2.7 options BIG pictures added

[Rik178m]

Just tried to find my total bmw magazine from ages ago that showed 3 car witha 2.7 and 1 witha 2.8 all by different methods (if anyone can remember that issue) only to find my dad threw it out last week! I remember the first car started out as a 2.5 but he changed the crank to a 525e item with 324i conrods I think. Can anyone shed some light on the type of conversion for me please.

[march109]

or if anyone has the mag and can scan it I'd love a butchers too.

[Chris-W]

Feb 2006 - you can have my copy when you drop the hoist off if you like?

[Rik178m]

Excellent mate Thanks! I'll scan it and put it up aswell

[march109]

Cheers Rik

[Simon13]

ahhh the zoners special edition! Jimbobs old car which Paul390 owns i think now, Karan's/Ian332i/Ste's old 2.7. Player 6's 2.8 and Brents H27 lump - he doesn't seems to be around anymore though

I went along to the shoot was a good day out had by all!

[Rik178m]

If these are abit hard to read let me know and I'll re-scan them

[Rik178m]

Is it as simple as just a 525e crank and rods in a 2.5 engine with a chip?

[daimlerman]

If you use a 320i head and a zone chip,yes!! I did it,so you can too!!

[Rik178m]

Says e used a 325i head tho. And whats this about lowering the block??

[march109]

I don't mean to moan but when I open those images I still can't read them when I zoom in, either the scan quality is shite or I just can open them properly, can you email then to me?

[daimlerman]

Rik178m,I used the cheap way to build a 2.7,ie,standard eta short motor with 320 head,325 cam and 325 inlet. The expensive way is to use a 325 head and 325 pistons.The cost enters here.The 325 pistons are shorter from the pin to the crown than the eta pistons.So you either settle for a comp. ratio of around 7.1(good if you plan a turbo )or you shave(deck) around 2mm off the top of the block.This brings the cam closer to the crank and affects the timing.To correct this you require a vernier pulley(more expense).It is probably cheaper to build a 2.8 than go down this second route.In all cases you require 320/eta length con rods.My cheap option gave 178bhp and an almost flat torque curve.In the real world this means instant grunt at anything over 2000rpm in any gear. I can pull out from behind a lorry that is running at 56mph in 5th gear and be doing 80mph by the time I pass his front bumper

[Rik178m]

March yep I'll try setting the scanner up again aswell whats your email?

Daimler- I was thinking about using a 325i head with ETA crankshaft and rods and 325i pistons which as the mag says will give a CR of 9.4:1. Would I need to do all the above aswell?

[daimlerman]

Yes!! I have not done this myself,I am talking theory here,but I would assemble one piston/rod/crank into the block and check the clearance at both TDC and BDC. If your crank comes complete with eta pistons compare the piston skirts as well,some 325 pistons need the skirt machineing for BDC. Ant is the expert on this,he posted the maths behind the measurments recently,be worth half an hour to search it out.

[Rik178m]

and your compression was 7.1:1? Did you use an early or late 325i? Yep will deffinetly search for it but I'm going to be late for work so I'll do it tomorrow

[daimlerman]

Rik178m,I used the cheap way to build a 2.7,ie,standard eta short motor with 320 head,325 cam and 325 inlet. The expensive way is to use a 325 head and 325 pistons.The cost enters here.The 325 pistons are shorter from the pin to the crown than the eta pistons.So you either settle for a comp. ratio of around 7.1(good if you plan a turbo )or you shave(deck) around 2mm off the top of the block.This brings the cam closer to the crank and affects the timing.To correct this you require a vernier pulley(more expense).It is probably cheaper to build a 2.8 than go down this second route.In all cases you require 320/eta length con rods.My cheap option gave 178bhp and an almost flat torque curve.In the real world this means instant grunt at anything over 2000rpm in any gear. I can pull out from behind a lorry that is running at 56mph in 5th gear and be doing 80mph by the time I pass his front bumper

I used option one!!

[Rik178m]

Sorry mate this is confusing me! Whats your spec exactly? and what compression do you have?

[daimlerman]

OK,one more time!! 325 block,525e pistons/rods/crank.320 head with 325 cam.325 inlet complete with 325 injectors and FPR.Compression ratio is around 10.1.This is the simplest build,no need to modify the block or the pistons.No need for a vernier cam pulley.

[Rik178m]

haha cheers. If I ran on a 7.1:1 would I be ok as I plan a turbo conversion just not for a while?

[Templ8e30]

It'd be seriously unresponsive with a 7:1 cpr and no turbo

Cheers,

Iain T

[Ant]

and no functioning squish and will eat headgaskets just for fun

you cant build an engine for N/A and then just turbo it, same goes in reverse.

decisions,decisions .......

[Rik178m]

ok cheers mate. Just to confirm when some one says bottom end thats the crank and rods but not the block -correct?

The mag says as above that a 525e bottom end with a 325i head (885) will give a 9.4:1 so is that a 525e block or 325i block?

Sorry if these questions are gettin daft now!

[daimlerman]

The 525e and the 325i block is identical. The combination you mention will use 325i pistons and therefore will require all the machining work to block and pistons. My reference to a 'short motor' would mean... block,crank,rods,pistons and any other part contained therein.

[Andyboy]

Why isn't there a sticky 'how do I build a 2.7' thread rather than going through this time and time again?? It's really starting to get boring now.

[Templ8e30]

Why isn't there a sticky 'how do I build a 2.7' thread rather than going through this time and time again?? It's really starting to get boring now.

Agreed, this is getting tedious

Cheers,

Iain T

[Rik178m]

Would be a great idea as you cant search for '2.7' either.

[daimlerman]

Perhaps Andyboy could write us one....

[Rik178m]

Can anyone see my confusion though after reading the magazine article it looks like you can just put 525e crank and rods in a 325i engine and bosh, job done!

Also is 7.1:1 a perfect compression for a single turbo?

[daimlerman]

I would suggest that you follow jazzman's build of a 2.8....

[Andyboy]

If the mods promised to make it a sticky, I could do it. It's painfully bloody easy if you're told how to do it.

[Chris-W]

If the mods promised to make it a sticky, I could do it. It's painfully bloody easy if you're told how to do it.

Promise.

[daimlerman]

Nice one !!

[Rik178m]

Awesome!

[daimlerman]

Thanks,Andy,knew you were the right man for the job!!

[Apex]

Why isn't there a sticky 'how do I build a 2.7' thread rather than going through this time and time again?? It's really starting to get boring now.

Thanks, I thought the same thing! I have had a scan threw this and come up with a few idea's.

Im planning to convert my 320I to a 2.7 over the next couple of months (the Police decided I drive too fast and have given me three months off driving) and am wondering if anyone who has performed this conversion successfully would be so kind as to construct a parts needed list compiling of what head, block and intake you used. Also I have been told a 3.0 or 3.5ltr ECU can run everything quite nicely.

Any advice would be greatly appreciated as im struggling to get a simple answer as to what is the best combination.

Thanks

Graham