Projects Shade tree Model A speedster kind of thing

I was taught that the job of the oil ring is to remove excess oil from the cylinder walls to control oil consumption because the compression rings could not do an adequate job of it.
Perhaps having the return holes in the back of the oil ring groove would help, but I wouldn't count on it. Oil ring design has been the same in every piston engine for over 100 years so it must be a pretty good plan. Your choice though and as you said, it's not a big job to remove them later and make a change.

 

Either way Fabber, I think your idea of opening up the grooves and using real oil rings is a good one.

 

I bought a lot of model A NOS piston rings off A auction site. It came with over 20 sets in various sizes. Let me check if I have some that are like you need.

 

In the '30s racecars those multi-disc clutchs were often used(with the flywheel machined off) so that they had a clutch available, even if they needed to tow or push start initially. Many of them that raced on the 1 mile or larger tracks needed a transmission with at least 2 gears to get up to racing speed without straining the drivetrain excessively.

 

Well I checked I have no sets that had the 1/8” oil control rings just 5/32”. I did take a look at my AR pistons and rods and they aren’t original. And have the late style rings in them. Must have been a early on warranty rebuild! ;-) .0025 oversized seriously. That is even more odd. Still has X beam rods though.

 

Thank you for looking, anyway. Mine have the early rods, too, but those pistons are definitely not the same as mine. .0025, maybe marketed for engines that had been honed several times but not bored? I think I'm going to follow Fabber's advice and just enlarge the bottom groove to 5/32. Anybody got any information on the pros or cons of the early x beam rods? Google is oddly silent.

 

I don’t know if you know someone with the tool to make the ring gaps larger. But NOS model A/B Pistons are cheap. Plus it gives you the better pin clips on each side of the piston pin. I think that is the problem with the X beam rod is the center single clip that held the piston pin in the piston would fail and score the cylinder wall. Just me thinking out loud. Awesome build I want a speedster now! I have the engine just need to get to work I guess.

 

I spent all my free time this morning on one piston. The wrist pin drove out pretty easily with a deep socket. Ground a little cutter that would fit in the 1/8" groove. Turning it out the thickness of the oil ring stack plus .002 involved some finicky measuring, but was straightforward.





Re-assembly was the catch. These early wrist pins are held in by a c clip in the middle of the rod bushing that rides in a groove in the pin. Here it is:



Like I said, the wrist pin drove out just fine, but putting it all back together wasn't so easy. I assumed that the chamfer on the pin would let it pass the clip, but it wouldn't. I tried carefully expanding the clip with a pair of needle nose pliers, but as soon as I tried to tap the pin in, it pushed the pliers off and the chamfered edge caught the clip. I finally made this little slug:



It is just under the wrist pin diameter and has a long, shallow taper leading to a sharp, square trailing edge. I put it in the rod (facing the right way, thank goodness. It would be just like me to get crossed up and end up with the dipper facing the wrong way...).



Then it was just a matter of pressing the pin in and letting it push the slug out as it went. The pin is a really tight fit in the piston. I used my patented shade tree press.



That rod and piston set in the background is from my father's old engine, late model with the H beam and external clips on the wrist pins. Had it out when I was puzzling over the rings. I know some of you sharp eyed guys will spot it and wonder. Anyway, hopefully, I can get the other 3 done over the course of the week. We'll see.

 

Dang, 12, I posted my diatribe without even checking the thread or seeing your response, so the center clip thing is kind of double covered. Oh well. I wonder of some of those clip failures weren't caused by guys just muscling the pins past those clips during rebuilds? My pins fit mighty close in the pistons, and I could hear that clip pop into the groove when I pressed it in. Seems like a pretty secure arrangement, unless that clip breaks.

 

By the looks of it you figured it out. I believe your solution is a solid fix and you will be back running in no time.

 

I think the pins come out easy because the clips are already held partially expanded by the pins, so when you tap it, it just pops past. When you are trying to insert a wrist pin, the clip is completely relaxed, and the pin fetches up against the perpendicular side of it. Just read over that explanation and realized how confusing it is. Here's a quick picture of what I mean:

 

I see what you mean. Lets see how the rest come out unless you have done the other three. I keep thinking that the
clips are in a grove like a grove on a ring. But of course that makes no cense, you would never get the wrist pin out.
But What the Hell do I know.. But your looking Good!! You are right I am sure there is some type of tool to insert
the wrist pin with the clip type..

 

OP, fantastic! You can knurl those piston skirts. There is a tool that mounts to a vise. An old engine shop will have one. We have also just used a sharp punch to make a zillion little divits in the skirts. This raises aridge of metal and makes them ‘bigger’. Knurling piston skirts was common back in the day.


Sent from my iPhone using The H.A.M.B. mobile app

 

Thank you, but I don't think I'll need to knurl them or upset the skirts with a punch. I'm just going to slap it back together and see what happens.

 

Well, I got the pistons in yesterday. Had to open up one groove a tiny bit on the lathe, which meant taking the rod and wrist pin back out, but I'm pretty good at that now. Spent most of this morning degreasing, scraping, wirebrushing, and painting. That's not any fancy paint, just good old Rustoleum, brushed on (what, think I was going to break out a HVLP on this rig?). Hunter Green and Black mixed 4:1, green to black on the engine. Probably should have gone 3:1 or even 2:1, it looked darker in the bucket, but oh well. I might throw on another coat, depends on how it looks dry. Safety red on the head and manifold. Everybody knows red adds HP. Anyway, you can't spell street cred without red. Haha.

 

Every time I see your work shop floor I smile. No sweeping, wiping up oil or worrying about over spray. Just have to make that stick is not a snake.

 

I am careful with the oil. Don't like spilling it on the ground. Somebody mentioned me not working under that pole barn. One reason is that the floor of that thing is just plain, fine dirt. Drop an oily bolt and you have to spend five minutes cleaning it, and I drop a lot of oily bolts. On that pinestraw, you just pick it up and blow it off.

 

I'm enjoying following this build and like the way you've been doing the freshen up on the motor. Nice to see a lathe in action, machining is another of my interests.

 

Thank you. I'm not a machinist, just a jack-leg with some machines. A real machinist would shudder at some of my methods, I'm sure.
Back to the paint project. After it dried a little, the green suits me fine. Not as dark as the original paint that was on it, but it's a Model A, so it will immediately start darkening it with oil and grease as soon as I get it back running. It'll knock some of that gloss off of it, too.

 

Just keeps getting better. Going to be such a cool car!

 

Making progress. It's back together and on the hoist. You can see the lightened flywheel. I've got a B distributor with the centrifugal advance coming in the mail, so I made a little pointer for TDC. If the rain holds off, I should be able to button it back up today or tomorrow.

 

That thing looks Mean Man...! TESTAROSSA!
(remember those printed wall papers?...You got the Real Deal in your shop!

 

Haha. Yeah, it's nice out there when it's nice out there. Bad weather kind of gums up the works.

I spent too much time this morning trying to drop the engine back in with the trans still in place, couldn't get the pilot shaft to line up. Finally gave up and did what I should have from the get-go and dropped the transmission and dragged it out from under the car, set the motor down on some scrap lumber, started manhandling things. Went back together like butter. Gave me an excuse to take the shift tower off and take a look at the insides. There's a little wear, but I think it's ok. Looks like Thanksgiving is going to put a stop to all of this foolishness for the next couple of days, though. Everybody have a good one.

 

First time that I've seen this, read through most of it in one sitting. What an amazing project. Great work - the wooden body pieces are beautifully done!

 

Just found this! Subscribed.


Walt
Outsiders CC

 

I stole a little time the last two mornings to get the engine back in. Still got the motor mount bolts to do, so that will be fun, but I hope to have it running again this weekend. Famous last words, right? It's a little too shiny for my taste, but, like I said earlier, I'm sure that won't last. I know that fuel line kind of looks like Dr. Suess made it, but... Anyway, thank you all for the comments.

 

Thats my Mom--------See what she started?

 

Used some holiday free time to catch up on this thread. I love the way you keep moving and adapting. Very, very cool!

Dude! Your mom is driving an early Mercury Body Speedster! That makes me smile.