Another "How much will it make?" Project "Special Needs"

[zums]

228*/252*-112* for a cam get you close
Well looks like this cam is designed to give maximun reversion and over scavaging of the intake, i also think you should go with a 2.125 valve on a 30* seat with a 93% throat, this should put you deep into the 9s

[CGT]

228*/252*-112* for a cam get you close
Well looks like this cam is designed to give maximun reversion and over scavaging of the intake, i also think you should go with a 2.125 valve on a 30* seat with a 93% throat, this should put you deep into the 9s

So your saying i could use more low lift flow to reach my goal, along with intake work?

[zums]

im no fan of low lift flow, that belongs in the blindly lead vizard crowd, the cam randy picked is for a clean chamber and good signal, nothing wrong with opening the ex valve early, pop ur piston in the bore and see where ur at when it opens, think you will be ok. check ur angle on all of those 2913 and eliminators, i dont know what edelbrocks problem is but every one i used needed a 0-.01 cut to get the angle right, get the plenum tuned up and you will meet your gaol, then you can drive around in an aerodynamic brick

[CGT]

im no fan of low lift flow, that belongs in the blindly lead vizard crowd, the cam randy picked is for a clean chamber and good signal, nothing wrong with opening the ex valve early, pop ur piston in the bore and see where ur at when it opens, think you will be ok. check ur angle on all of those 2913 and eliminators, i dont know what edelbrocks problem is but every one i used needed a 0-.01 cut to get the angle right, get the plenum tuned up and you will meet your gaol, then you can drive around in an aerodynamic brick

Thanks for the comments and advice. We think similiarly. These heads have had alot of attention payed to decreasing low lift flow and reverse flow. The only numbers ive personally witnessed get bigger with big low lift flow are bsfc's . And ive seen lower compression engines with much earlier than accepted Evos produce great low end torque. (1.4ishtq/cube). So i am not doubting or downplaying his cam choice by any means. Just trying to incite conversation.... Im open to ideas and theories from all camps.

Thanks again

[RevTheory]

I'm showing ~238/248 at .050 on a 108.

[CGT]

Thanks Rev. How did you arrive at those numbers? If you don't mind me asking.

[RevTheory]

Thanks Rev. How did you arrive at those numbers? If you don't mind me asking.

I certainly don't mind.

I did my own math using Vizard's "128" and then backed it up with Rick Jones' "Controlled Induction". They were within a couple of degrees of each other on intake duration and both called for a 108 LSA.

Being that you made efforts to reduce low-lift flow, I'm guessing Vizard's "COS Cams" would call for a tighter LSA but I've probably used up my bucket of favors regarding access to his program.

I hope that helps.

[CGT]

Thanks Rev. How did you arrive at those numbers? If you don't mind me asking.

I certainly don't mind.

I did my own math using Vizard's "128" and then backed it up with Rick Jones' "Controlled Induction". They were within a couple of degrees of each other on intake duration and both called for a 108 LSA.

Being that you made efforts to reduce low-lift flow, I'm guessing Vizard's "COS Cams" would call for a tighter LSA but I've probably used up my bucket of favors regarding access to his program.

I hope that helps.

Interesting that they both came up close. How did you arrive at the exhaust duration?

[RevTheory]

Interesting that they both came up close. How did you arrive at the exhaust duration?

That was the mathematically secretive part- I guessed, lol. I figured a 70% exhaust/intake flow differential at .500 lift.

That's the tricky part with flow specs, though. I've seen one program that only looks at high lift call for a ~10* exhaust bias where, on Vizard's "COS Cams" where the entire flow curve is looked at clear down to .025 lift, actually calls for a degree less than the intake.

The engine I saw that on had an 80% flow differential at low lift and gradually dropped to ~60% at .500 so I don't think it's wise to disregard low-lift numbers. You just need to set your open/close points accordingly.

[randy331]

That intake is going to need some work, on a head that flowed 280cfm the #3 runner tested dropped to 230, so get your burrs out

My testing matches your results pretty close. Flowed #6 with it bolted on a head that flowZ 290 with a radius, and it flowed 239 with the untouched intake on it.

Did a little work on the entrance and exit of the runner, and it flowZZ 268 cfm now.

I've seen that intake run good and I think it's a decent match for the cubes/combo of a " Special needs" project.

Maybe CGT should dyno the intake he has, and a dual plane, and a 2814 and share the results with us ??

Randy

[CGT]

That intake is going to need some work, on a head that flowed 280cfm the #3 runner tested dropped to 230, so get your burrs out

My testing matches your results pretty close. Flowed #6 with it bolted on a head that flowZ 290 with a radius, and it flowed 239 with the untouched intake on it.

Did a little work on the entrance and exit of the runner, and it flowZZ 268 cfm now.

I've seen that intake run good and I think it's a decent match for the cubes/combo of a " Special needs" project.

Maybe CGT should dyno the intake he has, and a dual plane, and a 2814 and share the results with us ??

Randy

I was gonna limit my testing to cam positioning, carburetors, and maybe some rocker ratio changes. But im open for suggestions for sure.

[randy331]

I was gonna limit my testing to cam positioning, carburetors, and maybe some rocker ratio changes.

I didn't see a tunnel ram on that list to test ??????

Randy

[zums]

I didn't see a tunnel ram on that list to test ??????

Randy[/quote]

Nah, that thing needs a super charger
The eliminator dose run good with some work, i have the same intake on my combo, the avr port csa stock is 2.66 compared to the 2814 stock which is around 2.88, i would like to see that test, thats the next intake <2814> on my bench for work with my new combo, little transition work in the plenum and its pretty decent
Tom

[CGT]

I didn't see a tunnel ram on that list to test ??????

Randy

Nah, that thing needs a super charger
The eliminator dose run good with some work, i have the same intake on my combo, the avr port csa stock is 2.66 compared to the 2814 stock which is around 2.88, i would like to see that test, thats the next intake <2814> on my bench for work with my new combo, little transition work in the plenum and its pretty decent
Tom[/quote]

I bet I can predict those test results....2814 gets beat on this size engine to 6500rpm or so, maybe even higher. Tested a 2814 against a World Products Vortec intake(61030?) and against a hurricane manifold. The World was the smallest intake and made the best power on a 383 to 6500 and equal to 7000. But you never know...if somebodys got one, I'll test it.

[zums]

bet I can predict those test results....2814 gets beat on this size engine to 6500rpm or so, maybe even higher. Tested a 2814 against a World Products Vortec intake(61030?) and against a hurricane manifold. The World was the smallest intake and made the best power on a 383 to 6500 and equal to 7000. But you never know...if somebodys got one, I'll test it



Id like to see the results , or atleast know the combo it went on, <specifics> were all the manifolds stock, head csa, cross over points of each manifold, i dont know the csa of a hurricane but if both the motown and 2814 were stock i could see the 2814 not turning on till later in the curve then the motown, motown is smaller out of the box, im interested in the 6600-8000 rpm range , but post what ya got
Tom