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Bulletproofing an M50/Turbo

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I've got in my possesion an m50 out of a late 95 325i (was manual) which is going into my E30.

I'm trying to make the thing as indestructable as possible... (the schnitzer carbon fibre valve cover definately helps :rolleyes:)

The plan is ARP head studs, MLS headgasket (think thick...) and planning on leaving the bottom end stock asides from ARP rod bolts, Not sure what else to do at this stage, the head will be cleaned up prior to re-installation.

Any worthy piston swaps to bump up the displacement/lower the compression?

For engine management I'm very very inclined to use a link setup (My uncles evo9 is on thier site, they are building up the evolink for the 9's off his car.. they've had it for about 3 months now..) but the concern for me is the system able to control vanos?

Another concern of mine is which turbo to use on this setup - Any factory vehicle's turbo's worthy? - I'm no good at reading compressor maps lol..

Primary concern is the ability to go fast, not explode.

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I've got in my possesion an m50 out of a late 95 325i (was manual) which is going into my E30.

I'm trying to make the thing as indestructable as possible... (the schnitzer carbon fibre valve cover definately helps :rolleyes:)

The plan is ARP head studs, MLS headgasket (think thick...) and planning on leaving the bottom end stock asides from ARP rod bolts, Not sure what else to do at this stage, the head will be cleaned up prior to re-installation.

Any worthy piston swaps to bump up the displacement/lower the compression?

For engine management I'm very very inclined to use a link setup (My uncles evo9 is on thier site, they are building up the evolink for the 9's off his car.. they've had it for about 3 months now..) but the concern for me is the system able to control vanos?

Another concern of mine is which turbo to use on this setup - Any factory vehicle's turbo's worthy? - I'm no good at reading compressor maps lol..

Primary concern is the ability to go fast, not explode.

guys in the states love the HX35 Holsets, or the HY35 have smaller exhaust housings if you want quicker spool, both T3 flanges. Last i remember Glenn had one for sale actually.

I'm pretty sure LEM wont do vanos but the Link+ might. Is vanos really a big deal anyway? could you lock it out if you decieded it wasn't worth much hp or tq?

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Guest Denny Crane

guys in the states love the HX35 Holsets, or the HY35 have smaller exhaust housings if you want quicker spool, both T3 flanges. Last i remember Glenn had one for sale actually.

I'm pretty sure LEM wont do vanos but the Link+ might. Is vanos really a big deal anyway? could you lock it out if you decieded it wasn't worth much hp or tq?

Bad move unless you're aiming to have most of the power at the upper end of the rev range.

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I'm running an EVOLink in my Mitsi so naturally this was going to be the choice for our S50 powered E30 project but after a little investigation we found that the Link ECU's (even the latest G3) doesnt have intelligent variable valve timing control. Simple vtec switching is possible but not more complex vanos control. This will be the reason why they have developed a new evolink for the evo 9 as the evo 9 has a mivec head on it which is intelligent variable valve timing. Their other ECU's dont have this degree of control yet.

One of the few full replacement ECU's that we found would do the job was the Autronic SM4 which will suit our plans perfectly.

As the M50 is very close in makeup to the S50, this ecu would be good for your project but for what you are doing you might want to investigate piggyback ecu's as a few guys overseas are running them on turbo'd M50's

Edited by Assault

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also - go buy Maximum Boost by Corky Bell and learn to read compressor maps - it will help.

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M52's use one step switching of the inlet cam solenoid to control vanos- so Link would be okay. Only the later M52's used vanos on both cams (M52TU fitted to E46's) S50 used stepless control of vanos, so a more spohisticated ECU is required. M50 has no vanos- which engine is yours?

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M50TU (Vanos on intake cam) conrod

So essentially on this engine vanos is one step is an on/off switch?

I think disabling vanos will be a backwards evolutionary step lol..

Learning how to read compressor maps won't be a problem - just finding the time to do it!

Am I on the right track with the building of the engine? Should anything else be done while I'm in there?

Edited by Surge

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I would say you'll be able to run up to 8psi max on the stock engine with the ARP bolts and studs, probably a bit higher if the head gasket drops the compression.

If you've got the cash, a garret BB turbo such as the GT2871R or GT30 series with probably a .63 exhaust housing would make a nice hairdryer, and reach boost threshold at a reasonably low rpm without running out of puff in the higher rpms.

Otherwise if money is an issue maybe look into the T3/T04e range of turbo's, they should suit your application.

These are just my suggestions based on what others are running on these engines but I recommend you talk to a turbo engine builder with some expertise in this area as they should be able to come up with an ideal set up for you.

Edited by Assault

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Yes the early vanos engines are just an on-off type affair, so pretty much any ECU will be able to control it. Engine build/spec. depends entirely on how much boost you want to throw at it and what your hp expectations are.Thicker headgaskets are not a good way to go, sure they drop compression but you also lose the "squish band" in the combustion chamber. And as Andrew suggested, read Corky Bells "Maximum Boost" if you haven't already.

Edited by conrod

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Bad move unless you're aiming to have most of the power at the upper end of the rev range.

I was thinking you could put in non vanos cams in there instead, or something along those lines. But from the sounds of it he'll be able to use the vanos anyway.

I'd always thought all vanos was stepless, learn something everyday.

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Engine build/spec. depends entirely on how much boost you want to throw at it and what your hp expectations are.

My expectations are see how this goes at a fairly low psi - Should be very responsive if I don't really muck around with the compression, Wait till the headgasket blows.. lol.. And then slowly upgrade the componantry.

The appeal of dialing up power after upgrades sounds good - Knock sensor could be the go too...

Thicker headgaskets are not a good way to go, sure they drop compression but you also lose the "squish band" in the combustion chamber.

I realise it's by far not the most ideal way of going about business, I'd prefer to either get some pistons made or salvage some factory BMW ones out of another motor - does the m20 share the same bore? I've got enough m20's lying around... Hell even better if the pistons by chance lower the compression so I can up the boost.

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I would do a little reading on general turbo dynamics before started as others have said ... If your looking at cracking the head open ... you may as well spend the $$$ on low comp forged pistons / rods. Do it once do it right I say.

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as far as the guys in the US are concerned APR studs and a MLS gasket is all that required.

dont know much bout the vanos.

Realy depends on how much boost your aiming for.

At the mo I am currently adding the same bits to my e28.

rebuilt 3.5L with 9.0-10.0 comp. pistons,steel head gasket,rings and bearings.

didnt go with the studs,just bought new head bolts.welded a elbo in front timing cover and fitted a high temp hose for oil drain

made the exchaust manifold (its not pretty) and as of yesterday a new 2.5' exhaust has been fitted from turbo to the back

as little tight in places but very tidy.

Looking to add 10lbs then we'll see....

ECU's too many choices-i have no idea what to use myself.Have leanings to EMS as this has the largest tuning tables I have come across.sum 'tuners' just keep things rich throught the rev range cause the tables have too larger incrimints.But this is only what i've heard,please do not quote me on this.

Check your oil pump, is up to the job? pressure losses when feeding the turbo at low revs

larger fuel pump?

bigger injectors or a RFPR?

all I can all say is good luck and the best advice that was given to me was Big Power

Good Reliability

Low Cost-cheap

Its not the black arts now pick 2

just do the research cheers martyn

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well that didnt come right :unsure:

Big power

Good reliability

low cost

can only pick 2

marty

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My expectations are see how this goes at a fairly low psi - Should be very responsive if I don't really muck around with the compression, Wait till the headgasket blows.. lol.. And then slowly upgrade the componantry.

The appeal of dialing up power after upgrades sounds good - Knock sensor could be the go too...

I realise it's by far not the most ideal way of going about business, I'd prefer to either get some pistons made or salvage some factory BMW ones out of another motor - does the m20 share the same bore? I've got enough m20's lying around... Hell even better if the pistons by chance lower the compression so I can up the boost.

Slapping an old set of M20 pistons in, is not really in keeping with your title of "bulletproofing an M50/Turbo" now is it? And neither is "wait till the headgasket blows" and "slowly upgrade the componantry(sic)"

You need to decide whether you want to do it properly, or on the cheap. As Josh said, do some reading on turbo engines first, and build it right.

Or else you can just slap it together with whatever is cheap and lying around, and we can all run a sweepstake on how long it will run before it goes bang! :rolleyes:

Edited by conrod

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Sorry conrod, doing it on the cheap isn't what I have in mind lol.. I was just curious if there was any pistons out of another engine that were stronger than the items in mine, aka more suited to recieving some additional aspiration.

Cheers for your reply topcat, Yeah the US guys (apart from e30tech guys..) seem to be giving the engines a quick recon then running lower psi's with them, I'm keeping my eyes on what the Swedish are doing...

As far as additional fuel requirements I'm thinking about running a second set (6) of injectors (to be controlled via whichever ecu I end up running) - Debating whether it's worth the effort to run ITB's and use a larger plenum.

From research the injectors run at nearly 90% duty cycle under full load in a standard engine.. So would be good to swap them with some that are less 'stressed' - Someone on here was using ford 5.0 ones?

The fuel pump will be upgraded.

I will be using a tubular manifold, positioning of the downpipe will be the issue, with the steering colomn in the way - I'm sure it can be worked around though, with a bit of heat shielding...

I'll most likely be getting DCH here to build the engine, with some parts I supply.

I've got to get my hands on maximum boost...

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sweet keep us updated on how you go ...

What our s50 'should' look like when done... note the dish and 'nipped' pistons to stop the piston edges from caving in and 'o-ringing' just give the head gasket a bit more support under higher boost pressure.

post-373-1176525532_thumb.jpg

post-373-1176525538_thumb.jpg

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Nice, The block will definately be O-ringed. Where does one aquire parts like that in NZ or did you order in?

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There are various suppliers for JE pistons around .. but in all honesty shop around, you can get em straight from the manufacturer customised for you anyways.

so overseas...

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Josh, are you using a metal gasket and o-rings? I thought metal gaskets didn't like o-rings too much? enlighten me please?

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I've got to get my hands on maximum boost...

I just ordered a copy from Amazon books. Cost NZ47.10 incl postage (standard post). Half the price of what they quote you here in NZ.

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why bother with O rings? unless your running big boost.this is only my thinking

I got a qaulity metal/graphit sandwich gasket from gaskets unlimited up in kumeu way.good work and made

a replica of the standard seal.i had mine made 30% thicker to help bring down the compression

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Josh, are you using a metal gasket and o-rings? I thought metal gaskets didn't like o-rings too much? enlighten me please?

We haven't started on the engine yet .. however its the next on the list. Copper seems to be too soft .. but im not so sure itll handle the higher boost pressure. Multilayer metal composite head gasket seems to be the go. The aim is to create a mini barrier or grip for the head gasket, to stop movement under high boost.

why bother with O rings? unless your running big boost.this is only my thinking

I got a qaulity metal/graphit sandwich gasket from gaskets unlimited up in kumeu way.good work and made

a replica of the standard seal.i had mine made 30% thicker to help bring down the compression

Well .. we will be push through around 18 normally and 22 pounds on 'go fast' days and upwards of possible 28-30 psi down the strip, yeah.. it will be needed. (end goal of 800bhp)

Not to rain on anyones ride when I say this, but lowering the compression via the head gasket severly limits how much pressure you can run. But again .. all depends on what you're after :)

I would say if your looking for over 500HP out of the m50 then o-ringing is a smart idea, depends again as other have said what your end goals are with the engine .. but I plan to do it right once.

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Next to every serious M50/S50 boost project I've seen has O-ringed the block. Prevention is better than cure.

The body work started Monday on the car so I'm hoping to have the shell back shortly (with wider gaurds) then it's onto getting the engine sorted..

In between then it's a case of going over all my links and trying to gather as much information as possible.

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From cometic...

Can MLS head gaskets be used with motors setup with o-rings or receiver grooves around the cylinder bores?

No. MLS head gaskets require smooth, flat and true head and deck surfaces to seal. Most of the time with o-ring setups the wire and groove fall where our gasket’s combustion seal is located; therefore, the wire will hold the gasket and not allow proper compression while the receiver grooves allow combustion gases to escape.

I haven't heard much about this issue, just curious as to your thoughts?

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