3MM head gasket

rrietman · Post by **rrietman** » Mon Oct 31, 2011 4:40 pm

anybody know of a source for a +3mm head gasket for a 250 engine?
Thanks
Randy

LOUD MOUSE · Post by **LOUD MOUSE** » Mon Oct 31, 2011 7:37 pm

Could it be a 305 would work?
I don't know for sure but "maybe". ...........lm

rrietman wrote:anybody know of a source for a +3mm head gasket for a 250 engine?
Thanks
Randy

rrietman · Post by **rrietman** » Mon Oct 31, 2011 11:04 pm

my thoughts as well. lets say you have a stock bore, the std head gasket is 1--1.5mm above that. so now with a +3mm 250, the bore is 57mm, stock 305 gasket is 61mm +/-. so instead of 1-1.5mm over, now the gasket is 4mm over the bore. still plenty of bearing on the steel mating surfaces(I think). I wonder is there some variation between different brands of head gaskets as to I.D.? find one with the smallest I.D. and try it? the actual 250 +3mm gasket is a little hard to find.
Thanks
Randy

Hahnda · Post by **Hahnda** » Tue Nov 01, 2011 6:48 am

I think I have some +3mm head gaskets for the 250. I'll check later this morning.

Hahnda · Post by **Hahnda** » Tue Nov 01, 2011 11:27 am

Yep I have a few of them actually. $15 shipped.

rrietman · Post by **rrietman** » Tue Nov 01, 2011 11:42 am

perfect. PM sent
Randy

rrietman · Post by **rrietman** » Fri Nov 04, 2011 8:19 pm

Thanks Kevin, awsome service. for anyone interested, after hearing from both LM and Les Barker that "maybe" a stock 305 gasket might work, here are a couple measurments. the Rocky +3mm gasket = 60.15mm, so 3.15mm over bore. the stock 305 (DK) gasket =62.5mm, so 2.50mm over stock bore. so my thinking here is that the stock 305 gasket might work at 5.5mm over bore. anybody have a real Honda gasket to measure?
Thanks
Randy

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