Cam replacement

OK, if you had a wiped lobe, you would know. POOR running, and you would SEE metal in the oil.

MOST of the time, not always but most of the time, you need to go to an adjustable valvetrain. Before you start pulling the intake off to replace lifters lets do a few things.

1. What cam did you put in the car? Can you link the cam card?

2. IF the cam is big enough, you need to get an adjustable valvetrain.

3. PUSHRODS ARE CHEAP!! It is easier to swap out a pushrod then a lifter.

4. Remember that if you DO replace a lifter, you need to replace them all.



So I would pull the push rods and see if they are bent. Use a flat surface and roll the push rod on the surface. IF you need to go adjustable, all you will need is a locking nut.

3/8
http://www.summitracing.com/parts/ARP-300-8243/

7/16
http://www.summitracing.com/parts/ARP-300-8245/



When I did my cam break-in, I had to stop 3 times. Cam is fine. It is better to stop and fix an issue than continue and do it wrong.


I applaud you for trying this on your own. This is a great learning experience and the next one that you do will be WAY easy!!! Keep up the good work!!!

 

Just out of curiousity, why would you have to replace a whole set of lifters, if only one is bad?? I've done 1 at a time without a 'comeback' as well as many GM mechanics!
Wondering too, how do you determine # 4 'pistion' is loose, by pulling the valve covers?
Understanding the OP is not a mechanic, #4 is a exhaust valve, which may have a broken spring and/or bad valve guide!!
I think he should have a mechanic look at it, as he could easily get in over his head trying to do a valve spring by himself!

 

Could be something very simple or very deep. A good mechanic will find that problem in no time.

 

I've never had a problem with replacing only a few lifters.
I'm thinking he meant the valve wasn't tightened down and the rocker arm was loose.
I agree, he should find a friend to look at it that knows engines.

 

No argument there. But since he is not a mechanic, it would be easier to just replace them all. Cheap enough.

Agreed. Sounds like the rocker arms are loose. Another reason to make it adjustable. That way the lash can be adjusted and if it is still getting clacking, a lobe might be wiped or there might be valve train issues as mentioned.

It could also be geometry. We need the cam card to see what is going on..

 

Here is a video that might help with setting the pre-load.

Hope this helps,
Dave

http://www.youtube.com/watch?v=89o5rLpbCgI