[Mk2] [NA] rev4na block rebuild advise on bearings please!

[mk2mattw]

I am in the process of rebuilding a spare engine I have,being honest I have not done a block rebuild before and looking for advise on how to make sure I get the correct bearings for the crank and the conrods-been told about some sort of numbering system on the caps to help identify which standard bearings I need?

Any advise from guys who have done it before would be massively appreciated:)

[ashley]

Have you got the BGB- it's all explained in there, and if you're planning to do it properly you probably want to get your head into the book!

There are different standard toyota bearing sizes, but if you use after market bearings (eg ACL) they just have one "standard" size...fit them and plastigauge to check clearances and Bob's your Uncle's Fanny

[mk2mattw]

Have you got the BGB- it's all explained in there, and if you're planning to do it properly you probably want to get your head into the book!

There are different standard toyota bearing sizes, but if you use after market bearings (eg ACL) they just have one "standard" size...fit them and plastigauge to check clearances and Bob's your Uncle's Fanny

Yea I have the Toyota manual-says for the conrod ones there are 3 different sizes, but the ones for the crank(can't remember the name but the ones that secure it to the block) supposedly only have 2 different sizes (no.3 cap is wider), been told that there are loads ofddifferent sizes for these and want to make sure im not going to end up with a paperweight rather than a rebuilt engine!haha

[Peter Gidden]

Have you got the BGB- it's all explained in there, and if you're planning to do it properly you probably want to get your head into the book!

There are different standard toyota bearing sizes, but if you use after market bearings (eg ACL) they just have one "standard" size...fit them and plastigauge to check clearances and Bob's your Uncle's Fanny

Yea I have the Toyota manual-says for the conrod ones there are 3 different sizes, but the ones for the crank(can't remember the name but the ones that secure it to the block) supposedly only have 2 different sizes (no.3 cap is wider), been told that there are loads ofddifferent sizes for these and want to make sure im not going to end up with a paperweight rather than a rebuilt engine!haha

Get the old shells out. Look on the back and they'll be marked if the're undersize. e.g. 0.25 or 0.5. If unmarked, they'll be standard size.

Then buy same size bearings from ACL, Clevite, King etc. Loads on ebay.

[ashley]

The standard Toyota bearings will have numbers stamped in them (1,2 or 3 for the big ends), the numbers should match the con rod numbers. But as said, after market bearings in the standard size just come in one size...but you still need to check the oil clearances.

The 0.25 or 0.5 Peter is talking about is if over size bearings have been fitted at some point because the crank has been ground down to remove any damage...so definitely worth checking what you have before you buy any parts!

[mk2mattw]

Says something about 3 different sizes I thought-these markings on the bearings will they be embossed or will it be quite hard to see? Appreciate the advise so far guys:)

[ashley]

[ashley]

And Mains:




But- again, if you buy after market bearings none of this matters

[mk2mattw]

Thats a great help! Tbh the engine was fine when I removed it-you could just about hear the tappets from cold (faintly) but I have replaced pretty much everything else on the car so it would be nice to have a basically brand new engine:). What I don't understand is how by using aftermarket bearings at a "standard" size would work if Toyota are specifying different bearing sizes?

[ashley]

If you look at the differences between the std bearing sizes you can see it's pretty small! But that is why you have to measure your oil clearances when using after market bearings- just to make sure you are within tolerance

[Peter Gidden]

Ash is bang on.

The reason for Toyota using 3 different sizes is down to mass production. If they only used the one size of bearing, they'ed have to machine the cranks more accurately. Remember, we're talking microns here.

So when they machined a crank they measured it and matched it to one of 3 bearing sizes, which are sub-sizes of a standard bearing.

If you need PlastiGuage PM me.

[mk2mattw]

Cheers for the advise so far guys! Have sent you a pm regarding the plastigauges!