I have a 1985 L98 short block engine that needs rebuilding. I am going to purchase a stroker kit for the block .030 over. I am going to transplant the engine into a 1979 Chevy 1500 everyday driver/towing vehicle. The build is to obtain the most amount of torque at the lowest rpm. The goal is to reach 475 to 500 ftlbs at or below 4500 rpms. This engine will be carb operated. Idle quality has to be smooth. I am willing to listen to cam and head opinions that will reach my goals. Anybody with experience with this combination, I would be grateful for your knowledge. Thank you MTM

 

Just so you know....max torque near 4500rpm isn't what many would qualify as a "torque build". That could qualify as a HP build....since HP typically peaks higher than torque. That said....I get it.

My build is a "torque build". It's AFR195's with mega-ported SLP intake using a high-lift, lower duration cam (single pattern 214/214 with .544 using 1.6rr) ....for a 383. Actually, I wish it peaked higher...though it may be due to cam setting and exhaust (not going into that here).

For highest LOW RPM torque, great heat port velocity is one thing to look for. AFR180s could be an even better choice...if you REALLY want torque and nothing else. Otherwise -- in a 383 -- you can't be AFR195 specifically BECAUSE of their amazing performance in low/mid rpms. (Along with higher rpms too). They have always been an "enigma".

I'm not hep with carb manifold options, but someone will surely point out a big-*** high-rise lower manifold (single plane stickin out the hood***) -- to help with low rpm reversion. Because I'm running FI, my LSA is 112...which wouldn't be as good for a carb. Knock that down to the 108 range. Typically, the theory is to install mechanical advance on a cam to push torque as low as possible....especially with reduced LSA. With good valve clearance, you might want to consider 8-deg advance.

Doubt you'd want to get into cams with 220 duration or more....unless you're really OK with letting the max torque climb to a higher rpm. You know...like 4500rpms. FWIW, my torque peak is 1K lower than that...and I'd measure in that 475-500TQ range on an engine dyno. Obviously, horsepower isn't as impressive due to the premature ejaculation of torque!

Obviously, gears are of great consideration.

If ONLY we still had a guy who he could emulate in his quest for diesel torque. (inside joke you won't get, sorry)


*** assuming you don't want to spring for a roots supercharger....or FI with a FFI intake

 

lol at the diesel torque.

I agree with the lower duration cam. For the intake for a carb, an edlebrock performer wouldn't be bad. That's a dual plane low rise longer runner intake. A nice power upgrade still.

You could also look into vortec style heads. They are optimized for lower power band punch.

Everything that has been suggested is a good option.

I actually just wrapped up a 383 for a 00 c3500. I used the summit vortec heads, stock l31 injection and manifold but went with a comp cc503. It's a little more cam than I would have liked but for the little bit I drove it (up and down the drive way, have not registered it yet.) it runs really well. Having a 4l80e and 4.10s with a ~2000rpm stall stock made me feel okay with throwing that cam in. It's a completely different build than what you're after though. I wouldn't go that route if I were you for that reason but it's something.

 

It's really only a L98 if the tpi is on it. I would either stay with the tied and true 010 block or the 87+ roller cam block.

 

This. If you're going to carb it just build it as any other garden variety SBC.

 

+1 for Vortec heads if you want to do it on a budget.

 

Ok... Maybe I'm on the wrong forum... Or redo my question.

I have a 1985 Corvette short block engine which is not an L98. It is my only engine to rebuild. I do not have a pile of engines to choose from. Ok, I am trying to make the maximum amount of torque(475-500) in the low RPM range. The engine will be used in my everyday driver work truck. I do not have the time or resources to experiment with different cam and head combinations. Was thinking someone here has built a similar engine and could give me specifics on the cam and head combination from real seat of pants or dyno time experience. Only Greg on post #2 came close on some advise but not really relevant since he is dealing with FI. AFR195 are great heads. So are the Vortecs. Compression makes power so I'm thinking AFRs maybe have an edge on the vortecs because of this. Now does anyone actually have these heads on their engine that can guide me with a cam choice that will produce the results I am looking for?

 

a 383 with AFR 195's and a Comp 276 would probably get you close to what you're looking for. Expect more torque than the dyno sheet because its a stroker.

http://www.compcams.com/Technical/Dy...6HR-10_001.asp


Edit:

That's a roller cam. 1985 should be a flat tappet block. Here's a 256 from Comp.

http://www.compcams.com/Company/CC/c...?csid=84&sb=2v

 

Interesting....You went from a 224/230 to a 212/218 when correcting link from roller to flat tappet. Seems a bit "over-the-map".

OP: Just because I'm running FI and you're going carb doesn't mean my suggestion is "irrelevant". The biggest difference between FI and carbs is the need to PULL fuel through the intake...which is why they typically have lower LSA.

If you will ONLY accept advice from an owner with a carbed, flat-tappet stroker, maybe you should look in the C3 forum? More builds like you want in earlier generations. Also, Bullet Cams will point you in the right direction once you nail down the rest of your combo. IIRC, there's a good vid on YouTube (Engine Masters) for a Vortec build. If I were you, I'd check that out.

 

For your review:

Cam: http://www.compcams.com/v002/Pages/392/XR252HR-10.aspx
Intake: Weiand Street Warrior #8125 designed to work with Vette l98
aluminum heads #113
Suggest 650 CFM carb if auto trans use vacuum secondary & dial in the secondary with a spring kit.

 

cam isn't big enough for his target 475-500 ft/lbs TQ...Heads would need to be ported for that level too.

That said, one of the best "stockish" TQ builds....in this forum...uses ported 113 heads, 383 stroker, and Lingenfelter 219/219 cam. FI though.

 

I was right. Wrong forum, probably wrong site. Cam timing is different between computer FI and carb street engines. I'll just drop in an early 70s Eldo 500 with a BOP turbo 400. That will geter done.

 

I don't seem so recall a special timing set for a Fi engine or carb. Or cams that say carb only. (Optimized for efi sure but that's usually a lsa grind) but hey, what do I know.

 

For one thing that he mysteriously had another engine as an option. Plus, I'm almost sure an FI cam won't fit under the hood of a 97 TA!

 

9.5:1 383
AFR Vortec 190 or 180 head
Cam with 212-215 or so on the intake side
Nice dual plane, 650-700 vs carb, HEI
1-5/8 header
Trick Flow makes a nice 175 head too.
Lots of reliable torque will idle like a baby and still hit hard in passing gear

Yrs ago did a 9.5:1 351 for a buddys 4x4, stock heads with pocket porting, XE truck cam (212@050) towed his race car up the grapevine well.

Probably coulda used more cam but had to pass Ca smog
Dont bother with that Caddy those are heavy boat anchors and finding parts are a bitch

 

I've got a few Pontiac 400s laying around if that's the case.

 

I'd probably get flamed for this, but your goals would be met easily with an olds 455.

 

Cuisinart your suggestions are interesting. Never used Trick flow but heard good thing from people who have. 175 maybe too small for my project but I'm not sure... That is why I came here in the first place. I appreciate all the suggestions but I still do not have an answer from someone who has actually done a build like this. I do not have an Eldo that was kind of a joke.. maybe. Cam timing is built in the grind and has nothing to do with the timing set. Greg most be friends with 84 to not be jumping all over him for that. Lets try to get back to my question. I need someone to que in that can say they done this ...and this is what made it work. Heads, cam, and compression.

 

My statement was quite literally a joke. I also don't build cars for a living so I don't know that much. You can advance and retard can timing by using the dot vs square vs triangle though. That's the joke I was trying to make. My bad.

 

Didn't jump on him. Inside joke about a former member named Phoenix. He knows it.

Cam timing events ARE built in to a cam but it's orientation to the crank changes where (in rpms) it develops power. That's often called cam timing -- which is different than ignition timing.

I had this same discussion (about heads) back in 2009. Port velocity vs HP, torque, longevity, design, water jacket, etc.... Seemed like it was easy to turn up failed/disappointing builds done with trickflow and other brands. Vortec was always the budget approach though...and a decent option. 113 heads can be awesome for a torque build and save a couple hundred after porting but MAY not be as reliable. Depends on the knowledge of the porter AND the specific casting.

Of course, I remember reading about people having problems with Eagle cranks back then...and a certain type of balancer delaminating. AFR is a brand I've yet to hear a failure about. Can't say I've see anything bad about Vortec's either...except their "special" configuration, bolt-pattern, etc... GM obviously was the first to really know/build heads designed for low-end efficiency....where towing torque is generated.

Can't tell you how many times Cuisinart (and even Tony Mamo) from AFR drilled port-velocity into our heads -- in order to convince us why AFR was the new, best street head (in addition to racing head). And, it was specifically for the low/mid lift numbers -- for torque. The ONLY mention of TrickFlow in this forum for the past 9-10 yrs has been for budget builders. If Ron (Cuisinartvette) mentioned the TF175's, that's because he knows how they flow in the lower ranges...meaning they aren't (and never were) a bad choice if maximum HP wasn't a goal. He also must know if they got past a year/so of "iffy" QC. Ron lives in car forums and is a great helper!

475-500 ft/lbs of torque isn't easy to hit...though it's easier to hit if you are building for HP. If you are building for torque and want it as low in rpms as possible, it's a lot harder. I was one of the few builders in this forum that looked into every supporting component that would contribute to torque...vs best possible HP. (Which isn't to say I didn't want BOTH!)