E30 Wiki - M20 Engine

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SilverShadow
Hartge Crew
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Joined: Sun Jan 16, 2005 11:00 pm
Location: London

Post Wed Aug 14, 2013 1:51 pm

I'm trying to do some research in rebuilding an B27 M20 engine.

I found a very good link in the Wiki regarding the head but nothing on the block?

Anyone know of a good thread or a link to rebuilding the bottom end?

Thanks

:cool:
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maggspower
Turbo Farmer Tractor Driver
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Joined: Wed Oct 12, 2005 11:00 pm
Location: Nowhere near South Wales, ok butt

Post Wed Aug 14, 2013 2:15 pm

I will be running a thread in the very near future on building a 2.7 to a fairly decent spec.

What do you need to know?
SilverShadow
Hartge Crew
Posts: 1362
Joined: Sun Jan 16, 2005 11:00 pm
Location: London

Post Wed Aug 14, 2013 2:56 pm

Cheers Maggs for the reply however I already 27 spec engine, a couple of years ago it started blowing blue smoke so I have decided to rebuild it. I'm getting the following work done on the head by Corry's:

Pressure test
Acid dipped
Stem seals
Exhaust guides
Lap valves
Skim

I just wanted to know what work should I take on the block? rings anything else?

I don't want to change any of the core components e.g cam, crack etc just the rebuild part if that makes sense?
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maggspower
Turbo Farmer Tractor Driver
Posts: 2376
Joined: Wed Oct 12, 2005 11:00 pm
Location: Nowhere near South Wales, ok butt

Post Wed Aug 14, 2013 9:59 pm

SilverShadow wrote:Cheers Maggs for the reply however I already 27 spec engine, a couple of years ago it started blowing blue smoke so I have decided to rebuild it. I'm getting the following work done on the head by Corry's:

Pressure test
Acid dipped
Stem seals
Exhaust guides
Lap valves
Skim

I just wanted to know what work should I take on the block? rings anything else?

I don't want to change any of the core components e.g cam, crack etc just the rebuild part if that makes sense?
No problem, heared good things about corrys, so you should be in good hands there.

If you are looking to rebuild the bottom end as well you need to have it all checked over and measured.

The bottom end will all need checking to see what is good enough to be reused, and what needs to be renewed. As a bare minimum you will need:

Crank polished
Bores honed
New rings
New main crank shells
New big end shells
New big end cap bolts

But from there you may want or could need, a rebore, new pistons, crank regrind, core plugs, little ends, main bolts, etc you just need to assess what you have within your current engine. There is no point in doing half a job at that stage.
jimbom30cab
Tech 1 freak
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Location: in the garage

Post Wed Aug 14, 2013 10:08 pm

heared good things about corrys
they did exactly the same to my m30 head, came back looking like new, they also changed any "suspect" rocker arms. how they know they are "suspect" I don't know.
SilverShadow
Hartge Crew
Posts: 1362
Joined: Sun Jan 16, 2005 11:00 pm
Location: London

Post Thu Aug 15, 2013 2:04 pm

Thanks guys for the advice!

I may not get the head skimmed if I can get away with it, been off the phone to Birds and they recommended that these heads were skimmed to specification and taking any further material off may not be a good idea.

Some pennies saved I guess!

:P
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