Some m20b27eta engine questions

[E30325es]

First off I would like to say hello to everyone being this is my first post here. I have been looking around this forum for a couple of weeks and must say its one of the better forums I have come across. Most of the people here know what there talking about and dont seem to carry a chip on there shoulder. And before anyone jumps down my thoart I have been searching around for over 2 weeks on this and many other forums and can't find a "real" answer, meaning one that everyone agrees on. Now for the questions. I have a 1987 325es with a blown head gasket. I am going to be rebuilding the motor for a turbo setup. I am looking to make 300-375 rwhp and wanted to know what stock engine parts, if any, are strong enough to handle that kind of power. If I use a 545td crank is that going to change my cr ratio? Now what is the differnce between this head and the "i" head besides the cam, valves, and ect, meaning is the actually head casting different? Is there a better head I should just put on instead of building the one I have? Ummm thats about all I can think of for now. Any inforamtion would be greatly appreciated and thanks for your time guyz and gal(s)..

[nando]

the e head has smaller valves, smaller intake/exhaust ports, and a low lift/short duration 5 bearing cam. the i head is far superior, not to mention the i engine has a better intake manifold, larger throttle body etc. realistically you'd need the entire i top end and motronic. I'm not sure if you could do 300-375hp on with the e induction system, but you're welcome to try.

[PeaveyBassist]

The b25 (325i) head also has more oil passages IIRC. m20b27(325e) bottem end with an m20b25(325i) top end and it will give you a good turbo CR of around 8:1. AFAIK The 325e crank should be good to handle a lot of power but if you can get a 524td crank for cheap, get it just in case.

Will

[E30325es]

Ok so what I understand is that the crank and rods are really strong. The weak parts of the engine tend to be the pistons and the head. Has anyone ever ordered one of those IPP's High Performance (HP) Engine Rebuild Kits? If so how do you like it?

[raimo]

the eta cranck has proven to reliable to 450hp with a turbo. until then, your safe, if you do not exceed 7000rpm. but who needs 7k+ on a street car anyway ...
the td cranck would be a bulletproof choiche. i know that alpina and hartge used the td cranck on their 2.7 n/a ~210hp cars.
i would say the rod are really strong, but they are forged. also, trying it with stock motronic ems is wasting time. get a real ems.

[SpecM]

-I believe the b25 head casting is slightly different. It has a larger combution chamber.
-eta and turbo-diesel crank size and specs are the same, just the td crank is forged and stronger.

[E30325es]

What ems would you recommend? Also if someone has an "i" head for sale let me know. My plan is to rebuild the bottom end with one of those ipp engine kits with the fordge piston and mate it with an "i" head for now till i get more money. But what exactly do i need to get the i head to run with the eta block?

[SpecM]

What ems would you recommend? Also if someone has an "i" head for sale let me know. My plan is to rebuild the bottom end with one of those ipp engine kits with the fordge piston and mate it with an "i" head for now till i get more money. But what exactly do i need to get the i head to run with the eta block?

-Nothing. They bolt right up. Just be prepared for a sluggish motor with that 7.9:1 CR

[E30325es]

I understand that the "i" head bolts right up to the eta block but do I need motronic to run that head. Can I use my stock harness and ecu with that combo?

[Dave]

I understand that the "i" head bolts right up to the eta block but do I need motronic to run that head. Can I use my stock harness and ecu with that combo?

1. Stop what you are doing.

2. Go to www.strictlyeta.net and study

3. Realize that its easier just to find a $300 M20B25 and motronic.