Engine rebuild and engine bay resto thread - 2240284 '72 CS

[wkohler]

Great work so far. You learn a lot on the removal that will help on the installation. After using a lift and dropping the subframe not sure I want to do it another way but I’m sure I’ll have to someday.

This is my solution for the angle issue: set right down on the mounts no problem.

These are photos that are like shooing the back of someone’s head since all the important bits are on the other side. I used a ratchet strap from the big hole in the motor mount bracket to the hook, some microfibers on the valve cover and then I was able to perfectly set the angle.

 

[Stevehose]

Today I finished stripping the block, it's off to the machinist tomorrow. A few notes:

The dipstick tube would not come out without violence but it's out and a new one on order to replace the now mangled one.

The crank sprocket is quite worn on the oil chain gear so I found one to replace it with. It took a bearing puller strung to its limit and a blowtorch to pop this sucker off. Old:

NOS made in W. Germany, feels like it was also used on a Tiger tank:

Crank came out without incident, all the bearing caps look like this, not bad for 51 years?:

Except the most rearward one looks like this with a little wear:

The rod bearings are a couple years old and all look like this, any comments of note?:

How about the end of the crank where the seal rides?:

The journals all look good? and measure 60mm and 48mm:

Block is now loaded up in the truck and off to the shop in the am, once I know what the bore situation is I will then order pistons:

The head is in triage in San Francisco having its fate determined. Now to order parts and fasteners and other "while I'm in theres"....$$$$

 

[wkohler]

I have had a really hard time finding standard main bearings. Last block I had done I picked up end of last year and I struck out a bunch. My machinist got lucky and found a set that had been sitting on a shelf in Colorado.

Perhaps someone has a surplus set and could help you.

 

[sfdon]

I have bearings in stock

 

[Stevehose]

Piston question - are there any limitations regarding piston ring sizes when getting pistons made, or can they be custom sized just like the pistons themselves?

Given the above, if my cylinders need boring, should I stick to the usual .25mm increments or just as much as necessary? How does this affect piston and ring availability? I want to be able to communicate this with the shop to avoid a SNAFU or FUBAR situation.

 

[HB Chris]

I think you will need to use standard sizes or rings will not fit.

 

[sfdon]

You want standard oversized pistons and rings.
Anything else will get expensive.

there are many companies that can make custom rings- we use TotalSeal

 

[rsporsche]

Steve, really glad to see the majority of the engine in such good shape ... obviously well cared for with one minor SNAFU.

 

[Stevehose]

Steve, really glad to see the majority of the engine in such good shape ... obviously well cared for with one minor SNAFU.

Thanks I am hopeful my attempt at self-inflicted FUBAR will turn out ok. Many questions still to come!

 

[rsporsche]

 

[DWMBMW]

 

[Stevehose]

Stan Dale is incredible for making the club what it is

 

[TodB]

Love the Fairlee shirt!

 

[Stevehose]

Block got decked today, .004" (.1mm) removed and now clean and true. Next up, order the pistons (eta 6 weeks), then they will measure each one and bore accordingly for each cylinder. I am going 89.5mm piston size and 10:1 compression. Will also replace the wrist pin bushings. So now my deck height is 217.5mm (stock) - .1mm = 217.4mm and will let the piston maker know the new decking measurement if it matters?

 

[Wes]

Do I recall you have some nice second hand pistons? Must be getting old..

 

[Stevehose]

Do I recall you have some nice second hand pistons? Must be getting old..

Yes, but unfortunately now only 5 are nice. They’re going to Don so hopefully he can find a 6th and transplant them yet again.

 

[Dick Steinkamp]

...will let the piston maker know the new decking measurement if it matters?

Here's a good article on that...

What is Deck Height? How to Calculate and What it Means

Deck height is a vital engine measurement that dictates rod length, crankshaft stroke, piston-to-head clearance and so much more. Here, we define deck height, how to measure it, and its effect on your

k1technologies.com

You may want to actually measure the deck height (crank centerline to deck) to make sure the block has not been previously cut. This AFTER the crank mains are line bored if that will be a part of the process.

I'd be most comfortable having the machinist responsible for the entire rotating assembly....including having him specifying and ordering the pistons. Otherwise, if something goes south, the finger pointing starts.

 

[Stevehose]

I’m back at the project after a month and a half road trip. In that time I ordered pistons from JE which are due any day now. These will go to the machinist who will then measure each one and bore the corresponding cylinder accordingly.

Thanks to Don my head is back, his wizard machinist managed to repair the damage instead of replacing an otherwise very nice head (1987 factory warranty head). Don is also rebuilding my oil pump which will be a nice upgrade in psi. I also had the VGS intake manifold port matched to the head while there. I have rebuilt and made some mods to my Weber side drafts and they are ready to go.

Today I got started on rebuilding my master cylinder, if all goes well I will post a dyi on that in due course. Then I removed all the engine compartment components, clamps, screws etc in preparation for sanding and paint. I plan on heating up the tar insulation at the edges to hopefully lift it up slightly, mask and paint, then push them back down over fresh paint in order to avoid a mask line.

I also managed to remove the original a/c decals and orange diagnostic cap without damaging them. I have replacement decals but will try reusing these first. The silver one is not easily reproduced correctly as it is 3d.

I also received the brake booster and steering gearbox back from their respective rebuilders and they look great. So glad I didn’t take on opening up the steering box.

Things will start to pick up engine-wise once the pistons come in but in the meantime the side projects are never ending and the parts accumulation is staggering (and $$$).

 

[HB Chris]

We need new a/c stickers like yours, none of the repops say 2.2 LBS. if you had your manifolds and valve cover vapor honed (it looks like they were sand blasted) you would be amazed at nice they will look. They will be a bit bright but just shoot matte clear ceramic on them.

 

[bluecoupe30!]

Wow Steve, I hope you don't have to take on a second job to pay for this rebuild. Today EVERYTHING costs more. And at this level, there is no going back. You have a lot of experience, great contacts, amazing advice, I am sure it will help. On a side note, up here I have been trying to get some basic engine block machining done. Non-BMW. Several shops we trusted, locally, have closed up, retired, property taxes killed the deal, and others have, well, somewhat less than 5 star ratings. Taking a while to get the overburdened, but dependable shop to get to my project, but just another example of how difficult it is to keep our projects moving forward. Best of luck! Mike