Projects A Speedster Comes Out of the Weeds—Build Thread

Harv,thanks for the info. More than I want to pay for an experiment.
I think I'll stick to my aftermarket intake and a Stromberg 81.

Thanks,

jim

 

OK, enough with the dancing. Celebration’s over. Back to the task at hand. A couple days ago I finally got some time to pull #1 piston. This was the hole with the cleanest piston top, but the dirtiest spark plug.

The results were inconclusive.


No obvious problem, like broken or stuck rings. One thing I noticed is that the top piston ring and bottom ring each have a super-thin companion ring. You can just see them here at the top of the groove.


I’ve not seen that before, but lord knows there’s lots of stuff that I haven’t seen. But it occurs to me that maybe those rings are supposed to be clocked, and having the gaps line up might create a path for oil?

Or maybe I’m grasping at straws…

The pistons are each stamped with a "1" at the top, which I'm taking to mean .100 O.S., a common Model A bore size. My good calipers and Crappy Chinese Bore Gauge seem to confirm this. My Crappy Chinese Bore Gauge also tells me the taper is OK.

Still three pistons to remove and examine with much dirtier chambers. I’ll keep you posted.

 

Dang. I remember this ride when ya dug it out.
Somehow I missed it not long after.
Great job.

 

Knurling is an enlarging operation...

Sloppy bores?

Could the problem in fact be valve related...

Staggering rings is absolutely essential as you are implying...

These are my waaaaay primitive non expert comments...

 

Your top ring has a spacer above it and that should not be there. The width of the ring is to narrow. They also do not look like they have enough tension on the cylinder walls but I could be wrong. I would remove them and check them in the cylinder. Keep them in order and the right side up. Gary

 

Yes, the pistons are knurled. I'm still processing that, but it's not ideal. Plan is for new valves and guides. I can feel a little wobble in most of the valves. And new ones are cheap.

Thanks, Gary. That top ring spacer had me baffled, so this is good to know. I'll check them like you suggest, because it's all useful information as I try to suss out this engine's overall status. Plan is for a hone and new rings.

 

Thinking out loud...no more...I have read and already saw it mentioned what I was saying by Roadster...

 

Maybe I missed it, but how do the bores look? Any hatching left, or smooth, or longitudinal scratches?

 

I've assembled engines with the rings staggered, put 10k miles on them and pulled them to change compression or make other changes and the rings quite often have lined themselves up

 

Oh damn @rwrj, you are prophetic. I pulled #2 piston today and got the bad news.



That’s #2 on the left, #1 on the right. Note the absence of retainer rings for the wrist pins on #2, and the wrist pin flush with the outer edge. The wrist pin has scored both sides of the cylinder walls badly. It’s going to need a sleeve.



Don't know why I didn't see this before. I guess I was fixated on taking it one cylinder at a time. It's just like when I found that counterbalanced crank last week--I totally missed seeing The Great Big Thing That’s Staring You In The Face.

Well, at least it answers the question of what's causing the smoke. I'm bummed, but I keep reminding myself that I knew there was a likelihood of finding something like this. So now my “simple” in-car ring and valve job looks to be morphing into a pull-the-engine overhaul.

Ah well, the car gods giveth (crank and cam) and the car gods taketh away (scoring). I’m taking a brief mental break to mull options.

 

Looks like someone did some sloppy work with some good parts at some point in the past. Sucks, but will be worth it in the end.

 

Man that sucks...silver lining is its repairable thankfully...you've lightened the load indirectly with of removal of many components already...yes time to step back to ponder the next moves...

...we'll be here following along @ClarkH...I suspect the retainer was never there as there would have been evidence on the wall...or does the piston drop down far enough for it to drop into the pan?

 

My brother and I were speculating along those lines. There's some nice machine work in there, and there's also some signs of amateur assembly. And you are correct: this ordeal will be worth it in the end. It was on borrowed time.

Wow @Stogy, I hadn't even thought of that, but you could be right. The piston does not come down that far. And there was nothing trapped inside the hollow wrist pin. So maybe it wasn't installed in the first place? Good grief. See @Squablow's comment above.

 

I wonder if the assembler forget any of the others?

 

Yeah, when somethings left on the bench or falls and rolls away under the toolbox does anyone know any different......at least it didn't wear right through and blow up Ole Stinky Poo

 

One way or the other, we'll find out tomorrow. But I don't see any score lines, now that I'm actually looking.

 

The circlip could have been beat to pieces, and made it's way out the exhaust, so check the valves really good on that cylinder.

 

Normally when a piston is knurled only the lower end of the skirt is done. You will need new pistons when you rebuild the engine and the correct ring set that fits the piston you use.

 

I don't know. I'm the voice of very little experience here, but it seems to me that the circlips couldn't have gotten out of there without some pretty catastrophic consequences to the cylinder walls. I think they were never installed. What a shame. I like those pistons. I think they are a pretty cool part of the car's story. They were working fine before. I'd keep them, but that's just me. I'm a sentimental fool. Of course, that's if you can get the bad bore lined and the other holes honed and have the pistons still fit. Either way, I'll be rooting for you.

 

The extra thin rings you see are used to save worn out piston ring lands... there is a special tool that cuts the worn ring groove oversize and the thin spacer rings resets the up/down ring clearance back to factory specs. Was a pretty common repair back in the day... I installed a lot of those in my time. If I remember right they were always installed under the ring not on top as in your pictures.

 

Thanks for this information guys. Sounds like these pistons are at the end-of-life. Not that it mattes, because I'm guessing the bores are sloppy anyway, and I'll have to go up to .125. And that's predicated on there being enough room for that with the addition of a sleeve.

 

Catching you all up on my progress. Pulling #3 and #4 pistons provided further validation that all of this needed to be done asap. Specifically, the babbit on #3 has failed.


Fortunately, it apparently hadn’t reached the point of damaging the cool counterbalanced crankshaft. But it was only a matter of time.

I’m speculating #3 was replaced at some point. It had different sized nuts (5/8 socket as opposed to 11/16 on the others). It also had 3 shims, whereas the others had only 1 each. Shims are used on Model A con rods to take up slack as the babbit wears. I’m speculating somebody replaced this single con rod and didn’t mic for tolerance and/or didn’t understand the purpose of the shims. Net result, it was assembled with too many shims, which made it loose and the babbit got pounded. Not that it matters, that’s just life in the world of old Model A engines.

Anyway, no turning back now. Engine had to come out.





I’m now in the process of tearing it down. I found it easier to pull the valves sitting on a stool with the engine on a cradle. I’ll move it to the workbench next to get at the cam and crank.



As expected, I found several loose valves, so the guides need replacing (was going to do that anyway). The valves themselves were a mishmash of at least 3 aftermarket manufacturers; probably each replaced only as needed. Four of the head studs have been re-tapped to 7/16 (stock is 3/8). You know, just more old Model A engine stuff.

Ever onward!

 

Looks like it was thrown together with whatever was laying around. Luckily a counter balanced crank and B cam were laying around!

 

Ha! Exactly. A Jekyll and Hyde motor. Somebody even went so far as chroming the flywheel housing and timing cover.

 

Can you imagine the tree of life for the sum of all parts within just that engine...sorry for the extent of wear but the next push of that pedal will feel like 4 more cylinders...and be better for your lungs...

 

I’m sure most of you interpreted my radio silence on the speedster as an indication that not all has gone well with the engine refresh. Good news is, it’s nothing catastrophic. But it’s not going to be the easy refresh I’d hoped for. Not surprisingly, all machine shops are backed up around here, 6+ months out. And the moment you say “babbit,” their eyes glaze over. So freshening this thing up is going to be a long-term operation; it will give me something to do this winter. And maybe next…

In the meantime, with several vintage speedster events on the calendar, I tried a Hail Mary to save my driving summer. Sitting in the corner of the garage I had a cheap used motor I picked up as a mockup/placeholder for my pickup project. It was the typical mystery motor situation: The Hamber I got it from said he’d been told it was a runner by the guy he got it from. I had the impression he’d checked the valves, and with the pan off I could see everything looked more or less OK. So I rolled the dice.

About this time I managed to screw up my back again, so I’m grateful to @Hitchhiker and my brother Ric for helping with the heavy lifting. (I’m also grateful that they kept any opinions they might have about a 60-year-old playing ice hockey to themselves, unlike others in my orbit.)

In hopes of giving the “new” motor a little pep I put an original police head on it and transferred the lightened flywheel, Mallory dual point and Stromberg carb + intake from the wounded original. When we went to start it, the thing coughed on the first try and fired up on the second. Ran good and strong, with a refreshing lack of smoke.

I spent late June and much of July putting the engine through its paces. Dropped in on a few cars and coffee events and trailered it to the family cabin near the border for some trial runs on the back roads of Blaine. All in all, I think it runs pretty darn good for a $100 engine. Doesn’t have quite the kick of the motor I took out of it, but it’s no stocker either.

 

Looks and runs great glad you got a good engine! Gary

 

Looks good in the video!

 

What about the time with the broken thing and the rescue at the place?

 

It's coming. Patience, man. I'm building drama here.