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Old 02-11-2016, 09:37 AM   #1
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connecting rods & piston measurements

Does anyone know the different measurements for the m96 connecting rods (2.5, 3.2, 3.4)
How about the piston wrist pin to top distances?
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Old 02-11-2016, 12:13 PM   #2
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Originally Posted by j.fro View Post
Does anyone know the different measurements for the m96 connecting rods (2.5, 3.2, 3.4)
How about the piston wrist pin to top distances?
I think all m96 rods are the same except the shorter 3.6 rods.

Piston pin height was raised 3mm for for 3.4 & 3.2 crankshaft.

Piston pins are offset 0.8mm to intake side.
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Old 02-11-2016, 12:23 PM   #3
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Originally Posted by j.fro View Post
Does anyone know the different measurements for the m96 connecting rods (2.5, 3.2, 3.4)
How about the piston wrist pin to top distances?


I'll measure that soon.
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Old 02-11-2016, 02:04 PM   #4
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Originally Posted by j.fro View Post
Does anyone know the different measurements for the m96 connecting rods (2.5, 3.2, 3.4)
How about the piston wrist pin to top distances?
Centerline of the pin to top of 3.2 piston is about 41mm. Hard to get exactly from centerl.

OE Rod weights vary mine were about 564 grams. LN's are 511.3 grams

OE piston's vary alot mine were about 506 grams. LN's 96mm's are 503.4 grams
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Old 02-12-2016, 05:57 AM   #5
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Thanks BPD!
Recently Mr. Raby has thrown us a crumb about a short stroke 3.6l beast. I'm wondering what combos might be possible without having to source really custom parts. To stay in F Prepared at 2500# the max displacement I can do is 3.4 litres. With a 72 mm stroke (that's a 2.5L crank), a 100 mm bore would yield right at 3.4. With the sort stoke and the right rods and flowing heads I'm guessing it would be a rev monster.
Any thoughts out there???
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Old 02-12-2016, 06:56 AM   #6
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Originally Posted by j.fro View Post
Thanks BPD!
Recently Mr. Raby has thrown us a crumb about a short stroke 3.6l beast. I'm wondering what combos might be possible without having to source really custom parts. To stay in F Prepared at 2500# the max displacement I can do is 3.4 litres. With a 72 mm stroke (that's a 2.5L crank), a 100 mm bore would yield right at 3.4. With the sort stoke and the right rods and flowing heads I'm guessing it would be a rev monster.
Any thoughts out there???
If you are talking M96 5-chain engine, the only "pratical" ($10,000) thing to do is install LN sleeves in a 3.2L to get 3.4-3.6L. Heads are the limiting factor for doing something they weren't designed to do. Valves are to small.
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Old 02-12-2016, 07:45 AM   #7
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"Piston pins are offset 0.8mm to intake side."
Very helpful piece of obscure but crucial info for a diy rebuilder.
Perfect example of why we need Jake's book "M96/97 -The Definitive Guide".
Imagine how many rebuilders missed that and assembled the engine assuming the wrist pin offset was zero?
Hopefully he will publish it?
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Old 02-12-2016, 08:10 AM   #8
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Originally Posted by Gelbster View Post
"Piston pins are offset 0.8mm to intake side."
Very helpful piece of obscure but crucial info for a diy rebuilder.
Perfect example of why we need Jake's book "M96/97 -The Definitive Guide".
Imagine how many rebuilders missed that and assembled the engine assuming the wrist pin offset was zero?
Hopefully he will publish it?
Valve reliefs in the pistons are more obvious. Most of what I put in my 1st post is in the Bentley manual.
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