Crankshaft threads

[Loren]

When I took my crankshaft to the machine shop they said it was too worn to economically repair.

But they just happened to have one they could regrind and sell me.

When I got the replacement home and started my re-assembly I found that the "NOS" bolt that holds the pulley on wouldn't thread into the crank.

So I decided to see if I could get a tap to straighten out the crank's internal threads.

After ordering a tap from an online supplier and waiting and waiting and waiting, I found out they had cancelled the order.

So I re-ordered it......same result.

Finally I ordered one on eBay, from China.

For one third the price of the one from the U.S. supplier I got a tap and a die.....and it came today.

Good thing too. The NOS bolt needed its threads dressed as well.

Carefully I cleaned up the threads in the crankshaft. When the two parts came together they threaded perfectly.

Can't get an American tap but you can get a Chinese one that works perfectly....no wonder they have the bomb.

Clearly this is not a high production item. The size was hand written on the tap and the die with an electric pencil.

The size of the threads are 1 1/8 x 14 which are not real common. If anyone should need to know.

[P15-D24]

Actually surprised you had so much trouble getting one. McMaster Carr has all three styles of taps listed in that size with no warning about availability. Not cheap (175.00) but available. I would bet any of the other industrial supply houses like MSC would also have them. 

[Loren]

6 hours ago, P15-D24 said:

Actually surprised you had so much trouble getting one. McMaster Carr has all three styles of taps listed in that size with no warning about availability. Not cheap (175.00) but available. I would bet any of the other industrial supply houses like MSC would also have them. 

 

The supplier I went to deserves the bad review as they didn't inform me that they twice cancelled the order. MSC-Direct. Their price for a tap was $125 and 152.00 delivered.

The Chinese Tap & Die pair were $44.76 delivered. Yes it takes 3 weeks from China but it came. The order from MSC-Direct took 6 months and it didn't come!

At the very least eBay would have refunded my money if it took over a month to get here, so there wasn't much risk.

Then when it worked it makes you think why use an American supplier with lousy customer service for more money?

Besides how often am I going to need a 1 1/8 x 14 tap & die? Just finding it the next time I need one will be a challenge! lol

[Plymouthy Adams]

as chasing threads already in place but needing dressing is a far cry from starting new threads in raw material.....I agree, the sensible and economical choice was the one you made....and given the rare use in the future...and as a chaser...will work time and again.  I have found some of the overseas taps are worthless for new thread cuts...excellent dressers.  Glad this worked out, my local sells quality taps and dies at a slightly better price than the one seller listed above.  If special order, usually fills within 5-7 days.

[Sniper]

Out of curiosity, did you happen to ask the machine shop if they could have done that for you?  They might have had the tools on hand and got you on schedule a lot quicker.

[Plymouthy Adams]

dang, I saw the power surge as soon as that light came on.....

[James_Douglas]

Thanks for posting the thread size.  I will write it in my master parts book if it is not there. Glad they had a crankshaft.

 

I have 4 spare engines for my two cars. I need to pare down. I think once I get the 265 built and in the car, I will rebuild the one that is in the 1947 which has a NOS crankshaft in it, a NOS came in it and the like. I will have a shop do it and test run it and break it in. Then build a crate with wheels and store it in the crate in a vacuum bag after pumping in some nitrogen. That should keep forever. In the event I every need an engine for either car...it will be there ready to go.

 

Then I can get rid of the rest of the stuff I am sitting on.

 

How is the rest of the rebuild going?

 

James

 

[Loren]

2 hours ago, Sniper said:

Out of curiosity, did you happen to ask the machine shop if they could have done that for you?  They might have had the tools on hand and got you on schedule a lot quicker.

 

I didn't discover it until I was about 2/3 rds into the assembly. Also I don't believe I will be going back to that shop. They seemed to forget my instructions for their own convenience.

[Loren]

52 minutes ago, James_Douglas said:

Thanks for posting the thread size.  I will write it in my master parts book if it is not there. Glad they had a crankshaft.

 

I have 4 spare engines for my two cars. I need to pare down. I think once I get the 265 built and in the car, I will rebuild the one that is in the 1947 which has a NOS crankshaft in it, a NOS came in it and the like. I will have a shop do it and test run it and break it in. Then build a crate with wheels and store it in the crate in a vacuum bag after pumping in some nitrogen. That should keep forever. In the event I every need an engine for either car...it will be there ready to go.

 

Then I can get rid of the rest of the stuff I am sitting on.

 

How is the rest of the rebuild going?

 

James

 

 

My Dad had a friend who loved motorcycles and when he was offered a great deal on a then new 1948 Velocette, he bought two. He rode one and the second one remained in the crate...in his living room!

I have a brand new 26-27 Model T block still in the crate that I've tried to sell a few times. I am thinking of making a plexiglass case for it and turning it into a bit of furniture.

Think of how nice your rebuilt engine would look under glass!!

On the storage of engines:

I've seen devices screwed into the spark plug holes that are filled with a desiccant that turns a different color when saturated. These are used for aircraft engines. I'd think they are probably available for sale from say Aircraft Spruce.

My Project:

Since my car is buried in warehouse #2 of 3 and my engine is going to #3 and we are moving, things are somewhat stalled at the moment.

 

[knuckleharley]

15 hours ago, Loren said:

When I took my crankshaft to the machine shop they said it was too worn to economically repair.

 

I dunno about "too worn to economically repair". I worked in a machine shop in Denver in the late 70's that did nothing but rebuild camshafts and crankshafts. We even welded broken ones back together,chromed the journals,and turn them back down to stock specs. The owners liked racing,so even a few "one off" stroker cranks were welded up for racing engines.

 

I was told it was the largest crankshaft rebuilder in the nation,and we even rebuilt a few that were 16 feet long and came out of the huge trucks used in the salt mines. Have no idea what it cost to rebuild one of those cranks,but I'm pretty sure the bill would scare you.

 

The bread and butter was regular automotive cams and cranks for distributors,though. People like "NAPA stores". And we kept busy doing it. They had already been in business (2 brothers) for something like 18 years when I was hired there,and their "plant" was a whole city block when you included warehouses for shipping. We even got in cranks to rebuild from as far away as Australia and Europe.

 

That business wouldn't have been as successful as it was if it cost that much to rebuild cranks. Granted,we did our own welding and chroming in-house,but it still wasn't "Free".

 

They were great guys to work for,too. A couple of their original employees were still working there when they hired me.

Edited March 7, 2021 by knuckleharley

[Sniper]

1 hour ago, Loren said:

I've seen devices screwed into the spark plug holes that are filled with a desiccant that turns a different color when saturated. These are used for aircraft engines. I'd think they are probably available for sale from say Aircraft Spruce.

Excellent idea, I jumped over to Aircraft Spruce, they only list ones for 18mm thread, I believe ours are 14mm.  Ebay and Amazon show them at that size.  Not super cheap but probably worth the cost to protect your engine.

[James_Douglas]

There is an Industrial Hard Chrome shop in San Jose, CA that I have used. My 2nd gear, although NOS would not spec out even with the thickest snap ring that would fit. The back side of that gear rides on the step on the main shaft and it was warn. Try finding a main shaft for a three speed that has BW overdrive. I looked and looked. {That said about a year ago one came up on ebay and I snagged it}

 

I had the shop hard chrome the rear of the rear face where it rides on the shaft step. That made up the clearance so that it was right on the low end of the specification. That second gear is very quiet and shifts great.

 

They had a crankshaft from a ship in there and it was BIG. They said they could do a car crank without any issue.

 

James.

[Loren]

1 hour ago, James_Douglas said:

There is an Industrial Hard Chrome shop in San Jose, CA that I have used. My 2nd gear, although NOS would not spec out even with the thickest snap ring that would fit. The back side of that gear rides on the step on the main shaft and it was warn. Try finding a main shaft for a three speed that has BW overdrive. I looked and looked. {That said about a year ago one came up on ebay and I snagged it}

 

I had the shop hard chrome the rear of the rear face where it rides on the shaft step. That made up the clearance so that it was right on the low end of the specification. That second gear is very quiet and shifts great.

 

They had a crankshaft from a ship in there and it was BIG. They said they could do a car crank without any issue.

 

James.

 

My business was making and rebuilding large diesel Turbocharger turbine wheels, so we did a lot of cylindrical grinding. Hard chrome plating goes along with that kind of business. Southern California used to be an aircraft industry center in fact that was the largest employer in the area. Not so much anymore.

The nice thing about chrome is that it is hard in the range 62 on the Rockwell C scale. Good chrome moly steel can be hardened to 52 c but it starts to get brittle. Normalized and tempered Chrome moly is very strong at 28 c but it can wear. Hard Chrome Plate it and you get the best of all combinations. Plus chrome plating makes an excellent bearing because it can be so smooth when ground. You couldn't get any better than a hard chrome plated and ground part.

Trouble is chrome shops are getting rare and grinding shops even more so.

If you think ornamental chrome is expensive, I would imagine Hard Chrome is worse.

[Eneto-55]

The plating shop where I worked in Tulsa back in the late 70's into the early 80's was United Plating Works.  I wasn't assigned to the chrome area, but the shop did aircraft crank rebuilds.  (I just got involved in the bead blasting & hot tin plating we did on the cranks before sending them out.)  UPW is still in operation, and I would imagine they are still doing all of this sort of work, as the main customers were the aviation & oil industries.