Main bearing question

[Type1234]

I'm having a bit of a problem sourcing main bearings for my Fastback 1600 engine. The bearings I have taken out are P/N. 131-105-531 but none of the regular VW suppliers show this number for bearings for a 1600cc engine. VW Heritage show 111-198-461 for my car. The engine is from 1970.

[Dave Summers]

198 in the middle is a kit number - possibly a full set of bearings. 131-105-531 is the number of the single part.

[broady_6]

Bearing wise I wouldnt shop by part number, you need to measure the crank journals and case bore to find out if you current parts are fit, and what size you need.

[Type1234]

Thanks for the advice guys. The part number issue makes sense if it's for that individual bearing. If I measure the crank journals and case bore will the suppliers be able to apply the measurements to a part number?

[broady_6]

They will just supply a set of bearing that match the measurements, assuming that your case and crank are within wear limits. As I say part numbers arent really relevent. Its more important to get the correct size parts, the part number could 123456789 for what it matters. Out of curiostity, why are you changing the bearings?

Some examples for you
https://www.heritagepartscentre.com/uk/ ... hrust.html These bearings are for a crank that is 0.25mm undersize, with a case that is 2mm over size and a thrust face that is 2mm under size.

https://www.heritagepartscentre.com/uk/ ... hrust.html

This set is for a 1mm undersize crank, a 0.5mm oversize case and a 2mm undersize thrust face.

Hopefully we can help you work out what you need.

[Type1234]

the reason I'm changing the bearings is because they are worn and the dowel holes are elongated due to the casing wear and end float.

[JSR-69]

Ouch! If the crankcase is showing signs of being worn you should get it line bored then install oversize bearings. Otherwise the new bearings will wear very quickly indeed.

Judi

[Type1234]

I'm getting hold of another engine which hopefully may have a casing that is not worn away. I will find out in a couple of weeks. If it's shot as well then I will be looking at the various options e.g. line bored. Thanks

[broady_6]

Do you have the proper equiptment or measure the case and crank? If not it might be worth investing or going to a machine shop and having the new parts properly mesaured too. As a guide, number 1 bearing, if you press it into the case, you should be able to lift the case by it. If you cant then the thrust face is more worn than is ideal.

[Type1234]

Pressing the bearing into the casing isn't an issue. I can lay it in and move it back and forward about the same 1.8mm as the end float before I took the engine apart.

[broady_6]

Bloody hell! Never seen on that bad. Please dont throw the old case away, Im sure its repairable, and the original cases are much higher quality than the originals.