a 2.7i question

[evandael]

i will have the head looked at, probably get the valves lapped and do some gasket matching.


digger, what do you mean by 27x? cam degrees? not sure if i'd go for a cam regrind at this point (slippery slope of mods ahoy!) but i'll think about it. if anything i can retard timing to try to get a bit more up top, but as i maintain, torque is the winner here. this is going into a heavy vert with a lukebox and i just like cruising in 3rd and 4th.


regarding tuning, i see mark d'sylva has a chip for the 2.7i with 10.2 compression ratio and 19# injectors. if i took another .75mm off the deck, it'd give me that compression ratio, but at that point i'm going to probably have ptv clearance issues (unless i flycut the pistons, but now i'm just making things more complicated) and it may compromise the block strength.

[digger]

take off what you need to get piston to head clearance correct

27x means a cam with duration in the 270's so for example a 272, 274 or 27x.....

[raudonis]

2.7 with 2mm block shave and b25 pistons has been done to death in Europe, here is all you need to know, just google translate: http://wp1016621.server-he.de/fotost...m20seite34.htm
If everything is done appropriately, you are good for more than 200 crank Hp and 270 crank Nm.

[digger]

2.7 with 2mm block shave and b25 pistons has been done to death in Europe, here is all you need to know, just google translate: http://wp1016621.server-he.de/fotost...m20seite34.htm
If everything is done appropriately, you are good for more than 200 crank Hp and 270 crank Nm.

thanks, thats a good link, you need a little more work to get 200bhp than what i gathered they said but i dont read german lol

the 2.7L alpina really only made 200-205bhp with all its mods but nice torque on bottom end and midrange from dyno ive seen when rebuilt

this would be very close to the B28 people like to build but the crank fits alot easier. performance would be very similar

[raudonis]

2.7 conversion with b25 pistons was popular before m52b28 filled the breaker yards and 84mm stroke crank got cheap.
100cc more displacement and more noticeable increase of low down torque can be had for not much more cost.
Much less decking of the block is required for b28 thus some people save money on adjustable cam sprocket.
I am not particularly fond of these conversions as both of them require old heavy stubby m20 130mm rods, plenty of people had them break and poke thru side of the block at 7000ish RPMs.

[digger]

2.7 conversion with b25 pistons was popular before m52b28 filled the breaker yards and 84mm stroke crank got cheap.
100cc more displacement and more noticeable increase of low down torque can be had for not much more cost.
Much less decking of the block is required for b28 thus some people save money on adjustable cam sprocket.
I am not particularly fond of these conversions as both of them require old heavy stubby m20 130mm rods, plenty of people had them break and poke thru side of the block at 7000ish RPMs.

most US b28 cranks have to have counterweights machined which is more difficult and $$$ than a $100 for a sprocket so this recipe should be more popular than it is. i bought an eta crank a few years back to do this for a nice daily driver but decided on bigger and better things...

ive only seen about 2 on this forum in 8 years or so compared to other 2.7 recipes. most in the US are looking to upgrade their ETA's (or use SETA as a start) rather than people upgrading a B25 i guess that is why head swaps on the eta far outweigh a "2.7i" with b25 piston combo

[Madhatter]

where are the people breaking rods? I think I can remember maybe 3 people in 10 years that had caps go and they were all well over double the horsepower.