What are the limits of comp cam OE replacement hydraulic lifters. Specifically reguarding lift and spring selection.

 

Putting it this way, on a 306 cam with .550 max lift springs, after spinning to 6500 several times I am in the process of replacing them with comp "R" lifters. They are ticking already really bad. they will bleed off too much.

 

Why did you only run a ..550 max lift spring with the 306?

 

i was thinking the same thing... might not be your lifters ticking if thats the case

 

306's lift is .540 so to me I could squeeze by

 

You need at least.050 clearance between coil's.That is checked space,not on paper.

 

The Comp R lifters are bad ***. I took my car to 7000 many times. There are two different Comp lifters. Whoever tells you Comp R's aren't any good need to get their head outta their ***. The Comp stock replacements are pretty nice. But for a few bucks more you can have the Comp R's and be done with it. I would suggest going with those.

 

Im also interested in knowing this. I have a 306 cam and springs with 370lbs open pressure. I plan on spinning it to 6700 rpm on a regular basis. Would that require comp-r lifters.

If i did get comp-r lifters, how much do you think i could get for my stockers (eBay maybe)?

 

Yes, go with comp-r's for 6700rpms.

I sold a set of my stockers for 55$ shipped through forums. I think that might have been a little high, but they only had about 35,000 miles on them.


Id say you can get like 35$-40$ for sure for them, if theyre working and not insanely high milage.

 

what about the CC305 cam? Does it need a lifter change as well?

Thanks

Joe

 

Contrary to popular belief,lifters do not"pump up" by there self for no reason. The main reason that you have trouble at 6000+RPM is valve spring pressure.You either float the valves or bounce them off of the seat.When you put slack in the valve train the lifter does what it is suppose to do and pumps up to remove that slack.At that point the lifter is holding the valve off of it's seat and it causes a miss untill it relieves itself and allows the valve to seat again.
I have had no problems with factory lifters in the engines I build.If you are shifting above 7000 there might be an advantage to aftermarket lifter's due to their quick responce to bleeding down(after you float the valves from lack of spring pressure)
99% of the time springs are the culprit.You say,they are what the cam maker recommends.Well what is recommended is NOT what you need all the time.
You see guys on here trying to run Hot Cam springs with a big ramp cam and that don't work.They blame the lifters(not knowing) and replace them and still have problems.So you need to figure out the problem BEFORE you start throwing money at it and parts to fix it.