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451 Build

Posted By: LOtownNate

451 Build - 08/27/15 11:51 PM

First time building an American V8. Want some opinions on what I have and maybe a guess on how much power it will make.Thanks

CP Flat top pistons
Indy EZ (full cnc MW size by MCH)
Indy single plane manifold
1.6 ratio rockers
Lunati solid roller (specs are 1.5 ratio)
Advertised Duration (Int/Exh): 279/285
Duration @ .050 (Int/Exh): 249/255
Gross Valve Lift (Int/Exh): .585/.600
LSA/ICL: 110/106
Holley 950

Posted By: dogdays

Re: 451 Build - 08/28/15 01:46 AM

Those heads could stand a whole lot more shortblock under them, IMHO. Then you wouldn't have to rev to the moon to get your 675 hp.

Let's see what the real guys say.....
R.
Posted By: AndyF

Re: 451 Build - 08/28/15 02:26 AM

Hmm, I'm not really sure. The MW heads on a 451 puts the torque peak around 5700 rpm so if you had a bigger cam you could shoot for a HP peak at around 7000 rpm. But I don't think you have nearly enough cam to carry the engine to 7000 rpm. I could load it into PipeMax and find out but my guess is that with that cam you run out of air 1000 or 1500 rpm before the heads are finished.

I built a 383 stroker a while back with a 270@050 solid flat tappet cam and CNC ported EZ heads. It made about 650 hp at 7000 rpm during the first dyno session so it was probably capable of 700 hp had we been able to sort it all out. With only 249 duration and .600 lift you'll be capped on power.
Posted By: LOtownNate

Re: 451 Build - 08/28/15 02:31 AM

With the 1.6 rockers wouldn't it be .624 & .640? Do the 1.6's effect duration also?
Posted By: LOtownNate

Re: 451 Build - 08/28/15 02:48 AM

What about this one...
Advertised Duration (Int/Exh): 285/293
Duration @ .050 (Int/Exh): 255/263
Gross Valve Lift (Int/Exh): .600/.600
LSA/ICL: 110/104
Or could someone recommend a cam? I have pac 1243 springs at 1.9 installed height. I think .700 is max lift with that installed height. remember I have 1.6 rockers
Posted By: Bigcube

Re: 451 Build - 08/28/15 03:16 AM

I agree with Andy, you need a lot more cam to use the heads you have on a small motor. That will need to spin to make some power.
Posted By: Cab_Burge

Re: 451 Build - 08/28/15 04:33 AM

Is this a B or RB block build workWhat is the lobe lift and valve lash settings for the cam? I like and use as much rocker ratio that I can get away with on the cams I pick now up The 1.6 ratio will make your cam have more duration and lift from the opening to the closing and it will open the valve further and quicker at the same time thumbs
Posted By: LOtownNate

Re: 451 Build - 08/28/15 05:39 PM

B block
Posted By: AndyF

Re: 451 Build - 08/28/15 09:07 PM

Cam choice depends on a bunch of variables which you haven't given us. Street car? Road Race? Drag Race? Jet Boat? How heavy, what gears, etc.

If this is a drag race car and you want to make maximum power then you'll need around 270 duration and as much lift as you can afford. You'll also need some gear and converter to make it work.

If it is a Pro Fairground car that goes to the burger stand once a month then put a smaller cam in there so you can drive it from light to light.
Posted By: LOtownNate

Re: 451 Build - 08/28/15 11:45 PM

This all got started cause most of my fathers friends are Ford and GM guys. They come over and glap their lips on how Ford/GM is better.

It will be a street/strip kind of deal. It's going in 70's Barracuda and right now it has a 4.10 gear. Don't have a converter.

Besides the Lunati Voodoo 40230733 i mentioned in the original post here are the valvetrain parts I have so far..

Isky ez roll lifters
HS rockers
Comp tool steel retainers
Pac 1243 springs
Posted By: AndyF

Re: 451 Build - 08/29/15 01:46 AM

Ah okay, solid roller cam, good heads, 451 inches, E body car with 4.10 gears and street/strip.

Given that I have a used cam that would work great. It is an Ultradyne R60 lobe. 259@050 and .694 lift with the 1.60 rocker arms. That will work with your springs and it will make really good power. Maybe 650 or so on the dyno, a bit less in the car. The R60 lobe is street friendly. I've used it in several motors in the past and it is the same lobe that Dwayne had(has?) in his RR.
Posted By: LOtownNate

Re: 451 Build - 09/08/15 08:43 PM

One of the cam companies specd me this one..

Advertised Duration (Int/Exh): 288/294
Duration @ .050 (Int/Exh): 256/260
Gross Valve Lift (Int/Exh): .680/.672
LSA/ICL: 109/106
Posted By: BradH

Re: 451 Build - 09/08/15 09:04 PM

Originally Posted By AndyF
Ah okay, solid roller cam, good heads, 451 inches, E body car with 4.10 gears and street/strip.

Hmmm... sounds familiar. whistling

MW heads are too big for that displacement and will kill the torque curve under 5K. If Trick Flow would get off their corporate a$$ and get the new PowerPort 240s into the publics' hands, I'd say that's what you'd want to run.

With better suited heads and a cam in the range that's been thrown around (255-260-ish at .050"), you'll still need a converter w/ a flash around 4200-4500 to launch hard, which will require really sticky DOT tires or slicks, and suspension updates, and...

Oh, crap, this is how it all starts. eek

drive
Posted By: 440Jim

Re: 451 Build - 09/08/15 09:49 PM

Glad you guys got him thinking about more cam duration than this first cam. The 4.10 gear is great, just need to matach the converter to the final cam selection. I would limit cam duration based on the compression ratio (which I haven't seen posted yet). But likely around 260 deg at 0.050" (like the Ultradyne Andy posted), but if CR is over 11.0, then a little more.
Posted By: LOtownNate

Re: 451 Build - 09/08/15 10:08 PM

CR is 11.0
Posted By: AndyF

Re: 451 Build - 09/09/15 12:30 AM

True dat. It is easy to make power these days, just buy some big heads and a big cam. But getting it to hook up in a street car isn't much easier than it ever was. Need a big ol Dana 60 out back with some mono leafs and Calverts and really good shocks and the list continues on and on.
Posted By: mopar873

Re: 451 Build - 09/09/15 01:04 AM

Since no one has said it yet, welcome! I commend you for looking forward to smacking up a few Ford and Chevy guys. The guys here are right, you're going to need more cam with those heads. Don't let other people tell you horror stories about too much duration.
My last Mopar was a 65 belvedere. That car was a 447" with -1 heads. It was 13.5:1 and had a 286@.050 roller. Obviously with your compression you don't need to get quite that hairy. Either way, I took the Dominator off that car and ran a Holley 1000cfm 4150 style and that car saw PLENTY of street time. With a 4500 stall ATI converter and 4.88s with a 30" tire you'd be surprised how well it behaved. I'm guessing with about a 27-28" tire in back and those 4.10s you'll have way more response than you'd expect.
Go have some fun and start thinking "rear suspension". Good working cars turn out nice when built from the back forward.
Posted By: Thumperdart

Re: 451 Build - 09/09/15 01:33 AM

I agree about the "too much duration" to a point and my street 470ci Dart has an Isky solid roller w/.682-.662 lift and 276-281 @ .050 and purrs like a kitten runs on 91 pump and race it on 101 pump. NO negatives except for the lack of traction even w/a 29.5x10.5 et slick........too much fun and TOTALLY streetable even in 112+ Vegas heat. thumbs
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