b25/b27 engine numbers

[steve_k]

right then folks i hope you can help me.

where abouts on a m20b25 should i be looking for the egine number? i;e the one which tells me if it's a b20 - b25 - or b27?

i've heard romur's it's on the bottom of the dip stick, or is that the wrong place?

alo if any one has the numbers then please post them up.

TIA

steve.

[Brianmoooore]

Flat machined area near the LH engine mount. Type number will start 20 ,25 or 27.

[steve_k]

Flat machined area near the LH engine mount. Type number will start 20 ,25 or 27.

thanks brian

[daimlerman]

Essentially,there are only two blocks,80mm bore and 84mm bore.
B25/27 are almost identical,the B27 has 'steam holes' between the bores,not essential as the B25 does not have them....
For the very best stroker build you need to start with the un-wanted B20,and have it bored to suit your pistons,more costly overall,but gives a perfect cylinder face.
........and an 320i engine number......

[yellowmellow]

DAMN I thought the best combo for a 2.7 conversion was an ETA bottom end with 2.5 head. That,s where I was heading (no pun).

[Brianmoooore]

DAMN I thought the best combo for a 2.7 conversion was an ETA bottom end with 2.5 head. That,s where I was heading (no pun).

It's a cheap and effective combination, but by no means the 'best'.

[m_jermyn]

You mentioned the the number would start with 20,25, 27....... This is my engine number whats that mean then 23714009?

[mrLEE30]

its a M20B23 from a 323???

[m_jermyn]

Nope its ETA

[mrLEE30]

ok!

[daimlerman]

DAMN I thought the best combo for a 2.7 conversion was an ETA bottom end with 2.5 head. That,s where I was heading (no pun).

The difference is inside the block...
Eta 84mm bore,just like a 325.
But has a longer stroke crank.
I used a standard eta short motor with a 731 head for my build.
If I was to build another stroker M20,I would be going 2.8.

[yellowmellow]

I just need to need to check out some of my part,s/engine numbers. Then ask you a few more questions- If that,s ok
Chees