engine and drivetrain 318 m10 vs 2002 m10

[cowlum]

Firstly a little grounding.

Here in NZ (prob the same elsewhere) 2002/E21 M10 engines very rarely turn up, when they do they are either expensive or f**ked.

318 M10s are everywhere, always a few on trade-me (same as ebay). Plenty of 318 parts cars. I mean e30 318s were so popular in NZ you cant go a day without seeing at least 5. So natuaraly 318 m10s cant be given away (obviously I mean dirt cheap)..

A basic 2002-m10 with single solex produces 100hp from 2 litres

A basic 318-m10 with FI produces 100hp from 1.8 litres

Is it just the FI that helps the 318 produce as much hp from a smaller engine or is it higher compression/better head???

I am looking to build a new M10 for my 2002 which currently almost runs MS (current poj coming to close) so pumps in heads are not a concern. I can get a 318-m10 in much better cond for less but I really would like the full 2 litre. Is it the stroke/bore/pistons...... that reduces the 318 down to 1.8???

Besdies the ancillarys (fi/carbs) what are the major differences between these two M10s.

TIA

[PSloan]

It's the pistons, rods, and crank. I'm running a 318i head on my 2002 block to make 2l. supposedly the cylinder head is designed in a manner that will increase efficency.

[PSloan]

BTW - i google earth'd NZ and it looks beautiful there. I'd love to visit some day.

[cowlum]

It's the pistons, rods, and crank. I'm running a 318i head on my 2002 block to make 2l. supposedly the cylinder head is designed in a manner that will increase efficency.

All three. Thats a shame! I was hoping to start on a turbo project in about a 1/2 year. Now I have to decide if the 2002 comes off the road for the 2litre to be rebuilt or If it keeps on terrorizing local streets while a 318m10 gets rebuilt in the garage.

Do you know much about compresion differences between the two engines and/or bore?

over the next month or two I want to compile a list of basic parts that I then spend 6 months collecting (taking time with parts always reduces costs heavily I have noticed)

[mikeS]

From what I recall, basically it's a destroked crank, which requires different rods and pistons. You lose about 200cc's, but generally shorter stroke motors will rev sweeter than longer-stroke motors of otherwise the same dimensions, provided you build it for revs. If you throw in a 2002 crank and rods, you'll have your 2 liters back, but I suspect that you can get quite a bit of power out of the 1.8 with the right compression, cam, turbo setup, whatever.

The 2-liter guys are never happy either, they always want to put in the E30-M3 crank and blow it up to 2.2 or 2.3 liters. Personally I don't think it's worth worrying about too much, because you can get a speeding ticket just as effectively with 1.8 liters as 2.3 liters.

Mike

[mikeS]

From http://www.strictlyeta.net/technical/specifications2.html

M10 1766cc SOHC chain-driven inline 4, 2 valves/cylinder, cast crankshaft

101 hp @ 5800 RPM

103 lb-ft torque @ 4500 RPM

Compression ratio: 9.3:1

Bore/stroke: 89x70 mm

Bosch L-Jetronic fuel injection

Exhaust control: 3-way catalytic converter with Lambda sensor

For the 2002, the bore was 89 mm and stroke was 80 mm.

So...the bores are the same, the blocks are basically the same, the crank has a shorter stroke. The rods are a different length to make the geometry come out right, valves are a different diameter than the 02 valves (bigger, I think).

If you can pick up a solid 318 motor, it should work just fine...decent compression (better than a standard 2002), etc.

Mike

[cowlum]

From http://www.strictlyeta.net/technical/specifications2.html

Compression ratio: 9.3:1

If you can pick up a solid 318 motor, it should work just fine...decent compression (better than a standard 2002), etc.

Mike

thanks mike

9.3:1 unfortunately doesnt bode as well for a turbo project.

[cowlum]

BTW - i google earth'd NZ and it looks beautiful there. I'd love to visit some day.

Yeah it is quite nice down here. However like the rest of the planet I spend most of my time in an air-con office messing with pcs or sitting in traffic wasting gas.

hope to make it to the states/cananda/mexico in the next couple of years

[mikeS]

Bah. Should be easy to reduce compression. Easier than raising it.

Mike

[Harv]

From what I understand, the 318 M-10 block is very similar to the S14 block. I don't think the cylinder walls are the exact same but the webbing looks the same. I just picked up a 318i motor (for safe keeping) and the block looks just like an S14 block. They are supposedly lighter, stronger, and more ridged that the older M-10 design. I guess the way they made the same HP was the EFi and the head design. The 318i head has the largest combustion chambers and flows the best of the stock heads.

John