M51 diesel conversion

[gareth]

back to technical stuff for a minute... does anyone have any details on what gear / diff ratios the M51 powered cars have? or indeed the M21 (E30 324TD)

[johnna]

http://www.e36coupe.co.uk/forum/viewtop ... 951c7d26a7

read the links, you should be able to chartyour course with all that info!

[gareth]

cheers mate. i didn't realise the ratios were on the realoem site!!!
the E30 324TD is probably a good basis for comparison. that's got a 3.25:1 diff. 316i touring (project car i've spotted) has a 4.27:1 (not a fantastic amount of use!!!!!!!), and for comparison only my 335i tourer has a 3.91:1 but could do with a 3.46:1 if i can find one.

so the diff is definately in line for replacement too (if i go for it) as the 4.27:1 is going to get me to about 60mph flat out!!!! all i need is a 3.25:1 M3 LSD then.... kerccchhhhiiiinnnggg!

[gareth]

jesus! just seen that the E34 525TDS has a 2.65:1 diff! with that in my tourer i'd be geared for 1000mph!

something i've noticed though, the gastet sets i've seen on realoem against each diff type i've looked up are so far all 'type 188' in the description. if this is the case, would the E34 diff (if it's a type 188) fit?

this small/medium/large case diff stuff so far still confuses the hell outta me! i've not seen another one other than my 3.91:1 LSD to compare aginst

[Chris-W]

E34 diffs don't fit your E30 without fabricating a new rear beam.

[gareth]

curses!

how about the guts of them? could i use say my 3.91 LSD with an appropriate crownwheel and pinion from another "type 188" diff? what wise is a "type 188"?

is this "type 188" idea crap? i thought thte E34 had a bigger diff but the realoem site seems to think different, unless i'm being really stupid!!!

[Scruffymurphy]

Did this conversion go anywhere?

Did anyone else do this conversion.

I've come accross a 325tds and was hoping to convert a 316 touring I have.

[maxfield]

I know of an M51 engine sat on a floor, doing nothing

[DanThe]

curses!

how about the guts of them? could i use say my 3.91 LSD with an appropriate crownwheel and pinion from another "type 188" diff? what wise is a "type 188"?

is this "type 188" idea crap? i thought thte E34 had a bigger diff but the realoem site seems to think different, unless i'm being really stupid!!!

188 is the diameter of the crown wheel in millimeters Gareth, so yes E34 diff internals will fit in an E30 case.

[mattyb]

slitly off topic but does anyone know if this would work on a 06 cdti vectra, my dads not mine.

[gareth]

i was trying to work out what the hell i was on about a few weeks back before reading the date... over a year ago!!! i know the answer now!

incidentally, i now have the CWP from a 188mm E34 525ix hydro lockable diff partly built into my mutant 3.38:1 40% lock hooligan diff!

oh, this conversion never went anywhere but i'd love to do it one day...
after a V12 E34 of course!

[DanThe]

slitly off topic but does anyone know if this would work on a 06 cdti vectra, my dads not mine.

Scandalous

[samm]

Opening one up as a newbie, Briefly just changed jobs need cheap reliable wheels and fancy an E30 tourer(you no that can't go to bed one might be about to show up on Ebay Fancy) On the diesel thing I have the advantage of living in France where the 324 diesel was offered,downside is reading of E36 tourings for 400 pounds don't exist here try 4000.
Anyway my new monthly drive is about 2500km and 324s are apparently reliable in that they always go pop at 200000km,so brief plan is find 324 diesel touring drive-pop-change engine for 325tds. Currently scouring the net for vehicle found one about 500kms away I hope to see on thursday, and info for when the pop comes if anyone has any info let me know,I forsee a car off the road for about six months but ending up with a keeper what do you think.
Thanks for the great site

[Andyboy]

I wouldn't be using an old BMW diesel engine in anything, too much to go expensively wrong plus you have fitting isues such as EWS, fitting a diesel lift pump in the tank etc etc. M51's use Bosch DDE which has an electronic throttle so you'll need to ditch the throttle pedal/cable and fit one of these instead. The M51 is also very heavy. The E36 unit won't fit into an E30 without an E34 diesel sump and yes, they are different to the petrol sump.

If I were to fit a diesel, I'd be looking at the 1.7 GM/Izuzu lump from a TD Astra Mark 3 turned round and mated to a Getrag Opel Manta 2.0 box which is a very similar box to an E30. You'll have to make your own mounts but it's a simple reliable engine that goes fairly well and 45 mpg. Loads of used engines, pumps etc.

If you wanted 40 mpg and a nice car to drive, put a 525e engine in. Straight swap it for a 320i/325i unit and add a 2.93 525e diff.

324d's do a lot more than 200'000 km's. I had an E34 524td (same engine but with DDE) with 300'000 km and it was fine. As for veg oil and various taxes, fuck 'em. Get it from the local takeaways, filter it through old tights and chuck it in. How can you pay tax on an oil that has been used? A Bosch pump will be okay.

[old_skool]

Guys, taxes don't really matter any more regarding oil usage. The government has kindly changed the law so that we can use 2500 litres of oil a year without any forms to fill in or any need to register.

I have to say this diesel swap looks like a real temptation. I guess the ideal thing to do would get hold of a complete E46 330 that has been rear ended and go about it that way. Then you'd have most/all the bits required and could foresee a lot of problems upon inspection/disassembly of the E46.

[Andyboy]

Then you would need to convert veg oil into biodiesel - forget putting veg into a 330d. Then you have the immense wiring issues of getting an E46 engine to work in an E30 - traction control, ABS, EWS etc etc etc.

[afromaan]

old man got a 525tds, used bio in it, f***** the pump up, had to hav £400 refurb to get it to stop leaking

[march109]

old man got a 525tds, used bio in it, f***** the pump up, had to hav £400 refurb to get it to stop leaking

Proper bio fuel shouldn't F anything up, just using waste or straight veg oil most probably will unless you have a bosch pump or an old derv. Older derv engines will run on nearly any old shite - mine does!

The newer engines usually require properly refined bio fuel. Wether thats bio petrol equivelent or bio diesel equivelent.

[samm]

duly went and found a 324td and bought it, got it 36 hours ago and I've done about 1400km already-had to go to work this morning. The having it go pop part is coming along great, have to top up the water every 200km, sounds like a really unwell tractor and will not accelerate- cruises ok though. and all this for about 1200 quid has ac and a mot. now all I have to do is buy a crashed 325tds and another car to go to work in and see if the wife notices.