New car surprises . . .

[Brentwood Bob]

Archie, good to learn about baking. The pictures helped to see what you found.
Sounds like you are in business.
Bob

[Archie Cheda]

Tom,

I do not see how Naval Jelly would have a short shelf life -- so long as the bottle is sealed. The modern version should change color if it lost its acidity.

Bob,

Glad to see you in person at the Turlock swap meet . . .

Archie

[Brentwood Bob]

Didn't need ice in the cooler at Turlock.
Will check on a rod, I just have to find them.
That rod you have to replace makes me wonder if it was a friday motor.
Bob

[Archie Cheda]

Bob,

Friday or Monday, or the guy's first day on the job machining rods. Still, the person putting pistons on rods should have noticed if he was paying any attention at all -- I noticed the asymmetrical machining on the small end right away when I bundled the rods. That lead me to check the alignment much earlier than I normally would have. Glad I caught it early in the process. From the various markings on the rod, I figure it has been in a factory motor and three rebuilds, so a lot of people were not paying attention. I quote the line I have read on this forum a number of times: "It is just an old engine . . ."

As to size on a replacement rod, 1.472" or smaller babbitt should work -- that is what the other three measure -- I'll be removing shims and scraping them. If it is a lot smaller I can bore the babbitt out and I can remove a few shims or even cut the cap before scraping to fit the crank, which is actually .033" under standard (1.499").

Thinking about cams, I can see why everyone is impressed with a new (Stipe) cam as most originals seem to be far from what they were when they left the factory. Even with the low spring pressures and low rpm, the lack of oil and air filters would lead to wearing off the tip of the lobe which is only a .030' radius. I think I'll make up a little sheet metal template for a quick check tool that I can carry in my pocket.

Archie

[Brentwood Bob]

42 and drizzle out this morning. Will put a rod on the agenda. Will not be able to give you a weight for the rod on the beam balance. Bathroom scale won't be close enough either. Will take a picture.
Bob

[Archie Cheda]

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Bob,

I'll match the weights of the rods after all the machining, so do not worry about that. If you send me a light rod, I'll just take weight off the others, which are not very close now. The ones I have all are for pistons with snap rings retaining the pins.

Thanks,

Archie

P.S. Let me know by email how much you want for the rod and shipping. If you want to barter for some machining, that would be OK as well.

[Archie Cheda]

I am enjoying this project so much, I am finding ways to make it go on forever . . .

About a quarter square inch of babbitt was broken off the front edge of the front main cap, the loose pieces long gone. I was going to use it as-is, this being an overhaul, but after reading many positive statements on this forum, I checked with Bill Barlow in Bend, Oregon and he is going to provide me with a freshly re-babbitted, rough-machined cap for a very reasonable price. There will be a slight delay, but this will give me time to find more things wrong with my 85-year old-parts . . .

I am also waiting to get my freshly-installed rod bushings burnished and fitted to my new pins. The rod from Bob weighed in at exactly the same weight (both ends) as the lightest of my other three rods -- thanks again, Bob. I got all the small ends to the same weight (within 1/10 oz.) and will do the big ends later. One of the bushings did not take much force to press in, so I know that it will absolutely need burnishing if it is not to become a full-floating bushing. I would have liked to do the burnishing and fitting myself, but I have not yet found a source for a burnishing tool. Ideally, I could use a rotary roller burnisher that I could use in my turret mill, but among the many on eBay, I have not yet found one in the slightly under 1" size. While I have the rods being burnished, I am paying the shop to do the pin-fitting as well so they can make a bit of money on the job. I am also favor using a .002" oversize bushing for the one rod if the shop has a source for one. Once I have the small ends to size, I will rebore the big end babbitt, hoping to have enough wiggle-room to get all the rods the same length as one (of my original set) is shorter than the others.

Since my last post, I also did a traditional valve lapping job -- my first time for this. By luck, all the valves seat well, pretty much in the center of the generous play between the valves & split guides. The seats were getting kind of wide, so I cut them with a multi-tooth angle cutter that I had on hand. It was something like 55 degrees, but that not being critical for the job, it worked fine. I made up a simple arbor and did all cutting powered by hand. This made it much easier to control the small amount of material that needed to be removed. I also checked my two sets of springs and they came in at 40# and 50# at 2-3/8" -- I'll be using the 50# set.

Today, I laid the crank in the bock saddles and checked some things. The end thrust clearance without the caps being installed is a bit high at .009", but with the cap installed it may be closer to the .005" limit -- I still have to check that. The radial runout of the flywheel flange is .0015", thanks to a lack of care during crank grinding. The axial runout at a 2" radius is also .0015", which translates into about a .005" runout at the edge of the flywheel, right on the limit. I may do some work on that flange to cut that down a bit. It may be that the flywheel will mount better one way than the other.

With the crank laying in its saddle bearings, I found that I could rock it quite a bit, with it pivoting on the center bearing. My first thought was some amount of bend in the crank and there definitely was a position with maximum rock and 180 degrees away there was no rocking. I did a bit of straightening by using a blunt chisel and big hammer on the too-small filets on each side of the center main journal. That cut down the rocking quite a bit, but part of the rocking comes from the center main being about .002" higher (with the block up-side down) than the front and rear bearings. At this point, I have the same .004" of rocking, no matter what position the crank is rotated to. Drawing on my machine tool rebuilding hobby, I used a straight edge to check the cap-seating surfaces in the block and they are very near to being in the same plane so the block has not changed shape. Before I do anything, I need to check the cam-to-crank distance and see how much wiggle-room my new timing gears gives me. If I have enough room, the next step is to scrape the center babbitt lower and then continue with the end saddles, finishing with fitting the caps to the crank. I will probably do the block now, but wait until I get the replacement front main cap before fitting the caps.

At this point, I think that the font and rear bearings were poorly fit because of the bent crank. I pulled the crank and put the three caps on with the same shims that were in it when I took it apart -- the center bearing had around .002" clearance and the end bearings were closer to .004". Once more, I am really glad I took this "running" engine apart.

Archie

P.S.: I sense that the state this engine is in will require a very careful approach to "fix" without making things worse. I will be taking my time and appreciate any insights that anyone wants to volunteer.

[Archie Cheda]

I just did some double-checking and, using a piece of ground tool steel round-stock, checked against my straight edge for straightness, I got the same "rock" with the center main being higher (engine up-side down). A test indicator shows the same .004" rock as I got with the crank -- the center main is .002" high relative to the other two. I will be scraping the center main deeper to account for this when I fit the crank to the block. (I will take pics.)

I checked the rear main cap by itself on the crank and it has .011" axial play. The wear on the thrust faces shows that the cap took up thrust in one direction and the block took up thrust in the other. almost five decades ago I learned to push the crank forward and aft in the block before tightening up the main cap that took the crank thrust, but I wonder if on this overhaul I should intentionally set up the cap so that I get the thrust down to .005". The thrust would only be taken by one half of the bearing, but the crank would not be floating around as much for a while. I am interested in opinions on this, remembering that this is an overhaul, not a rebuild. I am inclined to just live with the extra play and put it together "by the book". I guess the question I have is how much axial play in the crank creates a serious problem in a Model A engine?

I put the cam that came with the block back in and with the crank rocked against the front main babbitt in the block and the cam pushed toward the crank (as the valve springs would force it), I have .009" backlash in the timing gears, so I think I can get away with the main bearing fitting I have planned. With luck I can use my new gears, but I can fall back on the used gears as they seem to be in reasonable condition.

Thanks,

Archie

[Archie Cheda]

Although I have done a lot of scraping cast iron ways, scraping the bores of babbitt bearings is totally new to me. I have three scrapers from the Model A days and have only used them a little -- minor fitting of bronze bearings. Because the scraping motion is different and the material is so much softer, I spent several hours "warming up". I removed about half of the .002" from the middle block saddle babbitt. Using the crank as a "scraping master" is quite easy as the crank is not too heavy and has comfortable hand-holds.

Below pictured is the bearing with an early transfer of the spotting ink from the crank journal onto the contact areas of the babbitt. The second pic is a close up at the end of that scraping pass. Finally there is a long shot of the scraper in the position it was during the scraping. I use a water-based spotting ink from the Dapra Corp. rather than oil-based prussian blue. A little soapy water cleans it off my hands immediately and it is what I am used to. I do have some prussian blue, but have not used it in a long time.

My scraping and all the rest of my shop hobbies are strictly amateur -- a professional could not make a living at the pace I maintain with my shop hobbies. I have been paid to work as a mechanic and as a machinist, so I do know how to get the work out, but that is not how I do my hobbies where I move at a relative "snail's pace". There is no rush as I am waiting for my rod's to get the bushings burnished and fit to the pins and also waiting for the re-babbitted main cap. By the time I have received the rods & cap, I will have the block babbitt fit to the crank, thoroughly washed the block, and have the cam & valves all installed.

Unless something interesting comes up, I will be quietly working on my overhaul for the next few weeks.

Thanks,

Archie

[Chris Haynes]

Archie,
If your old block turns out to be the original one to the car then it becomes worth saving. Otherwise one in better condition is the wise thing to do.

[Turkey Broth Trading]

Archie;

Had not seen your thread until today. I had heard you moved "back west" from your outpost in Maryland. Talk to Calvin quite a bit, was at his place a couple weeks back.

Best of luck on your project.

We are having a "cool" spell here. The wind is howling and calling for -8F here tonight, high of +1F tomorrow. Hoping it is a little warmer in SLO.

Craig Donges

[31 Deluxe Coupe]

Howdy neighbors!

[Archie Cheda]

Chris, My car's original engine is long gone. I am not trying to save the engine that came with the car. I am overhauling my the gift engine I got from my 95-year-old cousin -- it turns out that it is one of those engines that "was running when we took it out of the car . . ." (The reason for removing it from the car was to replace it with a rebuilt engine that does not have to be towed to get started. When one is 95, one tends to forget things like that.) My current project is to overhaul this "running spare" engine -- I intend to do a very complete rebuild on another engine in about a year.

Craig, Good to hear from you. I try not to bring up the weather, but since you did, it was 83 degrees here today . . . I am in the process of trading a three-foot Challenge straight edge for a three-foot CD straight edge raw casting. Small world, huh?

31 Deluxe Coupe, Private message sent.

Everyone else, it only took another hour of scraping to be printing on all three bearings. When I get back to scraping, it should not take too much longer to get the print even across the bearing surfaces. Then I suppose I can scrape in the middle and rear main cap babbitt to the proper clearance -- probably .0015".

Thanks,

Archie