Need some help on motor question
 

new rebuild on my blown 468 bbc, merlin heads, iconel crane etc, all good parts. has only 14 hrs on motor about 8 on trailer tuning it, and driven real easy. #3 exhaust pushrod was loose, rocker spinning around, and guide plate broke. #3 intake pushrod broke, found about 3" of it over by #8 and rest in valley when intake taken off. All lifters look ok and cam looks ok when spinning motor around. Intake pop of has some black around it from backfiring. Heres issue, motor builder says motor backfired running way to fat caused pushrod or guide plate to break. for info had bad pushrod cam lifter in #5 cylinder, causing this rebuild, never figured out why, and here we are again. Also builder said i shouold be checking adjustment on valves every 10 hrs?? they are hydraulic. I think he screwed up the adjustment myself, or am I missing something here. Thanks for the info. The question is for whos paying for this one. Hes reputable and honest but i think 14 hrs is not enough time for this to happen unless something is defenitly wrong and he didnt fix it 1st time. motor is only 8/1 compression.

come on guys help me out here. Am I missing something, cuzz i'm haveing a hard time understanding why running fat breaks pushrods????

Merlin540 would have the best advice for you.......... he has tons of experience with the blown motors:D

did the rocker stud break?? did it have .080 wall pushrods??? a engine to fat wont break the valve train call me on my cell 513-477-2780 charlie amann white oak auto and marine:D

Merlin, rocker stud didnt break. I dont know wall thickness. Motor was rebuilt b4 cuzz I wasted a couple lifters and flattened cam lobes, rockers loose and wobbling around. Builder said even tho I had hydraulics I needed to check them every 10 hrs or so. I said OK, I know people with more hp then me and dont need to check.
Now this rebuild gets 14 hrs, and #3 exhaust guide broke and #3 intake pushrod broke. I also noticed a lot of play in other rockers and they seem to be sliding right on edge of valve. Everything just seems out of adjustment to me and he did it.
His statement was because it backfired through intake and was fat that pushrods broke?????? Beats me.. I'll try calling you in a couple daysThanks.

Shameless,

Merlin is hardcore and will shoot you straight! He has tons of experience with blower set ups! Hopefully he will guide me this winter with my set up!!!

I remember a couple of years ago at the lake cumberland poker run he busted a drive and a rocker arm. Idled to his trailer, changed the drive and rocker arm, put it back in the water and caught up to all of us at lunch:D :D

Now that sounds like my kinda hero

Motor builder agreed to rebuild at his expense. I just pay for misc. parts needed so I'm happy now. Guess it will be my blower motor spare, till I run out the warranty .