motor help!

[Cobain03]

i was having trouble out of a lifter (first one on the number 8) here recently. i would go to tighten it up cause it was pecking and it would hush, then come back. pulled the intake and it was locked up. so i replaced it. now upon reassembly, the second on on the number 8 piston is doing the same thing.

whats up? i HOPE the cam didnt get wore.

 

[Cobain03]

guys, im back again with the same problem. both of the back two lifters are pecking. by looking at the threads they are tightened down a whole lot more then the others and still pecking.

tell me something!

 

[GoinBroke]

I'm no expert but it sounds like it could be a collapsed hyddraulic lifter or a cam lobe has been wiped off. If you have a dial indicator you could compare the lobe lift (at rocker) of the suspect lifter vs one which looks ok. Was the engine rebuilt lately or been sitting for an extended amount of time?

 

[Cobain03]

fresh rebuild. this has happened to two of the same lifters twice. i would suspect that if was the cab, tht the other side would be doing the same. could it be the springs not giving enough to let the lifters contract/expand.

 

[GoinBroke]

Be very careful to not overtighten the rockers more than spec or you will have more issues than you have now. Does the engine have the stock valve covers and rocker arm set up?

 

[Cobain03]

stock rocker setup and chrome valve covers. if your referring to the thinness of the valve cover, that is not it. we have cut the old valve covers in half (long ways) and bolted them down so we can tighten them while the engine is running. the last two on the drivers side (cylinder 8) is going crazy.

 

[Max Power]

You should always replace lifters in sets, if one is bad, others will soon follow. Save a lot on gaskets that way.

Sounds like a bad lifter or six, cam lobes going south, or pressed studs pulling out of the heads.

 

[Cobain03]

how do i check about the heads?

 

[Max Power]

Just look and see.

Studs that are pulling out will be taller, and it should be obvious when looking at the base of the stud.

 

[dennis112]

Just look and see.

Studs that are pulling out will be taller, and it should be obvious when looking at the base of the stud.

Yeah, I've had studs gradually pull out of the head before. Drove me bonkers until I figured it out.

Run a straight edge across all the studs and see if the ones on #8 are appreciably higher.

 

[GoinBroke]

I have also heard bad things lately about flat tappets going bad during break in due to no Zinc in the standard oil these days. Comp Cam's break in protocol is to use Rotella T (diesel motor oil) for the high Zinc content. Just something to keep in mind if the studs pulling out are not causing the problem.

 

[Cobain03]

im going to completly flush my oil system and out and put in some 15w40 that my farm uses. although i do not know if it is straight, half or full synthetic. going to get a full new set of lifters also. should i go to advanced auto and get a set? or what do you reccomend