Engine choices?

[Hoobs]

Just thought I would get some opinions really.

I've decided that I want to keep my e30, now that it's been built pretty much how I want it, but I do want more power than the m20/2.5 currently puts out. As I plan to do hills I want there to be plenty of grunt to get me up them!

So, bearing in mind that I have a limited budget, what engine would be a good m20 replacement?

I'm thinking m30/3.5 & m10 gearbox as being the cheapest option but is it possible to fit one and not be stuck with epic understeer? Would an m52 be a better idea? Ideally, I want about 250bhp and 220+ ft/lbs of torque.

So, what do you reckon?

[Motorhole]

My vote would go towards M52. Alloy block and an easy 210+ bhp with a few simple mods and remap. All the stuff to do the conversion can be purchased off the shelf, loads of advice on here.

Alternatively, the 3 and 3.5 litre V8's frequently pop up cheap. Bit more work to fit these though I believe.

[Hoobs]

My e21 has an m52 & 220bhp but it's it's cost that puts me off. How much do you reckon it costs to convert an e30?

[Mikey_Boy]

Now here's a can of worms!!!

My two cents:

- M30 is a bit heavy
- S5x - bit pricey and also (dare I say it) a bit heavy and spin up bearings.
- S14 - very pricey (I know from personal experience!!) but well worth the effort..
- V8?? A lot of work and not that 'right'??

My vote on limited funds would be M5x...

But then, you could go Cosworth YB... Knife and fork engineering, reliable up to 300hp easy peasy..

Let the abuse begin!

[Motorhole]

Er...not got to the engine bit on mine yet! Assuming you already have the brakes, suspension & steering sorted, I guess around £300-£400 for a good engine, ECU, EWS & loom, (hopefully with an exhaust manifold!), another £180 or so for E34 sump, dipstick tube & M50 inlet manifold, re-use your M20 flywheel & exhaust if your on a budget, maybe even your clutch too if it's in good nick! £50 for a Getrag 240 'box, I think you can use the 325 propshaft. Plug and play loom is £90 from DanThe iirc, budget say another £200 for ancillaries, radiator & fan, gear linkage etc. If you do it yourself, guess under £1k is reasonable?

[Hoobs]

M52 is defo an attractive option. I've never been a fan of using engine from other manufacturers (I did dream I'd fitted an S2000 lump the other night, after reading the thread) but a turbo'd Audi/Volvo 5 pot might be a nice idea? Bottom line is going to be cost though, so M52 is most likely - so far anyway.

[leeparkes]

Why not turbo the M20?

[Jhonno]

Cost and reliabilty I imagine..

M52 would suit perfick I reckon.

[HairyScreech]

An engine swap would put you into sports libre would it not?
If so the best bet would be to go 2.8, cost would be about on par with a swap an would still give the 200-220hp wanted with out class change.

You would be looking at a 2.8 crank, a set of 320 rods, a stand alone ecu and what ever you want to bring over from the current m20.
I assume you already have an exhaust etc for your current engine and these could simply be reused.

[Hoobs]

I'm not too concerned with what class I'd end up in as I only compete for fun anyway, so it's only ever going to be me against myself. Reliability is definitely paramount in my book.

A 2.8 conversion, on the m20, is an attractive option though. I have some reading to do!

[HairyScreech]

In theory a good basic 2.8 build should be more reliable than a swap, its all quite tried and tested and isn't much different to what bmw offered as the 2.7 engine, so a good one should do thousands of hard miles.
All depends though, a bad build is no different to a bad swap.

I think you would be able to stay production modified with a 2.8 which always helps.

[Hoobs]

I'm confident enough that I can get the build done correctly, but I wouldn't bother unless I was to use mappable ignition. The generic chips that I used on a previous 2.7 were pretty useless and always felt like the weakest part of the whole conversion.

Enjoyed reading the build thread in your signature, even if most of it was like an aeroplane (went right over my head!).

Now that my car is about as light as I can realistically get it, I would actually be pretty content with a genuine, reliable 200 brake. What's the cheapest / simplest way to achieve that? In the past, a certain 'specialist' told me how, using their 6 branch and generic chip, my old 2.5 could make nigh on 200bhp! I was never convinced and I have often thought their rollers were a bit 'optimistic' but how much can I really get from a healthy 2.5?

[Mikey_Boy]

200hp is about the limit with a well sorted 2.5 - 284 Cam, decent compression ratio (so custom pistons), steel rockers, some easy headwork, a GOOD 6 branch and system and proper remap and/or MAF conversion...

2.8 a better route for the M20 in my humble view - bags of extra torque to pull you out of the corners...

[HairyScreech]

imo for the 200-220hp range he is looking for then a 2.8 fits the bill best, granted an m52b28 can make the power with less work, but that's totally offset by the effort and cost of getting it in the car in the first place.

£1000 spent getting the m20 to 220hp is better than £1500 spent fitting an m52.

[kipsy]

Hoobs did you do the before and after dyno with the 6 branch after?

[Hoobs]

The guys at Pristine are doing it over the week, as far as I know anyway.

I'm coming down on the side of thinking that I'll stick with the m20 but it's going to have to be done over time.

Initially, I am thinking of doing the AFM to MAF conversion using e36 328 parts. Has anyone else done this?

http://www.track-tv.co.za/forum/viewtopic.php?f=10&t=26

[HairyScreech]

i have been looking into the whole motronic 3.3.1 conversion.

by the look of it its just a case of a non vanos chip with an m20 map on it and some wiring in.

benefit would be a much better ecu, lambda, maf, sequential injection, knock sensing, coil on plug.......

its been done before with the m50nv ecu which is the 3.1, however the single vanos m50tu ecu is better, allows larger maf sizes for a start.

i have been picking over the diagrams for a bit but haven't got around to making a thread yet.

[Rallyprep_UK]

M20 stroker, I have been stockpiling bits for these with a view to building a couple myself at some point

Will

[Demlotcrew]

Taken from the link above.

People contemplating this as a power upgrade should not expect any major noticeable gains, unless their (big) AFM setup was not tuned optimally.

Seems like a good idea in theory, but in practice I think money could be spent else where.

[HairyScreech]

Taken from the link above.

People contemplating this as a power upgrade should not expect any major noticeable gains, unless their (big) AFM setup was not tuned optimally.

Seems like a good idea in theory, but in practice I think money could be spent else where.

Yes, i kind of feel that for similar cost the whole management could be fitted, this would not necessarily give increased peak power but will improve response and economy, which actually is more benefit on track than first thoughts may say.
If you can carry less fuel thats less weight.