Pick a Crankshaft

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Model T Ford Forum: Forum 2009: Pick a Crankshaft
Top of pagePrevious messageNext messageBottom of page Link to this message  By Gene Carrothers on Thursday, August 06, 2009 - 04:32 pm:

I'd like to hear some recommendations about which crankshaft to replace in my 12 Torpedo.
At this time I'm working with my original 12 block so a Model A or other crank is probably not a good option. What do you guys think of the new counterbalanced cranks?
My understanding is that there are three available:
1. New Zealand Bumac
2. Lakemn USA
3. Langs New Supplier one Made by Bill Dup???
I know several cranks have recently broke and wondered what others are using for replacements.

Thanks
Surf City Gene


Top of pagePrevious messageNext messageBottom of page Link to this message  By Darren J Wallace on Thursday, August 06, 2009 - 04:38 pm:

I would try to find an original one with the EE stamped in it. I've heard these are the best of the Ford made cranks.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ted Dumas on Thursday, August 06, 2009 - 05:00 pm:

I think if you thoroughly evaluate Bill Dubat's crankshaft and the work he did to develop it you will find it the best choice. The austempering of the ductile iron gives the fatigue properties of forged steel. Call him, he will be glad to answer any questions you might have.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Gene in HB on Thursday, August 06, 2009 - 08:57 pm:

Thanks Darren and Ted for your input.

Of course If I knew someone that had a good EE for sale that would be another story considering the price difference.
I've also been told by others that the counterbalanced ones run much smoother than stock and are worth the added dollars. On the other hand a local racer questioned the added rotating mass.

I'll try to contact Bill.


Top of pagePrevious messageNext messageBottom of page Link to this message  By David_Cockey on Thursday, August 06, 2009 - 09:46 pm:

The major benefit of counterbalancing a 3-bearing crankshaft in a L4 engine is reduced loads on the bearings, particularly the center one. An added benefit may be reduced crankshaft vibrations.

The difference in rotational inertia (mass) is negligable compared to the rotational inertia of the flywheel, transmission and rest of the driveshaft.

Counterbalancing a crankshaft is fundamentally different than a pair of Lanchester type balance shafts which run at twice engine speed and reduce/eliminate second order "inbalance" due to finite length connecting rods.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jack Watt on Thursday, August 06, 2009 - 09:55 pm:

What years did Ford put out the EE crankshafts?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Darren J Wallace on Thursday, August 06, 2009 - 10:54 pm:

Does '26-'27 sound correct guys?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ted Dumas on Friday, August 07, 2009 - 01:14 pm:

There is no magic about Ford EE Steel. It is AISI C1038 Plain Carbon Steel. I think it was used because it was less expensive than the FORD AA Steel, which is a chrome silicon alloy very similar to AISI 5130. The dimensions of the 26-27 crankshaft were changed to make the diagonal webs heavier. I think dimensions rather than steel alloy changes were the improvement in the crankshaft.

application/octet-streamFord EE and AA Steel
Ford EE and AA Steel.doc (20.0 k)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ted Dumas on Friday, August 07, 2009 - 01:16 pm:

This upload should be easier to decipher.

application/pdf
Ford EE and AA Steel.pdf (11.1 k)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Gene Carrothers HB on Friday, August 07, 2009 - 02:41 pm:

I think it might yield some interesting and helpful info if we knew what percentage of the BuMac or any other cast crankshafts that have been installed have failed.

Of course there are other factors that may cause a failure ie. quality of the installation or improper usage but I believe this factor would be a constant between a standard T crank and a new cast replacment. I think the more expensive new C/B crank would have an advantage by more than likely being installed to better standards or in a professional shop.

Thanks to those of you that have contacted me with help.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Norman T. Kling on Friday, August 07, 2009 - 03:34 pm:

Gene,
What kind of crankshaft was in your car that broke? Was it a standard Model T crankshaft, an EE or an aftermarket crank?
Norm


Top of pagePrevious messageNext messageBottom of page Link to this message  By Surf City Gene on Friday, August 07, 2009 - 04:06 pm:

Norm
I had an original early "beaver tail" crank that had been balanced and magnifluxed before I installed it.
I have recently heard about many others who had their new cranks break also.
I don't know of anyone that has broke a late model style crank though but have been told that every model T crank will break someday especially if you run it at low RPM's or lug the engine too much like what may happen running a Warford or other O/D trans.

This all has me confused about what to replace in my engine. Where to find a 26 / 27 crank is another story....


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jon W,. Griesenbeck on Friday, August 07, 2009 - 04:34 pm:

I broke a Bumac on the O2O tour but we don't know why. When the engine was built by a professional the first time. It sounded like a desel and the pistons were hitting the head. Also they say the cylinders had hard spots and as the engine warmed up it would cause the pistons to cock. The car was taken back to the engine builder and torn down and found those 2 items as well as the new sun gear being to large by 10ths. and the crank being bent. The crank was new out of the box. He took the crank to his crank grinder who straightened it, and reassembeled the engine installed it in the car and drive it over a 100 miles. The car is a coupe with a Lane gear box with a support bracket. The crank broke with about 3500 miles on it in the third rod journel. I have taken the engine to another professional engine builder to tare down and find the problem. After 2 builds with the first builder I wanted fresh eyes to look at it. After the 2nd rebuild the engine always had a vibration in it that I felt was not normal, esp. since the engine was suppose to be balanced and with a counter balanced crank shaft. I will let you know what we find. Many thanks, Jon I under stood that before this crank there were 2 other Bumac cranks that broke. One of them the pan was not straightened and that also caused a reg T crank to break. I also know Ben from TTP had one break.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ricks - Surf City on Friday, August 07, 2009 - 05:36 pm:

Gene, did they say your damaged block will be good as new?

The Chevy crank is looking better all the time.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Surf CIty Gene 12 Torpedo on Friday, August 07, 2009 - 07:20 pm:

Yes Ralph, A shop that Larry at Tin Shed works with is going to furnace braze the cracks at the rear main bearing mount and also repair the water jacket cracks that I had JB welded before. He says that the block will be as good as new and witha permanent repair to the water jacket probably better than before.

Yes your Chev crank looks very nice and the price is Really reasonable but I'm not sure how I'd sleep with a Ch*** heart inside the T and then the custom pistons and all. Did you buy the one at the swap meet?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Les Schubert on Friday, August 07, 2009 - 07:39 pm:

A few years aback i was helping a local guy assemble his engine. It had been line bored by a so called "professional" about 10 years before and the crank had been in it and bolted up all that time. We took the crank out and were installing a set of aftermarket "dunn" weights. In so doing we carefully put the crank in a lathe between centres and put a dial indicator on the centre main to be sure we didn't distort the crank as we installed the weights. Well the crank was bent. We debated trying to straighten it but I talked him into using another crank instead as I had one that could be ground to fit his line bore job. We tried to install that crank and found that it wouldn't fit right. We found that the line boring job was out of line!!!! Interestingly enough the bent crank after it stood for about a month returned virtually to straight (went from about .020 out to about .002 out. So we repored and relinebored the block and put his crank back in.
So;
I would not want to straighten a cast ductile Bumac crank and certainly not by bending it! Also I would want to figure out what caused it to bend.
I have hard time trusting a "professional" engine builder who got caught by pistons hitting the head and the "cock in bull" story about the cylinders is too bizzare for words. I mean maybe he had problems boring the cylinders but no reputable engine builder should get caught assembling a engine with imperfect cylinders.
IMHO


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ricks - Surf City on Friday, August 07, 2009 - 08:30 pm:

Gene, I can't pass up a modified Chevy crank that for less money than the price to modify one, so I bought that one. I'll let you have it for just a 10x markup - $200. - :-)

Dunno where to get Chevy rods. It appears the crank stayed the same part number for maybe five years, but I once saw a list, and the rod part number changed about every year. '28 rods are 2 oz heavier than '27 rods, for example.

rdr


Top of pagePrevious messageNext messageBottom of page Link to this message  By Robert Fultz on Friday, August 07, 2009 - 10:18 pm:

How about this crank. Anyone know the scoop on it? http://www.snydersantiqueauto.com/5078


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ted Dumas on Friday, August 07, 2009 - 10:50 pm:

Its Bill Dubats' crank.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Robert Fultz on Friday, August 07, 2009 - 10:59 pm:

Thanks Ted.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Gene Carrothers HB on Saturday, August 08, 2009 - 07:02 pm:

Does anyone have Bill Dubat's email or phone number?

Thanks for all your help
Gene


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jon W. Griesenbeck on Saturday, August 08, 2009 - 10:46 pm:

I know that Don lang ran one of the Dubat's on the O2O tour and I believe the California car also had one of these cranks. No problems were reported on these cranks from the tour. I have one sitting on my shelf and the workmanship is excellent.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ted Dumas on Saturday, August 08, 2009 - 11:41 pm:

Search for Bill's posts on the Forum and contact him thru e-mail.


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