M20 rebuild

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savy
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Tue May 17, 2011 3:07 pm

Hi guys, ive stripped the engine apart in order to do a full rebuild took the block to my local engine machinist and he said i need to rebore the block and need larger pistons. Wondering if i should go ahead with this? what would be the my best option and how i would go about doing this?
e301988325i
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Tue May 17, 2011 7:25 pm

make a 2.9 with oversize pistons £2,000 I'd say, or buy a s/hand engine if you're on a budget.

You're savvy enough to strip an engine, did the bores actually look bad?
I said:

Can anyone suggest how to test if the boot lights are staying on with the boot shut?

e30topless said:

lock the wife in there
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Gunni
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Tue May 17, 2011 10:02 pm

What are your plans with this engine?

my reccomendation is get another bottom end with no issues. It´ll be cheaper on all accounts.
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savy
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Wed May 18, 2011 7:43 am

Bores were not to bad slight scoring, and all the pistons were heavily scored. The plan was to just rebuild and freshen up the engine i.e. new shells etc. Before stripping the engine it used to make a slight knock on idle and would disappear at 2,500rpm when revved. Engines is from a 1987 Tech-1 (High compression). what would be the wisest option?
daimlerman
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Wed May 18, 2011 11:23 am

Hi-comp pisons are the valueble bits,and they are buggered!

If you are desperate to keep the engine number,then re-bore and new pistons is the only way,in this instance it would be an idea to research the big over-bore mentioned above.

If it's more a case of getting the thing running at a cost effective rate,then follow gunni's advice.

M20 is not a cheap engine to re-build,so the option of a decent,complete and heard running s/h unit should also be considered.
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78gizmo
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Tue May 24, 2011 10:30 pm

savy wrote:Bores were not to bad slight scoring, and all the pistons were heavily scored. The plan was to just rebuild and freshen up the engine i.e. new shells etc. Before stripping the engine it used to make a slight knock on idle and would disappear at 2,500rpm when revved. Engines is from a 1987 Tech-1 (High compression). what would be the wisest option?
Got a good complete high comp 2.5 here for £150 if you need a cheap option?
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