comp cam life
Thread Starter
Racer
Joined: Jul 2004
Posts: 468
Likes: 12
From: Pleasant Hill CA
comp cam life
does anyone have a ballpark idea on the life of a comp camshaft?? i have a comp cam in my 350 smallblock that has been in the motor for about 15 years?
it still seems to run good with no problems. however, i do not race the car just drive it on the street. i do change my oil every 3k. how long can i expect this
camshaft to last? thanks
it still seems to run good with no problems. however, i do not race the car just drive it on the street. i do change my oil every 3k. how long can i expect this
camshaft to last? thanks
Le Mans Master
Joined: Feb 2008
Posts: 6,536
Likes: 1,947
From: Folsom CA
I think the larger the lift the shorter the life with a flat tappet camshaft. Original equipment grinds do not have a lot of lift but they give you very long life.
Original cams usually have around .440 lift, some aftermarket performance cams have much more than that and put more presssure on your lifters and cam lobes.
Some switch to stronger valve springs than stock when they rebuild, this can do the same thing and shorten cam and lifter life.
If you want long life stay close to a stock grind and spring rate.
If yours is running great you should enjoy it and not worry.
Original cams usually have around .440 lift, some aftermarket performance cams have much more than that and put more presssure on your lifters and cam lobes.
Some switch to stronger valve springs than stock when they rebuild, this can do the same thing and shorten cam and lifter life.
If you want long life stay close to a stock grind and spring rate.
If yours is running great you should enjoy it and not worry.
Thread Starter
Racer
Joined: Jul 2004
Posts: 468
Likes: 12
From: Pleasant Hill CA
comp cam
i think i have approx 10K on the motor. i dont drive it everyday just on weekends and drive it more in the spring and summer. i beleive it is a 280 duration cam
with a 585 lift with roller rockers. i think it is very similiar to the old 30-30 duntov cam. it is a comp thumper roller cam. thanks
with a 585 lift with roller rockers. i think it is very similiar to the old 30-30 duntov cam. it is a comp thumper roller cam. thanks
Le Mans Master
Joined: Feb 2008
Posts: 6,536
Likes: 1,947
From: Folsom CA
.480 lift is calculated based on a 1.5 ratio rocker arm. 4.80 divided by 1.5 = .320 actual cam lobe lift
take this .320 and multiply by 1.6 and 1.7 and you have .512 or .544 actual valve lift
Changing from 1.5 to other ratios changes the amount of side thrust on your valve guides and starts shortening the life of the valve guide also.
No doubt horsepower can increase with more valve lift you just want to acknowledge you are playing a give and take game.
Many street engines run with .500 to .525 valve lift and live long lives just not as long as a factory might enjoy all else being equal.
Properly maintained who knows you may exceed 100,000 miles the way you are set up.
Mark
take this .320 and multiply by 1.6 and 1.7 and you have .512 or .544 actual valve lift
Changing from 1.5 to other ratios changes the amount of side thrust on your valve guides and starts shortening the life of the valve guide also.
No doubt horsepower can increase with more valve lift you just want to acknowledge you are playing a give and take game.
Many street engines run with .500 to .525 valve lift and live long lives just not as long as a factory might enjoy all else being equal.
Properly maintained who knows you may exceed 100,000 miles the way you are set up.
Mark
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Safety Car
Joined: Oct 2016
Posts: 4,617
Likes: 1,547
From: Olive branch Ms
Many engines came from the factory with 1.7 rockers, i.e. big block Chevys, Fords, and all LS engines. The big block has a good bit more spring force, stock, than a small block along with the 1.7 rockers. You are good to go. If you set the springs up 100-125 seat and 300 or less open the cam should last the life of the engine with good oil.
Le Mans Master
Joined: Feb 2008
Posts: 6,536
Likes: 1,947
From: Folsom CA
The big block has a head designed to run the big block rocker arms. I think we are discussing a 350 Chevy?
They were designed to run the 1.5 Rocker arms.
I do agree though that he is probably good for many miles and the upgrades he has are very common.
They were designed to run the 1.5 Rocker arms.
I do agree though that he is probably good for many miles and the upgrades he has are very common.
Safety Car
Joined: Oct 2016
Posts: 4,617
Likes: 1,547
From: Olive branch Ms
The later vortec heads identical in every way as far as rocker arms used 1.6 from the factory. I doubt the OP has 1.7. but it's possible. The point was a big block runs more spring and rocker ratio on the same lifter as the SBC so he shouldn't have anything to worry about. Once you get past break in you should expect many years of use from that cam.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
i think i have approx 10K on the motor. i dont drive it everyday just on weekends and drive it more in the spring and summer. i beleive it is a 280 duration cam
with a 585 lift with roller rockers. i think it is very similiar to the old 30-30 duntov cam. it is a comp thumper roller cam. thanks
with a 585 lift with roller rockers. i think it is very similiar to the old 30-30 duntov cam. it is a comp thumper roller cam. thanks
Roller tappet cams with billet core cams will last longer but I don't think that's what we/you are dealing will.
But with only 10K mi? I think your getting a bit superstitious.
Race Director
Joined: Apr 2015
Posts: 17,571
Likes: 3,461
From: Fresno California
Roller tappet cams used by the oems will possibly last longer, but not the roller tappet cams the aftermarket sells for old tech engines. The lobe design is much steeper, and failures of roller and needle bearings is fairly common. A quality flat tappet cam has always been my choice for longevity. The one in my '67 GTO has almost 32 years/90k miles on it and no signs of wear when I inspected it about 8k miles ago.