I decided to drive my speedster into work this morning as it was a nice day here in SE Michigan, and I figured there weren't going to be many left.
Accelerating from a stop light, I heard a noise that could be best described as dreadful mixed with disastrous. I shut the engine off as quick as I could and coasted into a gas station. Luckily they had fresh coffee as I waited for my ride to get my truck and trailer.
After I got the speedster home, I made my way to work where I commiserated with my fellow co-workers, including Aaron Rogahn. I returned home dreading the next steps. After a fortifying bracer of "Lily the Pink's Medicinal Compounds," I proceeded to pull the inspection cover and found this:
I then noticed that the engine at the back did not quite look as one would expect:
Time to find a new donor block and make a winter project of getting her back on the road again! Also time to apply the "Poor Man's Rajo" (28 Chevy Head with Adapter) that I just came across (with a SCAT crank this time).
Thanks for reading, sorry to spoil everyone's mood or dinner with pictures of such carnage, but I felt I should share...
The following picture is the car on a better day... More will come...
I remember seeing you and your car at the OCF!! Good luck and please tell us the cause if you can.Bud.
Sorry for your little problem.
Look at it this way - a lot of the fun of a T is working on them and you now have the opportunity to have a lot of fun
Rusty, before you toss the block, have a close look at the break in the casting. Often the broken crank is blamed for the breakout in the block, when the reverse can be the case. Broken blocks can crack away from the riser where the rear main bolts are bolted down, taking the crankshaft with it. The sharp angle between the back of the block and the register on which the main bolt nuts rest is a prefect stress riser. You may find that the surfaces of the crack near this area are somewhat polished, indicating that the web in the block has been moving on the crack before it finally let go with a bang. Let us know what you find on teardown.
Allan from down under.
I second Allan B's curiosity! I almost always do the forensics after a breakdown. Just part of always trying to learn more.
I am sorry to hear of your troubles. But every model T aficionado needs a tale to swap in the parking lots and club meetings!
Rusty, private message sent. Les Sumner
Rusty I know the feeling! I don't think it hurt my block as it broke between one and two
Sure do miss driving it hope to start working on it soon
Sorry to dredge a thread up from the depths, but I thought it would provide a good background to my ongoing work...
I was finally able to get in the shop to pull the engine and begin the tear down to save what parts I could:
The lighting in my shop is pretty lousy when it is dark out, however the pictures show the carnage:
I haven't studied failure mechanics in a long while, and as such probably I am looking at this incorrectly, but from what I recall, this shows the classic signs of a twist fracture, with no crack site evident (i.e. the failure didn't start at a crack point).
The block casting seems to point to a punch out (i.e. it was cracked by the twisting of the crank) as I didn't see any shiny wear spots...
(Sorry again for the lousy lighting)
The rebuild is now well underway, I have found a replacement block of a similar vintage, and the shiny new crank has arrived:
I went with the stroker version of the Scat crank as I figured, might as well go big or go home. The crank itself and H-beam rods that go with it are some nice pieces of machining (at least to my untrained eye...)
The new block is out getting the new pistons fit. I went with the HC pistons from Snyder's as the adapter plate for the Chevy head I am using really needed some extra squeeze based on initial measurements and talks with Joe Bell (who has been a great help as I prep to get the block to him for machining work and fitting the crank). Targeted CR right now is around 6.3 to 1 (based on simple-ish farmer's math, I'll be 100% certain once I have the plate in hand).
Next step is to either find a shop that can machine Teflon buttons to locate the piston pin since the new rods don't have a pin bolt, or to get the pistons machined to accept snap rings. I couldn't go with the Chaffin's snap ring pistons as I really needed the extra compression and the adapter plate I'm using is thinner than the original Jern's design so valve clearances are somewhat closer to begin with, without going and milling the plate down more to raise compression.
More news as it happens (or not, if folks tell me to quit spamming the forum...)
Thanks for reading,
(Message edited by rustyjazz1938 on November 25, 2016)
Maybe it's the lighting, but the break on the left side of your pic looks rusty, like it's old?
David I see the same thing.
NO way this could be considered as spam. It is most certainly T related. Jim
Rusty, I think there is interest enough to request a new picture of this area.
this looks like an old crack but a better picture would tell us more. J
Aren't these cranks still under warranty ? I'd be giving Henry or Edsel a call.
Hello all again,
I appreciate the interest and comments, however, I fear the poor lighting (it gets really dark in my shop after sundown) of my pictures has caused some confusion. Here is a picture of the back of the block with the flash on the camera turned on (I didn't do this originally as I did not want to give the impression of shiny areas):
The fracture in the block has no rust in it, it really looks to my eye (inexperienced as all get out) as a blow out failure. You can also see the material left on the center main journal which pushed the crank back the distance required to fracture the back webbing. My apologies for any confusion...
Burger, even if the crank was under warranty, I wouldn't claim it, as I fairly certain that the failure is of my own actions (higher compression -> more torque than stock, plus 3:1 rear axle gears -> SNAP!)
All the more reason to build it up...
Thanks again for reading,
Warranty claim or not, it still might be interesting to talk with either one of those boys.
Very interesting, even if disappointing. And Burger is right, It would be interesting to talk with Henry, or Edsel.
This demonstrates why I have a few more engine blocks than I do cars. Blowing a block to pieces may not be a common failure? But it does happen.
2X what James said. If the people that are calling this spam because you have hopped up your engine some, think this does not happen to a stock Model T, well it does and has. Keep posting.
Mark, Amen to that! I broke the crank on my entirely stock '14 at the Centennial just 2 years after I bought it. I know the engine had something done to it just before I bought it, but didn't know just what was done to it. I later surmised that they tightened the center main and thereby stressing the crank at that spot. After a few miles with the crank twisting at the center main bearing with every revolution, it broke. Fortunately, it was a clean break and didn't damage the block.
This was caused by the stupid blankety blank so called mechanic and their desire to have a quiet car to sell. Thanks a lot.
So, yes crankshafts can and do break in stock T engines.
Something I didn't know until a few weeks ago is that Model T's aren't the only vehicles to break crankshafts. My neighbor has a GM somewhere in 1970's motorhome which he restored and has been driving on vacations for some time. Last summer he had a sever knocking and the oil pressure dropped. He had it towed home. Dropped the engine and found that the crankshaft was broken and the rear main bearing broke right out of the block which ruined his engine.