Hey guys,

So a lot of you probably read my previous thread:
http://forums.corvetteforum.com/c5-t...-no-sense.html

Weeeellll, looks like I had a lifter explode. Had a lifter tick on my drivers side head, pulled the valve cover, and found 3 roughly 1 inch long clock-like springs.



I can't imagine these coming from anything but a lifter, eh?

So about to pull the heads off and inspect the damage - but wondering what type of lifters I should get to replace these. These were stock LS7s and didn't make it 100 miles. I'm thinking defective from the factory?

Anyone have experience with Lunati lifters?
http://www.summitracing.com/parts/lun-72332-16 - Would this be a good replacement, or should I go for comp lifters (or any other ideas?)

Thanks,
Mike

 

Lifters are down in the block not under the valve covers.

Looks like you have some rockers coming apart.

 

I'm aware of where the lifters are (no arseholleyness intended here)... But the springs could pass up past the pushrods.

I dont think Comp roller rockers have any springs like this in them do they? (Please correct me if I am wrong so I don't pull my heads off for no reason. :>)

 

Uhm... maybe? Seems unlikely, but now that you mention it those do look like mangled cup retainers.

Dunno ... never used 'em. I'm assuming you've inspected all the rockers? Got them on base circle and tried to wiggle them all?

 

Yea... No real wiggle there on the questionable rocker/(valve) compared to the others. But I can push the pushrod in about 1/8-1/16 (not the best with my guestimations) inch on that one whereas all the others I can only push down 1/16-1/32 inch. Seems like another sign of lifter.

But I've never had these comp rockers apart - so I dont know how they are assembled.

 

I think you are correct on the clips......hopefully, just replace the lifters and you are good to go. IE....none turned sideways......

You might look at Brian Tooley racing. He sells lifters and I think folks like them.

Nice rockers. Do they fit under the stock valve covers w/o mods?

Ron

 

Thanks for the info.

I didnt think my cam was too insane, but from what I read on some forums - the aggressiveness of the cam slope can tear lifters up more than anything. Could my shorter duration but more valve opening be causing this? (CUSTOM GROUND ROLLER 226 229 DUR AT .050 .598 .610 112lsa
CRANKSHAFT HAS BEEN REGROUND AND BALANCES ALONG WITH ROTATING ASSEMBLY
NEW ALUMINUM CNC PORTED HEADS WITH 2.02 AND 1.58 STAINLESS STEEL VALVES, VALVES SPRINGS TO MATCH CAMSHAFT
COMP CAMS ROLLER ROCKER ARMS). Also I think the 1.72 rockers are adding even more lift right?

Or is it most probably just factory failure, or failure of my builder to use better than stock LS7 lifters? (he stands by they are great lifters). Im thinking go better regardless just because it seems these GM lifters are prone to failure (my GTO has a bad lifter, old engine that came out had bad lifter (and the other LS problem - piston slap) and a few more I have seen with recently the lifter tick tick tick tick). Though this failure is the best I've seen yet of a lifter to launch the springs into the head. Lol. Hopefully my cam is ok.

And yes sir, the rockers do fit without mods!

 

Anyone else have opinions on brands of lifters and what the best bang for the reasonable buck is?

 

Be careful to examine your cam lobes when you can see them. To have those retainers migrate up to the top is VERY unusual. I like those rockers you got. Make sure and get the newer lifter trays if you haven't already. I'm using the GM racing lifters now for about 8 years without problems. Figured if they're good enough for endurance racing, my street only driving won't test them. Good luck.

 

The cam spec won't tell the whole story on the agressiveness of the lobes. You would need to know the lobe profile, who designed it etc. If you can get that from your builder it would be great.
Comp had some lobes that were very agressive called LSK that were known to beat up the valvetrain. LSL lobes are more gentle. EPS has their own that work great and are easy on the valvetrain.
So that info would be good to know.

Yes, the 1.72 will give a smidge more lift. That is why I didn't try them because I'm really close on piston to valve as it is......nice rockers though.

Ron

 

Hmmmmmmmmm.... Have found several more springs - IN BOTH HEADS!!! (up to 8)

Multiple lifter failure?!?!?

I see no springs in the rockers at all.

 

Ok... Getting to work on ripping this motor down to figure out what happened here. Appears to be multiple lifter failure on both heads. Anyone have any clues to why/how this could happen on a new motor with very little mileage?

I am up to 8 springs that I have found, equal length, and 4 half o rings - under the valve covers. Majority of springs were in the drivers head. Weird thing is majority of Orings was in passengers.

Here are some pics of the progress and found springs/orings. Anyone please give thoughts if you have them.






Found these "spare" parts under both valve covers.

Anyone care to speculate? Heading out now to get a little deeper into this.

 

Damn that is strange. Keep us posted.

 

They look like valve seal springs to me! That would explain the oring pieces also. Any chance you are beating the valve seals up? I would pull some springs and inspect the seals. This would answer why the pieces are in the valve covers!

 

Don't think so... I'm not burning oil at all. So that doesn't seem like it could be, right?

 

I don't see how retaining clips from the lifters could migrate all the way up the pushrods, and into the valve covers. Secondly, when you pulled the pushrods, any "bad lifters" would start popping apart as the pushrods were the only thing holding them together, with the retainers beaten out of them. Did any of the pushrods want to "shoot" out of their respective lifters? If not, I'd still agree with "pitstop", that it's the oil seals getting mashed by lack of clearance between the seals and valve retainers.

 

Not sure...

When I pulled the pushrods none of the lifters poped the rods up or look off from looking down the pushrod hole.

Found 1 more spring. Up to 9 now.

All pushrods look good with no damage.

Engine never burned oil so I'm hesitant to think valve seals but I'm the first to admit im dumbfounded right now.

Slowly taking it apart... Heads coming off not too far away.

 

Pull some valve springs first! I am going to bet that you will find valve seal damage. It's a lot easier than pulling the heads! Good luck.

 

Hmmmm.... If it is valve seals then don't my heads have to come off anyway? (never done valve seals, myself)

With that many valve seals gone wouldn't I have been bellowing a cloud of smoke?

(Not trying to be argumentative or resistant... Just trying to think this through here).

I'm starting to wonder if this was a late april fools joke and my builder put these springs in one of the oil ports to mess with me.

 

You will need a valve spring compressor and a hose to supply compressed air to the cylinders through the spark plug hole. This can all be done without pulling the cylinders heads. It's possible that your engine builder didn't get the seal properly seated over the valve guides. It's also possible that you are compressing the springs so much that the retainers are contacting the seals themselves by either having too much lift or the springs being shimmed too much. I am 100% sure that your having a valve seal issue!