3.5 rebuild help

[whipsey]

i've been given a 3.5 lump from an e28 i wanna rebuild it before it go'es into my touring what parts need replacing to fit is there a break down for this i want to change any problem parts etc new gaskets all round can any one help?

[Yaninnya]

You need to strip the engine first to check what is worn. What's the milage of the engine?
Jan

[Andy335Touring]

What sort of rebuild are you thinking of and what sort of budget do you have ?

[stonesie]

At the very least you will need the full gasket set and all the oil seals, budget for new bottom end bearings and rings too, although you might not need them

[whipsey]

basically i wanna completly rebuild it if poss i wannted to increase the power as well it's not going to be done overnight so cost wise it's not really a problem i think the mileage was 89000

[whipsey]

where can i get a good engine stand that would hold the weight of the big six?

[stonesie]

Machinemart should do 1


www.machinemart.co.uk

[Speedtouch]

I doubt it would need rebuilding with mileage of just 89K - it's probably just about nicely run-in.

[whipsey]

probably not need it but i wanna try and increase the power etc

[MJG]

Don't really bother about increasing power above about 260bhp without turbo. Even then just a rebuild with fresh big ends, new rings, a bore hone, new cam chain tensioner, new oil pump, new water pump, new distributor, new thermostat, new oil and filter obviously, that's what I'd do. And obviously new gaskets including head gasket (after a little skim to ensure flatness). Budget for about £300 for a DIY rebuild (rough guess from experience of buying certain bits).

I'd just chuck the engine in as it is with fresh oil and filters and enjoy the stupid performance. A 3.5 is a really powerful and torquey engine to start with, not just coming from a guy who thinks a 318is is quick or anything, but it was faster in my e28 than many fast jap cars with 250bhp+.

[whipsey]

what sort of power would it be pushing out as standard i'm keeping the car on the 316 tourer diff and 14" bottletops till i've used up the eight spare tyres i've got for it

[Andy335Touring]

the diff will blow before you wear the tyres out

i'd say cam and chip is your best bet with out spending mega bucks but i'm not sure how chippable the old E28 ECU's are ?

You could convert it to the later E34/2 ECU/wiring loom/sensors but it might be a PITA to do ??

[maxfield]

what sort of power would it be pushing out as standard i'm keeping the car on the 316 tourer diff and 14" bottletops till i've used up the eight spare tyres i've got for it

That will be seriously quick

[DRIFTBOY]

[quote="MJG"]fresh big ends, new rings, a bore hone, new cam chain tensioner, new oil pump, new water pump, new distributor, new thermostat, new oil and filter obviously. And obviously new gaskets including head gasket (after a little skim to ensure flatness). Budget for about £300 for a DIY rebuild (rough guess from experience of buying certain bits).

quote]

Sorry, but £300 - no chance!

Oil pumps for these are around £200 on their own.
You can measure the old one for wear and your engine is low milage for an old 3.5 so shouldn't need one.

Even so, for a full D.I.Y. rebuild I'd say your looking at nearer £700 for a basic big six rebuild including machining work, unless you use all very cheap parts.
Add £1000+ more for a camshaft, cylinder head work (porting), manifolds matching to head, chip, decent exhaust etc. - and depending how far you take it it can get much more expensive again.


If I was to do another conversion, I would just stuff the engine in and thrash it!

[whipsey]

If I was to do another conversion, I would just stuff the engine in and thrash it!

i like the sound of that he he

[DRIFTBOY]

The way I see that option is - cheap engine and even fairly tired / high milage ones should still put out 200+ bhp, and if it does go bang another engine can realistically be bought from £100 and should be no more than £250.

For the grunt they have that is cheap as chips!

[whipsey]

i've still gotta get the rest of the bits together though first engine mounts etc has anyone got a link for me that tells me what i need?

[MJG]

Sorry for my inaccurate estimate, I'll gladly stand corrected there.

Whipsey as for what's needed, just do a search. I did and I found out all I wanted to know.

Andy335/anybody else - has anybody actually obliterated a small case diff with 220lbft? What exactly broke? Mine will be welded and I know generally the spider gears break, but I've also seen the ring gear chip teeth with the pinion too.

The e34 wiring swap is easy. You need from the e34...

engine loom
crank pulley
ecu

there you go. Lol. You also might want to run a non-3.5 flywheel, I used an e28 525i item.

[whipsey]

the engines from an e28 though will the looms still fit?

[Andy335Touring]

Andy335/anybody else - has anybody actually obliterated a small case diff with 220lbft? What exactly broke? Mine will be welded and I know generally the spider gears break, but I've also seen the ring gear chip teeth with the pinion too.

Toby ran his 335 on the old small diff to start with but it wasn't long before it started whining. He didn't wait for it to break, he changed it.

[whipsey]

what if it driven carefully how long do you think it would last?

[Andy335Touring]

Not sure tbh

[gooner1]

Why would you do a 3.5 conversion and then drive carefully

[Speedtouch]

The later 179 Motronic 1.3 ECU is a direct swop for the earlier 150 Motronic 1.1, the advantage being that it is easier to chip and has better resolution (for improved mapping). I did this swop on my E34 535i and it's made it smoother running. Also have an M30B35 chip for sale if you're wanting a little more

[ed325i]

I think Theos 335 only made 190bhp so they do need rebuilding if the miles are high.
If I was to rebuild one I would go for a cam and total seal piston rings.

[whipsey]

Why would you do a 3.5 conversion and then drive carefully

cause i need to buy a new dif if i don't lol

[DRIFTBOY]

I think Theos 335 only made 190bhp so they do need rebuilding if the miles are high.
If I was to rebuild one I would go for a cam and total seal piston rings.

I remember that thread of Theo's, I think it showed 199bhp at Castle Coombe.
And to honest, I don't think a camshaft - especially on it's own, would make a worthwhile difference for the cost involved.

I think Toby Unna got it spot on, get a mega-mile scrapyard engine, bung a turbo on it and see what breaks first!

[Jhonno]

if i was rebuilding i would deffo fit a cam and look at some headwork whilst i was there.. seems daft not too whilst its apart for some decent gains

[DRIFTBOY]

That's what I thought, but having done just that myself, I'm personally not sure the gain to be had from head work and a camshaft is worth the money.

I only say that so that if someone, like me, hasn't got fortunes to throw around then they might want to consider spending the cash more wisely.
It depends how far down the n/a route you are prepared to go I suppose, and how much spare cash you have, but the way I see it, I could have done a cheap turbo conversion on my engine for about the same money as the n/a mods and ended up with a fair bit more power.

[Jhonno]

have you put yours up against Theo's? See how they compare? That'll show any gains from the work done if any..

[DRIFTBOY]

I haven't seen Theo since his trip to the 'Ring, but yeah, that would be an interesting comparison.

I passengered in Gareth's a while back and that felt good.

We are all running different diff ratios though.

Maybe we'll find out at Santa Pod in september ?

[whipsey]

i've still not managed to have a go in one yet do you think i'd be better off getting a stainless system and filter? i did just see an advert for a company that will do a race head though

[DRIFTBOY]

E30 M3 exhausts are popular for this conversion, and it's not much work to make them fit.

Standard air filter assemblies are known to be good with a genuine (Mahle) filter element.
I recently swapped my K&N cone for a standard set up and I can't tell any difference at all in how it goes.

If you get the head ported it is worth getting the inlet and exhaust manifolds matched to the ports, and you might also need to cut a bit out of the inside of the gaskets.

[Speedtouch]

Phew that's a relief (my E34 535i has a K&N cone filter)

[whipsey]

what about a custom stainless system i'm under the impression that because the engine is from an early car i won't need a cat fitted