Metric Mechanic Roadtrip

#1

In 2 weeks Fish Bratton and I are going to spend 4 days at MM. Under their supervision we’re each going to build a motor. I’m looking forward to it with all the excitement of a schoolgirl and her first prom.

I’ve gotten pretty tight with MM over the past couple of yrs. A lot of time spent on the phone and a lot of $$. When #7 (or was it 8?) failed last year they recognized me for the pitiful wretch I was and said words to the affect of “jesus christ Scott, we can’t take this anymore. Just come to our shop and we’ll help you build a motor”.

A week ago I called them up to take them up on this offer. Their reaction was…“Why don’t you bring Bratton? He seemed like a really nice guy when he was here last week, and dang if he didn’t show a knack for a micrometer.”

So Fish and I are going to spend 4 days with one of the best M20 shops in the nation. We’ll buy whatever we need from them and build it in their shop.

I think that Fish is interested in building a whole motor. I’m mostly interested in building a bottom end so I’m going to bring two.

Building an engine with some of the finest BMW engine builder’s in the nation…Damn man, how many car enthusiasts get this kind of focused learning opportunity?

Schoolgirl. First prom. I can’t wait. Should I wear chiffon?

#2

Wear the pink dress, you’ll look darling in it. Is Bratton is bringing the bouquet?

#3

jlevie wrote:

He’s bringing his new ride. A 2011 Cummings Diesel equipped Dodge.

#4

Awesome! I’d love to do something like that.

#5

No dresses, no flowers, just engines and parts. I may bring a video camera though… This trip is going to rock, not like prom, but more like after prom!

#6

Please take notes and share with those of us who have no idea what we are doing and don’t want to follow in your footsteps (with the 8 motors I mean…).

#7

Very Cool.

#8

FishMan wrote:

You guys gonna flip a coin to see who ‘wears the boutonniere’ so to speak? :laugh:

Is this what the E36 rods are for? :woohoo: :laugh: :stuck_out_tongue:

On a serious note, is there any way we can convince you to run the motor’s oiling system as it came from Germany adding only a crank scraper and one pressure gauge at the filter sandwich? I will send you $100 after the 4th race weekend run with that configuration.

#9

Steve D wrote:

[quote]FishMan wrote:

You guys gonna flip a coin to see who ‘wears the boutonniere’ so to speak? :laugh:

Is this what the E36 rods are for? :woohoo: :laugh: :stuck_out_tongue:

On a serious note, is there any way we can convince you to run the motor’s oiling system as it came from Germany adding only a crank scraper and one pressure gauge at the filter sandwich? I will send you $100 after the 4th race weekend run with that configuration.[/quote]
The E36 is the DD.

Re. oiling system. My oiling system is pretty simple and works fine. And I’ve lots of supporting data. Metric Mechanic baffled oil pan and the I-J scraper. No oil cooler. I’d prefer that my oil pressure was a little higher at high rpm, but in terms of starvation, I’m good.

There is one interesting thing I’ve noted tho. I’ll start another thread on that.

#10

I’m jealous. An experience like that would be well worth the drive.

#11

Every one blames LeMons for the shortage of M20’s on the West Coast… Sounds like it’s something else!!!

Ranger this is a cool trip… Can you blog on it later? (without giving away the farm of course)

#12

very cool. pics or it didn’t happen!

#13

kgobey wrote:

[quote]Every one blames LeMons for the shortage of M20’s on the West Coast… Sounds like it’s something else!!!

Ranger this is a cool trip… Can you blog on it later? (without giving away the farm of course)[/quote]

I’m going to take as many pics as time allows and I’ll write up stuff afterwards. The MM guys emphasize that 85% of their time is taken up by measuring. Assembly just isn’t that big of a deal. It’s the process and fanatical attention to detail in the measuring that I want to learn. I’ve done some of this and I’ve read a lot, but there’s just no substitute for years of experience. So there’s no better learning environment than to have an experienced guy behind you guiding what you do.

Already I’ve grown to understand what a slipshod effort it was when I took the bottom end of #3 to a local shop to have them build it with me. I involved them because I wasn’t comfortable building a bottom end without help. Now I look back at that effort and am forced to recognize that their (the local shop) “fanatical attention to measuring” was a joke. It was “slap some plastigauge on there and throw it all together”.

#14

Are you going to spend some time on the flow bench to do some parts-bin optimizing of intake & exhaust manifolds? With all the effort you go through I’d like to see that beeg motor make some real powah.

In my experience with engine builders, the number of super secret tricks they reveal will be inversely proportional to the number of photographs you try to take.

It does sounds like a fun experience though. Something for the bucket list for sure.

#15

Rich is going to get involved in head work but I’m oriented on the bottom end. As I’ve been since HS. Seriously tho, I want to be able to build as good a bottom end as anyone, and I think that’s do-able in my garage. But for me, head work will always mean taking the head to a machine shop.

#16

Ranger wrote:

[quote]…but I’m oriented on the bottom end. As I’ve been since HS. [/quote]LOL. That’s funny right there.

#17

Rich and I are at MM. I left Savannah Wed afternoon and treked 7hrs to Birmingham to pick up spare #2, Skeen’s old motor. Then Thur at 05 I drove another 10hrs to Richland, MO.

Mostly what we’ve been doing is a lot of parts cleaning and measuring. My idea of taking lots of pics didn’t work out. Isn’t any use taking pictures of cleaning and measuring. Am taking lots of notes tho.

Rich and I are staying with Jim Rowe, owner of MM, and his wife Mary. They’ve been incredibly gracious. We get up, Jim fixes us a big breakfast, we work in the adjacent shop until mid-afternoon, go out and eat a huge lunch somewhere, and then work until 8PM or so until Mary drags us away for dinner.

Every step takes a lot longer than one would imagine. So we work for 12hrs and I look back and feel like I didn’t accomplish much.

#18

You da man…

Looking forward to reading what I’m sure will be your detailed write up…

Then I can obsess about the mistakes I just made when I refreshed my motor last month

#19

You have searched for enlightenment grasshopper, and found it!! Chuck

#20

The biggest take-away, I think, is going to be the obsession with “perfect”. For example, we balanced all the rods and pistons within .1g. Jim did the cylinder walls until their were right and straight within a ten thousandth. Then with my 12 pistons and two blocks we identified the best piston for each cylinder.

Then with rod bearings installed we matched the best rod for each crank journal. In some cases we had to use an odd-size bearing.

What I’m repeatedly reminded of is the bottom end that I built with a local shop in Savannah 2yrs ago. That was my only other attempt to really gain experience building a bottom end. Compared to MM, they just slapped the bottom end together with some plastic gauge to identify gross problems.

The biggest take-away, I think, is going to be the obsession with “perfect”. We balanced all the rods and pistons within .1g. The BMW spec is 10g so we’re 2 orders of magnatude more precise.

Jim did our cylinder walls for us because we would have screwed it up. He honed the cylinder walls until their dia and straightness were within a ten thousandth. Then with my 12 pistons and two blocks we identified the best piston for each cylinder. When the variance is cylinder wall is only a 10kth and you’re still matching the best piston to go into each cylinder, you really end up getting the perfect fit for each.

The objective in each case was to get each piston-cylinder and rod bearing-crank gap perfect. The level of precision that Jim requires is significantly more than what the Bentley requires. We’re measuring with a precision of 1/4th of a 10th thousandth. So the gauge has single 10kth broken up into 4 lesser graduations. So whereas the BMW spec might be 18-28 10kth, we’re measuring with an additional accuracy that allows you to say absurd things like "ok, that time I got 20 and a quarter 10kth. A quarter of a 10kth. Dang.

MM’s standard is to get everything to within a 10kth of their target dimension. That is just hellacious. The mics and dial bore gauge that I brought can only measure down to 5 10kth so they aren’t even useful.

Being obsessive about every measurement takes a lot of time tho. That local shop and I had a motor built in about 6hrs and it’s taking us days now.