dynoed my 416

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I used a slide-a-link system from competition engineering and adjustable pinion snubber.Talk about hook I snapped an axel (8 1/4).can,t wait to get the 8 3/4 rearend in.Should lift the wheels up now:cheers:
 
I don't believe the heads are aa problem. That is a smallish cam for a 4" engine. So I'd expect those numbers. You can tell by the flat peaks that it is not a max effort deal. Slip ina cam with 250°@.050 and that lift, even in flat tappet form, and those numbers will go up a bit, the torqu will peak close to the same, but it will not be as flat. For the cam you have, the 750 carb is fine, because it's almost done at 5800. But, you would have more power with a bigger carb. I spec 870 Avengers for my mild 408-422. I wouldnt play with rockers. Get a better cam, or run it. I think it will be a blast to drive.
 
A cam with a lower (tighter) LSA like in the 108 range would create more cylinder pressure and more peak torque but would reduce vacuum at idle and give a much more lopey idle too.

I'd try to find out what those heads flow at what lift before getting another cam though.
 
Could you give us the complete rundown on your motor? Cam specs, pistons, crank, etc...? Thanks
 
I don't think lobe centers alone will change much of anything. It's just a mild cam on that package. Not sure what every part is in it, but I'm sure cylinder pressure is not a problem...lol. Taking out valve train geometry loss (worse with hydraulic rollers than even std LA) and the usual rocker ration errors, that cam is only about .520/.530 lift at the valve. It's not meant to make mad power, just stone reliable and torquey. With plenty of bolt in expansion available. I also agree if getting the most out of the engine is you ultimate goal, a flow test of your heads (not advertised "stage II" from Shady Dell, is the first order of business.
 
moper said:
I don't think lobe centers alone will change much of anything. It's just a mild cam on that package. Not sure what every part is in it, but I'm sure cylinder pressure is not a problem...lol.
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Cylinder pressure equates to torque, no more, no less. There's actually a mathmatical formula for it. Increase cylinder pressure at a given rpm and presto! More HP. Hence the idea of tightening up the lobe center (not to be confused with "Installed Centerline"). If he wants more HP, he will need to increase cylinder pressure. Of course, a new cam would be required anyway. :)

moper said:
Taking out valve train geometry loss (worse with hydraulic rollers than even std LA) and the usual rocker ration errors, that cam is only about .520/.530 lift at the valve. It's not meant to make mad power, just stone reliable and torquey. With plenty of bolt in expansion available. I also agree if getting the most out of the engine is you ultimate goal, a flow test of your heads (not advertised "stage II" from Shady Dell, is the first order of business.
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I totally agree with dumping the Hydraulics in favor of solid rollers at the rpm range that moparmade is lookin to make power.
 
I agree, and I understand how it all works together, I just thought what you were saying was tighten up the lobe centers, and it will gain power. My point was, in this engine's case, I don't think it will. Reason being there's already such a small amount of intake charge as a result of medium rates of lift and short advertised duration now. Changing the valve timing with no other change in lobe shape wont really help anything. I'm also assuming this roller is a 112 or 114LSA cam that is installed at 112ICL. You need more intake charge (read as "duration off the seat) before LSA really becomes an effective change on this particular package. Flat power peaks are not effected much by LSA changes because they are already maxed out at most rpm points. Hence the flat curve. You can get more by optimizing the airflow for the particular power range, and that would include (in my specs anyway) a tighter LSA and an installed centerline of closer to 109. But, that change will require more carb and will put more slope in the torque peak, while still remaining at that same peak rpm point. Translation, more cyl pressure after torque peak for more hp. Peak torque is simply the point where the package feels it's most efficient. How well it carries the efficiency beyond that is the hp potential and defined by much more than cam lobe and timing. I think we're on the same page, just looking from two different angles...lol.
 
ramcharger said:
Exactly! :)
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Neither of you know anything!!!

Both of you go to your rooms... :-D

j/k

Always good to read what people are thinking. Neat to pull nuggets of info out that others think of to explain a difference. As long as it's civil.
 
crackedback said:
Neither of you know anything!!!

Both of you go to your rooms... :-D

j/k

Always good to read what people are thinking. Neat to pull nuggets of info out that others think of to explain a difference. As long as it's civil.
Click to expand...

LOL! It appears we both saying the essentialy same thing in two different ways. :-D
 
71FJ6Demon, the specs are,
416 c.i.
Edelbrock air gap intake
Holley ultra hp race carb, 50 cc squirters, 750 cfm
Comp custom grind hydraulic roller, 236 @.050, .550/.570 lift
forged pistons, set to zero deck
forged crank, H beam rods
1.5 pro magnum roller rockers and roller lifters
Edelbrock heads, slightly massaged, flow 268 @ .550 lift on intake, and I can't remember the exhaust.

Anything else?
 
Moper, you are so very correct with your explaination of the lost motion with the terrible valve train geometry the small Mopar is blessed with. With the lifter and pushrod not in plane with each other. These engines lose just about .010 of lift on the pushrod side of the rocker. Which adds up considering the multipication of the rocker arm. Yes that .550 lift cam is really only in the .530 range as installed. We cannot use the formula straight up like the Phord, Chevy folks do. Lobe lift multiplied by rocker ratio...just will not be accurate with our small Mopars. This really needs to be in the considerations when in the planning stages of our build ups. It has been my experience that with the small Mopars...the use of 1.6 rockers will give 'back' the lost lift. Using 1.6 rockers will give, at the valve, within a thousandth or two of what the cam is speced out to be with 1.5 rockers. Very good Moper...I was thinking I was the only one who saw this. Lead on buddy.

TB
 
340sFastback said:
Some cam manufacturers specify lift at the cam and lift at the valve and they take into account the lifter angle. Here is the cam I just bought:

http://www.cranecams.com/index.php?show=browseParts&action=partSpec&partNumber=699641&lvl=2&prt=5
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That cam card gives theoretical lift at the valve using a almost perfect 1.5 ratio.

Brian at Indio Motor just put a new cam in his w-2 360. It was somewhere around .595 lift with a 1.5 rocker. Lift at the retainer was in the .570 range.
 
D- lol..thanks for the kind words, but there's a few others (at least) here with a lot of good knowledge. Not only do they possess it, they dont mind sharing and aren't Aholes about it. One thing I like about this site in particular is a good atmosphere to toss around ideas and get feedback with respect, regardless of level of question. Being a tech guy other sites, I can safely say other sites are not so blessed.
 
moper said:
D- lol..thanks for the kind words, but there's a few others (at least) here with a lot of good knowledge. Not only do they possess it, they dont mind sharing and aren't Aholes about it. One thing I like about this site in particular is a good atmosphere to toss around ideas and get feedback with respect, regardless of level of question. Being a tech guy other sites, I can safely say other sites are not so blessed.
Click to expand...

Man do I agree with that statement. Moper helped me out with something I totally forgot about with a carb and it really woke up my car.

I know sometimes I come across in the written word as gruff. Just my writing style. Don't like to write more than necessary.

Even if you disagree with someone around here, rarely does it deteriorate into a "you're an a-hole" slapfest.

I particularly like the responses at other boards like "there's no way your car runs those numbers with THAT combo...." Ummmm, yeah, OK! :thebirdm::bootysha:

Good community with good folks! :thumbrig:
 
Did you evr install this engine? I have practically the same thing in a 408 roller, best of 12.26 through a 3000 stall and 3.73 dana.
 
Nice numbers. That thing should go like a ***** on the street.

For comparison, my 340 dyno numbers were 458HP at 6000RPM and 462 ft-lbs at 4300RPM. You can't beat the torque of a stroker, and that will be a lot of fun on the street.

A bigger carb will make better numbers on the dyno, but may or may not be better in the car. I would not consider headers other than TTI or Doug's, just because of fit. If it was a drag car, that's another matter.

I predict high 11's.
 
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