Supposedly overcammed works out.....

[RustyRatRod]

RustyRatRod wrote: "That's because your combo is NOT overcammed. It's UNDER converted."

Thanks for the advice, Rusty. I don't want to hijack the thread, but how high a stall speed do you think is desirable in a car driven on the street? I don' think I want to have to rev up to 3,000 before it would connect.

Modern converters just don't work like that anymore. Now you can have a custom converter built that can easily be street driven and flash to 5K on demand if you want or need it to go that high. They are tight for street driving but when they see an instant blip of full torque, they can go into the stratosphere. I would call a good converter company, tell them what you have and what you want and go from there. Certainly it sounds as if you need more converter than you have now. While you say you don't want to have to launch 3K everywhere, I completely understand that. But by the same token, you also don't want the converter so tight that you basically get nothing out of it.

 

[txstang84]

Modern converters just don't work like that anymore. Now you can have a custom converter built that can easily be street driven and flash to 5K on demand if you want or need it to go that high. They are tight for street driving but when they see an instant blip of full torque, they can go into the stratosphere. I would call a good converter company, tell them what you have and what you want and go from there. Certainly it sounds as if you need more converter than you have now. While you say you don't want to have to launch 3K everywhere, I completely understand that. But by the same token, you also don't want the converter so tight that you basically get nothing out of it.

True statement...even though a 3k stall says 3k, that's for a rated torque input at a given RPM...usually the rated stall. But, if the engine isn't putting out that much torque (e.g., off idle, or mild accel), the "stall" is lowered because the torque output is lower. If you're just putting around town, a 3k stall will start moving the car probably from 2-2200. Weight of the car and gearing also are factors affecting the rated stall.

 

[Mo-Par]

Rule of thumb-Its not to big if it works.

 

[1970 La]

Yeah I was not impressed with it either. I did have a .484 lift mopar in a 318 and it worked great. I sent my .508 in to Bullet and they reground it as a solid.

Specs:

In 252 @ .050
Ex 253 @ .050
seperation 108
Lobe lift .344
Duration @ .020 281 In 284 Ex
.516 lift with 1.5 rockers
Lash @ .016

Have not ran it yet but I have it installed in a 11.1 340. Will run it come spring.

Well did not get to run as soon as I thought but took my dart to the track last night with the bullet regrind. A little about the car, dodge dart weighing 3300lbs, 11-1 340 unported J heads 1.88/1.60 valves, victor 340, a body 18 spline 4 speed and 28 x 9 mt slicks.

7.84 @ 86.8 1.70 60' off of the trailer

7.73 @ 87.9 1.67 best

I think I can get a 7.6? out of it. I'm sure a 1.65 60' will knock it dead. Been a long time since I ran stock heads Realy enjoyed racing it. Oh yeah still running stock 273 rockers.

 

[Abodybomber]

Nice to see. Great 60 foot,1/8 th mph.

 

[RustyRatRod]

A lot of Jim Laroy's (IQ52) pump gas builds have what a lot would say too was big of a cam, but his dyno numbers say something else. An engine's compression is but one small part of the picture. As long as you have a good induction, good head flow and good exhaust, the engine WILL make power. The build I would love to see on the dyno, no one will probably ever do. I would love to see a stock compression, stock cube engine (say a 360 would be good) built with unlimited mods to the heads (any head) cam, induction and exhaust. I think the results would be surprising. ....and I'm not even talking about blueprinting compression. Leave the decks alone and the only limitation to the heads would be stock spec chamber size.

 

[Abodybomber]

Rusty Rat Rob,thank you. Someone has included ,the whole picture.

 

[1970 La]

I think getting the most cranking compression out of the camshaft/engine is where its at. If you have a good hooking track why not build the most low end possible (make the car accellerate) 1/8th mile don't have a 1/4 mile track to test on. The engine I'm running has 175lbs cranking compression I really should advance the cam timing, ground on 108 and I put it in at 106.5. 104 should take the bog out of it. By the way I am not saying the cam is too big for my combo it's just where this thread lead me.

 

[Abodybomber]

:cheers: Yay! Someone gets it.... A certain person here,doesn't understand this..

 

[frosty_the_punk]

A lot of Jim Laroy's (IQ52) pump gas builds have what a lot would say too was big of a cam, but his dyno numbers say something else. An engine's compression is but one small part of the picture. As long as you have a good induction, good head flow and good exhaust, the engine WILL make power. The build I would love to see on the dyno, no one will probably ever do. I would love to see a stock compression, stock cube engine (say a 360 would be good) built with unlimited mods to the heads (any head) cam, induction and exhaust. I think the results would be surprising. ....and I'm not even talking about blueprinting compression. Leave the decks alone and the only limitation to the heads would be stock spec chamber size.

This!

I would love to see an engine build-off competition where shops are required to use a factory rotating assembly and equivalent combustion chamber size.

A "modify the top end and bolt it onto a factory short motor" competition, if you like.

 

[Abodybomber]

This!

I would love to see an engine build-off competition where shops are required to use a factory rotating assembly and equivalent combustion chamber size.

A "modify the top end and bolt it onto a factory short motor" competition, if you like.
Bellissimo! And multiple track times...

 

[moper]

In my 408 with 10.5:1 compression, I'm running a Comp Cams CRS 292H-10 with a 727 TorqueFlite and a 2,200 stall converter.

Total lift: .501. 292 degrees duration at .006 and 244 degrees at .050; .334 lift at .050.

I sure wouldn't want a bigger cam with the automatic and this converter. It is supposed to be a street car! It will barely idle.

Taking a different and probably more unpopular route here - you are not over cammed. You have either a tuning issue or base engine problem. It should idle like a kitten with that camshaft. I won't dispute that you should get a positive result from a modern convertor - but not because the engine's running the way it should. You'll still have a doggy engine in front of it. If a 4" stroke has less duration than 250° .050 it should idle under 800 easilly and it would work with even a stock low stall convertor. The ones I build get decent mileage in addition to opwer because the convertor is tight.

In regard to the stock lower end -

I agree it will never be built. The problem I see is no piston would work on that "stock" combo shortblock and a cam you would need to run. Even a 7.5:1 piston .125 down will hit a 2.08 valve with a big camshaft. You need some valve pockets - and then you've just upgrade the bottom end.

 

[goldmember]

This thread is about big cam grinds,that shouldn't work,but do.All the cam tech guys say " too big!",but you did it anyway.(lol). Mine,mild 408,9.7 real world compression.Mildly worked Eddys,air gap manifold.Chose a old Comp 312h-06.Hyd flat tappet,[email protected],106 I/c installed at 104 per cam card. Was mildly surprised,at the responsiveness of ole biggie.Idled about 1100 in drive,with a wicked chop.Mid range torque ,off the hook. For reference,this cam 2 sizes bigger than the Comp 305 Magnum.What's your story?

I guess the question is kinda vague to me. I only concern myself with ET slips. Idle etc ar not at the top of my list of what means a cam works. Yes, I've run the large Comp [email protected] hyd cam in a 360 20 years ago. It ran well with 4.56 gears and loose converter,but I've built lot's of combos that were better with other grinds. I've been over and undercammed on many visits to the track.LOL

 

[goldmember]

Taking a different and probably more unpopular route here - you are not over cammed. You have either a tuning issue or base engine problem. It should idle like a kitten with that camshaft. I won't dispute that you should get a positive result from a modern convertor - but not because the engine's running the way it should. You'll still have a doggy engine in front of it. If a 4" stroke has less duration than 250° .050 it should idle under 800 easilly and it would work with even a stock low stall convertor. The ones I build get decent mileage in addition to opwer because the convertor is tight.

In regard to the stock lower end -

I agree it will never be built. The problem I see is no piston would work on that "stock" combo shortblock and a cam you would need to run. Even a 7.5:1 piston .125 down will hit a 2.08 valve with a big camshaft. You need some valve pockets - and then you've just upgrade the bottom end.

I agree with Moper and yes [email protected] is a tractor cam in a 4" combo(unless it's for a daily towing pickup truck) the cams not one that I'd use but put a real converter in it get it tuned and you'd be OK.

 

[Abodybomber]

The original intent of the thread: Having /wanting a bigger cam than anyone recommended. (And it still kicks ***.)