handfulz28

I'm curious what the highest torque anybody has ever seen out of a 454. I'm talking well mannered boat motors also, so nothing too radical. But I'm curious of the theory behind what it takes to maximize torque for a given displacement. How much does compression ratio, cam selection and other factors come into play. And what are those "other factors"...intake runner length, head flow, combustion chamber size/layout, exhaust flow through heads, etc.

Thanks for the insight.

scarabfun

i'll let you know in a couple weeks after mine are dyno'd. mine are bored 40 over 9.5-1 comp. merlin rec.port heads (iron) & a custom grind cam. shooting for 500hp & 550 on the tq. these are not that rad but fully balanced/blueprinted.full roller motors.my last set ran real strong. on these i did up the cam so i'm curious to.i also run gil full dry exhaust. i do run premium gas though

handfulz28

oooff...500/550 on 9.5:1 is pretty big numbers for a 454...what does .040 over get you ci wise? What intake setup?

jayhawk261

My .030 over 454 with 9.6:1 made 501 hp and 535 ft*lb of torque all by 5200 rpm. Nicely mannered and sounds great.

Rookie

iTrader: (4)

462.8

I was once told that good flowing heads, the smallest runners with highest air velocity possible(some wedge heads to accomplish this), and a decent size SOLID ROLLER cam (emphasis on SOLID ROLLER) will make the most torque. Also stroke increases Torque, and bore increases horepower. This is what I have been told correct me if I'm wrong.

I will know how the formula works in a couple of weeks after going to the dyno. I did the 454 0.070" over, 9.6:1, solid roller, wedged heads. I didn't think it was worth the extra $2000 for a stroker kit for the extra 25HP, 27TQ.

jeff1000man

I run my 468 at 10.5:1 Compresion ration and a pretty wild cam. It idles good, and sounds like a pro stocker coming into the dock. Runs 93.

Key to good torque numbers are to acheive the highest velocity without sacrificing volume.

049 chevy ovals and merlin ovals are really good for the budget minded. Use aan intake like an edelbrock air gap. If you can rev it a little, use the tall single plane to keep from sacrificing your top end HP. Make sure you put your 1" open spacer on it.

If your engine doesn't eventually transfer that torque into HP then the engine is a terd and needs to go back to the drawing board. Without torque there is no HP, but it eventually needs to transfer over.

I spent a lot of money trying out the soild rollers, but I keep coming back to an old reliable solid type flat tappet cam. You can keep a good eye on your lash and if they are broken in properly, will give you years of good service. The 454 is a small displacement BBC and there really is only so much cam that you can throw at it before it is just wasting energy. (this is in a mrine app though)

Good luck with your project.

jeff1000man

I think you would have gotten a lot more than 25 HP out of the stroker if you really had all of that work done to the heads and you are going with the big roller set up etc.

Let us know what it does.

What are your cam specs?

scarabfun

i run performer rpm intake. 500 hp is the upper but i should be there. i think 40 over is about 468 cu. i'll post my dyno sheet's when there run. i also have custom grind cams. don't know the spec's off hand my engine shop has them. like i said these are prof.balanced full roller but idle was good. these were in for freshening and a cam change while were in there

Rookie

iTrader: (4)

You and I agree with my head porter, most velocity through the smallest runners to get the most manageable torque in a "marine" application.

I know I might have gotten more, I like to be on the conservative side of things. I was looking at it this way, if I was going to to spend the money on a "Quality" rotating stroker assembly I would be looking at $2000 not the eagle or scat stuff. For that kind of money I would just put a blower on.

I am just doing a quality inexpensive rebuild using my existing Merc 425 rotating assembly-balanced, fully wedged and ported merlin heads, solid roller, and Weiand Stealth intake.(floors welded up and matched to the heads).

Cam is: in ex
Dur. @ .050 252 264
LS 108
Seat Dur. 290 300
Gross Lift .636" .636"
Heads flow to 0.650"
This set up made 1.33HP/CI in a 502 and 1.34HP/CI in a 540 with 9.8:1
I'm hoping for 1.25HP/CI.

BUIZILLA

actually, .040 is a 464.... 468 is + .060