Getting the most torque from a 454...on 87 octane
 

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.

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

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?

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.

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.:D I didn't think it was worth the extra $2000 for a stroker kit for the extra 25HP, 27TQ.

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.

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?

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

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.

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

yer right. think i am at 60 over.

You running dry pipes in that boat?

Who spec'd that cam out? Are they a marine guy. Looks a little agresive for a wet set up. It should no doubt make great power, but I would check before I bolted it in.

Good luck

Yes they are Stainless Marine dry to the tips. (4" out the back of transom)

Heads flow Int. 377cfm Ex. 268cfm @ 0.650" with wedged Rec. port Merlins around 316cc

And yes, the cam was spec'd by a well known marine head porter and the first question was, "what exhaust do you have?" He use to build engines for A and B class offshore boats. I think he has a couple World and National titles. ;)

Then that engine should make a little more power than you are thinking.

Post when you get it off the dyno. It should be a monster.

Good luck and congrats

Rookie, what rpm range do you expect that engine to run in? Just curious. Those specs look like they will produce a lot of hp but at a high rpm. My guess would be about 600 hp at about 6500 rpm.

On the dynosheets the 502's HP started to taper off around 5800 but still had good power at 6000. I'm assuming my 470's should start to taper off at 6000 and pull power till 6200. I will either prop to 5800 or rev limit at 5800. I think my power will exceed the speed of my drives. From what I hear TRS's hit a wall somewhere around theses speeds.

I run 72 with 850HP now, thats 12HP/MPH. If I'm anywhere near 1200HP that would put me at (1200HP / 12 HP/MPH) = 100MPH. Realistically I'm hoping for 85mph. all my friends run in the 90's now maybe I'll be able to cruise with them.

Patrick, Jeff
9.6:1 what octane should these be run on? I normally run 92

got the dynos on this yet?

Yes
I had a nice flat torque curve and the power wasn't really falling off to fast either. I didn't want to spin it any more on the Dyno than 6500.
I was told that I am leaving power on the table cause I am running only 750cfm Barry Grant carbs, I would have exceeded the 600HP barrier if I had a larger carb.

560 TQ @ 5250 and 590 HP @ 6250-6500

The 565 that we also dynoed that week made just shy of 800HP naturally aspirated. That was fun to see.

http://i43.photobucket.com/albums/e3...ne/470dyno.jpg