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Is Mach 1 piston same as Mark 3?
Posted: Wed Dec 04, 2024 7:11 pm
by Settio
Hi
I need a 75mm piston for my Mach 1.
I have just found a Mark 3 widecase piston at a good price, I believe they one and the same, but am hoping for confirmation from those with greater knowledge.
Attached is a dimensioned drawing of the Mark 3 item.
Thanks in advance, Richard
Re: Is Mach 1 piston same as Mark 3?
Posted: Wed Dec 04, 2024 9:19 pm
by Bevel bob
The Mach 1 and Narrowcase Mark3 both used the Borgo forged piston with the raised ridge in the center. Nominally 10 to1 CR but probably more like 9 to one . I suspect the Widecase piston would be similar , but cant be sure.
Re: Is Mach 1 piston same as Mark 3?
Posted: Wed Dec 04, 2024 10:06 pm
by Duccout
I think, from what it says on the Lacey web site, that their wide case piston gives a lower compression in a narrow case engine; but I am not sure.
Colin
Re: Is Mach 1 piston same as Mark 3?
Posted: Thu Dec 05, 2024 7:41 am
by Bevel bob
The pictured piston is definately different to an orriginal M1 Borgo. But may be perfectly suitable . checks need to be made for squish and valve clearance .
Re: Is Mach 1 piston same as Mark 3?
Posted: Thu Dec 05, 2024 7:44 am
by Eldert
Hi Richard
piston looks the same . could be a Wössner piston drawing
keep in mind they use a odd size piston rings . if you need a replacement you have a hard time finding them .
Eldert