any improved higher RPM breathing.

This doesn't bode well for the increases of the manifold alone, maybe it adds a little but it can't be much. In their defense its a smog legal combo, so that tied their hands somewhat.

The idea of machining out either the stock TBI manifold or the Performer one to allow more crossflow between the TBI bores is an interesting one. This is common trick with carb 2 plane manifolds to increase the higher RPM flow and it could really help a TBI manifold.

Has anybody tried this? I'm very interested because I've got myself about 98% convinced to yank out my stock L03 and replace it with a sleeper 383 motor that will pass visual and sniffer smog. I would need to keep the stock TBI manifold on the engine.

If anybody wants to try this out, let me know, I can do the machining here in my shop and send it back to you if anyone doesn't mind sacrificing a manifold to the HP gods if it doesn't work out.

Some porting on the stock intake manifold could also help, this is a common trick for engine builders supplying parts to racers in classes that require stock parts.

Here's a couple guys that do this, looking at their sites is interesting:

www.castheads.com

www.gesslerheadporting.com

Paul T.

dctrumpet

iTrader: (10)

titchener.... Where do you live?

dctrumpet

iTrader: (10)

I have bored my 3704 to 50mm (2"). I have yet to install it, but it should do well with my 454 TBI unit and the 68# injectors among other mods.

I am actually looking into doing to my manifold what CFM-Tech has done with their power plates (TBI spacers).

http://marine-performance-parts.com/...rformance.aspx

titchener

DC, I'm in Brisbane, CA, close to San Francisco (but I don't play for the pink team).

The dyno testing you're talking about on your combo and the manifolds definitely sounds interesting, please post the results if you do it.

If you're interested in having your manifold "improved" let me know, it will be a freebee if you handle the shipping costs, but you've got to understand the 1 out of 10 rule will probably apply- ie, out of the 10 great ideas you have to make your combo go faster, usually around 1 out of 10 actually works (at least that's my number, maybe smarter guys do better).

If you haven't seen the machining work I've done on my "quad TBI" prototype, take a look at:

https://www.thirdgen.org/forums/tbi/...ken-tbi-2.html

Paul T.

dctrumpet

iTrader: (10)

LOL!!! I know you're area well. I went to school south of SF. I lived in Walnut Creek for 5 years. Love the Bay Area.

I will have a manifold for you. I will send it to you once i get it. It will be a used stock tbi manifold.

I was told by Comp Cams and two others who tune for a living that the following setup that I will have should bring me a strong 375hp.

3704 manifold bored to 50mm
7.4L TBI base with 1/2" mounting adapter/spacer
68# injectors with 1/4" spacer
adjustable fuel pressure reg
255lph fuel pump
RHS heads with 76cc chambers flowing at 230cfm 2.02/1.60 valves
Comp Cam 8-304-8 cam
1.6 Magnum roller rockers
and of course a few other mods.

I currently have headman headers with 3" high flow magnaflow cat and 3" magnaflow cat-back along with UMI's sfc, lca, ta, adj pan hard, wonder bar, etc and 9bolt borg-warner 3.27 rear end.

dctrumpet

iTrader: (10)

I will be doing pre and post dyno.

I currently have a stock 350 bored .040. with a stock TBI manifold, xtremefi's modified 350tbi unit with flow-matched 55# injectors and removed smog, open element air-cleaner, etc. All the basic TBI mods.

I am going to dyno it to prove what the HP really is. All the "masters" who dyno "stock" L05's state they are lucky to pull 190-200hp. GM states that the stock L05 TBI is 220hp.

titchener

That's a pretty good looking combo. My ballpark rule of thumb on airflow of the carb or throttle body is take the peak HP and divide by 1.65. I believe the stock 454 TBI units flow around 620 cfm, which divided by 1.65 is almost dead on 375 HP, so it sounds your your 454 TBI unit should do the job for you.

After you run the combo on the dyno, as you probably know, looking at your MAP readings will show you how much full throttle pressure drop you have across your TBI unit. If its too high, doing the "shared port" intake manifold mod we're kicking around would probably help (ie more HP), but I wouldn't do it until you see how it runs now and check the pressure drop, your first shot out of the box seems pretty well matched.

If you want to send out a stock manifold thats fine, I won't cut on it unless looking at it convinces me it might do some good. I'm actually trying to find a extra stock manifold now to take a look at, I want to see if it looks like matching and porting the runners some would help in addition to the "shared port" trick.

I have a Caprice that requires the special manifold with a larger distributor hole and I haven't been able to find one locally so far, but I'm sure one will turn up at some point, so you might want to wait until I get a chance to take a close look at one to see if this has a chance before going to the trouble of sending yours.

Paul T.

dctrumpet

iTrader: (10)

I will be in Fairfield, CA in October. It might be interesting to drive down to where you're at and see what you've got going.

I will send you that manifold. I will have my stock tbi manifold as an extra if i ever need it. Like I said i am going to use the bored 3704.

I found a deal on eBay with a manifold, tbi unit with injectors and afpr for a CHEAP price.

I also have about 6 injector pods in great shape if you ever need one. I bought it from a guy who was looking to get rid of them.

I also have a ton of gaskets, orings, etc for the TBI, injectors, pod, fuel inlet and outlets, etc including the teflon gaskets.
----------
I was wrong about the intake i bought on eBay, lol. It's an edelbrock performer with everything and not stock. I will PM you the link.

CHeck it out and if you want to take a look at it let me know and if you want to do some mods to it then let's have at it.

titchener

DC, definitely plan to stop by when you're in town, check your PM for contact info.

Paul T.

dctrumpet

iTrader: (10)

Awesome. Just PM'd you.

dctrumpet

iTrader: (10)

I was going to do my own "research" here. I was going to do a few combinations which included the following:

Stock TBI manifold
3704 Performer manifold
3704 Performer bored to 50mm

Pod assembly with 5.7L 55# injectors
Pod assembly with 5.7L 65-68# injectors.

5.7L TBI unit modified for flow
7.4L TBI base.

TBI spacers/Adapters

I would take the combos above and mix and match them to see which gives the best flow and horse. Each one I would datalog and dyno. Obviously using afpr on all of them with a 255lph fuel pump.

Nothing would change with the setup except the manifold, TBI unit and injector combo.

Only wanted to do this to see what the difference would be. I already know that the 68# injectors on the bored 50mm 3704 with the 7.4L TBI base should be the best.

titchener

Sounds like a good set of stuff to test. My 2 cents would be to take the 55# injectors out of the picture to simplify things, you would have to run too high a pressure to support 375 HP with those. Even with the 68's your are going to have to run a pretty stiff pressure, a quick calc says you would need to run around 30 psi to support 375HP with 68's, doable but that's starting to get up there, the 55's would need too much.

How are you doing your chip tuning?

Paul T.

dctrumpet

iTrader: (10)

I have been using winaldl and sending my data to Brian Harris and he modifies the bin and then i burn the chip using Craig Moates' flash/burn.

So you're saying that I should run bigger injectors than the 68# ones when i install the cam, heads, new intake and? I have the pressure behind them with the 255lph pump. Can the stock regulator diaphragm handle 30 psi?

thomas1976

Stock LO3 intake manifold has 46mm bores and a 20x20mm crossflow hole in the casting between the 2 bores.

3704 perfomer TBI has 42mm bores without crossflow.

titchener

The 68's will work for 375 HP with a pressure of around 30 psi, which your Walbro 255 will supply fine.

However you might be in trouble using the 255 pump with the stock regulator, I've seen others state that the 255 pump puts out too much flow for the stock regulator to be able to bypass, and at idle the pressure can't be turned down enough. However, since you need to run at 30 psi you might be able to get away using the stock regulator, maybe some guys that have run high pressures like this (Fast355?) can comment on this one.

To be able to try using the stock regulator though you will need to put a stiffer spring in it, I think these may be supplied with the Jet regulator kit, you have one of those, correct?

The other way to go is to use an external regulator, the Aeromotive Aeromotive 13301 is a good choice for this and it comes with both a high and low pressure spring. It also can be vacuum referenced if desired, which lets you run lower pressures at idle and high pressures at full throttle, but this makes the tuning more complicated.

To use the external regulator you connect it in series with the return line and
either take the spring out of the stock regulator or fab up a block off plate and gasket to use instead of the regulator.

Earl's sells AN fittings with the TBI inlet/return o-ring style connectors on the end of them that can be used to make the TBI fuel hook ups look clean if you decide to go with an external regulator. The Earl's TBI inlet 16mmx1.5 to -6AN fitting part # is 991955 and the return 14mmx1.5 to -6AN fitting is part # 991954.

Paul T.

dctrumpet

iTrader: (10)

I do have the AN fittings already. I am going to use those when i change things out. I have several sets of springs and regulators that are adjustable.

I may go with aeromotive or fuelab or something like that. I have seen guys use a block off plate and also open the port in the top of the fuel meter cover as well. I may not need to go that far.
----------
I am currently using the 255 fuel pump and CFM-Tech's afpr with my 55# injectors. I am only about 250hp right now anyway.

titchener

Fellas, I'm working on getting one of the Holley TBI manifolds and hope to have it in my hands in a week or two. As they claim 6000 RPM capability it will be interesting to see how the runner cross section area compares to a stock TBI manifold and the Edlebrock one. The only rub on the Holley manifold is it apparently is substantially taller than the stock manifold, which could cause problems on some cars.

I've also got an older Performer (not RPM) carb manifold lying around that will be interesting to compare these manifolds to, when I get the Holley I'll report back how the runner sizes compare.

Paul T.

dctrumpet

iTrader: (10)

Paul,

Just got the used Edelbrock Performer TBI in today. I will ship that one to you. I am waiting on the stock intake and I may wait to ship both at the same time.

titchener

Sounds good, when I get all 3 manifolds in hand (stock, Edelbrock, Holley, actually 4 including the Performer carb one I already have) I'll do a comparison of the runner cross section area, plenum volume and feasibility of machining for cross barrel flow. This should give us a reasonable idea of which one would be best on a built up TBI engine.

I wish I had a way to test them on an engine also, but that's not in the cards for me right now.

DC, don't waste money shipping them individually, I need them all to compare them anyway. Once they're here and measured I'll talk to you about whether machining them for cross-flow appears like it would work, and then we'll get them back to you.

The other thing I'm going to look at is the possibility of making a replaceable center divider section on the manifolds. This would allow quick testing of cross flow versus no cross flow, and doesn't end up ruining a manifold if it turns out no cross flow is better.

Paul T.

dctrumpet

iTrader: (10)

I will ship as soon as I get the stock intake. I have always wondered what it would be like if the bores were machined to look like CFM-Tech's Powerplate.

Their power plate is patented (as it should be), but doing that to a manifold should work good.

What do you think?

http://marine-performance-parts.com/...rformance.aspx
----------
I ordered the Aeromotive afpr 13301. What would you charge to make a cover plate for the stock regulator? I know I can take the spring out and leave the diaphragm in place, but I would prefer a block-off plate. I know others might be interested as well.

I currently have about 8 complete injector pod sets without injectors. I was also wondering about porting out the passage way in the fuel meter cover to allow more flow. Any ideas?

Here is the link I have been reading:
http://members.shaw.ca/betterthanyou...to/fpr/fpr.htm

robertfrank

iTrader: (27)

Sorry to bring up an old post but I was wondering if anything came of this? I am heavliy contimplating (spl?) getting a RPM manifold with my ZZ4 heads and cam.

titchener

Robert, economic pressures kept me from moving ahead with an engine build, but I did get my hands on a Holley 300-66 TBI manifold. If I had to pick one based on what I've seen, I'd go with the Holley, it looks like a pretty nice piece. I think its got to be better than the Performer TBI, based on the poor dyno curves for the Edelbrock manifold.

The Holley manifold also has a center divider that lends itself easily to trimming it down for some crossflow, which can help higher RPM power.

The only rubs on the Holley are it raises the TBI mounting surface up compared to the stock one, which could mean hood clearance problems on some cars, and although it has an EGR fitting it doesn't look like the stock EGR valve would bolt up directly, the flange matches up ok but the Holley flange has a steeper angle that I think would cause interference, so some kind of adapter would be required. Maybe that's something you can get from Holley, I don't see how any EGR valve would fit without one.

Paul T.

Ronny

iTrader: (1)

This is possible solution to clearance issue.

robertfrank

iTrader: (27)

Ronny, how hard was it to adapt this manifold to use with TBI? What adapter did you use and how did you set up your throttle brackets? I am SERIOUSLY contemplating getting this manifold.

Ronny

iTrader: (1)

I have manual trans but it is a 4+3 so it does pull out of overdrive with a kickdown . It therefore uses I suppose a similar cbale to that of auto trans. I used an adjustable Edelbrock bracket. I used all my stock GM cables(throttle and kickdown). I used Aeroquip fittings at TB. I believe we ordered out several to get clearance. We used push fit Aeroquip fittings and same fuel line. I will post a pic?

Ronny

iTrader: (1)