call to all HAMB engine gurus...mystery?

are the push rods the wrong length giving you some bizzare geometry?

 

Man I feel the pain!! Being in the engine bizz for a long time I run across a lot of experts. Think they have seen and done it all. I get to see new things all the time and some that have no explaination like this>>>>.

 

WTF! is the the front main off of a blower motor? Or did someone drop a bare block off of a fork lift?

 

Lifters are harder than a *****'s heart, so my guess is Chinese parts

 

Could you explain the fuel pump eccentric BEVT ????. I am confused. Weird why only the drivers side exhausts. You sure they put the right valves in that side of the engine. Something is fishy! I would see if you have some sort of legal action against the builder. I know I would be pissed. Also when you turn the motor by hand and nothing interferes, but when you start it up the lifters (as you already know) will pump up and eventually float, especially if there is heavy oil in them. But the way they broke is a wild one.

 

I think he said no bent pushrods. Rest ***ured, they'd bend way before a lifter would break.

 

This **** came to me on a monday morning after the weekend a circle tracking. The dude said it was running fine until **** came flying out of the block and knocked the fuel pump off. The front main cap was gone and we think that is what knocked the pump off. This insane ****er was upset about losing a 115.00 FUEL PUMP. So when you hear some ***** tell you he's seen it all or he has a replie for all **** known to man give me a shout!!! I get piles of this **** guys bring me to try and fix>>>>.

 

JB Weld will fix that.

 

this is the 2nd post about the problem..the first was really just my grief over a lunched engine..picture a hydraulic lifter broken horizontally clean in half with hardly a scratch anywhere else..the "little seating of the cam with a mallet" (not hammer)was an initial scratching of the collective head over the problem, the fuel pump gear turned out to be a much easier solution..J.Cougar and Lux know the skinny on this thing, they're the ones with their fingers innit every day, and yes, after the second go around this engine now has cracked lifter bores and it is still as big a mystery..I'm going to do some detective work on going back to the original owner and see if there is a reciept, build sheet, anything..little consolation...

 

I'm glad I wasn't around to hear that one let go

 

Just curious do they look anything like these Cadillac lifters?

 

EXACTLY.
ours broke a little south of where your did.

 

Hey LUX. **** like this just bugs the **** out me. I went to the parts search for the 472. Man all the parts for the engines are the same except for the valves. In 1974 the valves are 1/4" shorter than all previous years. If someone mixed parts on the rebuild this could be a big problem>>>>.

 

Not my lifters ,I found this pic over at http://www.cadillacpower.com/forum/index.php
Those came out of a Cad motor that broke a rod and cam also. I figure these dropped far enough down the lifter bore(after the cam
Broke) that whatever else was failing around hit hem and snapped
them off. I'd just never heard of lifters failing in this fashion and
saw these while I was rooting around over on the CadillacPower
board.

 

apparently, side loading on a big caddy is an issue. add some offset, deck the heads, and a larger cam, and presto! instant problems.

 

I'm not familiar with early Caddy, but make sure all the OIL GALLEY plugs were put back in on that side- we got a Pontiac back one time from machine shop, they forgot to put in the screw-in oil galley plug in back by distributor- no oil pressure on one side of engine on fireup.

no oil pressure- lifters don't pump up- too much clearance- stuff can start breaking

or valve adjustment is way off, or pushrods too long, or coil springs on those lobes are binding, or bad lifters, or lifters getting stuck in bores, or ??

 

you may have hit it there- if there's an aftermarket hipo cam in that Caddy, with reduced base circle to give more lift, the lifters may be dropping out of lifter bore, then oil ring ridge getting stuck coming back up and breaking lifter

again, I had another Pontiac, that with Comp solid flat tappet cam, had such a low base circle on cam, to give more lift, that even with aftermarket poly adj. nuts on stock studs, all the way down still had way too much lash clearance- I had to washer each adjusting nut with 3 washers each, to take up the clearance

cam companies cut down base circle to get more lift- peak of lobe can only be so big before it won't go in block, so at that point, they reduce base circle to get more lift/difference between base and full open

this can wreak havoc with valvetrain geometry/rockers/adjustment/lifters

 

I agree with the ****ysis, that makes all the sense in the world, the only weird thing is why only on that side and only the exhaust valve lifters. Perhaps the casting is not real critical (for stock) around the bottom lifter bores and the ones that broke are a little off from the rest. But that is the best explanation yet!

BTW does the cam manufacturer sell special lifters for use with the cam? I know when I bought my ISKY cam, the manufacturer suggested their lifters and adjustable pushrods, which I did use.

 

you needed longer pushrods!
I have run into this a bunch. the base circle difference is betweem -
-400 and 400+ cubic inch poncho motors. Cam builders ( typically comp) usually go for the most commonly used size- the 400= c.i.d. circle.
Heads will do that to a pontiac, also.