M30 typical items that need a refresh before going into e30

[jamie850]

Hi, Picking up my 3.5L m30 soon and thinking about which items will need to be replaced?
I was thinking:
sump gasket
and plastic timing chain tensioner (but leaving on the same chain?)
conrod to crank bearing shells

while its out of the car.

I'm debating on taking the head off and cleaning up the ports with a die grinder and lapping in the valves. Has anyone done that and found it worthwhile?

thanks

[DRIFTBOY]

Hi, Picking up my 3.5L m30 soon and thinking about which items will need to be replaced?

Assuming the engine is in reasonable condition and not a rattly knocky old thing:

sump gasket

Good idea, could save a load of hassle later.

So could crankshaft rear oil seal while you're at it.

and plastic timing chain tensioner (but leaving on the same chain?)

The chain guides do wear and the plastic one gets brittle, I've not heard of them causing much trouble though.

conrod to crank bearing shells

Might not be necessary but I would, just for peice of mind.

I'm debating on taking the head off and cleaning up the ports with a die grinder and lapping in the valves. Has anyone done that and found it worthwhile?

No!
Unless the head needs to come off or the top end is rattly (like a lot of them are) I'd leave it alone.


I'd also put a new water pump on, cheap and easier with the engine out.

Make sure the crank sensor lead is out of the way of the water pump pulley too, they can cut through them if incorrectly routed.

Also put threadlock on the large timing cover bolt that also holds the crank sensor bracket on, these are known to come loose and leak oil.

The oil spray bar for the camshaft is held on with two small banjo bolts.
Get new ones, and washers, as BMW modified them because it was quite common for these to come loose and starve the camshaft of oil.

Depends how far you want to take it really, but they are the first things I would do.

[leeparkes]

The oil spray bar for the camshaft is held on with two small banjo bolts.
Get new ones, and washers, as BMW modified them because it was quite common for these to come loose and starve the camshaft of oil.

Crimp the spray bar in the middle aswell, here's a link/guide

http://www.cscoupe.org/tech/spray_bar_fix/70590.html

Also ive read somewhere about a return valve in the oil filter housing that can fail, not a major issue when they fail but it just takes that little longer to build oil pressure up, better return valves were fitted to later M30's, 1991 onwards i think.

inlet maifold might be an idea as that also would be awkward to swap with the engine in the car as it would fail the brake servo when trying to remove.

[DRIFTBOY]

Good point, inlet gaskets worth doing with engine out too.

I never knew that about the oil valve thing, interesting!

[Driftben]

Hmmm ya I didn't know about the valve too. Need a part number so I can get one

I have gone to town on my m30 mainly because I'm supercharging but also iv never rebuilt a engine before so it's a large learning curve.
It's wise to take the cam cover off to check the rocker arms as they are prone to breaking and stuffing the cam lobes.

Just a though

[mybmw6]

I have gone to town on my m30 mainly because I'm supercharging but also iv never rebuilt a engine before so it's a large learning curve.

Hahaha tell me about it! I was doing a simple swap, now there isn't one peice of the engine currently touching the other.... But as you say, a large and I'm sure at a later stage helpful learning curve! Lets hope I remember how it all goes back together

[Driftben]

Haha ya that's the main problem. I have a garage full of engine. I'm hoping I know where it all goes

[gareth]

have a close look at your clutch. expensive but a lot easier to do when out of the bay as the box doesn't clear the transmission tunnel....

looks like your clutch will be getting a hard life too.

inlet gaskets, definately! one of mine had split so i sealed the gap with silicone, only to find a few years later that it was 50% blocking one inlet port!

[DRIFTBOY]

have a close look at your clutch. expensive but a lot easier to do when out of the bay as the box doesn't clear the transmission tunnel....

It does if you chop the top bell housing bolt lug off the top of the gearbox!

It's still an arse of a job though, so I'd put a new one in now if the wallet can cope!

looks like your clutch will be getting a hard life too.

I'm using a standard LUK clutch which has covered about 20,000 miles now, and it's coping with forced induction admirably!

[Driftben]

have you got a standard flywheel driftboy?
how much BHP do you think your M30 is running? im looking for a clutch and flywheel combo with me supercharged M30.

dont want to go overkill with the clutch..

[e21Jason]

m30's use the large bmw clutch so stock is preety good, I am actually using an s14 uprated one on mine as it is smaller and lighter.

The rockers tend to brake at high revs so you should be okay with the SC if every thing else is stock. IE you do not want to rev more


Jason

[DRIFTBOY]

I'm using an E28 M30 solid flywheel (the E34 M30 is a dual mass, and about 50% heavier) and it should be running at around 300bhp at the moment, although I can't say for sure just yet.

[Driftben]

Crazy question but what does a dual mass flywheel look like? Looks like I could get away with either a standard m30 clutch or a s14 uprated one.
Jason is there and mods to fit a s14 clutch or is it a straight swap?

Thanks gents for the info.

Ben

[e21Jason]

s14 clutch is a smaller dia so you need the s14 flywheel to match.

Jason

[Driftben]

I see. I'll start having a look about. Might be easier to find a m30 setup? S14 stuff are like rocking horse poo.

[e21Jason]

S14 stuff are like rocking horse poo.

Mitehave some e28 stuff knocking around give me a dew day to look down the lock up

Jason

[Driftben]

Ah lovely cheers Jason

[jamie850]

Thanks guys,
I'm looking to get the engine in first and running, then later when I've got more money put in a hot regrind cam, some motorbike throttle bodies on a homemade manifold and a megasquirt ecu.
I'll get the sump, inlet and crank gaskets all changed and give the rockers and bearing shells a look at too.
If I check the crank bearings for wear and they are ok, I assume that I can put them back in as long as I keep them in the same place? Does anyone know the standard thickness / tollerance the shells should be if I measure them?
where is the best place to get M30 parts such as gaskets and water pump?
Jamie