82mm Bore & Pistons

[BenH]

Hi All

Has anyone had any experience with boring out to 82mm and using the high compression or a standard piston?
My barrels are measuing a little over 81mm but the tolerance i believe is 1.5 - 2 thou but i am more pushing 5 thou so would be to worn to run new 81mm pistons.
Is there any Pros or Cons going to the 82mm or anything i should be aware of and is there enough meat in the liner to go that far ?

[AustHaflinger]

Hi Ben, I have no knowledge of the pros and cons of boring out the standard barrels and I am not sure there are too many on here who have done it but hopefully someone can help.

My previous owner went to the extreme of modifying 87mm VW pistons and barrels which after a couple of issues have been sorted and work well - but both barrels and pistons required a bit of machining.

Garry

[BenH]

Thanks Garry

That sort of mod for me would be a bit over the top, I see on Haflingertechnik that you can purchase 82mm high compression pistons so I am leaning to that option so I am guessing it has been done.
A little curious though if having high compression pistons is it going to create other issues as well

[AustHaflinger]

Well if Haflinger Technik have the pistons I would be asking Dale (Haflinger Technik) about how much you can bore the standard barrels.

If you are using the standard bored barrels and the 82mm high compression pistons, based on my experience, you will not have any issues elsewhere. The bottom end certainly can handle and extra increase in power without issue.

My engine is 762cc (stroke is standard), has high comp pistons and larger valves and I have had no issues with the standard bottom end.

Garry

[wojo12]

Well if Haflinger Technik have the pistons I would be asking Dale (Haflinger Technik) about how much you can bore the standard barrels.

If you are using the standard bored barrels and the 82mm high compression pistons, based on my experience, you will not have any issues elsewhere. The bottom end certainly can handle and extra increase in power without issue.

My engine is 762cc (stroke is standard), has high comp pistons and larger valves and I have had no issues with the standard bottom end.

Garry

Ask Bernard Callahan on this forum. He rebuilds Haf motors all the time.

[BenH]

Thanks Gents
Thats is a good start to work with and good to know the bottom end can handle the changes