[suzukitas]

Was just throwing a g13 engine back in a sj80 today and noticed the size difference on g13a (1324cm3) g13b(1298cm3).
I sure someone will answer this easy as to where the difference lies, just curious that's all.

[fordem]

The stroke is longer, the bore is the same.

[suzukitas]

So just the crank is a little different, block height remains same?

[fordem]

Let me rephrase that - the difference in capacity comes from a longer stroke, and whilst I'm not 100% certain, I believe the block crank & rods are different.

[alien]

Fun fact - it was changed so the swift could race in rally (under 1300cc).

[MrRocky]

Some may say its not noticeable but i prefer the 1298cc donks
Just have a nicer feel through the revs

[suzukitas]

block is bigger? by how much? I used the g13b and it had square timing belt and I changed to round? problem?

[suzukitas]

Just measured block, they are same.

[fordem]

suzukitas wrote:

I used the g13b and it had square timing belt and I changed to round? problem?

The belt profile needs to match the pulleys - square tooth belt with square tooth pulleys, no problem - round tooth belt with round tooth pulleys, no problem - round tooth belt with square tooth pulley (or vice versa), PROBLEM.

You'll find many such minor differences, some of the crank pulleys are four hole, some are five...

[henno]

alien wrote:

Fun fact - it was changed so the swift could race in rally (under 1300cc).

Holden famously did the same thing for Group A homologation: the 308 becoming 304ci to be under the 5L capacity limit.