Best cam for choppy idle and low end torque?

-
scott2683

scott2683

Well-Known Member
Joined
Nov 17, 2011
Messages
384
Reaction score
71
Location
Indiana
Hello folks,

I'm looking at putting a different cam in my 318. The engine was rebuilt by the previous owner, bored .030 over and higher compression pistons, it has stock heads with 340 springs. The car has 3.23 gears with stock converter and I'll be running a 27" tire in the rear.

I'm looking for a cam that will give me a nice choppy idle and give me great low end torque. This car will mostly be street driven, I doubt it ever sees the strip.

The last 318 we built we used we used comp cam XE268H but I've been researching and a lot of guys like Lunati Voodoo cams and Hughes whiplash. I've done research on all 3 and and I still can't decide which would be best for my application. I do plan on upgrading the heads in the future, but those are on the back burner for now. The guy I bought the car off of said it had a mild 340 cam in it now. It has a completely smooth idle.

Any help at all would be appreciated. I know this subject has been discussed quite a bit, and I've got through all 130 pages on the forum trying to educate myself the best I can.

Thanks for the help,

Scott
 
Low end torque is a 260ish cam. Its not gonna sound choppy unless you pull a plug wire. Whiplash or Thumpr are probably what you're looking for. Your low duration stump puller cams are gonna sound like low duration cams. Hughes Whiplash part number is 1326, it might be right up your alley. The comp thumpr is a roller.
 
Since the car is mostly street driven, save yourself some expense and install one of these. LOL

I can't figure out why the URL won't load. Go to YouTube and search on Sound Racer V8.

Gotchya!
 
Last edited by a moderator:
Choppy idle and great low end torque, shouldnt be in the same sentence when applied to a short stroke engine like a teener.
Low end torque requires the engine to ingest a lot of combustible mixture,trap it early,compress it into a little tiny space, lite it to burn creating as much pressure as possible without detonating,on the end of as long a lever as fits in the engine, so that the expanding gas can push for as long as possible.
A choppy cam doesnt trap early(thats partly why its choppy).No trap equals no torque.A large total-volume chamber sitting on a small swept volume cant compress.No compress equals no torque.A short arm releases the pressure too soon. No pressure equals no torque.
The point is,that a teener, with no other changes will lose low-end torque with every next bigger cam you put into it. And it will lose it plenty quick.
Now,I see that higher compression pistons have been installed.And thats a good thing.It will pull up the low-end torque.Maybe youre ok with giving some up for the choppy idle.
Of the cams you are contemplating chose the one with the earliest intake closing event to trap as much mixture as possible, and that will likely build the most torque.The 340 cam duration specs are a pretty good balance between power and torque, if a little shy on lift.
If you want what you want, I think you will need a new personality for your 318. A stroker kit will do it.It does it by increasing the swept,increasing the stroke,and increasing the pressure.Then you can give up some of that torque with a bigger cam. This will give you the choppy idle you want,AND a net torque gain, and as a bonus,more horsepower too. It gets a bit pricey though.
A bigger motor will do it too, for all the same reasons.
Or you can shave a BUNCH of weight off the A, and keep that teener, with any cam you want.
Personally, Ive built several teeners for my personal cars and I wont do it again.
 
Here's a 318 with a Whiplash cam. Nice idle.

[ame="https://www.youtube.com/watch?v=ufRTSVOnmDQ"]Plymouth Duster Hughes Whiplash cam - YouTube[/ame]
 
Links won't load on here.
 
The DEH265 Comp will sound choppy in a 318 and have gobs of bottom end torque.
 
[ame="https://www.youtube.com/watch?v=ufRTSVOnmDQ"]Plymouth Duster Hughes Whiplash cam - YouTube[/ame]
 
RustyRatRod said:
The DEH265 Comp will sound choppy in a 318 and have gobs of bottom end torque.
Click to expand...

I don't like the hot start problem this guy has but the cam sounds good!
 
Last edited by a moderator:
Thanks for all of the replies and videos guys! I really appreciate the help! I'm going to continue researching cam options, I'm sure I'll be back with more questions
 
318, stock converter, 3.23's, 27" tire.....??? I could throw a dozen "big noise" grinds out there...if you're man enough to "lug" them around town. :D

I personally would have gone right to the one below that RRR brought up...
RustyRatRod said:
The DEH265 Comp will sound choppy in a 318 and have gobs of bottom end torque.
Click to expand...

http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=635&sb=0

Similar stroke engine...Similar sound! [ame="https://www.youtube.com/watch?v=G1PxzJRpq-M"]Mopar 383 with Comp Cams 265DEH. - YouTube[/ame]
 
Great explanation! Thanks!

AJ/FormS said:
Choppy idle and great low end torque, shouldnt be in the same sentence when applied to a short stroke engine like a teener.
Low end torque requires the engine to ingest a lot of combustible mixture,trap it early,compress it into a little tiny space, lite it to burn creating as much pressure as possible without detonating,on the end of as long a lever as fits in the engine, so that the expanding gas can push for as long as possible.
A choppy cam doesnt trap early(thats partly why its choppy).No trap equals no torque.A large total-volume chamber sitting on a small swept volume cant compress.No compress equals no torque.A short arm releases the pressure too soon. No pressure equals no torque.
The point is,that a teener, with no other changes will lose low-end torque with every next bigger cam you put into it. And it will lose it plenty quick.
Now,I see that higher compression pistons have been installed.And thats a good thing.It will pull up the low-end torque.Maybe youre ok with giving some up for the choppy idle.
Of the cams you are contemplating chose the one with the earliest intake closing event to trap as much mixture as possible, and that will likely build the most torque.The 340 cam duration specs are a pretty good balance between power and torque, if a little shy on lift.
If you want what you want, I think you will need a new personality for your 318. A stroker kit will do it.It does it by increasing the swept,increasing the stroke,and increasing the pressure.Then you can give up some of that torque with a bigger cam. This will give you the choppy idle you want,AND a net torque gain, and as a bonus,more horsepower too. It gets a bit pricey though.
A bigger motor will do it too, for all the same reasons.
Or you can shave a BUNCH of weight off the A, and keep that teener, with any cam you want.
Personally, Ive built several teeners for my personal cars and I wont do it again.
Click to expand...
 
Lunati bracket master 2 .480 lift 230 duration at.050 sounds awesome has great pull.
 
lunati , comp and hughes are the best way to go ... i have a whip lash cam in my car now but i ran a lunati and was happy with it but the hughes whiplash cam does sound better here is a video of my car with lunati cam in it part # 10200702LK

[ame="https://www.youtube.com/watch?v=2VhEDOdt2MM"]drews car - YouTube[/ame]
 
Call up howards cams, tell them what you want.
They will custom grind you a cam with the specs you need, They will give you a grind # and you call up summit racing order it through them. The price is under $150 shipped!! for a custom ground hydraulic flat tappet. Hard to beat that price , and they have lobes for the .904 lifter.
 
You must log in or register to reply here.
-

Back
Top