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how to tell difference between 2.5 and 2.7 ?????????????????
Posted: Mon Nov 05, 2007 12:47 am
by e30turboed
i may be going to view a car this week supposedly has a 2.7 in it. can anyone tell me how to tell the difference ?
Re: how to tell difference between 2.5 and 2.7 ?????????????
Posted: Mon Nov 05, 2007 12:56 am
by mattG
good question, they mainly have a longer crank, maybe you can take out a spark plug and measure the depth at BDC
Re: how to tell difference between 2.5 and 2.7 ?????????????
Posted: Mon Nov 05, 2007 1:28 am
by Onz
i know the oil dipstick should be different but I dont know what the differences are.
Re: how to tell difference between 2.5 and 2.7 ?????????????
Posted: Mon Nov 05, 2007 6:23 am
by daimlerman
It sould have a custum chip of some sort.And a shed load of grunt from around 2000rpm.....
Re: how to tell difference between 2.5 and 2.7 ?????????????
Posted: Mon Nov 05, 2007 12:13 pm
by Onz
3rd gear lasts much longer too and torque is easier to find.
Idle should be slightly higher than 2.5, mines set just below 1000 at the moment but it has been tuned to be slightly higher too occasionally

Re: how to tell difference between 2.5 and 2.7 ?????????????
Posted: Mon Nov 05, 2007 12:17 pm
by bazza93
daimlerman wrote:It sould have a custum chip of some sort.And a shed load of grunt from around 2000rpm.....
would'nt that be the same with any 325 with a wild chip fitted ??????
Re: how to tell difference between 2.5 and 2.7 ?????????????
Posted: Mon Nov 05, 2007 12:31 pm
by maxfield
mattG wrote:good question, they mainly have a longer crank, maybe you can take out a spark plug and measure the depth at BDC
That's probably the best way.
Re: how to tell difference between 2.5 and 2.7 ?????????????
Posted: Mon Nov 05, 2007 12:50 pm
by e30turboed
so if i check in my book for crank throw standard and see if it has more.
Re: how to tell difference between 2.5 and 2.7 ?????????????
Posted: Mon Nov 05, 2007 1:15 pm
by frankiej
It sounds like that's what they're saying.
Re: how to tell difference between 2.5 and 2.7 ?????????????
Posted: Mon Nov 05, 2007 1:17 pm
by maxfield
I think the M20's stroke is 75mm.
Re: how to tell difference between 2.5 and 2.7 ?????????????
Posted: Mon Nov 05, 2007 2:17 pm
by daimlerman
bazza93 wrote:daimlerman wrote:It sould have a custum chip of some sort.And a shed load of grunt from around 2000rpm.....
would'nt that be the same with any 325 with a wild chip fitted ??????
A zone chip from Ant will have '2.7' written on it,like mine.Mine also now has a small 'Miller' sticker....I understand that other chip suppliers fit a similar label.Sometimes a label is attached to the outside of the ECU,so that it is visible without opening up the ECU.
Re: how to tell difference between 2.5 and 2.7 ?????????????
Posted: Mon Nov 05, 2007 2:22 pm
by bazza93
daimlerman wrote:bazza93 wrote:daimlerman wrote:It sould have a custum chip of some sort.And a shed load of grunt from around 2000rpm.....
would'nt that be the same with any 325 with a wild chip fitted ??????
A zone chip from Ant will have '2.7' written on it,like mine.Mine also now has a small 'Miller' sticker....I understand that other chip suppliers fit a similar label.Sometimes a label is attached to the outside of the ECU,so that it is visible without opening up the ECU.
thats a fair point worth looking at then
Re: how to tell difference between 2.5 and 2.7 ?????????????
Posted: Tue Nov 06, 2007 10:04 am
by Onz
so what is the thow of a 2.7? And do Alpina, Hartge and ETA 2.7's have the same throw?
Re: how to tell difference between 2.5 and 2.7 ?????????????
Posted: Tue Nov 06, 2007 8:25 pm
by maggspower
crank throw is 81mm, i dont think people are going to be too chuffed if you start taking out spark plugs and filling them with all manor of coat hangers welding rods and rulers
try checking the engine numbers by the engine mount on the inlet side of the engine bay, this is not foolproof though as a 2.7 can be made from 2.5 or 2.0 litre block, and of course the eta bottom end. Or if your realy lucky a 324 torbo diesel crank!!
i think the best way of checking would be the ecu, followed up by the old arse dyno
you should feel the difference, if you dont its either a 2.5 or a crap 2.7, no point in paying for and having the 2.7 kudos without the 2.7 grunt. good luck
Re: how to tell difference between 2.5 and 2.7 ?????????????
Posted: Tue Nov 06, 2007 8:44 pm
by e30turboed
well he was a blagger no paperwork, reckons its 2.7 and still on 2.3 standard fuel injection

i just thought whatever didnt even bother looking at it. rusty, no mot, ripped seats for 2k i dont think so. hes in dream land.
Re: how to tell difference between 2.5 and 2.7 ?????????????
Posted: Tue Nov 06, 2007 8:53 pm
by maggspower
yeah theres alot of them about
anyway keep looking, or better still make your own 2.7

Re: how to tell difference between 2.5 and 2.7 ?????????????
Posted: Wed Nov 07, 2007 11:52 am
by NK
e30turboed wrote:i may be going to view a car this week supposedly has a 2.7 in it. can anyone tell me how to tell the difference ?
infact i drive a 2.7 can i help?