People building m20 themselves

[PeaveyBassist]

Those of you who have built an m20 by yourself, stock or stroker...whatever. Did you get a book on engine assembly so you made sure you knew what you were doing the whole time? I have a spare block (I think its a good one) and I might want to build it. Who has some info on building an m20 for me?

Will

[MR 325]

No books for me, just the help and supervision of somebody who's a pro.

[nando]

all on my own. I read some basics online.. bought a bearing gap checker for like $2. made sure everything was clean and torqued to spec... the M20 is a very simple motor, I don't think you'll have any problems.

one thing though, make sure you use a NICE ring compressor. I tried to use a cheap one and I ended up breaking a ring... that cost me $75 for another ring to be overnighted to me, 1 extra day of downtime and another $25 to buy the tool I should have got in the first place. lesson learned..

[PeaveyBassist]

Well I know to check clearances and all that. But things like the cam, I know you're supposed to put assembly lube on it when you install it or whatever. I just want to make sure I dont miss little things like that that could potentially ruin alot of money/time spent on building it. Pretty easy though for a first time builder?

Will

[AdamF 88iS]

M20s are very simple to build, probably the easiest of all BMW motors. You just have to remember details, stuff like all the main bearing caps should be numbered 1-7 and placed back in their original spots... rod caps can't get mixed up either. When you put the caps on make sure teh little key notches are both together ('key to key' as they say), lube the pistons/cylinders with ATF when doing the ring compression and piston insertion...

And probably the #1 rule- BE CLEAN. This is most important on the bearing shells and teh crank surfaces they contact- any little bit of dirt or whatever is unacceptable. Wash out all the oil passages thoroughly and make sure those surfaces stay absolutely clean.

[winstontj]

Buy yourself a Haynes, Chilton, Bentley... remember that you get what you pay for so those are listed from cheap to most expensive. Haynes is ~$20 and Bentley is ~$80.

Also if I were you I'd get yourself a blown up M10 for like $50... or go to the junkyard and pickup a jeep 4.0L 6-cylinder motor from the scrap pile... disassemble it and then sell it back to them for scrap iron... You'll learn a lot about stuck bolts, screw extractors, using the "BLUE WRENCH" (torch), etc.

Tear apart something you don't care about breaking... then you'll be farmilliar with the way things look inside. Next when you do the M20 get yourself a few boxes of ziplock bags and a few sharpie markers. LABEL EVERYTHING and be super anal. Get a GOOD torque wrench. Often the dial/bar kinds are the best/most accurate IMO. Follow the manual exactly and don't skimp on parts or machine shop work. Get a digital camera and web hosting... start taking & posting LOTS of pics. Do you have any friends who have rebuilt motors?

Also no matter what they say... gasoline and a toothbrush IS an excellent cleaner/degreaser....

Good luck and do it... I did my first motor at 14 and it still runs. It was a Chrysler 2.2L turbo (from a chrysler laser)... smoked like a bastard but it's still running today. I used silicone on the head gasket... had NO F*CKING CLUE about what I was doing but no joke the motor is still running in my home town today....

[rs4pro3]

Just be clean and lube stuff properly when assembling, I use engine lube ussualy on the cam and rockers to keep them lubricated during intial start up, then flush it out after a few hundred miles.

[nando]

label everything? lol. it's not that complicated. just keep everything in one place. unless you really have a hard time putting stuff back together...

[backtrail69]

I built my M10 by myself. Very self explanatory. I just had a bud who had did it before help me alone with the process. But reading a book would work just fine.

[xLibelle]

i rarely used reference material but thats mainly beause i had everything laid out from the teardown.
When i did have to look, i checked the shop manual, NOT the Bently.
I can send it to you one evening, find me on aim.

[Jesse30]

i rarely used reference material but thats mainly beause i had everything laid out from the teardown.
When i did have to look, i checked the shop manual, NOT the Bently.
I can send it to you one evening, find me on aim.

can i get that shop manual?

sounds like it would come in handy on my build

[kendogg]

Buy yourself a Haynes, Chilton, Bentley... remember that you get what you pay for so those are listed from cheap to most expensive. Haynes is ~$20 and Bentley is ~$80.

Also if I were you I'd get yourself a blown up M10 for like $50... or go to the junkyard and pickup a jeep 4.0L 6-cylinder motor from the scrap pile... disassemble it and then sell it back to them for scrap iron... You'll learn a lot about stuck bolts, screw extractors, using the "BLUE WRENCH" (torch), etc.

Tear apart something you don't care about breaking... then you'll be farmilliar with the way things look inside. Next when you do the M20 get yourself a few boxes of ziplock bags and a few sharpie markers. LABEL EVERYTHING and be super anal. Get a GOOD torque wrench. Often the dial/bar kinds are the best/most accurate IMO. Follow the manual exactly and don't skimp on parts or machine shop work. Get a digital camera and web hosting... start taking & posting LOTS of pics. Do you have any friends who have rebuilt motors?

Also no matter what they say... gasoline and a toothbrush IS an excellent cleaner/degreaser....

Good luck and do it... I did my first motor at 14 and it still runs. It was a Chrysler 2.2L turbo (from a chrysler laser)... smoked like a bastard but it's still running today. I used silicone on the head gasket... had NO F*CKING CLUE about what I was doing but no joke the motor is still running in my home town today....

Who the hell sold you a Bentley for $80?

Will, get yourself a Bentley - complete engine assembly and disassembly instructions are in there. It's not biggie, just use common sense, and alot of clean space. Lay everything out, in the order than you removed it. Then, re-assemble in reverse. Keep everything marked.

[Rennwagen]

Two most important things you can do while assembling is to keep everything clean and torque everything to spec. All the lubrication your going to use can pick up alot of dirt during reassembly. Make sure you have a full weekend, start in the morning and work until it's done. You don't want to drag out the build over an extended period of time, you'll lose shit. Also an engine stand is great if you can find or borrow one.

[Mr Deagle]

keep everything clean

THE most important thing!!!

[winstontj]

Who the hell sold you a Bentley for $80?

I don't even own a bentley manual...

I thought I read on here - or maybe I thought I saw it listed for that at BavAuto??

How much are they? I own a Haynes and a Chilton manual and they work fine. The two combined with the HTK and realoem have everything I need. I'm actually going to purchase an m20 shortly that I will rebuild, stroke, bore, etc so I am interested in how you guys say this can be built in a weekend... I would assume that removal takes a full day (by yourself), dissasembly takes a full day to do it right, drop at machine shop... anywhere from a week to three months... assembly can be done in a day or two but you need to take your time to do it right. Often you'll have to measure the crank journals to the bearings and have the crank repolished, etc.

Are you talking about a rebuild just throwing the parts together or a real one where you actually measure tolerances before you start torquing?