JT's M20 Build Thread

[JehTehsus]

what fuel pump are you going to use? what if anything are you doing for E85 regards to the hard lines?

how does the nuke fuel rail attach to the manifold?

This actually raises a couple of good points... I don't have a fuel pump picked out yet, this is something I need to get done. I would like to go with something entirely internal to the tank (I have the dual stage interior/exterior setup at the moment)... at this point I have only done some cursory searching; seem to recall that there were a couple likely candidates, and I decided until I yank the pump out and measure it I would leave it for now.
I am going to be replacing all the factory lines with PTFE, although I admit I haven't given a ton of thought to the hard lines at this point. I will need to look further into compatibility of various options with ethanol. Do you have any recommendations?

Fuel rail fitment looks ok to me. I will definitely need to fabricate up a bracket, but I don't think it is going to be a major nightmare to make (although in hindsight it may have been smarter to get the powder coating done after making the bracket). Here's a couple pictures I just grabbed quick:

May as well upgrade that mild clutch now. You're building a bigger, more potent M20 that breathes, not a lame unopened stock motor like mine, you'll nuke that stage 2 clutch at 15psi let alone double that

So the IE guys claim it is good for 500ftlbs... is this significantly exaggerated? I know it won't be able to handle my full power goals, but at 30 lbs boost on a stroked m20 (even 20 is possibly starting to push it) I feel like I may be getting into 'destroy your drive train' territory, rather have the clutch slip than blow my transmission and/or diffwhen I don't have another one lined up.

I have a lot of work ahead of me; just getting the stroker together, running and tuned is going to take me a while. I've also got lots of other things on the car that need doing as I plan out and collect the turbo bits, even if I only get half the rated holding torque out of the clutch over the next 12 months I will probably be happy with it.

[varg]

I am looking at the 25-30psi range.

May as well upgrade that mild clutch now. You're building a bigger, more potent M20 that breathes, not a lame unopened stock motor like mine, you'll nuke that stage 2 clutch at 15psi let alone double that

[digger]

what fuel pump are you going to use? what if anything are you doing for E85 regards to the hard lines?

how does the nuke fuel rail attach to the manifold?

[JehTehsus]

Bit more progress today... redid the front main because I wasn't perfectly happy with it. Also, rear main is now in place. Next up I need to give the oil pan a thorough cleaning and get the rings on the pistons - and I will leave things there over the holidays.



Not the best quality of photos today, but she'll have to do.

[JehTehsus]

got the ingredients for a really badass build here. definitely invested in some high end components. please go twin turbskis or twin scroll setup. that or a compound turbo setup . sub'd

A twin turbo M20 does sound hella cool... we shall see

[digger]

I am looking at the 25-30psi range. Don't currently have plans to go beyond 30, hopefully with the capacity to not blow everything to pieces if I get a brief surge. All that said, I am still trying to make up my mind on some elements of the turbo setup, so things may change a little.

I did consider the Mahle pistons... my understanding was they were more suited to an N/A motor and didn't offer any particular advantages for a boosted setup. I figure I should be in alright shape with the IE Ross pistons. I'm curious to see if the oil squirters help much with reducing piston temperatures, may leave me some more wiggle room in intercooler selection.

Wrt to the injectors, are you talking about fitment in the stock fuel rail and/or the connectors? I have some spacers in place right now so the clips seem to be holding them fine in the Nuke rail (I'll dig up a picture tomorrow, now that I'm thinking about it my spacer scheme may not work that well, a second opinion would be great). I'm replacing the entirety of the factory wire harness between the engine, ecu and rest of the car, so wiring the injectors in isn't an issue.

yeah pistons probably wouldnt be capable of 25-30 psi. would be fine for a low boost setup
since there are retention clips the issue is null and void, the issue comes when you dont have clips between injector and rail on those inejctors as they can unseat

[hkv]

got the ingredients for a really badass build here. definitely invested in some high end components. please go twin turbskis or twin scroll setup. that or a compound turbo setup . sub'd

[JehTehsus]

Here's some pictures of my fuel rail at the moment:








As you can see, I ended up adding some small spacers/standoff washers between the clip and the rail. Can anyone see any issues with this? I believe the standoff length is almost 3mm... which is just a hair under what it should be, so there is the tiniest amount of deflection in the clip (effectively pushing the injector into the rail).

I also need to fabricate a bracket/mount for the rail to the intake manifold, but I have yet to get there.

[JehTehsus]

I am looking at the 25-30psi range. Don't currently have plans to go beyond 30, hopefully with the capacity to not blow everything to pieces if I get a brief surge. All that said, I am still trying to make up my mind on some elements of the turbo setup, so things may change a little.

I did consider the Mahle pistons... my understanding was they were more suited to an N/A motor and didn't offer any particular advantages for a boosted setup. I figure I should be in alright shape with the IE Ross pistons. I'm curious to see if the oil squirters help much with reducing piston temperatures, may leave me some more wiggle room in intercooler selection.

Wrt to the injectors, are you talking about fitment in the stock fuel rail and/or the connectors? I have some spacers in place right now so the clips seem to be holding them fine in the Nuke rail (I'll dig up a picture tomorrow, now that I'm thinking about it my spacer scheme may not work that well, a second opinion would be great). I'm replacing the entirety of the factory wire harness between the engine, ecu and rest of the car, so wiring the injectors in isn't an issue.

[digger]

welcome

how much boost are you looking to run?
Did you consider the Mahle MS 2.9L pistons? or the RHD flywheel?

take note of the fitment of the ID's

https://www.bimmerforums.com/forum/s...ector+dynamics

[mike.bmw]

Awesome first post! I'm looking forward to seeing more.

[JehTehsus]

Hey everyone,

Relatively new to R3V here (lurked for a while), but I've been slowly cooking up an M20 turbo build some people may be interested in.

Eventual 'end-game' here is a fun powerplant for a track going E30. Not interested in racing or formal competition, per say - just having some fun driving (and a lot more building) on a great platform. I am also using this project as an opportunity to learn the in's and outs of building a performance motor (so please, if you have any comments feel free to assume I am ignorant of the finer points and don't hesitate to point out the obvious). So to that end I have decided on building a turbocharged M20 stroker.

I started roughly planning out the build mid-late last year, and actually began collecting bits sometime around March or April. Stoker motor goes together now, with budget and overall complexity dictating that the turbo goes on next winter. So at this point basically everything is together for the first stage of my build, and I have finally begun! (Just in time for a Christmas vacation... got to keep the lady happy though).

A quick breakdown of what is going into the build:

• IE 2.9L stroker kit (turbo), with their forged rods. Decided to leave at their recommended 9.75:1 CR. May bring it down slightly with HG adjustment once I get the blower sorted out.
• Fully tricked out Bimmerheads stage 3 race head (with a nuke gear). It's so beautiful I almost don't want to put it on the car.
  • To save you looking it up, the highlights are +1mm supertech valves w/performance springs, HD rockers, welded coolant channels, a 284/280 cam and beautifully done P&P.
• MLS HG.
• MS3-pro Ultimate. I write embedded software for a living, so open source is a major + for me.
  • Converting to fully sequential. Yes, I know, I could have swapped an M/S/xxx/50. Individual coil packs for the plugs.
  • Adding a knock sensor and oil and fuel PTS sensors as well. On the fence, but may do individual EGTs. Obviously going wideband O2.
• Injector Dynamics ID1050x.
  • Fuel system is being setup for flex fuel/e85 (if anyone has any flex fuel sensor suggestions, please let me know). Also running the ID750 filter with PTS, which will be plumbed into the MS3.
• Extensive machining on the bottom end (done locally here on Vancouver Island), including:
  • Bore and hone for oversized pistons. Torque plate hone (speaking of which, if anyone nearby needs a torque plate for an M20 let me know).
  • Cleaning (not hot tanked... good ol' intermediate bearings).
  • Align bore. Decked and finished for MLS HG.
  • Piston oil squirter installation. Various other odds and ends as well.
• Coated main and rod bearings.
• ARP everywhere: HG bolts, rod bolts, caps.
• Oil pan baffle and crank scraper.
• IE lightened aluminium flywheel.
• Powdercoated valve cover and intake manifold. My reading indicates the stock IM isn't great... but IMO the look is iconic and I figure the boost will mostly offset serious flow issues.
• Various other goodies like a nuke fuel rail and vacuum station.
• Lots of replacement bits, oil pump, waterpump, hoses, etc.
• Went with an IE stage 2 clutch kit for now... see how that holds up.

Plenty of other bits and details, I can certainly get into it further if there's interest. Now for what everyone really wants: build photos:


What a beauty. Shortly before I bought it off my friend.


Pulling engines works best when you're dressed for it.


Off to the machine shop.


Really happy with the local Victoria Powdercoaters shop. These look fantastic.



She really is a work of art.




Back from the shop.


30 years of rust.



A few quick coats of engine enamel.


FML... cast iron, wet coast... (Not sure if this super light surface rust is enough to ruin the MLS surface once I have brushed it off... lesson learned).




I paid the machinist to check clearances, but a second set of eyes never hurts.



I feel like I did a shitty job here with the gasket maker (permatex #2). Going to redo this weekend. That and the gasket set I used seems to be sub-par (look how much it sticks out into the oil pan, is that by design?).


Replaced the old style IM shaft gear with the newer sintered version.



Guess who just got a new rear main seal kit in the mail?



The dining room table is a wonderful place for piston assembly... if you are lucky enough to have a wonderful girlfriend.

And finally, some goodie shots:








Should I try my hand at anodising or stick to paint? I am actually liking the black engine enamel... I figure a few passes with that and manually cure with a heat gun?






"While you're in there..." change the steering rack, right? Z3 tight ratio.

Anyway, I have tons of other photos if anyone is interested, and I can always get my lazy ass off the couch and walk down to the shop if I need some more. This weekend I am going to pop the crank back out and remove the front main seal, clean everything again and put on the new front main (less gasket maker this time, and a better gasket) and rear main, which just arrived. Going to get the rings on the pistons this week, and when I get back from holidays the pistons and block are going together, and if head/valve clearance checks look OK it should all be coming back together and going into the car sooner than later.

Once she is running I really need to replace the seats, they're totally trashed. Then it's full steam ahead on saving for and specc'ing the turbo, intercooler and associated fun stuff.