The motor is on the stand, and when we were setting the valves today, we ran into a problem. After setting all the valves, we rotated the engine two revs, and checked everything again. One problem: The pushrod came out of the pushrod cup in the lifter, but did not leave the lifter entirely. This happened only on the exhaust side. My question is what can be done?

The engine is a 400, Aussie heads, milled pedestals, 1.8 intake rockers, 1.73 exhaust rockers, Lunati 00094 cam, anti pump-up lifters. Thanks.

 

The lifter could be defective. Maybe its internal piston is hanging up in the bore, and throwing off your preload setting.

Which lifters are you using?

Did you try just resetting the preload on that lifter?

 

Crane anti pump-ups. The lifter doesnt seem to be defective. We checked before installing. We will try resetting tomorrow. Do you think it would help to maybe go the extra 1/4-1/2 turn that is still able to be used per Lifter manufact. instruction? Right now it's at 1/2 turn preload. Thanks.

BTW, 6 of the 8 have posed this problem, but never more than 2-3 at a time. I neglected to mention this earlier.

I should also note that there are zero problems on the intake side. Could I need longer exhaust pushrods if none of this works out?

 

Ah, since you had previous problems with other pushrods, all on the exhaust side, now I'm wondering about your rockers. I noticed the different ratios.

Since the long side of the fulcrum can't change (to maintain correct valve stem alignment on the rocker tip), the short side is changed for different ratios, and that could require different pushrods. Also, if the intake and exhaust rockers are not the same brand/model (and maybe even if they are), the position of the pushrod cup on the rocker, relative to the valve stem tip, might be different.

Another cause could be different valve stem lengths, or possibly the exhaust valve seats, if you had them replaced (but the machine shop should have checked that).

You could spend some time to check it out and find the exact cause (not a bad idea if you plan to push the engine pretty hard), but unless you find a major defect, the solution is probably going to be different pushrods for the exhaust side.

With anti-pump up lifters, you are safe going to the maximum preload spec, but I don't think that will solve your problem. The pushrod cups in the lifter and rocker are each deeper than the maximum preload (0.060" right?), so if pushrods are coming out, more preload won't help.

 

Problem solved. The 3/8 pushrods made it look out of alignment, and also, preload was incorrect. Everything is fine now, just freaked me out. The machinist said Cleveland's are a tad funny in valve adjustment, but he helped out. Thanks again bubba.

 

I have good news and bad news. The motor runs, the cam is broken in, but not without incident. About 2 minutes into break-in at just 2300 RPM, the motor started backfiring through the carb, and basically running like hell. Thank God for kill switches. Anyway, we take the valve covers off, and, low and behold, #6 exhaust was off, pushrod was in the lifter valley, and my heart was in my shoes! We fish the pushrod out, check for straightness(which was perfect), and then notice the rocker arm. It almost made me sick. I saw more raw aluminum than anodized. A little work with the file(no trunion or tip damage) and it fired right up, no more backfire, and sounding much healthier. Through open headers it sounds like a slightly detuned Pro Stocker, with excellent throttle response and great power. And a note to those whose engines have been out for awhile, they make awful noises with the dizzy 180* out.

Well, now it's off to see how long cast pistons can stand 12:1 comp.

 

Sounds like you have serious valve train geometry problems that should be checked b4 you run the engine again. CHECK EVERYTHING!!! Assume nothing is correct.

 

The engine ran for well over an hour today, with speeds varying from 1100 to 6400 RPM, in neutral and in gear. Nothing at all. Took V/C's off, checked r/a's again, and had absolutely no problems. It's still together, even after running it hard again after putting it back together. Who says that a long stroke and big cam can't rap? Instant throttle response, no hesitation. Goes from 1000 to 6400 with no problem, almost effortlessly.