4 replies to this topic

[cossy820]

hi all,

spent this eve measuring the piston ring gap on my 99hb81p engine. manual says should be a maximum of 0.305mm or 12thou, i've got over 1mm or 40thou on top compression ring!!!
So i'm fairly sure they need replacing, my problem now is i don't know if my pistons are standard or not,

cylinders 1 and 2's pistons are both numbered: 21964 G8 Front No7 A
cylinders 3 and 4's pistons are both numbered: 21964 G8 Front No6 A

Also the top of engine block is stamped with an "A" but nothing else.

Can anyone tell me if these pistons will require standard Rings?

thanks

[Cooperman]

Witht that ring gap you probably need a re-bore and new pistons, not just rings. Measure the ring gap about 1/2" from the top of the bores and it should be less than at mid-stroke. Check this and post the results.

[Carlos W]

Sorry to hi-jack thread, is your mailbox full Cooperman?

[Cooperman]

Sorry to hi-jack thread, is your mailbox full Cooperman?

Thanks, it certainly was. I've just completely cleared it out.

[cossy820]

Thanks for tip, i'll give that a go tomorrow.

I kind of though it might need a re-bore so have arranged to get it all measured up professionally in the next week.
Assuming i do need the engine re-bored, new pistons etc. whats the best road to go down? my main criteria is keeping project low cost.

thanks again