E46 330CI engine rebuild options

[Alexanderfitu]

Hi all

I have a nice E46 330ci that I have done lots of work to, including supercharging, and sorting all the rear subframe mountings etc.

The engine consumes large amounts of oil under high vacuum conditions (overrun, long idling etc). It is currently using about 1.5L every 500miles in mixed driving. In any other case, I would suspect valve stem seals and just replace them, however, this engine (M54B30) is known for having poor oil control rings that also give this symptom, additionally, its likely the head bolts will pull the threads out of the block during a rebuild (nice). So just popping the engine out, swapping the rings, a light hone and new seals seems out of the question.

I keep toying with the idea of buying another engine and just doing a straight swap, but I think its likely that I will be in the same situation.
I also cannot find anybody who wants to do a light rebuild for less than £10,000.

Thoughts or advice very much welcome.

[Whatapex]

How about using the block from an early 90's 325 or 525. They are cast iron,so should be a bit better suited for a rebuild and boost.

[Alexanderfitu]

Hmm not a bad idea. I wonder if the head would bolt straight on?

It is a teeny tiny amount of boost in the grand scheme of things (6psi)

[Caddyshack]

Richard at Barkers Motor Works in haslemere managed to use an e46 crank in an e30 block…give him a call

[SouthHamsGaz]

Have you ruled out the CCV?
My old M54 engined Z4 used a lot of oil.
I did the 'O2 Pilot mod' which completely solved the issue.
If you aren't aware give it a try, really easy and costs pennies.
https://gumptiontrap.wordpress.com/2020/04/06/how-...

[Alexanderfitu]

Yes, I did all the usual culprits when doing the supercharger install.

New ccv, ofh gasket, oil cooler and rocker cover gaskets. There are no external leaks and the Ccv is not pumping oil into the intake.

Unfortunately for me.

[Alexanderfitu]

Caddyshack said:

Richard at Barkers Motor Works in haslemere managed to use an e46 crank in an e30 block…give him a call

Thanks, I will touch base with them and see what options I have.

[carpetsoiler]

You can't use the M50 block. The coolant passages are different.

You can get the block Timeserted. I do enough of them. The last M54 I built didn't have an issue with the threads pulling out the block. They only pull if the engine's been seriously overheated. The last M52 block I Timeserted (it pulled 8 threads when I initially tried to tighten it down!!) has been running strong since.

Feel free to send me the block and I'll Timesert it for you. Not cheap but I have all the correct jigs and Timeserts for such a thing.

You can also get M52/M54 ARP head studs, which are the correct length (don't use M50 ones, they are 15mm too short).

[Alexanderfitu]

Thanks for the info.

Does using headstuds negate the need for thread repair?

I will pm you. Don't mind spending money, but not significantly more than the value of the car!

[SteveR1979]

Would also suggest speaking to Hack Engineering!

https://www.hackengineering.co.uk/

[Alexanderfitu]

Thanks, email sent to Hack Engineering. They are fairly local to our workshop too. Watch this space

[carpetsoiler]

Alexanderfitu said:

Thanks for the info.

Does using headstuds negate the need for thread repair?

I will pm you. Don't mind spending money, but not significantly more than the value of the car!

Sadly that's a link I've never been able to corroborate. For what it's worth I've never had a thread pull with studs, but that's not to say it won't happen.

No worries, drop me a line, would definitely be able to sort something out, and for a ste sight less than £10k into the bargain!

[carbonblack]

Would swapping in a different engine be the most economical repair?

Given an E46 330 can be had for less than £4k you could run it for a couple of months, ensure the engine is of reasonable health and doesn't consume too much oil, and then swap it in?

[Alexanderfitu]

carbonblack said:

Would swapping in a different engine be the most economical repair?

Given an E46 330 can be had for less than £4k you could run it for a couple of months, ensure the engine is of reasonable health and doesn't consume too much oil, and then swap it in?

I have thought about this. I have seen three of these m54b30 s in this state (in cars) including mine. I'm concerned about doing a swap and having the donor engine have the same problem.

If I can get one cheaply enough, it's the easiest option cost wise, only taking up my time. It does end up giving me a spare engine that can be sent off if it does have issues.

[rottenegg]

If it were me, I would just do the stem seals in situ and be done with it. 6 psi isn't going to blow the engine's roof off.

Alexanderfitu said:

I also cannot find anybody who wants to do a light rebuild for less than £10,000.

I wonder in the future if this will be the aftermarket standard issue price for a new EV motor? It's just like builders, teeth suck, "10 grand mate".

That is a ridiculous price. I would rather pay BMW that and get an engine that is at least built properly.

Or just stick an N55 in it. You will get bored of the supercharger anyway, especially if it's one of those stty Rotrex centrifugal jobs that do nothing until about 4000rpm.

Edited by rottenegg on Sunday 9th April 11:58

[rallycross]

Find a good 2nd hand engine as a rebuild is going to be an expensive waste of
Money and may end up less reliable than a good 2nd hand standard engine.

[ingenieur]

carpetsoiler said:

Alexanderfitu said:

Thanks for the info.

Does using headstuds negate the need for thread repair?

I will pm you. Don't mind spending money, but not significantly more than the value of the car!

Sadly that's a link I've never been able to corroborate. For what it's worth I've never had a thread pull with studs, but that's not to say it won't happen.

No worries, drop me a line, would definitely be able to sort something out, and for a ste sight less than £10k into the bargain!

The reason studs don't strip threads is that the stud is already wound all the way into the block. You also have more thread on the block side than within the nut. Also the washer lets it slip better when torqueing down. There is of course absolutely no guarantee but you help yourself by doing it that way compared to using standard bolts in situations where it could be an issue.

Other important thing is to make sure there's no dirt, oil or coolant in the holes in the block as the amount of pressure you can create when torquing down a cylinder head is insane and if there's any fluid trapped in there it will find a way to come out by cracking something.

[Alexanderfitu]

rottenegg said:

I wonder in the future if this will be the aftermarket standard issue price for a new EV motor? It's just like builders, teeth suck, "10 grand mate".

That is a ridiculous price. I would rather pay BMW that and get an engine that is at least built properly.

Or just stick an N55 in it. You will get bored of the supercharger anyway, especially if it's one of those stty Rotrex centrifugal jobs that do nothing until about 4000rpm.

Edited by rottenegg on Sunday 9th April 11:58

I did think about doing them in situ, but a lot of work to do it and then find out the consumption is from the control rings.

I am quite happy with 300bhp out of the centrifugal charger. I have 700+bhp cars, and this is is about revving out and enjoying the experience rather than outright power. If the think wasn't burning oil, I wouldn't do anything else to the engine

[Alexanderfitu]

ingenieur said:

The reason studs don't strip threads is that the stud is already wound all the way into the block. You also have more thread on the block side than within the nut. Also the washer lets it slip better when torqueing down. There is of course absolutely no guarantee but you help yourself by doing it that way compared to using standard bolts in situations where it could be an issue.

Other important thing is to make sure there's no dirt, oil or coolant in the holes in the block as the amount of pressure you can create when torquing down a cylinder head is insane and if there's any fluid trapped in there it will find a way to come out by cracking something.

Yes, makes sense!

[ingenieur]

I should add the issue of dirt / water / oil in the holes for the head bolts could be all of the problem. If the bolt has bottomed-out on something in the bottom of the thread hole as you tighten more it will put increased pressure on the threads until they give way.