AC398

Hey Im planning on rebuilding my motor next semester in my engine class im taking. This is gonna be my 2nd motor i build from the ground up and my teacher whos been building engines and racing for like 40 years is gonna be helping me. I have a 350 right now and plan on spending around 5-6k for everything. I will be doing all the machine work myself with the teacher as the school has good equipment. I want to have hp somewhere in the 700 range at the flywheel and rev out to 7000. I will be doing the neccessary precautions for this hp, I already have a 12 bolt rearend, and will be getting a turbo 400 as well, and all the suspension work to go with it. Ok while i have knowledge of how to build a motor i have limited knowledge in cams, different strokes, and general application. My primary use for the car is gonna be drag racing so while i will drive it on the street very very sparingly its gonna be a mostly drag only car so im looking for an aggressive setup and want everyones help and suggestions
I was thinking of building a 383 with an Eagle forged crank and rods, not sure which pistons i should get to handle the hp i want but JEs look a little expensive, and i will be getting a custom ground cam for sure but im not very interested in the idle quality i want domething thats gonna move above 3000 RPM and go till 7000. I was thinking about 11:1 compression and For the heads and valvetrain I want AFR 210s and i plan on upgrading the valvesprings for the cam. For the intake manifold im gonna go with a stealth ram and port it out to match the heads. I was also thinkin about sprayin 100-150hp on it but that might be overkill. My goals are 700 hp and i dont even know what 1/4 mile time to expect with a setup like this. Now is what im thinking the way to go, is a 383 a good idea, 350 better, what other options do i have, what would you guys reccomend for my goals??
Thanks

Irockz

iTrader: (1)

I'm not sure,but I think a Stealth Ram will be lacking in the HP range your looking at.I may be wrong,but I'm pretty confident that 700hp is carb range.
If you've got 5-6 thousand to spend,lots of cubic inches would be the place to spend it.An aftermarket block and rotating assembly will put you into the 421-434 ci range,with cash left over for a solid roller valvetrain,some wicked heads,topped off with a carberauted induction,maybe a good snort of juice if you shop wisely.
This is all considering the free machine work,but that hp level will still be tough to get.
One last note,if your not worried about street manners,compression is your friend.

F-BIRD'88

A 700hp 383 is not going to be very street friendly unless its a turbo or supercharged motor or nitrous assisted.

A 700hp motor in a stock weight third gen will run 10's @130 ish mph.

At that point it is well advided to go with a Big Block over a small block as it is much more reliable. Cost will be about the same or less.

For the street I'd be thinking of a 468ci low compression supercharged big block. We're talking true pump gas friendly 7.5:1 compression and not more than 6500rpm.
A 468 with a 8-71 will get you there and live forever.

Starting with a 502ci motor is another consideration.

A full race 700hp 383 is going to get old in a hurry but, a well done moderate Blown 700+hp Big block will get the same or more power and be much more street friendly.
Do you want to go fast for a short time or a long time?
Do you want something that flys, yet you can jump in it a go, or do you want something that will require a high level of mantainance?

This is what I'm talking about.

Just a note. This buildup uses stock open chamber oval port heads that have been ported with larger valves.
This thing is just scratching the surface. A simular motor with a little more cam and warmed over Dart Merlin heads would make very close to 800hp, if not more.

AC398

well hmm i hadnt really thought about putting a bog block in it. Ill have to look at the prices for blocks and heads and everything else. are all those parts they used stock pieces?? going carb would probly be a lot easier to tune. I like the idea of a 700 hp small block though and i know its possible. what about a 406 is it a big block or small block what bore and stroke??

F-BIRD'88

Yes the basic components of the motor are stock GM parts.

70-76 pssenger car low perf 454 BB Block, crank, heads. but have been upgraded where nessessary.
use "049" or "781" gm open chamber oval port heads with "full porting" and larger 2.19-1.88" valves.
The TRW 2377 forged pistons are replacement forged flat tops. the cr will be
7.7:1 with 119cc heads Supercharger motors need to use larger than typical piston ring end gaps and a low compression ratio to be reliable under boost on pump gas.
A stock GM cast crank balancer is not a good idea for a supercharger motor. A aftermarket steel balancer with a dual crank keyway is used on a Supercharger motor..
Supercharger motors without a intercooler use modest 26-28deg ignition timing (38deg N/A) to avoid detonation under boost.

High octane 110-114 race gas or switch to Methanol will allow more boost, more timing and more power 900+ hp with a simple blower pulley fuel octane and jet change for the track. but you can get 700+hp relabily on 92-94 octane premimum.

A 406 is a small block. A big block 454 based motor is the way to go for 700 "street" HP. It will cost less to build and last longer. Hooker makes BB header for the third gen F body cars. The conversion swap to a BB is not real difficult.

Your professional local source for tips on building a street blown BB is Oddy's Automotive in Elma NY. Jimmy Oddy has forgotten more supercharger power knowledge than most will ever learn. Provides full machine shop and dyno service.

Do an Google search on "Jimmy Oddy" and "Oddy's Automotive".. That will keep ya busy for a while.

Another good source is BDS Blower Drive Service.

F-BIRD'88

If you would be satisfied with 600 reliable streetable hp I'd recomend a sb 350 based Supercharged motor but for 700hp a big block is the way to go.

The key ingredients are the same thou.. Low 7.5:1 compression forged pistons, blower friendly hyd cam 6-71 or 8-71 BDS blower. twin 750DP carbs, ported large valve stock 76cc or Sportsman II large chamber heads. Larger ring gaps
and modest ignition timing.

Neither combination are really difficult to build. Just certain areas need specific attention.

AC398

for the small block idea i kinda wanted to go the other way around NA w/ high compression, race motor, i cant afford a supercharged small block. as for the big block im going to start looking at prices and different places i can find parts for them but is it possible to build that big block and supercharge it for like around 6k, cuz i need to buy everything from the block to the carb . Also im not too worried about streetable for any motor i stick in my Trans Am becuz im really not looking to drive it on the streets much except for some races and special occasions. I was thinking too what if i took that 468 youre suggesting and make it NA with like 10:1 compression and a wilder cam, how would that setup look or would it require aftermarket crank, pistons, and rods to go with it.

and i just looked somewhere and for a dart big block they want 1900$ which would rape they amount of money i have so it looks like im gonna need to find used parts

As for the 383 i originally wanted that now looks like isnt happenning , is it really that much less reliable than the big block w/ stock parts your talking about and how much more maintenance or trouble is that 383 gonna give me?
hye man thxs for all your help i appreciate it

daverr

iTrader: (1)

Big Blocks will make 700+ HP NA why supercharge?

F-BIRD'88

So will a small block but its way too radical for practical street use. A moderate blown BB is more fun in the long run on the street.

F-BIRD'88

Why do you think you can't afford a Supercharged SB.?
the only non stock parts nessessary are the forged pistons and ARP bolts. the reast of the motor you can build in your garage at home using a standard FM rebuild KIT. Then bolt on a 6-71 or 8-71 blower kit and go.
You can port the Oval port heads yourself.
A rebuildable 454BB core can be had for $500 $700
If you want big street power A pump gas friendly supercharged motor is the cjheapest way there And it will last longer than a radical N/A motor of equal or even close to the power. Why do you need a Dart block?

Read the article... No Dart block no after market head no roller cam no forged crank Stock oiling system No roller rockers 700hp at 6000rpm will live all day. uses 90% stock or stock replacement parts. it's so straight forward a build, a no brainer. The blower makes the power.

a full race 700hp N/A small block will last you how long?
and cost how much? RPM costs $$$$ RPM breaks parts, even expensive parts.

How much does 114 octane gas cost? Do they sell it on your street corner?

If you want to build a blown small block do not bother with a 383. Build a 355 ci motor. The blower makes the power. Spend the $$$ you would on a 383 stroker kit and buy good SB heads like RHS or Dart 200/215 cc iron lightnings with large 72+ low compression chambers.
The only non stock SB parts are the TRW FM 22 cc dished pistons the rest is a "stock rebuild" othe than opening up the ring gaps a bit. Again no roller cam no roller rockers no
aftermarket block or crank is nessessary.
If you're willing to fully port your own SB heads you can do it with smog 441/920 487 76 stock heads.
This motor will eat any N/A $$$383$$$ that you can build and for $less$$$. And last much longer.

flaming-ford

iTrader: (7)

F-bird'88 realy knows his stuff. Check out some of his latest posts in the search function and you'll understand how smart the guy realy is, advice from him should be headed.

Basically he's telling you a 383 that's even close to streetable and making 700hp isn't going to happen. Durability is going to go straight down the crapper with that much power and it will be quite hard to make it for 5k or so.

400 sbc is a little better idea but, still not thinking big enough + it's pricier than a 350 setup.

454 big blocks are kick *** motors, a supercharged 700hp motor that's streetable would be killer!!!!

Just for ****s and giggles though any1 feel like telling what it would take to make the most streetable 454 big block naturally aspirated.

AC398

ok well it looks like im gonna build the 468. so can i take any 454 block or does it need to come from a 70-76 car. For the connecting rods and crank i can just use stock replacement gm/aftermarket parts? You said use "049" or "781" gm open chamber oval port heads , is 1 type better than the other or does it not matter?

oh and one more thought if i wanted to build this motor NA would it be possible to reach 700hp on these internals with some more compression and a wilder cam becuz i believe the cam in that article was pretty tame. Also do i have any options for stroking it with a different crank and would that be better or what??

daverr

iTrader: (1)

Big blocks in the 500+CI range make it very easy to make 700HP NA. Why go thru relying on a poweradder to make x amount of power when u can make the power all motor.Cubes make a big cam more streetable.

Speed cost money period. Im in the middle of building a 18* 426SBC motor.It`s taking me almost three years to build it .Price everything out and save up.

F-BIRD'88

You're missing the whole point here. The beauti of this motor is it doesn't need to rev high to make the power.

No you will not make 700hp using stock parts even with a big cam.


yes the cam is small and right off the shelf.. thats the whole beauti of it. The blower make the horsepower for ya.. Don;t need $$$$high rpm don;t need high compression don;t need special $$$high rpm parts$$$

The compression must be low 7.5:1 is best. The motor must be assembled properly as any performance motor must be. The blower does all the work.

Any 454 from 1970 to mid 80's will do. A 468 is a .060+ bored 454. Either oval port open chamber head will do. They are functionally the same. They are very common mid 70's smog heads.
This motor makes peak hp at less han 6000rpm.
A N/A motor that makes 700hp will have to $$$rev high$$$
To get 700 hp out of a N/A 468 with ported oval port heads will take 14:1 compression and a full race high rpm "supergas/ super stock combination. It will cost double what this basic 700hp blown BB costs to build including the blower. Show this to your teacher. If he has half the racing knowledge you say he does he will agree.

Why do you think all hi perf offshore marine racing motors are low compression Big Blocks. Many with a blower.
Cheap( er) much longer lasting.

Why do you think guys like Jimmy Oddy raced blown BB's over a radical N/A motor? Got tired of breaking motors and being broke.

A buddy of mine built and raced a 700 dynoed hp small bock (406)
18deg Brodix heads big .700" lift race roller cam dominator carb etc etc etc> Yada yada yada...I can tell you exactly how to build it. But can u pull it off? Can you do the mantainance?
he did it about as cheaply as can be done yet a low cr blown oval port BB is much cheaper much less mantainance. Fully streetable.
You can drive it to the track. You can drive it every day.
You can fill up the gas tank at the corner gas station.

F-BIRD'88

Or build the blown BB in the mag article and make 700 streetable HP now and still be driving it 3 years from now.
Needing only a few oil changes and sparkplugs for maintanance.
A 350 small block built with exactly the same concept will make 600+hp.

A supercharged pump gas low compression motor BB or SB is the cheapest, most reliable way to make big horsepower.
Forget about strokers, long rods yada yada t=yada.
Build a stock ci motor 7.5:1 cr (350 or 454 based)
Bolt a 8-71 and two holleys on it and go.

Shops like Oddy's Automotive build these all day long for Street Machine's and Marine applications.
Because they deliver the goods all day long and stay together. You can too.... for a lot less... for a lot longer, 'cause I just told you how.

BlueBeast

guys i have been tossing around a big block idea for a while now and i think this post has made my mind up for me. i have a 454 to start so i am atleast have that much. i alos have the stock crank that came out of that motor, will that work for a blown 454? i have always wanted a blown big block and that look and sound of one. the motor came out of a 87 truck i belive, 2 bolt main truck motor. will that handle what i want to do? i am going to buy the 4 bolt caps that are splayed for more strenght. thanks guys any more help will be great .

iroczracer07

iTrader: (2)

Since you already have a 350, check this combo out:

350 block with a stroker crank of 3.750 to get you 383 cubes. Use rods in the 5.565-6.000 size category. The longer the better as long as you have the proper clearance. Use Sealed Power Forged pistons with Moly rings, that will generate around 9.2:1 compression. Use Clevite bearings and a standard volume, high pressure oil pump. A Comp Cams 280 or equivalent cam. Roller timing chain and 1.6 rocker arms. A.F.R. 195's and 1 3/4 headers. The idle quality will be slightly rough but this motor will live on 92 octane with ease. The Edelbrock Air Gap R.P.M. intake and a Holley HP carb are also needed. They also keep the price of your motor down when compared to E.F.I. Power should be in the 400 horsepower range with ease. You can substitue the cam for the LT4 hot cam if you want a more streetable idle that will still be in the 400 h.p. range. Add to this mix a 3-400 h.p. shot of nitrous and you will quickly realize your goal of 700 h.p. and 10 second 1/4 mile times at around 135-139 m.p.h. Don't get me wrong. The big block combo F-bird 88 mentioned earlier is sweet, but you already have a 350 block. Either way you go, I'm sure you won't be disappointed. Neither combo will rev to 7000 r.p.m.'s, but believe it or not, the lower rev's will actually extend the life of your combo. Just my

daverr

iTrader: (1)

Three machine shops in my area absolutely refuse to build/ sell a 383.What they told me that 383 are too much much stroke for a too little of a bore.People who are restricted to a certain displacement will go with the biggest bore shortest stroke.

Since pump gas is very popular on this forum.Check out this all motor combo.

1000 HP pump gas

grumpyvette

F-BIRD'88
is correct, any combo you can assemble that will use a 350 block as a base your building from and used to make 700 hp on a steady basis is going to be both expensive and highly stressed.
can it be done? sure! but youll have a huge problem completeing the project given the limited budget and skill levels that are obviously part of the thread.

DO YOURSELF A HUGE FAVOR
buy a few books, FIRST it will be the best money you ever spent, read them, and you will be miles ahead of the average guy. youll save thousands of dollars and thousands of hours once youve got a good basic understanding of what your trying to do!

then Id look thru the ADDS on USED RACING ENGINES

http://usedracingparts.com/cgi-bin/u....cgi?md=search

http://www.autoracingtrader.com/racing_engines.htm


http://www.racingjunk.com/exec/ca/browse/6/

starting with a base like this is a senceable start

http://www.racingjunk.com/exec/ca/vi...assembled.html

AC398

i already well i decided im goin w/ the 454 supercharger combo and ill sel my 350 for some cash, now makes that whole stealth ram i have at my house pointless. And i am new to this and ive read my *** off about all this stuff and its like theres always more to learn, but thats the best part. Thanks for all your help guys. im gonna start looking for parts and im sure ill be postingsome more questions on here, then When school starts in february ill probly start a new thread for the build

F-BIRD'88

Better to just recall the old thread and continue to avoid going over a lot of material that has already been covered.

Good luck to ya.

flaming-ford

iTrader: (7)

yep sounds like you have a heck of an idea, biggest thing is take your time and don't be afraid to *over research*.

i'm busy building my first motor and have researched it so much that i know more than practically any1 about it, it makes me feel confident knowing that i know all the importants and in's and out's of that particular build up combination. Thought being that i won't ruin it somehow building it...

Not that i won't but, if i do it was free so who cares hehe.

iroczracer07

iTrader: (2)

To each his own, as I say. Just remember that the most important thing is to enjoy the experience. Good luck.

AC398

nm

AC398

Hey F-Bird 88, I found a complete weiand 6-71 supercharger setup for sale on the internet. This is what the guy says about it "For sale weiand bbc 6-71 blower. Comes complete with everything needed including bird catcher, carbs, throttle linkage,thermostate relocator,pullys,crankshaft adaptor,intake manifold,ect.ect.Ran 10.90s on my 454 bbc.Looks evil. Going with different combo for spring and no longer need. Can be used on sbc with different intake manifold.Thanks for looking."
He wants 2000 for it and i think it s a good deal, whats your opinion on it? I need to call him and ask him if the intake manifold is for oval port heads and what size the carbs are. Even if the intake manifold isnt for oval port heads a new intake manifold is only $300 i think.What do you think about this deal?

grumpyvette

http://store.summitracing.com/defaul...h.asp&x=27&y=8



I think youll be FAR better off buying a BRAND NEW 871 supercharger for a few hundred more VS taking a chance on what could be old worn junk parts the guys trying to unload

even the NEW 671 kit is a better deal in my opinion

http://store.summitracing.com/defaul...h.asp&x=27&y=8

theres a few guys that DO give great deals ,there are others that knowingly sell junk, knowing your chances of getting your money back are slim because they can swear they sent you parts in good condition that YOU then screwed up EVEN IF THATS NOT TRUE

89ta383sc

I have a sb motor that will be around 700hp. I have alot of money in my motor. I hve 5 grand in the long block. The only reason I stayed with a sb is for smog. Right now I have a bigger blower with intercooler on the way. The water injectin is ready to be hooked, and I still need to figure out what size injectors to run.
By the time I am all done I will have 13 grand in it.

F-BIRD'88

It is going cheap for a reason.
You can probabily count on it needing a full recondition.

Holley and BDS provide this service. Its not cheap.
Thats assuming there is no real damage to the blower case, rotors or drive.

I'd pass on it and buy a new set up from BDS or Holley/Weiand. In the long run you'll be much further ahead.

sstpres

I thought I might offer another approach to making 700HP.

If you want to use a SB and your on a budget, N20 is your friend. I run with a friend that has a rather straight forward 408 SBC with a street roller cam. It's all forged internals but nothing fancy. Out of the box Brodix heads. The motor is in a Gen1 Camaro that weighs 3500lbs. It's very reliable and he drives it around a lot. It's a 10:1 motor running on pump gas.

When he goes to the track he cracks the bottle on a Nitous Express Gemini plate system, puts in race gas and runs 10.30's @ 135MPH.
That's getting D**n close to 700HP.

AC398

thats cool but ive thought about that and dont wanna rely on nitrous, and id like to have the power available all the time and its only legal to spray on the track so i decided against that route

AC398

l

AC398

Hey F'Bird 88 I found this setup for sale on the internet seems like a good deal as long as the parts are actually in good condition like he says

BBC 461(SD) rotating assy. & Oval GM Heads

Stock cast crank(30 over), I beam Rods (20 over) TRW flat top pistons (9.0:1), Hyd Roller .610 lift cam, Hyd Lifters, 1 set of GM 820 heads(ported w/ 2.19 valves & 1.625 springs), 1 set of GM 780 stock heads.
$800 with your choice of heads

Comes with New Rod and Main Bearings and freshly polished crank.
This combination went 11.70 @ 114 in a 3500lb Chevelle(footbrake).

You also said to use '049"or "781" heads. Bu the 820s he has are open chamber w/ a 113 cc head just like a set of "781". or i could get the stock 781 heads hje has instead of the 820s and port them out. whats better?
This seems like a good long block just needs pushrods and rocker arms, since the cranks been ground 30 over though makes me wonder how much use is on it ? is that important even if its freshly polished and reground?

F-BIRD'88

It's critical to get the compression ratio right Low (7.5:1) is best.

This motor probabily had the 820 heads shaved down and may have had the block decked to get the cr up for a N/A motor that runs 11's @114. (9.5:1 or more)
A .030" under crank is not the best for your plans.
A stock or .010" crank is best.

Althou this motor is not difficult to build, you do want to do it right the first time. Try to avoid getting in to something that althou looks like a good deal at first, will cost you more in the end cause some of the parts are not there or are not exactly the parts you need.

I would start with my own core and build it correctly for the blower instead of trying to make someone elses stuff work.
Find a complete stock 454 motor ( that has never been rebuilt) with the 049 or 781 heads (they are common and have the large, low cr chambers.) and rebuild it. The pistons you want are TRW/ Speed Pro L-2377-030. Flat top forged. rebuild the stock rods using ARP bolts.
Rod resizing and crank mains size and roundness is critical (align hone).
Big Blocks are practically indestructable but need to be build correctly (accurate machining and assembly.)

Possible sources are engine machine shops, wrecking yards, Buy and sell classifieds ( Auto Trader) etc.
many times you can buy the whole vehicle with the motor you want/need. mid 1970's/ early 80's era BB pickup truck, Monte Carlo, Station wagon, Impala/ Caprice. And get the TH400 trans with it.

AC398

Ive been looking into this build more and more and I think I may wanna build this same exact motor but NA with the same compression ratio and parts just minus the supercharger. I was reading that article and it was saying the motor in NA form would make about 500 hp.If i went that route i could take the 2700 i was planning on using for the supercharger and buy a turbo 400 and have something I could use right away and always supercharge it later. SO i think thats gonnabe the route I go for now.
As for the block I found agood block its 454 need to be bored 30 over but its been hotanked and magnafluxed and the picture look good. Its only a 2 bolt main but if dont get a supercharger i shouldnt need a 4 bolt.

F-BIRD'88

The parts mentioned will not give you enough compression ratio for 500hp N/A with the desireable large chamber oval port heads. You'll need different pistons for a N/A motor.
You want to use TRW L-2465 pistons with a 24.5cc dome with the 049-781 (118/120cc) oval port head to get a 10:1 10.5:1 cr. Use a Edelbrock Performer RPM intake, 850cfm holley and a Comp cams 294S-10 solid Magnum Cam.
Pn# 11-219-4 Comp #11-551-5 is "just right" too.

Fully port the 049, 781 oval port heads with new 2.19x1.88 valves.
this builds a kick *** 500++ hp street friendly BBC. Easy 11's.

You can't have it both ways. A street pump gas blower motor wants a low (7.5:1) compression ratio.
A powerfull N/A pump gas motor needs a higher 10:1 compression ratio.

AC398

sounds good to me, i was kinda thinking along those lines but knew youd give me the right answer. well this is gonna be the route i go and i wont be changing my mind anymore seeing as how class starts in 2 weeks. Thanx for all the help so far

sqzbox

When you get that 700hp motor done, what are you going to put it in? Have you thought about all the other stuff your going to need ? Shall we start at the end of the crank shaft!

Bullet proof parts,
1. flex plate
2. High stall converter
3. transmission
4. tranny blanket
5. motor and trans mounts
6. cross member
7. front and rear yoke's
8. drive shaft
9. U-joint's
10. rear end
Not so bullet proof parts
1. sub frame connector's
2. traction bar's
3. wheelie bar's
4. roll bar
5. multi-point racing harness
6. helmet
7. high volume fuel pump
8. racing slicks and wheels
9. Bad azz brakes
10. trans cooler
That's just 20! I'm sure I've left out something.
You'll need more money to get your car ready to race than you'll spend on the motor. BE READY!

AC398

o believe me i know and ya ive planned already for most of those parts trannys on its way n the next couple of months already have a 12 bolt w/ a spohn driveshaft and i will be dooing my suspension over the summer so im all ready to spend a **** load of cash and get it done

AC398

hey i found a big block chevy crank for sale for a 2 piece rear main seal which is what the big block im getting is. Its an actual GM forged crank, the forging part # is 7416, which im trying to look up right now but i cant find part #s fopr cranks on the internet, at least not yet. Anyways heres what he has to say about it.

Just back From The Crank Shop And In The Box From The Machine Shop. 4" Inch Stroke. Forging Number Is 7416. .10/.10 And Magnafluxed. Ready to Run!

Seems like a good deal, its the right stroke and i have a bunch of pictures from him and its been magnafluxed and its only 10 under so it seems like a good deal. The guy wants 300 which is less that half the price of a forged eagle crank and just as much as a cast one so i think im gonna buy it. whats your opinion?

Also what do you think about this set of aftermarket heads, theyre Brodix OEFI heads oval port, brand new just been sitting for like a year or two. the OEFI threw me off but theyre for a carbureted big block. he wants 1500 theyre originally like 2100 and heres what the seller says about them
These heads are Aluminum Oval port heads that feature 258cc intake runners as well as 2.250 intkae an 1.88 Exhuast valves,1.550 Valve springs for up to .600 lift hese heads are great for low RPM Pump gas hydraulic cam or small solid cam applications such as Jet Boats,Street Rods or Bracket cars great buy at $1485 Delivered.
I think these look good and theyd perform better than a stock set and theyre not too much $$. let me know what you think

Oh and i also just bout an edelbrock torker II manifold for oval ports off ebay it was a good deal, less than half price after shipping and its clean

F-BIRD'88

The steel crank and brodix oval heads sound good.

The Torker II intake will really, really limit the power.
The only good thing about it is its low profile. But it still won't fit under the stock hood of a third gen car.
So what's the point. You got it for a "good deal" cause it sucks.
The cost in horsepower is huge. We're talking 50++ horsepower.
I've had the Torker II oval port manifold and seen direct dyno comparisions between it and a base performer dual plane.
The dual plane is better overall. The raised plenum Performer RPM manifold is much much better.
Sell the Torker II
Get the Performer RPM.
Don;t matter how good of a deal the Torker II was, you're going in the wrong direction.
Take advantage of my experience and build it right the first time. Mine is a proven dynoed power full combination.
But the forged Crank and Brodix oval port heads will work good with the Comp cam I recomended.
The Brodix heads can use some simple port cleanup and profiling.
Just realize that you can get the same or better power using self ported 049-781 GM oval port heads with big valves for less $$$. All you have to do is the porting and have a machine shop do the machining (valve job)
The TRW L-2465 piston's dome shape is made to match the factory high perf square port "open chamber" head ( LS-6 , Ls7 454)

The GM oval ports chamber shape is *not exactly the same*. Slight relieving on the chamber wall or edge of the pistons dome is nessessary to ensure sufficiant clearance at all points at TDC. Only minor grinding is requireed but do not over look it. The Brodix oval port heads probabily also will need this minor clearance grinding to clear the piston domes. this clearance checking and releiving is recommended by the manufacturer but the novice may overlook it.

AC398

ok
well i already paid for theblock crank and rods im just waiting for them to come by mail. Now with these pistons how much clearancing will i have to do to make them work and what am i supposed to do. Do i just take like a die grinder asnd grind off a little bit of the dome on the piston or grind off some of the cylinder wall at the top of the block or both. Also how do i figure out how much to take off. Do i put the whole block togwetherand then bolt the heads on and then check for clearance but how would i be able to gwet the valve to max lift to check and then take the appropriate measurements. Or is therre a way where you can do all the math and figuring out what needs to be clearanced a different way. I dont really have experience with this so im not sure exactly how you would come up with how much to grind and where. Also is it possible to get a piston from another brand that makes pistons specifically designed so you dont have this problem cuz it would be easier to go with those
write me back and clarify the piston thing a bit for me
thx man

AC398

ok im looking to buy the pistons right now and that part # you gave me for the TRW pistons comes up as speed pro forged pistons but they have the right dome size (24.3) on summit. However all the speed pro pistons start w/ the part # TRW-L and then the #. So are they the same company, can i go ahead and get these pistons. Also ive decided on GM performance parts oval port cylinder heads w/ 118cc combustion chambers. On Summit for the speed pro piston w/ a 24.3cc dome and the 118cc chamber it lists compression at about 9.61. Thats a little lower than what i want. 10.5-11 compression would work for my application so i was thinking i either want pistons w/ a bigger dome (dont know about valve clearance though) or GM also makles the same exact heads w/ a 110 cc chamber and with the pistons you recommened that would raise compression to 10.4. The heads w/ the 118cc chamber though also have 315 cc intake ports as opposed to 290cc so i would like to use the 118cc chamber w/ a larger dome would that cause valve clearance issues w/ a valve lift of .600??

F-BIRD'88

Yes those are the right pistons. TRW is the manufacturer. Speed Pro is a marketing division of Federal-Mogul like Carter ( carbs and fuel pumps).

The cr listed is for a .030 over piston with a niminal deck clearance of .025" and a .039" head gasket with a 118cc head. (9.6:1) but you want to have the block "decked" to achieve a true "o deck clearance) resulting in a optimal quench clearance of .040" including the head gasket.
The cr will now be 10.09:1 with a 118cc head.
just right for 92-93 octane gas. 11:1 is too high. 11:1 with improper quench clearance is way too high.

On engines with big sized bores like a bbc you don;t want to get too crazy with compression ratio. causes more headaches than its worth. Keep the actual cr under 10.5:1.
You'll be much better off. the difference between 10:1 and 11:1 compression is less than 4% theretically and typically less in actual use. The difference between a motor that detonates at WOT and one that doesn;t is night and day.

it's all in the details
what ever head you use be sure to mock up the motor and check piston dome to combustion chamber wall clearance at TDC. should be *no less* than .060" at all points.
Minor piston dome grinding or minor combustion chamber wall edge grinding may be nessessary.
(this must be checked) the L-2465 is speced as a replacement for the 454-465HP LS-7 open chamber head only. All others must be checked for dome clearance.
use play doe at the close points like combustion chamber walls. you'll see where the close points are. Usually right at the bore edge.
Your heads may clear fine but don't take it for granted.

Valve to piston clearacne is another matter. it is not checked with the valve at full lift. (at this point the piston is more than half way down the bore.)
Valve to piston clearance is critical within 30deg on either side of TDC when the piston is near the top and the valves are in overlap. use playdoe on the pistons or light "checking valve springs" to check VTP clearance .100" minimum.

Air_Adam

- Fast
- Cheap
- Reliable

Choose two.

F-BIRD'88

Don;t know of any other piston with a 24cc dome that will garranteed 100% clear any and all of the different variations in combustion chambers available. its up to you to check.
if you use one of the the cams I speced with this piston the valve to piston clearence *should* be ok. Again check it your self.
Decking the block and milling the head reduces valve clearance.
Any BBC with a dome piston needs to be checked. Any cam bigger than 242@.050 needs to be checked for VTP clearance. Degree the cam timing. Cam installed position affects VTP clearance. (advance/retard)
All roller cams need to be checked. ( all) Any more than .530" valve lift needs the valve retainer to guide top/seal clearance checked.
the maximum valve lift has nothing to do with VTP clearance. the cam duration and overlap and cam installed C/L position , does.
When in doubt check. "measure twice, cut once"
Don't assume it all bolts together like a stock rebuild.
This is not a particularly hard motor combo to build but certain things need to be checked and verified to bring it all together.
An experienced automotive machinst/ engine builder can help you with it all. it's all about the details.

AC398

hey i just logged on to post a question that came up and its funny to see that you had logged on again and answered it before i even got to ask. Some mind reading there. But ya i was looking at the heads and saw the combustion chamber was semi-open and wanted to make sure it would work w/ the pistons but you got it done in the first line.

AC398

ok well the set of heads i was looking at i just found out are rectangular ports and not oval ports. Hpowever i think they may still be good for my application. The GM oval prts have 290CC intake runners but only come w/ 110 cc ombuistion chambers. The set i was looking at(which summit had listed as oval ports even though theyre not), is a little confusing but the gm website says "These high velocity 315cc long intake runner and 300cc short runners enhance mid-range throttle response and torque" From that statement im assuming the heads have both 315cc and 300cc intake runners for different cylinders. Im not sure if these heads will make my operating powerband too high for the rest of my combo but i think they may work out well since the intake runners are only 10-25 cc larger and shouldnt make a drastic difference in low end torque while allowingmore airflow and i get the 118cc chambers. Also i have a couple of books on BBC and to quote one of them How to build max performance chevy rat motors says" If the rpms on a race motor will go over 6600or if you are building a large cubic inch engine then use a square port head. Large cubic inch motors over 460 CI can move up to the larger square port intake volumes of 300cc or more depending on size of motor, rpm range, and intended use. I think since ill be building a 468 and these rectangular intake ports dont have a much bigger cc differnence over the large oval port heads and the valve sizes are still 2.19/1.88 this will be a good set of heads for my combo. Ill be driving it on the street some but its gonna mostly be for dragging seeing as how i have 3 other cars and i think ill be able to benefit from the added up top flow and i think these heads will work good for dragging when im in the 3500-6500 rpm range. What do you think?

F-BIRD'88

Its actually a toss up on a 468ci . Both can work well for ya.
The smaller port oval ports will make more torque but not by a lot. Pick one or the other. Just get the matching intake manifold. The GMPP aluminum heads are very good. Edelbrock PerformerRPM heads are essentually the same thing. All BBC heads have "good port" "bad port" pairs. No a big factor. Even the "bad port" flows huge.

Just be advised that even with these heads piston dome to head combustion chamber needs to be checked. it's not a big deal. If any material needs to be trimmed from the combustion chamber, it will be minor.
Build the motor with the cam and block machining preperation I outlined. Use a 850 or 950cfm holley, good Hooker headers, big exhaust and you'll make 550+hp easily. probabily closer to 600 on pump gas.

AC398

ok cool thx, i just came up w/ another question while doing some researching cuz i had completely forgotten that chevy cranks come tuftrided from the factory. My crank has been underground .010 on the main and rod journals and im sure it wasnt tuftrided again since it wasnt mentioned in the ad and the guy i bought it from is either a mechanic or works for a machine shop so he would have mentioned it particularly if it was done. I assume that i probably need to get this done to the crank before i install it. should i definitely get it done and anyone have an idea on what it costs?

F-BIRD'88

having the crank "ICED" is another option.
Cryonic heat treat. Really makes the crank durable.
Just be advised that a forged crank, any forged crank that has been re-heat treated needs to be checked for straightness. This can be done in the block with the main bearings installed using a dial indicator once the block has been checked for bearing saddle alignment (alignhone) The crank likely is ok, but check it....See what i mean about using other peoples used stuff. Thats why I recommended you find your own rebuildable engine core to start with. Used speed parts are always "for sale" for a reason.
There are no shortcuts when it comes to building a BBC right the first time.