[68Chevele]

I am putting a 468 together and have someone that is willing to let me test out his comp cams Austempered Ductile Iron -8 cam. I have some roller springs he brought over and they are #210 [email protected] 1.95 and #[email protected] 1.31 open pressure. Are these going to be too much spring pressure for this type of steel. I do not trust Comps springs at all as others I know have has springs of theirs break in the past and will not run the Comp stuff. Any insight will be helpful.

 

[BillK]

How big is the cam ? Part number ? What rpm are you planning ?
Personally I have never had an issue with Comp springs.
Looks like most of the -8 cams call for a 953 spring which is 148 @ 1.900 seat and 456 @ 1.250 open .650 lift

 

[68Chevele]

How big is the cam ? Part number ? What rpm are you planning ?
Personally I have never had an issue with Comp springs.
Looks like most of the -8 cams call for a 953 spring which is 148 @ 1.900 seat and 456 @ 1.250 open .650 lift

It looks to be an X-tream energy cam, .639, .646 lift 236° 242° on a 110 LCA. From what I have read the 953's are to light to drag race with, ok for street use. The 952's look to be better and the springs I have are just a little higher on the open pressure.

 

[Malibu ss 64]

I know someone that used that cam on a -8 core and 929-16 springs ran constant 10’s.

 

[69-CHVL]

Sometimes I wonder if a -8 core is the way to go as maybe it flexes just enough to live a long life in a misaligned block.

 

[BillK]

the springs I have are just a little higher on the open pressure.

Probably close to 60lbs higher ? The rpm range on that cam is only up to 6200 rpm. I guess the real question here is if the camshaft material can deal with that type of pressure. Have you called Comp and asked them ?? That would have been the first thing I would have done.

 

[BillK]

I reached out to someone I have know for 25 years at one of the cam companies (not Comp) and he said that 450 or so would be the most he would feel comfortable with on a SADI cam. I dont question his judgment but then again I am not one to take risks when it comes to engine failures.

 

[68Chevele]

Probably close to 60lbs higher ? The rpm range on that cam is only up to 6200 rpm. I guess the real question here is if the camshaft material can deal with that type of pressure. Have you called Comp and asked them ?? That would have been the first thing I would have done.

Last time I have talked wit anyone at Comp was when Scooter Brothers worked there. Now you your likely to get someone who is a salesman rather than a good tech, kind of like when I called QF on an issue like talking with a box of rocks, not to insult rocks. I talked with one of the local builders here and his feeling were a little more pressure on a any kind of roller cam is better that not enough when racing so I put the springs in at a little higher installed height. I will also do what Joe Sherman always said about running a roller cam "never let the engine idle too low it's bad for roller cams".

 

[BillK]

I talked with one of the local builders here and his feeling were a little more pressure on a any kind of roller cam is better that not enough when racing

Easy to say and very true with a billet cam but I am not sure if I would trust that on a cast one. I guess you are going to find out

 

[ironhead]

I have a comp SADI with 200/500 lb and a 30/70 rev kit to boot.Lobes look fine with no measureable wear.Cams .652" lift solid roller.