hyd roller cams?

[twoslo4five0]

what is the diffrece between a comp computer controlled hyd cam and a reg hyd roller cam?both are hyd rollers so whats the diffrece.i ask cause we have a bunch of hyd roller cams here on the shelf but they were all out of carberated race cars.this will be going in a late 90s l31 votec motor

 

[79rustyk10]

Im guessing computer controlled means its for some sort of late model fuel injected engine.

 

[thedrip]

the "computer control" cams have different overlap to make them run smoother at idle. most EFI systems don't deal too well if vacuum at idle gets too low.

 

[twoslo4five0]

this is true but tuneing is reguired for any cam in a l31 so if the lift and duration is the same then whats the diffrence

 

[twoslo4five0]

the "computer control" cams have different overlap to make them run smoother at idle. most EFI systems don't deal too well if vacuum at idle gets too low.

wouldnt the idel rely on the duration and lobe seperation?if all was the same then what would be diffrent between the 2?

 

[k20]

typically the efi cams are 112-114 lobe separation. I have seen identical cams (saw it more with crane actually) that would fall into 2 or 3 categories in their catalog, it might be listed under hydraulic roller, but then again under efi cams, and then once more under nitrous cams.

 

[twoslo4five0]

really?so the number might crossreference?

 

[k20]

It might, no guarantees, but I did notice that when I was looking for my cam in crane's catalog.

 

[twoslo4five0]

here is what james at blue torch said about it on pirate

the computer cam is a cam or group of cams that have a grind that can be tuned with the computer, hyd cams are just cams that use oil pressure to maintain valve lash instead of it being a solid lifter(no internal piston to take up slack in the valve train w/oil pressure) that needs the valves adjusted to maintain proper lash in the valve train. A cam for a carb'd engine will differ in that it may not pull as much vaccum at idle compared to that of a computer cam, the computer cam pulls enough vaccum at idle for all of the sensors in the intake to monitor the engine rpm and air/fuel ratio etc. etc.
Let me know if I can help you in anyway.

 

[k20]

Well it depends one which series of computer cams and generation of engines you are talking about. The way I read what he said, it makes me think of the newer engines that have something similar to VTEC, cant remember exactly what GM calls it, I think its only in the LS2 and newer engines. Believe its called cam phasing or some such nonsense.

The Lt1's, lt5's, ls1's and vortec's (as far as I know) dont have this and the computer controls on them rely on a 'mild' enough grind to allow the computer to not receive contradicting vacuum, speed, knock, etc readings which would confuse it. Basically it boils down to that you could run a 'efi/computer' grind with a carb and it would be just fine. If you tried to run it the other way you may or may not be able to tune it to run properly. Actually, IIRC the cam that is in my truck now has a 112 LSA and can be run with EFI.