Rebuilding M42 high-comp...

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Omi
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Post Fri Feb 02, 2007 6:38 pm

Getting an engine rebuilt for Scumball, before going the turbo-nutter route later.

It's getting skimmed and the compression is going up...

- How far can the the block/head be skimmed to increase compression without interference?

- Tim recently had grief with small end bearings after raising compression, I'll try and sort those too, but is there anywhere else that requires attention with higher compression ratio?

- I'm wanting a lighter flywheel. Is the M40 unit (3kgs lighter) a straight, bolt on swap? Can this be lightened further?

- Any other tips?

Cheers,

Omi
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appletree
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Post Fri Feb 02, 2007 6:46 pm

think the best fly wheel to use is a 325 one IIRC you have to get some other bits to go with it but it is doable, theres a firm down bristol that will lighten and balance a flywheel for $35 though.
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m-dtech
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Post Fri Feb 02, 2007 6:57 pm

yep, m20 flywheel fits in the gearbox bellhousing

also might need to change the starter to the m20 one or swap the ring gear.
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tim_s
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Post Sat Feb 03, 2007 10:56 am

appletree wrote:think the best fly wheel to use is a 325 one IIRC you have to get some other bits to go with it but it is doable, theres a firm down bristol that will lighten and balance a flywheel for $35 though.
what firm's that? im in bristol...

omi, my CR is nearly 11:1, and i need steel backed small ends as standard bronze ones couldn't take it it seems. on a standardish engine i really don't know.
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appletree
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Post Sat Feb 03, 2007 11:36 am

sorry tim seams there not in bristol, don't know were i got that from.

also prices seam to have gone up slightly 0r are miss quated in there advert in Practical Performance Mag as they advertise ltn flywheel + resurface £35

heres a link anyway

http://www.mspd-engines.co.uk/machining_page.htm
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stuartgallafant
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Post Sat Feb 03, 2007 6:34 pm

omi, depending on what engine it is, will be how afr you can go...

tell me what engine it is, and i'll get you the data you need. its all supplied on the TIS computeras at work, and gives you info on the machining limits and such
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benjy
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Post Sat Feb 03, 2007 8:54 pm

Could you send me that info for the M42 an M44 engines pls?? cheers benjy 8)
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Post Sun Feb 04, 2007 12:51 pm

benjy, i'll get as much as i can for you both 8)
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