Author Topic: 400Four pistons in 350Four cylinder  (Read 1180 times)

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Offline andyman

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400Four pistons in 350Four cylinder
« on: December 16, 2019, 10:56:32 AM »
Hey guys!
Is it possible to install 400 pistons in the 350 cylinder?

Greets Andy

Offline wwsummersjr

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Re: 400Four pistons in 350Four cylinder
« Reply #1 on: January 05, 2020, 01:25:37 PM »
I've read the block needs to be machined & a few head bolts different length.

Offline wwsummersjr

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Offline andyman

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Re: 400Four pistons in 350Four cylinder
« Reply #3 on: January 06, 2020, 05:56:15 AM »
This is my Thread yes, but in this Thread i asked if it is possible to put the 400 PISTONS in the 350 CYLINDER!

Offline hondaron

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Re: 400Four pistons in 350Four cylinder
« Reply #4 on: January 06, 2020, 07:13:23 AM »
With the bore of the 350F 47mm and the 400F being 51mm I'd think that would make the 350 cylinders pretty thin, but figured someone that has tried it would weigh in 😊

Offline andyman

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Re: 400Four pistons in 350Four cylinder
« Reply #5 on: January 06, 2020, 11:09:47 AM »
Hi!
With 51mm pistons the 350 cylinder is 1,75mm thin, the 400 cylinder with the 54,5mm bigbore kit is 1,25mm.......so i think it might work

i heard that the rings of the 50mm bigbore kit for the 350 make problems....

Offline web

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Re: 400Four pistons in 350Four cylinder
« Reply #6 on: January 06, 2020, 11:29:24 AM »
Pretty sure that 1.25mm can't be true anywhere in the top of the bores... maybe the skirts but not up top.

Now maybe on a bike engine you can go thinner than on a car engine, but anything less than 3mm on the thrust side would seriously creep me out...

But you know what, maybe this is one of those "try and see" things, where you spend some money, learn some lessons, and end up going with the whole 400 block in the end after all  ;-)