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Diesel ?
Posted: Fri Jul 11, 2008 8:57 am
by maderdog_1024
Hi, this is my first post so be gentil !
Has anyone converted a car to derv ?
Im looking to buy an e30 touring, but the 325i and 320i are both thirsty and the m40's cant pull the skin off custard.
Im not new to E30's and have done various swaps from m10 carb to efi and m40 to m20.
I was looking at the 525tds and wondered if it would be a viable engine choice for an e30 tourer.
I have been reading the m50 developments thread and notice that the 2.5/2.8 m50/m52 engines are a fairly easy swap and im assuming that the 525tds will be of similar ?
From what i have read, the 525 m50 is used with e36 mounts as the block has mounting holes for both. Was there a 325tds ? if so then this could be a go go.
Obviously, there would need to be a custom prop and exhaust not to mention different engine looms and gearbox issues.
However, if the engine can physicaly fit in the bay then all the other issues are minor.
A diesel tourer would be a very usable car, its a pity that diesel technology was not all that good back then.
They did try with the m21 ? but wasnt a big success.
Comments / advice appreciated.
Re: Diesel ?
Posted: Fri Jul 11, 2008 9:04 am
by maderdog_1024
just found on ebay some pics of 325td engine bay;
525td
and for comparrison m50/52
it looks a little bigger than the m50 and possibly sits higher ?
Re: Diesel ?
Posted: Fri Jul 11, 2008 9:53 am
by e30_Turbo
25TD - No IC - 115bhp IIRC
25TDS - IC - 140bhp IIRC
I can't see what would cause any problems as the older dervs are very basic and don't have many extra bits needed to get them running. The turbo is side mounted and low down, would need to check the clearance on the chassis leg and engine mount. I wonder if the exhaust downpipe would be ok as is.....
In PPC there was a simitar with a TDS lump, said it went quite well.
I've also seen/heard the TDS lumps can be tuned to over 180bhp with gob loads of torque too, I car share with a work mate who has a early e36 325TD and he gets 40+ mpg's.
And make sure whatever derv you do fit has the bosch fuel pump, other makes don't even come close and the bosch will eat cooking oil all day long, others won't.
HTH, Fozz
Re: Diesel ?
Posted: Fri Jul 11, 2008 5:33 pm
by pacerpete
Don't bother.On a very good day you may get 40mpg out of an e30 with a tds engine fitted . When you factor in the cost of the engine and the conversion and also the 10% cost premium of diesel over petrol fuel a 35 mpg 318 starts making a whole lot of sense !

Re: Diesel ?
Posted: Fri Jul 11, 2008 5:38 pm
by dimebag_from_hell
pacerpete wrote:Don't bother.On a very good day you may get 40mpg out of an e30 with a tds engine fitted . When you factor in the cost of the engine and the conversion and also the 10% cost premium of diesel over petrol fuel a 35 mpg 318 starts making a whole lot of sense !

X2
Re: Diesel ?
Posted: Fri Jul 11, 2008 5:53 pm
by stonesie
Or a 325 on gas

Re: Diesel ?
Posted: Fri Jul 11, 2008 10:51 pm
by S2Avant
or an M50 on gas

Re: Diesel ?
Posted: Fri Jul 11, 2008 10:57 pm
by Jon_Bmw
The turbo will clonk the engine mount, I am almost certain.
And as Pete says.
Re: Diesel ?
Posted: Fri Jul 11, 2008 11:28 pm
by suzie650
If you can come across a good 324td touring, that would certainly be cheaper. The old M21 is underrated. Stick an intercooler on it and you're looking at 150-170bhp without anything else. (More if you tamper with the max fuel adjuster)
And IIRC they're Bosch Pumps as well
Re: Diesel ?
Posted: Sat Jul 12, 2008 12:37 am
by gareth
the whole time veg oil was 40p/litre, this could be worthwhile but now it's the same price as diseasel.
it'll be less work to do a LPG conversion, keep your power and it'll cost less to run than a BMW diesel by a stretch
Re: Diesel ?
Posted: Thu Jul 17, 2008 5:31 pm
by lloydp
I was thinking about this the other day, and agree--when diesel was similar to petrol and veg oil was cheap, it would have made sense. Now, no way.
For example...
I usually get ~36mpg from my m40b16 touring, and petrol is £1.16/L where I am.
Diesel is £1.31/L, so to get the same 'apparent' running cost I need to get at least 41mpg, so for the conversion to make any real sense I think it needs to be getting over 50mpg at these prices.
So, one day...M52b28 + LPG ftw!
Re: Diesel ?
Posted: Sun Jul 20, 2008 1:48 am
by maderdog_1024
Fuel economy is a bonus however for towing a nice diesel would be better as it has the torque to pull the 1.5 tonne trailer.
1.7TD isuzu/vauxhall engine - under powered for car i think
2.3D ford sierra - 68bhp ?
2.5td bmw lump
2.8 isuzu trooper engine tdi lump, quite good engine and popular conversion in landrovers.
tops speed is not an issue, torque is though.
Re: Diesel ?
Posted: Sun Jul 20, 2008 1:57 am
by gareth
a 3.5 M30 has more torque than a 2.5 TDS lump

not the most economical though unless LPG is used.
this might be useful for you...
http://www.unixnerd.demon.co.uk/bmw.html click on the "E & M numbers" button to see a table of specs for various BMW engine types
Re: Diesel ?
Posted: Sun Jul 20, 2008 2:54 pm
by maderdog_1024
cheers for that gareth,
looks like the 318 td is not a bad compromise
down on torque in comparison to m20b25 but more than the m20b20
failing that the 325tds lump with a 525tds sump looks like it would fit.
Re: Diesel ?
Posted: Sun Jul 20, 2008 3:07 pm
by fuzzy
welcome to the site from a local guy from broxburn

Re: Diesel ?
Posted: Mon Jul 21, 2008 11:38 am
by Morat
pukka biodiesel is 95p/l round here

Re: Diesel ?
Posted: Tue Jul 22, 2008 10:08 pm
by funky-monkey
What about putting an M57N in, enough torque to spin the world to other way.
