2.7L on a budget

[MattE30]

I remember this post being on e3s, but I forgot the information, and I am now interested. It is my understanding that you can use eta parts to build an inexpensive 2.7L M20. Shed some light please.

[rwh11385]

Re: 2.7L on a budget

I remember this post being on e3s, but I forgot the information, and I am now interested. It is my understanding that you can use eta parts to build an inexpensive 2.7L M20. Shed some light please.

As i remeber, the eta crank with i rods, but the i pistons must be shaved a couple mm so they won't hit the valves. The longer stroke + same rod = problem.

On the other hand, you could get customs pistions :shock: for $850, not really a budget.

[AdamF 88iS]

You need '88 only SuperEta pistons. They are the best way to do it on a budget. You can use any eta crank and any 'i' head together with those.

[MattE30]

i rods or eta rods?

[rs4pro3]

E rods with super eta pistons. The I rods are to long for the eta crank's stroke.

[65Matt]

Can you buy Super Eta pistons new? Anyone know the part number/ cost? I would imagine they would have to be overbored, too.

Edit:
Here's a page I ran across that shows the differences between the pistons:

http://home.netpower.no/pberg/Mahle_m20.html

[Bill 84 318i]

The bore of eta, supereta, and 'i' engines is the same.

[Fred]

Can you buy Super Eta pistons new? Anyone know the part number/ cost? I would imagine they would have to be overbored, too.

Edit:
Here's a page I ran across that shows the differences between the pistons:
http://home.netpower.no/pberg/Mahle_m20.html

BMW list price is $834 a set, though I'm sure you can find places that carry em for less.

Fred

[george graves]

Uhhhh??? - am I the only one that think $800 for psitons is not exactly a way to go for a budget re-build?

George gRaves

[E30godz]

not NEW, i think that should be used as a reference... junkyards and ebay is where to look for a set. easily 100-200 bucks.

[Fred]

Uhhhh??? - am I the only one that think $800 for psitons is not exactly a way to go for a budget re-build?

George gRaves

Like Ian said, that is the list price of brand new pistons from the dealership. BMW's list price for an E30 ABS computer is $900, but they go for like $50 at junkyards.

Fred

[modifiede30]

I'm in the process of building a stroker based on the super eta. I have an "i" engine in the car, and I was able to obtain the whole super eta free. Aside from replacement parts, I can build this stroker for less than $500 if I do all the work on my own-which I'm doing. I just finished porting the head and intake, and the engine block is bare, the 274 cam was just recieved, and I'm about to buy the bearings and piston rings. These are all that's left.

You can find a whole super eta engine relatively cheap. If you do this, replace the cam and buy inner springs and you've basically created an "i" head. This allows you to recoup a good bit of money by selling your "i" head once you've finished the conversion.

I've yet to see any performance numbers but even if the horsepower comes to the same as an "i", you've moved your useable torque range down the rpm range about 1000 rpms. As a result, the need to get to 6900 rpms is eliminated, especially since you'll begin to loose torque since its no longer an "i" powerband engine. Here is a breakdown of my costs.

Valve Springs: 39.00
Head Set: 59.00
Block Set: 24.90
Cam Regrind: 149.00
Porting Kit: 35.00
Rod Bearings: 32.90
Main Bearings: 38.95
Piston Rings: 101.40

Total: 485.15

Not a bad price for a stroker. A few other things will be necessary but to me, they're just maintenance items. The headers are already in the car, throttle body is already bored, the 19# injectors are already in, and the m30 afm is done. I also just recieved a racing dynamics straight pipe with resonator. I figure by the time this is installed and ready for next year's track season, I'll be having a bit more fun.

[MattE30]

modifiede30....what about pistons and rods?

[modifiede30]

Crank, rods and pistons are all from the super eta. However, I may see if I can find alternate pistons from a european model to raise compression. The compression from the super eta is 8.5:1. You can bring this up to 10.0-10.5:1 with european 528e pistons depending on year. Remember that the super eta is essentially a stroker mechanically, except for the cam and valve springs of the head. Other than these components, its a stroker (of course you need the "i" intake and ecu components).

[MattE30]

how much was your eta engine you bought?