mopar440ish
Member
I'm running a mild cam. Or will, I have it, installing it in my 340/372 70 Duster. It's a 4 speed, and I'm just wondering if any one here has actually run this combo? How's does it feel, perform?
Feel of this comp cam
- Thread starter mopar440ish
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if you can find the specs, look up the 68 340 4spd camshaft. seems like those are close to the specs of the 68.
mopar440ish
Member
Hi I did look them up previously actually. They are close for sure.
We put one in my son's 440. Excellent idle with just a hint of a lope. Good street low/mid range torque. He is running 3.23 gears with some pretty tall tires.
mopar440ish
Member
Good to hear. Thank you for the reply.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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In my alloy-headed 11:1Scr/367/A833/3.55 streeter,
I have run something very close to that, namely; 223/[email protected] and 270/276/110 advertised @.008 tappet; (notice that from .008 to .050 the intake ramps total 47*)
If idling around and/or low speed operation is not on the table, then the following conversation can be ignored.
In my experience, with my cam, it needed a starter gear of at least 2.66x3.55=9.44. More is better.
In my combo with 180psi or more CCP; I ended up with the Commando trans, at 3.09 x 3.55= 10.97
This takes off like 4.12s would with the regular 2.66Low trans; and the slowest speed it will idle around at is 4mph@550rpm@5degrees advance. I was able to get it down to 3.6mph@500rpm, so then, parading was possible.
This cam, by far, was my favorite combo. With the high compression and Alloy heads, she continued pulling long after her Power-peak. She put up with gears way lower than most guys would ever run, and cruised at very low rpms returning excellent fuel-economy, yet was easily a 12 second car.
As for the Summit cam;
Neither the LSA, nor the advertised lift spec's, are listed; those can make or break your 4-speed combo, especially with hiway gears. It affects your driveability at slow speeds, and especially the slowest speed at which you can idle around at. High cylinder pressure can become an issue, cuz you don't have the fluid coupling of the Convertor, to absorb the low-rpm jumpiness. So if your combo is for street, and you like to idle around, then your combo needs to be well thought out.
Notice that the ramps total 46*,(which seems pretty good), but the advertised is not spec'd. More than likely, that is a .006 spec, making the cam appear bigger than it would at .008 tappet rise. Depending on your Scr (Static Compression Ratio) this may or may not become an issue.
A slow-ramp/wide LSA cam will want to get quite jumpy at this very low rpm, and the ignition will need to be retarded quite far to suppress it, so your tune becomes very important. For this reason, and for low-rpm parading with a manual trans, I recommend a faster rate off lift/tight LSA cam. But this may increase your cylinder pressure so you gotta be careful with iron open-chamber heads, so as not to get into detonation at WOT.
For these reasons, I eventually went to a longer period cam to get rid of some CCP, so I didn't have to retard the ignition timing so much.
As for me, I would not install a cam that I did not know ALL of the specs of.
I have run something very close to that, namely; 223/[email protected] and 270/276/110 advertised @.008 tappet; (notice that from .008 to .050 the intake ramps total 47*)
If idling around and/or low speed operation is not on the table, then the following conversation can be ignored.
In my experience, with my cam, it needed a starter gear of at least 2.66x3.55=9.44. More is better.
In my combo with 180psi or more CCP; I ended up with the Commando trans, at 3.09 x 3.55= 10.97
This takes off like 4.12s would with the regular 2.66Low trans; and the slowest speed it will idle around at is 4mph@550rpm@5degrees advance. I was able to get it down to 3.6mph@500rpm, so then, parading was possible.
This cam, by far, was my favorite combo. With the high compression and Alloy heads, she continued pulling long after her Power-peak. She put up with gears way lower than most guys would ever run, and cruised at very low rpms returning excellent fuel-economy, yet was easily a 12 second car.
As for the Summit cam;
Neither the LSA, nor the advertised lift spec's, are listed; those can make or break your 4-speed combo, especially with hiway gears. It affects your driveability at slow speeds, and especially the slowest speed at which you can idle around at. High cylinder pressure can become an issue, cuz you don't have the fluid coupling of the Convertor, to absorb the low-rpm jumpiness. So if your combo is for street, and you like to idle around, then your combo needs to be well thought out.
Notice that the ramps total 46*,(which seems pretty good), but the advertised is not spec'd. More than likely, that is a .006 spec, making the cam appear bigger than it would at .008 tappet rise. Depending on your Scr (Static Compression Ratio) this may or may not become an issue.
A slow-ramp/wide LSA cam will want to get quite jumpy at this very low rpm, and the ignition will need to be retarded quite far to suppress it, so your tune becomes very important. For this reason, and for low-rpm parading with a manual trans, I recommend a faster rate off lift/tight LSA cam. But this may increase your cylinder pressure so you gotta be careful with iron open-chamber heads, so as not to get into detonation at WOT.
For these reasons, I eventually went to a longer period cam to get rid of some CCP, so I didn't have to retard the ignition timing so much.
As for me, I would not install a cam that I did not know ALL of the specs of.
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from an old motors manual. no duration given that i saw but lift for auto and 4 spd. sorry for the chitty pic.
What intake, gears, heads are you going to be running? RBKT is correct, but the comp has more .050 ground into it and it’s in a 110 LSA. Here’s the listing of the full specs.
COMP Cams 20-309-4 COMP Cams Magnum Muscle Camshafts | Summit Racing
A comp XE262 or XE268 would possibly be a better fit, depending on the cars intended purpose. I’m taking from the first post that you’ve got a 360 stroke for 372 cubic inches.
COMP Cams 20-309-4 COMP Cams Magnum Muscle Camshafts | Summit Racing
A comp XE262 or XE268 would possibly be a better fit, depending on the cars intended purpose. I’m taking from the first post that you’ve got a 360 stroke for 372 cubic inches.
I did . Pulled like a big block on the bottom. Dead on the top. Preload at 1/4 down. And see if you can find other lifters . We have been having problems with Comp Lifters ticking on start up
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mopar440ish
Member
It's a comp cams from summit, not a summit cam. It has the specs in the screen shot. I already have it, came in the 340/372 and I just wanted to know about it before putting it back in the car
mopar440ish
Member
Yes, 360 stroked 340. Already have everything but wondered who ran one and what it's like. I'm not getting another cam, it's just out of car now so...
vntned
Well-Known Member
I ran that exact cam in a 360. It is a great daily driver cam that makes good power. The 360 I put it in was essentially a stock 360 with 0.060”, (371cuin), pistons that put the CR at an actual 9.4:1. The heads were stock 587s with 1.88/1.60 valves, unported. Had an as cast LD340 intake manifold. 750cfm StreetDemon. 340HP exhaust manifolds. 4spd and 3.55 gears out back.
I daily drove that setup in my ‘64 Dart for nearly 4 years.
Ran lower 13s. Best was a 13.3, but it consistently ran 13.4-13.6s.
Averaged 12mpg, and I ran it up to 6000rpm regularly. All my friends were very impressed with the combo and it caught a lot of guys off guard. Beat a guy with a Scamp that had a 383 crammed in it. He was convinced that I was spraying nitrous to be able to beat him like I did through stock exhaust manifolds. He made me pop the trunk to look for a bottle. Lol!
I ended up pulling that setup and stuck it in a Duster, as the Dart is getting a 340 W2 setup next.
Great street cam! Easy to live with and runs hard! I’d buy it again for the right motor.
I daily drove that setup in my ‘64 Dart for nearly 4 years.
Ran lower 13s. Best was a 13.3, but it consistently ran 13.4-13.6s.
Averaged 12mpg, and I ran it up to 6000rpm regularly. All my friends were very impressed with the combo and it caught a lot of guys off guard. Beat a guy with a Scamp that had a 383 crammed in it. He was convinced that I was spraying nitrous to be able to beat him like I did through stock exhaust manifolds. He made me pop the trunk to look for a bottle. Lol!
I ended up pulling that setup and stuck it in a Duster, as the Dart is getting a 340 W2 setup next.
Great street cam! Easy to live with and runs hard! I’d buy it again for the right motor.
Are you SURE that's for a small block? I ask because that's the same Nostalgia grind they offer for the big block....it's their version of the Road Runner cam. It's a great grind.
vntned
Well-Known Member
The Comp 268AH-10 is for small blocks.
mopar440ish
Member
Awesome. Thanks for the info and the rest. I appreciate it
mopar440ish
Member
Yessir
That's a pretty good grind for a small block, then. It'll probably suck your eyeballs out on the bottom end.
mopar440ish
Member
My 1st sb to mess with. I thought the rockers were a bolt down, torque and go? Should I use adjustable rockers?
mopar440ish
Member
I'm liking the reviews
mopar440ish
Member
Ps I have x heads with 2.02s
Oh, one more thing to consider. That particular camshaft is not ground on the typical Chevy style lobes Comp uses on most all their off the shelf stuff. It's ground on real Mopar lobes that take the .903 Chrysler lifter diameter into consideration.
mopar440ish
Member
Like the 440 6 pack with fast ramps?
Adjustable rockers are good . But you can always shim your shafts to get the correct preload. Zero to 1/4 turn with adjustables. One important thing is clearance the rockers for the retainers being used. All 340 rockers are clearanced from the factory for the performance springs. 318 and 360 2bbl were the same rocker but required less clearance and usually not done on some. Same with iron adjustables from early 273's always check clearance
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