Engine Build : M20B27 or M20B28?

[Brook-e30 0]

Ok so i've got an m20b25 engine that i want to build into either a m20 2.7 stroker or convert to 2.8 by using m52 crank etc.

Im a bit of a noob when it comes to engines. Have been doing some research and still have no idea what the better option will be?

I have access to workshop and my experianced family members as well as alot of factory BMW engines so getting these parts shouldnt be hard.

A disadvantage to the 2.7 would be that i dont have access to an eta block.

Please any feedback on the better/cheaper/easier engine swap would be much appreciated!

Thanks all.

[Jamez 2147483647]

build the 2.8, all you would need are the 2.8 crank and b20 conrods (on top of rebuilding the whole engine)

Iif you do the 2.7 you will be having to buy more parts

edit- or you could just M50 it

Edited April 3, 2010 by Jamez

[Brook-e30 0]

build the 2.8, all you would need are the 2.8 crank and b20 conrods (on top of rebuilding the whole engine)

Iif you do the 2.7 you will be having to buy more parts

edit- or you could just M50 it

This is true...

Unfortunately M50 would be to expensive for me as I dont already have the engine.

[Jamez 2147483647]

whats your budget for this stroker? you would have to spend a decent amount of cash to make it worth it.

if your wanting to go really cheap, sell the M20b25, buy 2.7 on trademe and bolt the head on that comes with it.

thats the cheapest way I can think of doing it.

Edited April 3, 2010 by Jamez

[Brook-e30 0]

Unsure on what im wanting to spend at this stage. Will try keep cost at a minimum. I have free access to pretty much all parts for the 2.8.

But what would that be the better option when it comes to power and reliability?

Edited April 3, 2010 by Brook-e30

[pureboiracer 0]

2.8 more power and a stronger crank. this would be your best option imo

[antony 0]

If you want to do things cheapish, look after your B25 and save.

Theres no point having a rundown 2.7 or 2.8, will only cause you trouble (read: more money).

[pureboiracer 0]

i have a b25. its only .6 of a second slower than a b27 round manfield.

[Brendan 0]

Ok so i've got an m20b25 engine that i want to build into either a m20 2.7 stroker or convert to 2.8 by using m52 crank etc.

Im a bit of a noob when it comes to engines. Have been doing some research and still have no idea what the better option will be?

I have access to workshop and my experianced family members as well as alot of factory BMW engines so getting these parts shouldnt be hard.

A disadvantage to the 2.7 would be that i dont have access to an eta block.

Please any feedback on the better/cheaper/easier engine swap would be much appreciated!

Thanks all.

I have done all the research and have built a 2.8 for my touring now running using the steel M52 crank and spacer.

118kw@back wheels

280 nm torque

272 shrick cam

std va;lves springs

Hartge 2ltre rods

std pistons

fully balanced

head slightly ported

headers

std clutch

slightly hotter plugs

std injectors

new accessories

go to www marlin sports- its all there

[*Glenn* 855]

+1 on that Brendan ... would love to see the car after our talk today

Edited April 16, 2010 by *Glenn*

[*Glenn* 855]

If you want to do things cheapish, look after your B25 and save.

Theres no point having a rundown 2.7 or 2.8, will only cause you trouble (read: more money).

Cheap will never work properly on any car

[mr E34 11]

It's all go is it Brendan, any more major work/tweaks?

[Brendan 0]

It's all go is it Brendan, any more major work/tweaks?

Hi Glenn and MrE34

So far the car is really terrific- Very smooth to drive and heaps of torque - sounds much better too .I deliberately set out not to tune it too hard - theres no point sacrificing drivability as I wanted to use it every day like I have for the past 18 years. It has a slightly lumpy idle but bugger all considering the cam its running. The other issue is that I didnt want to go the next step of grunting up the head work or turbo - big valves etc etc as these do have a weakness in the head castings and its all more cost. Where do you stop.

What I have ended up with is a dead square unstressed engine which is very smooth and very very driveable.

The car has a few other non std things:

Nolathane suspension throughout with fully adjustable back end ,Bilsteins all round with HD springs HD sway bars back and front ,Strut brace, sports drilled discs, short shift, M3 seats , dunlop falkens onto E30 accessory Mags which I scored from Ernst- these were made by BMW as a gen E30 accessory mag and are easier to clean than the BBS mags

next stage is spruce up the body work a bit and I'll pop a few pics on here when I remember.

Brendan