glyif

m10 engine rebuild for learning

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(edited)

hello,

 

i am a car noob, have done some basic maintenance but nothing really mechanical. I have an M10 engine that has low compression on 2 cylinders, is it doable for a noob to rebuild an M10? If so, are there any guides or anything like that? also what tools/setup would i need....

Edited by glyif

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Give it a shot, there is enough info on this forum to teach anyone. Just do your due diligence and read read read! Good luck! 

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(edited)

To quote the immortal Ms. Frizzle, "Take chances, make mistakes, get messy!"

 

Look at the "project blog archive" and find someone who has documented his process (Jgerock's jumps to mind).  

 

As mentioned, read read read.  I have a "newbie" intro guide to rebuilding the cylinder head here... Plan on downloading the BMW factory manual.  Find an experienced machinist "with the heart of a teacher".  Maybe start with something simple to get your feet wet, like resealing the steering box.

Edited by AceAndrew
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do it, they're simple, just break it down methodically, catalogue everything as you go (zip lock freezer bags are really handy for grouping bolts etc), take pics and as mentioned read tons. You need a socket set and a few spanners, valve spring compressor, piston ring compressor, patience and lastly, you need to clean everything to within an inch of it's life. 

 

remember engines are engines, so all principles can be applied to the m10. oh and an engine stand makes the process much more enjoyable. 

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Completely do-able. (ask this noob) 

 

M10 was the first motor I've ever built, and (I think) mine is still doing great! I just have a bit of an ignition and after-work-cold-weather induced laziness problem dealing with it, haha.

 

All the above advice is credible. BMW bluebook manual is essential, as is any Haynes as support. Make a blog or a thread and people can chime-in and help out, there's amazing knowledgeable people on this board that can support you along the way with any questions. 

 

You're gunna need a good torque wrench/breaker bar for tearing it down and building it back up, and have your machinist measure all your bearing/race clearances and measure on assembly with plastigauge. Be sure to free-spin things as you go to check for any binding, better to catch it earlier than later- I had a set of rods with a few that were ovalized, had I not caught it, it woulda ended badly!

 

Engine stand is 40 dollars worth of invaluable convenience. 

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morning, I asked the same question a year ago and the folks here on the FAQ are super helpful and have more experience at doing this than you will believe.Search this section using " engine rebuild and you will be over run with info, especially look for the following thread, see below, also AceAndrew has been very helpful, as well as many others, but as some one above said, just read everything here in the forums about pistons, heads, etc, good luck.

Tips/advice for a higher performance M10 rebuild?

By RenaissanceMan, February 4 in '02 General Discussion 

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"Rebuild an M10".... therein lies the rub, as Shakespeare would say! Does it have to run when you are done :):)

 

Just kidding. I feel myself to be mechanically inclined, but never rebuilt a motor, however that is exactly what I just did over the past year. But I had my brother at my side who has 40 years of auto mechanics and race motor building. But again, he always worked in the world of American muscle/Mopar and shook his head through the whole project trying to understand "this German thing".

 

I will start with three key points I feel were very important and then some references.

 

1) I researched and studied and took notes for months, writing out step by step procedures and checklists, printing diagrams and torque setting tables, collecting FAQ posts about each major step in the process. I had a binder 2 inches thick by our side as we tore down, prepped and put it all back together. Because to be honest, it is quite possible to "f up" one seemingly minor thing, and your rebuild is toast or won't run like a new engine. Not meaning to scare you, but attention to detail is key (and for any motor build I am sure)

 

2) What is your definition of "rebuild an M10". I luckily had the time and resources (still paying some of those off :) ) to do it right, meaning I replaced just about everything that was supposed to be replaced on the engine. Kept the block, crank, cam, head, etc., but had everything machined and evaluated and all wear parts replaced. Get's expensive fast.

 

3) Experience! Kind of horse before the cart, but if you don't have it yourself, seek it out. I was fortunate to have my brother at my side and after I read a 2 page dissertation about how to install a particular engine part, he patiently waited and then picked up a rubber mallet, held the part at a slightly different angle than the book-learning said.. and gave it a whack saying "Yes, but this works much better!". A slightly made-up example, but people who have lived and breathed this know the tricks. The FAQ is full of crusty old geezers with a heart of gold that will guide you every step of the way. It may take 5 pages of arguing and debate, but the truth is out there.

 

But, the experience of rebuilding this motor will NEVER EVER be forgotten. It is completely a bucket list item for me and along with owning and knowing how to tie a bow tie and having a Zippo in your pocket (regardless if you smoke or not), this is one of the top 10 things a man or woman should do in life... ha ha, OK enough philosophy.

 

So to me, first step is  ... step 1):

 

o Read the Haynes manual relevant chapters over and over and over and take notes and maintain the order they have things in. It is that way for a reason.

 

o Read the 2002 service manual over and over and over and do the same, especially noting the warnings they give on certain steps.

 

o Get Macartney's BMW 2002 restoration book and although this is not a step by step resource, it has many of the gotchas and watch out for items that come with experience. 

 

o Finally, the resource I really found useful was a set of Roundel(?) articles by Mike Rowe about engine tear down, evaluation and rebuild. These are a step by step set of instructions much like the Haynes, but a little more precise I think. I can send these to you (PM me) and I really should post these on the FAQ articles section... I will look into that.

 

I say go for it!! With a cross of the fingers, I turned the key on our first start and she jumped to life and purred as I never thought she would again. I am still dialing in the valves, timing, and carb a couple months later as it breaks in, but that is the continued fun of ownership.

 

Randy 

 

PS - Also as far as time investment, mine took a year because the motor and brother were in Charlotte and I am 4 hours away in Raleigh. So we tried to meet monthly for a couple of days, but it turned out to be usually every other month. Also, sometimes ordering (or figuring out how to pay for) parts slowed down the build.

 

 

 

 

 

 

 

 

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Study the BMW shop manual posted on this site!

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Study the BMW shop manual posted on this site!


Stay organized. The M10 engine was brilliantly designed. Plus fewer parts than a common American V8. You can tackle the project and the satisfaction you will have when it first fires when you’re done.
Matt


Sent from my iPhone using Tapatalk

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(edited)

This will be an excellent exercise for you!  Start a project board in your garage, and outline each task you need to accomplish.  Then add sub-tasks as you go through each major task.  That will help you remember how to proceed with the rebuild process.

 

Major stuff I recommend to start with is a complete set of long/short, metric sockets in 1/4 and 3/8 drive.  Someone mentioned a breaker bar, but do not ever use your torque wrench to loosen bolts.  I often use a 1/2" breaker, with a 3/8 adapter and smaller sockets, although it is better to use 1/2" sockets.  I also would recommend a high torque electric impact wrench.  Harbor freight sells an affordable 110V model with cord, and a FANTASTIC cordless one (the Earthquake XT model).  Lastly, be sure you have the engine mounted in an engine stand.  Yes it is possible to do it on a bench, but the stand is absolutely the way to go. 

 

When tearing down, it was already mention you should put every loose part into plastic lunch bags, and label EVERYTHING.  If you have space, group assemblies and their parts.  If you have boxes/bins for those assemblies, that is even better.  By the time you have it all apart, the process will be way less intimidating.

 

If the block is OK, you will want to replace bearings, rings, cam chain, gears, and tensioner.  Don't reuse any of those old parts if you intend to actually use the engine.  Re-using old cam drive train parts is false economy.  Also buy a complete engine seal set.  That way you shouldn't be missing anything.

 

I highly recommend tearing down the head to all component parts, learning how to measure guide wear, and then learning to lap in your valves.

 

For specialty tools like ring expander, ring compressor (for piston install), valve spring compressor, you can contact your local auto parts chains (Oreilly, Auto Zone, etc.) and ask if they have those tools for rental.  You just leave a cash deposit, but you borrow them for free.  When you return it, you get your cash deposit back. 

 

Good luck, and have fun.   

 

Jose

Edited by DaHose

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7 minutes ago, DaHose said:

For specialty tools like ring expander, ring compressor (for piston install), valve spring compressor, you can contact your local auto parts chains (Oreilly, Auto Zone, etc.) and ask if they have those tools for rental.  You just leave a cash deposit, but you borrow them for free.  When you return it, you get your cash deposit back.  Good luck, and have fun.   

 

Jose

 

alternative is to buy the cheapo tools you'll find on amazon/wherever. Wouldn't last long in a professional environment, but will be fine for a very occasional home build and it's nice to know you have them when you need them. 

 

10 bucks for a ring compressor (which will actually last forever): https://www.amazon.com/8milelake-Piston-Ring-Compressor-4/dp/B073W9FNQF/ref=sr_1_1_sspa?ie=UTF8&qid=1521827578&sr=8-1-spons&keywords=piston+ring+compressor&psc=1

 

etc...

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Yep, that compressor is a winner.

 

Amazon is great for delivery, but if you have a Harbor Freight nearby, they are a great beginner tool option.  I actually purchased a set of their PIttsburgh sockets many years ago, and beat them hard, but they wouldn't break.  So I kept trying them out.  I used to have a mix/match of old Craftsman/Mac tools.  Those random sets now sit in my spare box for a rainy day.  My daily use sockets, wrenches, and even ratchets, are all HF Pittsburgh ling.  From 1/4, to 3/4, they all survive abuse with impact tools, never strip bolts, or strip out, and they carry lifetime warranty.  If you know how to find good quality tools, there really are some gems in HF.  If you ever need to warranty anything, walk in to the store and they just hand you the replacement.  My good friend HATES shopping at HF, but they are like a candy store for me.

 

Jose

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1 hour ago, DaHose said:

do not ever use your torque wrench to loosen bolts

@DaHose, is there a specific reason why i shouldn't use a torque wrench. i believe you, but just curious ;)

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(edited)

That right there is so doggone purrrdy, there Paul.

 

glyif - You never loosen with a torque wrench, because they are generally designed to work one way, particularly the click or break-beam type.  Working them backward is no bueno for their assemblies.  Although a straight beam torque wrench would be ok, as it is just a straight bar of steel, and often the scale reads both ways.  Another big concern is that you don't know what the required break-away torque might be, and it is rough on the wrench mechanism.  You might crank your wrench up to max., but what if the fastener needs more torque than your wrench is rated for?  If you stop when it clicks, maybe things would be ok, but if you are at max. and go just a little more, it could break the wrench.  That is particularly possible with a smaller torque wrench, like a 3/8" drive.  if you use a digital, then you could damage the load cell and there is no fixing that.  You toss it and start over.  I have one clicker, and a couple of very nice digital torque wrenches which are extremely accurate, but expensive.  No way do I want to damage my digital torque wrenches, so they never get used for anything but torque specific tightening.  Although digital wrenches are designed for backward torque, however manufacturers will warn that backward readings might not be as accurate, as they are designed to work with normal direction threaded fasteners.

 

Jose

Edited by DaHose

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