SPC Meyer

I was thinking of tryin to build an engine using these specs,
this is out of Ryans engine combination and bible site.
(Combos 93 to 100)


Displacement: 350 cu. in.

Carburetor: Holley 750 double-pumper

Heads: GM L31 Vortecs, pocket-ported, with 1.94/1.50 in. valves

Intake: Edelbrock Performer RPM Vortec

Camshaft: Comp Cams Xtreme Energy 268 hydraulic, with
0.478/0.480 in. of lift and 224/230° of duration @ 0.050 in. of lift.

Exhaust: Hedman 1 5/8 in. headers

Distributor: HEI

Comp. Ratio: 9.4:1

MAX HP: 409 @ 6000
MAX Torque: 427 @ 3500

The vette I have is a 78 with a 3.08 rear and freshly rebuilt TH350 with original stall torque converter.

My question is, how would an engine act that reaches its peak torque way before max HP is reached. I chose it cause it looks cheap to build "non roller cam". What would be a good stall speed and rear end gear. Thanks

STL 71 C3

build it....then talk about problems like all of us do....
Why would you ever want to work out issues that don't exist?

BTW, you can't build an engine that reacts different than any engine out there...... HP/ TQ numbers will cross at the same point everytime.....

SPC Meyer

I dont know, how do you answer a question with three more questions. I'm askin if anyone out there has seen numbers like these. I dont know what issues your talkin about either. I like the setup cause it looks like it has low end torque but thought it might be sluggish on the highway. I'm also pretty sure that engines do act different from each other, some make power in the lower mid and higher rpm's right? This setup looks like it would make power all through the rpm's if you look at the HP but looks like it makes power in the lower rpm's when your lookin at torque.

I'm also pretty sure this forum is here so that beginners like me can ask the more knowledgeable guys questions and get helpful answers

STL 71 C3

yes....you are right....
questions about what is wrong....(past tense) and questions what could go wrong.....future or (search)

then there is present....

Do you even have an engine to build? What stage is it in?

STL 71 C3

i have problems finding answers to existing issues.....
good luck to you with hypothetical issues.

SPC Meyer

I never asked what could go wrong with the setup, just wanna know how it performs with those numbers. Right now the engine has a stock bottom end but the owner before my father said it has a edelbrock performer intake, carb and whatever cam kit he put in it, its definitely not stock. Its all edelbrock but when I rebuild it I'm gonna start fresh so I know whats in it. I have rebuilt engines before just never a 350.

AGVI

Hey There, I can assure you that there are many very nice and helpful people on here that will chime in soon.

SPC Meyer

yeah I've posted a lot of questions here and have always been given good answers, this is the first time I've been given a poor reply. As we say in the Army, "there's always gotta be one."

gkull

First delete that link to ryans pages It is infected with a trojan

hugie82

@3500 peak torque is a good street engine compared to many stock engines come in @2800-3300rpm. Just install a higher stall speed converter to make up bottom end torque.
Personally I'll never build another 350 , when a 383 kit is so cheap or if your bottom end is solid, run an edelbrock top end kit until it blows then do the 383

lars

All engines reach peak torque before peak hp. The numbers look completely normal - typical street engine build of a 350 with very normal and expected numbers. Torque and horsepower curves will always cross at 5250 rpm since horsepower = torque times rpm divided by 5250. You can't change that point, no matter how you build an engine. The 268 cam is a common street cam that will produce good throttle response and low/mid range torque. It's going to poop out before 6000 rpm, though.

You don't need much of a stall converter for an engine like this - a stock setup will work just fine. If you get the stall too high, the engine will simply feel sluggish and doggy from off-idle.

Lars

AGVI

Lars to the rescue again!

SPC Meyer

Thanks guys, I'll build it and let you know how it goes.

Crepitus

FYI http://www.compcams.com/v002/Pages/388/XE268H-10.aspx
same cam and intake

lars

That looks more real-world.
Lars

MotorHead

The peak tq on my 427ci is @ 4750 RPM and peak HP is @ 6500 + RPM, I still have 360tq at the wheels at 2000RPM

I don't care where the hp and tq curves cross

Shark Racer

Yeah, my blue car has a power band like that one and it's insane to think how hard the car pulls BEFORE it hits the meat of the powerband.