call to all HAMB engine gurus...mystery?

What is breaking the hydraulic lifters clean in half in our fresh Cadillac (68-69 472) engine???..OK, we first drilled up decent oil pressure, probably because of cosmoline/vaseline/90W used in the fresh build (We didn't build it,perhaps the first mistake)drained that mixture and put in fresh oil..fired the engine for 30 seconds or so and had no pressure, took it down and had two broken lifters on the exhaust side, cause of low or no oil pressure..remedy, new high pressure oil pump from MTS (supposedly the shop that built the engine) and sixteen new stock lifters..fired it up for 30 more seconds and broke four more lifters, same place horizontally in half on exhaust side..the big mystery is there is no other damage anywhere, straight pushrods, etc..WTF is going on? anyone got any ideas? before we go looking for another block and complete teardown...

 

can you put up some pictures of the damaged engine components? and maybe some close ups of the valve train?

 

Who maufactured the lifters?

 

Post pic and I'll reply on my new computer>>>>.

 

i dig the new computer!!

 

how big is your cam? too much lift? i dont know alot about the caddys but sounds like something may be out on the valve train geometery.

 

You should see my OLD computer. NOW About those pics of those lifters????????

 

Don't think lifters break in half after 30 sec because of lack of oil
Something is hitting something else.
Started a chevy once it worked for 30 sec, thene two intake valves gave up. Someone had mounted two pistons backward so the cutout for the valve was to small. Causing the valve to hit the piston.


Lift off the head and take a look.

 

We need more info about the engine. Is this a bone-stock rebuild ? What machine work was performed ?

You definately have a valvetrain geometry problem, question is why or how ?

 

same lifters? same lifter holes? Its probably the lifters, change them all, and try it again, I doubt its a very high lift cam in a late caddy, the valve train is weak in them,the rocker ***emby cant take much unless its beefed up. probably another chinese lifter story, there failing alot, between the no zinc oil and the bad lifters the flat tappet cams are having a hard time lately, also put some zinc break-in additive in the oil for the cam. or use rotella oil

 

At first glance, I would say that you have a valvetrain problem (as opposed to bad lifters, lack of oil, lifter bore clearance, etc.) It sounds as if there is not enough clearance. Pushrods aren't always the first to go. I'd look at piston-to-valve clearance, coil bind on the springs, retainer-to-guide clearance, rocker clearance, to start....cycle the engine by hand with the plugs out & watch every valvetrain ***embly individually.

I don't recall how the camshaft is retained in place in terms of thrust, but if something is wrong & the cam is walking, that can cause broken lifters as well. While we're on that road, have you confirmed that the cam isn't broken?

 

Why don't you tell them about the cam end play screeching and the hammer part.

I'm no engine guru but I don't think it should be much of a mystery.

You had a good thread started with some viable answers and more questions to reply to... what happened?
http://www.jalopyjournal.com/forum/showthread.php?t=254628

 

I always prime my lifters and let them sit in an oilbath for a day before mounting.

 

Third post on same problem. Last reply NEED PICS OF LIFTERS!!!!!!!!!!!!!!!!!!

 

Maybe, im taking for granted who ever built the engine checked the geometry, If I remember correctly you cant go to big on the cam on the 472 without some piston clearance problems and or valve spring coil bind, but the 1st to go is the pushrods, also, the rocker ***embly is wimpy on those motors, 1 bolt holds 2 rockers down, no guide plates. hard to believe the lifter would break, Im trying to figure out how you would even know it is broken if it was broke horizontal and still in the hole, tell us what does the motor do? pop? make noise? what happens when it is running that you know something is wrong? theres more to this story, we need pics

 

Picture a shattered lifter , there is your pic.

 

Too big of a cam , period. Piston got hit, pushrods knocked out the cam, lifter bore cracked, this thing is done.

 

hmmm, I didnt know there was another post on this subject, what we have here is a "failure to communicate", after I read the screeching noise, and the hammer part, I'd start looking for a parts put in the wrong place like the cam thrust plate or washer, cam is hitting the side of the lifters, just take a lifter out and look down the hole, when all else faile look in the book, its not rocket science!!

 

Nice computer....does it run Windows'78 ???

 

If you think the computer is nice,you should see my telephone.. I'm not having a mid life crisis,I just refuse to grow-up!!!!

 

I highly doubt axial force on the lifter is going to cause it to break horizontally. That rules out things like VT geometry, too much lift, or piston/valve interferance. Besides, your lifters would have to be made out of the ****tiest material ever to break before a pushrod or valve stem bent.

I would suspect the cam is walking and the side of the lobe is hitting the lifters.

 

Cam walk or wrong lobe profile for the lifter being used.

 

Could be coil bind. I havn't seen any Cadilac engines apart, but some engines have trouble with the angle the pushrod goes into the lifter. If the angle is to severe it really gets to be a weak spot, and they wear the blockes out with high spring pressure. Maybe this has something to do with it. The oil pressure issue sounds like the pump needs to be primed. If memory serves me I think the pump is in the front cover, and engines with the pumps in the front cover are hard primers due to the long pickup tubes.
Jeff

 

Even tho they are the 'correct' lifters, when you open it up, visually check that no grooves on the lifter are dropping below the bottom of the lifter bore; here's the logical interference that could separate a lifter horizontally. If Cadillac's didn't have excellent nickel content in their block castings, you'd likely be shopping for a new block, too.

 

Sorry to hear about the engine grief. If this was turned over on the engine stand with the crank wrench you probably would have felt the valve hitting the piston and investigated. Bummer for sure. With stock pistons what is the max valve lift on a cad 472?

 

AGAIN. we didn't hit the stupid cam with a hammer. The ******* fuel pump eccentric was BEVT causing the issue.

as far as the broken lifters, I figured it out.

CORE SHIFT + LARGE AFTERMARKET CAM = excesive side load on the Lifter. the broken lifters in question are ONLY the drivers side exhaust lifters.
here's the funky.
NO bent pushrods.
NO coil bind.
NO piston interference.
NO retainer/guide clearance.
It took a minute or two to test for all of this while thrashing on several other cars for the round up.

Beleive it or not, We aren't hammer heads. We didn't build this thing, We're just facing the consequences.

 

I Initially suspected the lifters as well-2 in a row, nothing bent, nothing binding. The second set ( we replaced all 16) were Melling lifters (=made in the U.S.A.) which we have used a ton of. They also snapped like candycanes.

 

nope. this thing turned over by hand like ****er. And when I say by hand, I mean I used my HANDS to spin the flywheel. smooth as silk.

 

could you have a small base circle cam that is allowing the lifters to run too low in the lifter bore?

 

That's what I looked for first. ironically, the lifter "guts" stay in thier place even after they were broken (kinda cool actually.)the broken "top" half simply slides up and out of the bord, leaving the "exploded diagram" version of the inside of the lifter in place. The pushrod had enough that they didn't get out of sorts-they stayed where they were supposed to!