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Thu Jun 06, 2024 7:39 pm

Hello, I was wondering if anyone could help me identify problems with my main bearings for a 1957 beetle. I'm including some pictures. Also are there any resources like specific books out there that show bearing condition to identify issues? I have no idea how to tell if these are good or bad. Thanks!

Fri Jun 07, 2024 8:40 am

You are showing only the side that inserts into the case. It looks like they are loose in the case, just a little bit. The one dowel hole is buggered up (from being beaten by the crankshaft) and needs to be resolved before new ones get installed.

Right now your case needs to align bored (that #2 bearing has been pounded on, by the crank) but that other side of the bearing surface (where the crank spins) is what needs to be seen too!

Fri Jun 07, 2024 3:47 pm

Thanks Jimbo...is there anywhere to learn your knowledge through any books? My sons and I are new to building out a vw. Appreciated.

Fri Jun 07, 2024 3:52 pm

I'm going to take more pictures of the other bearings and the case and crankshaft. Maybe someone would be willing to identify more problems. I hope so, it would help a lot!

Fri Jun 07, 2024 4:50 pm

If your engine case has a ridge in the main bearing saddle where the bearing groove sits, it can give you a visual and measurable amount of pounding the case has from loose bearings. If you can feel anything it is too much.

Fri Jun 07, 2024 5:04 pm

forhumanuse wrote: Thanks Jimbo...is there anywhere to learn your knowledge through any books? My sons and I are new to building out a vw. Appreciated.

Maybe. Never had to look for it. It was mostly learned “hands on”! I eventually became an ASE Master Technician for several years at a general automotive repair shop. Before I started working there, the place was a known ACVW only repair shop. So, the shop still worked on ALOT of ACVWs. I typically worked on several cars a day, with 50% of them being ACVWs! After a while and a shit ton of night classes, I ended up being a “drivability technician” for all models of cars and trucks. Hell I even worked on several forklifts and a few skip loaders!

Fun times! Really good money!

Some of the build threads have a ton of info within them. Read through them all. They all have some piece of the puzzle within their pages. You can learn quite a bit from them.

Fri Jun 07, 2024 5:28 pm

I think it's a skill you learn over time with lots of experience, it isn't easy. My two sons and I are doing this and it's not easy. The hope is to get our car running.

I'm going to post some pictures. A followup question would be for the sake of knowledge...what would happen if we put the engine back together as is, with new bearings, connecting rods, pistons, cylinders and rings with all rebuilt or new top end. Would the engine last for a while or would it last a few months? We want to do this the right way but want to understand where we can cut corners if needed for cost. Thanks!

Fri Jun 07, 2024 10:32 pm

If you want to save money, take it to a machine shop now. Let them suggest what should be done.

If you want to understand How you will save money, buy some calipers and a set of inside bore measuring tools. Then you will know what is required to be done.

Saving money is important, but knowing what you have and what needs to be done are very important when talking to a machinist. Could be the difference between turning a crank down to the next size or just paying to have it polished!

Fri Jun 07, 2024 11:06 pm

Makes sense! Appreciate the advice Jimbo

Sat Jun 08, 2024 7:00 am

The crankshaft needs a certain amount of clearance between it and the bearings for oil. Too much and it knocks, too little and it seizes. The bearings are a slight interference fit in the case; they are just slightly larger than the case bore so they lock in place. #1 is the flywheel end bearing, and it controls the fore-aft movement, also called the thrust bearing. This is the one that typically gets loose in the case, and requires a line bore. Line bore is when the case bore is precision bored oversize. The crank can also be ground undersize, and the #1 thrust end of the case can be remachined to make it tight again. So there are multiple different bearing sets to accommodate all the possibilities..
You cannot do any of these things, but you should get some decent measuring tools to check your work as you go. Good measuring tools and knowing how to use them sets a successful build apart.

Sat Jun 08, 2024 3:24 pm

Great information for us, it's very much appreciated. Thank you!

Sat Jun 08, 2024 7:08 pm

Where are you in CA? We could suggest a few shops to visit to help you.

36hp bearings can be difficult to find…especially ones to match your crank and case cuts. Most of the time you just cut both to match the bearings you can find.

Sat Jun 08, 2024 8:17 pm

The CIP1 bearing are okay. They work and measure out okay. They have several sizes available.