M20 strocker bottom end bearings

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dje30
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Sat May 17, 2014 12:22 am

Hey guys quick question
M20b25 block
M20b20 conrods
M52b28 crank
What bearings should I use for the bottom end?
Thanks
David
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reggid
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Sun May 18, 2014 6:17 am

first thing to find out is double or single tangs. if crank not been ground std bearings from KS or similar would probably work. need to measure....
E30 325is with M20B31
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dje30
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Mon May 19, 2014 6:35 am

How do I find out if it single tang or double?
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reggid
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Mon May 19, 2014 8:34 am

E30 325is with M20B31
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Paynts
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Thu May 29, 2014 7:11 pm

Hi guys since we are all talking about the same thing on this thread and Reggid seems to know his stuff i thought id post this here
I'm on my 2.8 build
Have sourced m52 crank single vanos 130 mm rods so far,

First problem is mains, the crank won't drop in because the original crank had been reground,

I'm tempted to take the bottom end and rods to my local machine shop and get them to polish the standard m50? M52 crank and source and fit new mains and big ends, I'm a little nervous of just buying my own shells for mains and big ends and putting them together myself, I ve got a decent Mic and have checked my new crank and its not badly out of round etc , but actually measuring and ordering the right shells might be more problematic than just doing some measuring and ordering, mainly I'm worried about ordering the right diameter mains shells,

Any advice.? I've built plenty of standard road car engines but have always got the machine shop to do the bottom end after they've re ground the crank etc
Secondarily I think I know the answer to this but stroking a part worn block, what about the step in the bore where the old piston/ rod combo bottomed out, is honing good enough? Has anyone had a broken ring problem? Years ago they used to fit dodger rings for rebuilding worn engines, but I'm guessing this is now only folklore
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reggid
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Thu May 29, 2014 10:26 pm

yep some stuff is for the pros. you could try and find OS bearings to suit the smaller journal etc to match everything up but id rather get someone who knows what they are doing
E30 325is with M20B31
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