325e Stroker

[iliad]

Ok guys i know i am a noob, but i wasn't able to find much info online.
I am trying to find out what is involved in making a stroker engine. I have a 325e with the 2.7 eta engine, so i know I need to keep my block and buy an i head. Now after I have installed the i head do I need to change out the intake manifold as well? Are there more parts I need to swap? What else is involved? Thanks in advance,
Brian.

 

[echothreezero]

The answer to all your prayers

 

[E30m42cab]

There's always the M30B35 and M50B25 swaps too.

 

[E30m42cab]

http://www.bimmerfest.com/forums/showthread.php?t=263978 Imagine that with a turbo!

 

[Doughnut]

There's always the M30B35 and M50B25 swaps too.

I'm currently looking at buying this :
http://cgi.ebay.com.au/BMW-E34-535I...oryZ6763QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Been in contact with the seller too!!

 

[E30m42cab]

That's the spirit Joseph!

 

[echothreezero]

I looked seriously at doing that (m30), but my reasons against were:

Weight distribution would be worse than an m20.
Have to run an electric fan.
Cost to benefit ratio marginal.

The first two can be helped to some extent by using engine mount position III but this also means cutting and refabb-ing the firewall.

Hence my decision to go the bastion of cheap power - FI.

 

[iliad]

So what would happen if i keep my stock eta block and intall a 325i head with a 325i intake manifold?

 

[E30m42cab]

waste of time. Honestly. If you want power, turbo the thing. I don't know why you'd call it a stroker... it's still going to be 2.7L with the eta block.

 

[echothreezero]

I don't know why you'd call it a stroker... it's still going to be 2.7L with the eta block.

Not quite. The eta and the "i' blocks are the same. Its the crank, and rods that you want out of the 2.7. By "converting" the eta to an"i" (use the 325i head and pistons and skim the block or 320i/323i head and eta pistons) or using the eta crank and rods in an existing "i" engine you have in effect created a stroked "i". The bores are the same.

Its better to start with a 325i and an old 325e motor than the other way around as you want all the i intake, airflow meter, etc, and ecu and so on.

I'd only do a 2.7 conversion if I was rebuilding my motor anyway. If you do it all properly, with a 268 cam an ecu remap, etc you might be looking at around 150-155kw (same as m30).

However, spend the same amount of money freshing up your top end for boost, throw on a turbo or screw and run a mild 6-7psi and you are probably in the area of 190kw. That's nearing e36 m3 power!

 

[leadtrombone]

in the same vain here. Are all the M20*** engines essentialy the same Block with different cranks and heads. (and intake/exhaust manifoldss....)

Mine is a 320i... and wondering what cool options i have when/if i get the chance to do a neato upgrade.

 

[iliad]

Not quite. The eta and the "i' blocks are the same. Its the crank, and rods that you want out of the 2.7. By "converting" the eta to an"i" (use the 325i head and pistons and skim the block or 320i/323i head and eta pistons) or using the eta crank and rods in an existing "i" engine you have in effect created a stroked "i". The bores are the same.

Its better to start with a 325i and an old 325e motor than the other way around as you want all the i intake, airflow meter, etc, and ecu and so on.

I'd only do a 2.7 conversion if I was rebuilding my motor anyway. If you do it all properly, with a 268 cam an ecu remap, etc you might be looking at around 150-155kw (same as m30).

However, spend the same amount of money freshing up your top end for boost, throw on a turbo or screw and run a mild 6-7psi and you are probably in the area of 190kw. That's nearing e36 m3 power!

I figured that,
so its going to be much more expensive doing it backwards with the eta engine, I would have to change out the instrument cluster as well because of the higher rpm's in the i cars. So you recommend me turbo it with low boost rather than going through all that. I just recently redid the whole top end of my eta with timing belt water pump etc... will I be able to run low boost on the stock engine or will i have to change out components as well. Thanks in advance,
Brian.

 

[Doughnut]

You should be able to run low boost on your stock engine internals, without any major dramas.

Though imo you will get bored turn the boost up and throw a rod, No matter what path you take (2.7, m30 FI etc..) it is going to be time consuming, frustrating and expensive.

 

[echothreezero]

in the same vain here. Are all the M20*** engines essentialy the same Block with different cranks and heads. (and intake/exhaust manifoldss....)

Mine is a 320i... and wondering what cool options i have when/if i get the chance to do a neato upgrade.

Nope. m20b20/23 has 80mm bore. m20b25/27 has 84mm bore. Also m20b20/23 doesn't have the extra water journals for better coolant flow.

Read the article I linked for info on all the blocks/heads etc.

 

[echothreezero]

I figured that,
will I be able to run low boost on the stock engine or will i have to change out components as well. Thanks in advance,
Brian.

You will need a ecu remap or piggyback ecu or whole new ecu (like a link, motec or megasquirt).

Also, by top end rebuild do you mean cams, valves, head??? If not, you would be wise to at the very least replace your head gasket with a metal one, tidy up the head (mild port/polish) and use stronger head bolts (like metric blues).

Also there's the fabrication to consider. A 2.7 rebuild will be cheaper and possibly more reliable, but the extra power from turbo is worth it in my opinion.

 

[iliad]

You will need a ecu remap or piggyback ecu or whole new ecu (like a link, motec or megasquirt).

Also, by top end rebuild do you mean cams, valves, head??? If not, you would be wise to at the very least replace your head gasket with a metal one, tidy up the head (mild port/polish) and use stronger head bolts (like metric blues).

Also there's the fabrication to consider. A 2.7 rebuild will be cheaper and possibly more reliable, but the extra power from turbo is worth it in my opinion.

I wouldn't know how to remap or piggyback the ecu so I will look into that.

I pulled the head, sent it to a machine shop and had it taken apart, cleaned, valve job, checked the cams installed new springs... I only put a regular head gasket back on, but I did install the metric blue bolts. I'll look into purchasing a metal gasket.
Thanks again.

This is the kit I was looking into buying
http://cgi.ebay.com/ebaymotors/84-9...ryZ33742QQssPageNameZWDVWQQrdZ1QQcmdZViewItem