What Are the Bore Centers of the 1UZ?

[cribbj]

What is the Bore Spacing of the 1UZ?

This is a question that gets asked every so often.

Here's the procedure I used to get a good measurement of the bore centers:

1) Laid a new head gasket on a piece of paper and traced the two outer bores.

2) With a compass and a straight edge, find the centers of the bores.

3) Measured the distance between the circle centers with a rule

4) Result: 12 15/32" or 316.7mm

5) Divide that figure by 3 to get the bore centers

6) Result: 4.16" or 105.6mm

Anyone have a better or more precise measurement, please chime in.

 

[Zuffen]

John,

Wouldn't it have been easier to use digial calipers and measure from the front side of two bores?

This would give the same dimension as measuring from the centre of the bores and much easier.

 

[cribbj]

Your way would have been the preferred way IMO, but I didn't have a block "at hand" to do it (my two blocks are at the engine builder's shop). So I only had the gasket set to work with at the time.

BTW, based on these measurements, Dennis drilled those ally plates for the COP's and they aligned perfectly with the spark plug tubes.

Still think it's kinda odd that Toyota went with a fractional figure for these bore centers, instead of a round number like 105 or 106mm. If anyone else can get a more precise measurement, it would be interesting to know.