The Stovebolt Site Forums The Shop Area Engine Shop 1951 Chevy 3600 216 connecting rod

There is major engine knocking coming from my '51 Chevy 3600 (216 engine). friends think a connecting rod issue. I'd like to repair (if affordable), but can't do this type of work, so if my mechanic is willing should I go ahead, or look to replace the whole engine? Any idea the number of mechanic hours required? And as long as he's in tehre shouold I do other repairs or have him look for other potential issues? I'm looking for any advice from those who have gone through the process. Thank you.

Most likely it'll require a total teardown and rebuild. You might get lucky and be able to remove connecting rod bearing shims and get a few more miles out of it, but if the bearings are worn enough to hear a knock, other engine components are likely to be worn out as well. That might be worth a try, but your best approach might be to shop around for a decent used replacement engine. Lots of guy go for a later 235 with full pressure oiling. I've heard of the 216 being referred to as a "splash and clatter".

If your mechanic is younger than his mid-70's, he's most likely not very experienced with the lubricating system 216 engines use. It's not terribly difficult to fix properly, but it does take a skill set that mostly went away in the 1970's or before. There's a very labor-intensive and time consuming procedure involved in getting the rods to fit the crankshaft properly and to make sure the oil squirters in the pan are aimed correctly to keep them lubricated above idle speed. A 1954 or newer 235 will be almost a drop-in swap but Ray Charles would be able to "see" the difference in the two engines.

A full rebuild on a 216 would probably cost somewhere in the ballpark of $3K or so, or possibly more, depending on whether or not the engine need to be bored, new pistons, regrind or replace the crankshaft, etc. One modification that's definitely worth the money is boring the block to 3 9/16" and installing standard size 235 aluminum pistons, bringing the displacement up to 224 cubic inches and putting less load on the rods with aluminum pistons instead of cast iron.
Jerry

Jerry -- Too bad he's so far away from you -- sounds like a good candidate for your 216 into a fire-breathing Cadillac monster rebuild ...

Yep- - - -a 258 cubic "216" with a 3/8" stroker crankshaft, roller bearing rocker arms, roller valve lifters, pressure-lubricated rod bearings, and aluminum pistons- - - - -all with an original-appearing exterior, might be a real attention-getter! Us oldtimers used to call an engine like that a "sleeper"! Is "Minnie-Soda" as far away from Tennessee as central Oklahoma? I'll be sending a modified spray-oiler 235 that way soon.
Jerry

Will a rebuild service like Jasper Engines not rebuild a 216?

That's about as likely as finding a chicken with lips! I helped a high school classmate install a Jasper 216 in 1965, and that was one of the last times I've ever seen one. Jasper and some of the other professional rebuilders stopped building Babbit-rod engines at least 40 years ago, mostly because of lack of demand. An oldtime machine shop near my home scrapped dozens of reconditioned Babbit rods several years ago, because they hadn't sold one in years.
Jerry

Sound like if I found a local mechanic willing to repair it would cost about as much as finding a working used, or rebuilt complete engine.

Any suggestions on a source for rebuilt? Jerry, is that something you do? Wheee I live in Minne-soda is about 5 hours farther away from Tennessee than OKC.

morerog,

Just a suggestion, but you can always do a web search of Craigslist, Facebook Marketplace, eBay etc to see what may be available locally.

I have had some success using this ad search engine: Searchtempest

Nice thing about using this to look at FB Marketplace ads (at least for a little while) is that you don't have to have a FB account to view. After about 15-20 minutes of searching the FB findings list, it will start prompting you to sign in to FB.* If you haven't found something local in that time, may not be anything close by. If you do find something there, maybe you know someone who does have a FB account and can contact the seller to start the discussion process?

Also doesn't hurt to look here Our Own Swap Meet Forums

Good luck in your quest!

* To get past this issue, I just close the web browser, wait 15-20 minutes and then start my search again to get past this annoyance.

I'm an oldtime dirt track race engine builder who likes to tinker with oddball modifications that other people say are impossible. Like Hank Williams Jr. says, "It's a family tradition!" Dad was a master mechanic whose chosen obsession was modifying flathead Ford V8's in the late 1940's and early 50's, and I grew up around a racing shop in Nashville Tennessee. Yes, I build engines, but not commercially. Drop me a private message and we can discuss what's involved in building your engine, either stock or modified.
Jerry

UPDATE : 10 months later. Found a '41 216 locally and got the new engine running. Now for the next stage of projects!