Z_Maniac

Sup folks - Just wondering what route I should go here next.

I had my mechanic install a CC305 cam, 1.6 RRs NSA, with it came new Crane Springs, Retainers, locks, Guideplates.. yadayadayada...

I however used my stock lifters, stock pushrods (it's a 94 so I hear they're already hardened). Everything was good for the first 1000 miles as I was babying it and since then had changed the oil. About last week I finally installed the new program that I had gotten from PCMForless w/ your basic cam, firmer shifts, and power program. Car ran good and shifts awesome. However, last week I noticed car started having a misfire almost and ran really rough. I checked for burnt plugs and didnt find any. Soon after I started hearing a clicking or ticking noise so I called my mechanic back and asked to check it out. After I got to his house we opened up the valve cover and to my dismay this is what we found.

The stud had broken and in turn I found the rocker just sitting there! The pushrod was bent and broken in half and we couldnt find the other half!!! One of the other RR was pretty loose but didnt come off. We were trying to see the extent of the damage to the head w/o taking off the intake, head, etc as it started raining and it was getting pretty dark out there but you can clearly see that the area where the pushrod was a hole that is now an eggshape instead of your regular circle hole so I'm assuming the valves were shot.

My mechanic seems to think it wasnt that bad and just by replacing the lifter, pushrod and maybe having the head welded will be fine....... Is this the right way of approaching this???? Or should I go a different route???? I know my mechanic knows what he's doing as he has a couple of cars in the low 11s already and he is sorta the group mechanic so I dont doubt his skills at all but kinda feels weird about him doing a patch job!!! For example using different size studs on the car???? Is this even ok to do?????

Please help as I wanna make sure I'll be getting this fix the right way and if I need to buy better parts as opposed to him wants me to pick up replacement pieces alone, I'll do what it takes.

Also, what could've caused the problem? I know I had babied the car before the incident and I might've gotten on it a few time but that was after the break in period and I had already changed the oil then...... Sorry if this was pretty long but wanted to vent out.

Thanks.

Fastbird93

I just want to get a good understanding here. You're saying that the hole in the head where the pushrods comes through got elongated???

Ouch. I'm not sure if that could be welded up or not. The thing I'd be more worried about is the other piece of a pushrod making it's way freely around your oil pan, until it catches something, gets ground up, and costs you a short block.

12SCNDZ

What rocker studs did you use?

Are you sure the rockers were adjusted correctly?

Frank

Z_Maniac

The studs I got used from another board member here and they were 3/8"s and as far as the rockers being adjusted properly, I hope so... This wasnt his first install on these cars and since I had the NSA he used the guideplates with them.....

Should I just get a used lifter to replace the one I had as well as the pushrod or which replacement part should I get?

Thanks.

12SCNDZ

If you can locate a good used, low milage, lifter..Go for it. You can also buy singles from GM. These lifters don't have typical wear patterns like flat tappet lifters do, so mixing them shouldn't cause a problem.

I'd invest in a complete set of COMP "Hi Tech" pushrods, though.

I need you to clear this up... The hole where the pushrods goes through, to the lifter is egg-shaped? If that's the case, no big deal because your guide plates center your pushrods.

PLEASE, don't tell me you used COMP guide plates! The ONLY manufactuerer that makes bolt-on guide plates for the LT1 is GM Performance Parts (GMPP)! If you have anything but GMPP plates on it, it's probably what caused your failure. Any GOOD mechanic/engine assembler knows to check the roller tip of the rocker to see that it's centered on the valve tip. COMP plates (or any other typical SBC plates) are wrong for these engines, because the LT1 has .050" wider valve spacing.

How do I know this? Because I originally bought a set of COMP plates, and quickly realized something was wrong. The roller tips on a few rockers were only touching half of the valve tip (side to side). You'd be surprised at how many "professionals" don't know this! I called COMPs tech line to find out that they don't even make plates for the LT1, because of the unique spacing. If you tried running the engine like this, I can see how it would break a pushrod, or a rocker stud...Because your trying to side load both.

Frank