But Ma, it followed me home

[otto_kretschmer]

Old on the top right, the ones I made this morning on the bottom left

I'm having lunch right now. I'll see how the new washers work later this afternoon.

New thrust washers are only $12 a set so sometimes I wonder why I'm doing things like this. Then I wonder why don't I just get a new car and not mess with a 65 year old car that was pulled out of a barn. New washers may not work so why not see if I can make them myself?

[otto_kretschmer]

Originally Posted by herr_oberst

Fantastic! Is the factory thrust washer aluminum, too?

Its odd. I have two engines worth of parts, and some parts of a 1275. Some of the thrust washers are aluminum and some are bronze/brass/copper

I don't know what alloy I used. It was just a bit of scrap aluminum sheet I had laying around.

I don't have a clue why BMC went with a thrust taken by the middle web of the block. Every other vehicle I've seen takes it at the flywheel end. There are four thrust washers. Two are on the web on each side and two are on the main bearing cap on each side. None of the washers have the same thickness. So with the tolerance stackup with the cap and web thickness and cap location I would have to do a blue check to see what washer parts are taking the thrust.

When I get the right backlash on the dial indicator I'm going to call it good and move on.

[otto_kretschmer]

I was flip flopping this week. I discovered the OEM thrust bearings are steel with a copper surface so I ordered a set of new bearings and they came today. I installed them and found the run out to be .008, so a step backwards. I don't see any oversize thrust washers available for the 948 engine so I'm forced to make something on the lathe again. The two I made on Monday I'm not happy with so I'll try again but I'm want to ask people here what they think about material.

Should I use aluminum, brass, bronze or copper? I'm going to Industrial Metal tomorrow for a look at whats available. Maybe they have 2 1/2" hex or round stock. If not, I'll have to use sheet again and cut it on an arbor.

6061-t6 sheet may be what I end up with.

[otto_kretschmer]

3rd attempt at making thrust bearings.



This time I used 120 grit sand paper and ground the bearing down to what I wanted.

Runout tolerance is .002-.003 and its at .002 and I can torque the main caps and start on the rods and cam.

[herr_oberst]

We all know you're giving this a lot more thought and effort than the manufacturer did when they built the engine. Fun to watch the progress. Can't wait to see it assembled.

[otto_kretschmer]

This is the collection of thrust bearings I ended up with. The new set, the old and the three I made this week.



Unfortunately the bearings on the web will take all the thrust. I used the old bearings with the ears on the cap and all they do is prevent the bearings on the web from rotating. I was thinking about making the cap bearings but I would have to do it on the mill, make a tool to hold the material on our rotary table, and the mill is down for a month so I'm not going to bother. I think the upper bearings can do the job alone.

[Steve F]

Otto, Is that lathe an Emco model? That green looks familiar

[otto_kretschmer]

It's a Grizzly. Made in China. It's ok. Does the job for what we need. I cut threads for a bicycle headset lucknut.

I had a thought this morning. I could have taken the old bearings and used silver solder to add a couple thou on the thickness and sanded them to size. I may do this for the cap bearings.

[Scott Douglas]

When you make these bearings, do you make two sets the same size so when you cut them in half you can get perfect halves?
In other words when they're laid flat on a table and two halves are put together do they make a perfect circle?

[otto_kretschmer]

No,

just take a hacksaw to the ring after I'm done on the lathe and cut it in half. Good enough. The OEM bearings are punched from steel sheet with a die and then plated with copper. They're made by the hundreds of thousands.

I don't want to make the bearings too tight either. When the engine gets hot, the aluminum parts expand more than the steel and iron parts so the tolerances and fit must be considered. All these bearing do is keep the crank in place. Too tight and things will bind. Its probably better to be on the loose side.

Its not hard to get these bearings out with the engine assembled in the car. Drop the oil pan and the pick up tube then remove the center bearing cap and the bearings come out. Most cars you must remove the tranny and flywheel.

I torqued the main cap bolts today and the crank spins freely so that gives me confidence that I'm on the right path. This is my first car rebuild in 24 years so I'm taking it slow. I rechecked the runout after torqueing the bolts and its still at .002.

[Alan A]

For future reference - BPNW stock 5 thou oversize. Moss stocks 3 thou 5 thou and 10 thou oversize.

[otto_kretschmer]

Originally Posted by Alan A

For future reference - BPNW stock 5 thou oversize. Moss stocks 3 thou 5 thou and 10 thou oversize.

Do you have a link? I only see the std thrust bearings at BPNW.

https://bpnorthwest.com/austin-healey/thrust-washer-set-std-848-948/

[RobFrost]

I'd love a Sprite if I had more garage space. There's a bmw crossflow head goes on that engine, and they take a supercharger nicely too. Just saying.

Sent from my SM-G988B using Tapatalk

[otto_kretschmer]

Pistons and rods are in.



More parts coming in tomorrow.

[DonDavis]

I saw a really sweet looking orange Bugeye headed west on the Red Mtn 202 near the Higley/Greenfield ramps. He was scooting’ along at nearly 80. My cruise was set at 72 and was pulling away rather quickly.

Had a personalized plate that read “59…”.

Anyone you know?

[otto_kretschmer]

nope, but I'd like to meet him some day

I'm still waiting for the machine shop to finish the head.

[otto_kretschmer]

Got the head on and torqued.

Set the valve lash today too... .012 according to my book. Hope thats right. It seems too loose, especially for a water cooled engine.

baby steps