Gap Clearance for compression ring on M52 pistons

[dude8383]

I need to know the minimum and the maximum!

Well actually, from my calculations the minimum is .013304.

The rings that came with the Maxsil pistons are from Hastings and basically the formula goes like this:

bore x .004inches = min gap clearance

There is no mention of the MAXIMUM clearance!


Any help would be much appreciated.

[dude8383]

I found some interesting info...

These rings are not made exactly for BMW use, but it is for my piston diameter (84.5).

Basically its from a Ford.

1993-97 152cu. in. Eng. 2497cc, Vin: B 2.5 Litre
84.50mm
3.327
qty of compression rings:
12 - 1.5mm
qty of oil rings:
6 - 3.0mm

[PiercedE30]

Gap 'em loose if you ever think you will throw a turbo/supercharger/any form of nitrous on it.

[dude8383]

Gap 'em loose if you ever think you will throw a turbo/supercharger/any form of nitrous on it.

Won't happen any time soon and if anything I will drop in different pistons!

Do you know what the maximum is?

Man I was hoping you would chime in...

[quillbro]

Id drop it in and test with a feeler gauge to make sure theres a decent amont of clearance, maybe 15-20 grand. A little loose is better than too tight. Be on the safe side.

Then again ive only built motorcycle motors but its pretty much the same theory

[dude8383]

Id drop it in and test with a feeler gauge to make sure theres a decent amont of clearance, maybe 15-20 grand. A little loose is better than too tight. Be on the safe side.

Then again ive only built motorcycle motors but its pretty much the same theory

Well thats what I did and the first piston is at the minimum clearance of .013!

I just want to know what the max is because I feel like I should gap them a little past that but I don't want to go overboard.

[PiercedE30]

Update:

Set my piston ring gaps.
1st ring: 0.013-0.0135" across the whole motor.
2nd ring: 0.014-0.0145" across the whole motor.
Oil Ring: 0.0165" all the way across.

That's what I set mine to.

[dude8383]

That's what I set mine to.

Whats your bore?

84.5 as well?

[PiercedE30]

Nah, I'm still at 84mm.

edit: On the turbo M52 me and buddy are building we will be setting the top ring clearance to like 15 thousandths.