The Stovebolt Site Forums The Shop Area Engine Shop 55.2 235 Valve Lifter Discrepancy

I'm still on the "teardown" part of my 55.2 235 rebuild, so I am cleaning, photographing, & storing everything like advised for later assembly...

Question- is there a reason, or should I be concerned about a difference in the last lifter (toward the firewall)?

It measures the same dimensionally as the rest (2.8" L x 0.99" diameter), but is manufactured different.

The lifter in question is also heavier- 5.09 oz. (144.3g) vs. the rest at 3.30 oz. (93.8 g).

Reference block # 3838233 Head # 3835913

Seems to me they should all be the same, but is there a mechanical reason this would be done?

Thanks for any advice!

There is no "factory" reason for a different lifter. PO(previous owner) may have had many reasons to put in a different lifter. Not many would be good ones. If you are pulling it down to rebuild then you are planning new lifters and cam I would expect. If the cam is alright and the plan is to reuse it and you have kept all the lifters in order then you should be OK. That is a lot of if's. The single lifter might have been used or scored or...whatever it should have been replaced as a set and might be a good reason to look at the cam real close. And at the lifter bore in the block. It is worn a bit different from the rest. May have been put in as a temp fix and now you get to do the proper fix, use a new set. Maybe the original pushrod failed, PO put 1 new lifter and 1 new pushrod in and called it a day. I would not recommend you do the same. Weight difference could be just a different manufacture or vendor or it could be something else. I have not seen a "shouldered" lifter but that is just me. Others might know if there was a Part number change....but only P/N change I know about would be for hydraulic verses solid. You can put new lifters on an old cam. You cannot put a new cam in with old lifters. Too many changes to materials in the last 60 years.

Thanks Steve- It is a lot of "ifs," and I plan to get the cam inspected to see if it is ok to re-use and kept the lifters in order just in case. Aside from the oil ring stains from sitting, the lifters (aka tappets??) look flawless, but they'll be replaced if the cam fails inspection & has to be replaced.

I appreciate the walk-through answer.

I just didn't know if installing a heavier lifter would have had any bearing (pardon pun) on causing other issues, or if it might have been done to increase compression in that cylinder or something.

Thanks!

At the RPM the average 235 usually runs, one overweight lifter shouldn't present a problem. If I was bulding a tight-winding small block Chevy V8 like a 302, I'd be upset about a lifter a couple of grams heavier than the rest, but that engine would go to 8K RPM on a routine basis. If a stovebolt engine sees 4K even occasionally, I'd be surprised. Small bore/long stroke engines build lots of torque, so high RPM that would result in valve float from a heavy lifter just isn't necessary.
Jerry

Thanks, Jerry- That makes sense & it was the fifty (50) grams difference that made me ask. It was enough to raise a brow at, but the differences you mention in running RPMs put a better perspective on when this (weight) would be cause for alarm.