Any vintage car guys here?

Well that’s neat ! As a former pilot, I had no idea these had made the jump over to aircraft! I’m assuming experimental category?
Yep. Just google Subaru aircraft engine. There's more out there than you think. Got a demo ride in a Kitfox convo at Oshkosh once. Very impressed with it, compared to the Rotax anyway...
Here's a 180hp convo...


1696970060996.png
 
Yep. Just google Subaru aircraft engine. There's more out there than you think. Got a demo ride in a Kitfox convo at Oshkosh once. Very impressed with it, compared to the Rotax anyway...
Here's a 180hp convo...


View attachment 252992
That’s a sharp set up ! I did fly one of the first kitfox airplanes up here years ago with the rotax, must be fantastic with subaru! I like the clean reduction gear !
 
That was the sound of the 103 year-old crankshaft breaking....clearly not a positive development.

Well dang Pete! That was very unfortunate, but you’ve got an interesting story to tell. I’ll bet you’ll be the only guy in the room to say “ Today I pulled the motor on my 103 year old car! “
BTW, how nice was it to have a good clean shop to work in? 😉
 
So, some sad news on old Henrietta - my 1920 Model T Ford runabout/pickup. Mrs. and I were out in a large country fall fair parade on Sept. 2 and on the way home, about 500 ft from our house, I heard..."BANG, crunch crunch crunch". :wtf::yikes::yikes::yikes:

That was the sound of the 103 year-old crankshaft breaking....clearly not a positive development.

The Model T engine is a 2.9 litre inline flathead four with a very low compression ratio (about 3.82:1) so nothing is highly stressed, but crankshaft failures are not unknown - and I had one. The crank has only three main bearings and they are of the poured babbitt type which means that aside from getting a new crank, you need to melt and pour molten babbitt material (basically a tin-lead alloy like solder) into a mold to form the bearing. The process is simple and low-tech but I do not have all of the magic ingredients - most notably time and so I have found a guy who is a Model T specialist rebuilder and so I am going to pull the engine and transmission and take it to him for a rebuild.

Dammit.

I actually have been given (gratis) a replacement crankshaft - but it is even older than my broken one and I don't want to do this again. Fortunately, a modern 4340 alloy forged crankshaft replacement is available from Summit Racing and so, for the princely sum of only about $1600 USD, that is what I am going to have installed.

I started stripping down the car yesterday - drained the coolant, removed the radiator (its brass and weighs a ton) and moved the steering column out of the way - so just a few more steps to go before the big pull. Anyhow, here is a photo of Henrietta taken this morning.

View attachment 252990
Bummer. That'll teach you to speed shift.
 
Hokey Dokey Sportsfans - here is an update on the 1920 Model T pickup:

A few weeks ago my two colleagues and I pulled the engine and transmission out of the Model T (see photos above). The engine and trans share the same oil pan so it is not practical to pull them separately or to even separate them in the vehicle. The job is not very difficult as there are very few engine controls to deal with (no emissions stuff, only a single fuel line (no vents or evap system), choke and throttle linkage and the mechanism for the manual spark advance) and the electrical system is literally one wire to the generator and one wire to the starter plus the four spark plug HT leads.

The timer (aka distributor) is mounted directly on the front of the camshaft and you simply remove one retaining bolt and set it aside with the ignition leads - and all of that stays with the car. The photo below shows the junction block on the engine-side of the firewall - which is about 80% of the vehicle's electrical system.

Model T - engine electrical system.jpg


The big problem is that the three pedals (from left to right CLUTCH - REVERSE GEAR - BRAKE - seems pretty intuitive doesn't it?) - stick up pretty high and make it difficult to get through the small cut-out in the wooden firewall.
1920 Ford-T - interior.JPG


So - we had to de-mount the firewall from the front of the body cowl (the metal section in front of the windscreen) to get the pedals out through and lift the powertrain. We also had to undo the front body mounts and tilt the entire cab assembly up about an inch or so to allow the rear powertrain mount to slip under the lower-front of cowl and forward so that we could lift everything up and out. It only took about 45 minutes to organize all of this - and she was out!

The transmission and control pedals just stay with the whole assembly as shown below and note that the firewall has been set-off to the driver's side of the vehicle. Note that the entire floor of the cab is also out of the vehicle which exposes all of the underneath workings of the vehicle to view from above. The other cool thing about the Model T is that it sits up very high so you can lie down on the floor underneath and slide around and access all fo the fasteners without a hoist. In fact, the frame rails are nearly 24" off the ground - so tons of room below.
Model T - hoisting the engine.jpg


I then lagged a few pieces of 2x8 PT lumber onto the floor of my little box trailer and bolted down the engine stand that my two Michigan Ts buddies loaned me - and I plopped the powertrain assembly onto the mount, tarped it up, and drove 450 km to Orillia to the engine rebuilder. The red lifting fixture screws into the four sparkplug holes - which use tapered NPT pipe threads just like the plumbing on your toilet....
Model T - engine-trailer-mount.jpg


Powertrain - rear view - note how high the shifting and brake control pedals stick up. This causes most of the heartburn in removing a Model T powertrain from the car as the pedals will not go through the small cut-out in the firewall. It was p!ssing down rain on the day this was all done (dammit).

Oh yeah - and the Model T also has no oil filter so many folks added a screen to pick-up debris floating around in the engine. Mine unit has that screen - which sits inside the transmission beneath the coffin-shaped sheet metal cover visible in the photo below. The oil splashes around in there because the flywheel is whirling around - and the screen picks up crap as it goes by.
Model T - engine-trailer-mount_REAR.jpg


And here is the whole assembly ready to be hitched to the car for transport day. Due to work commitments (again...dammit) I couldn't get away until late in the day and since it is quite far to Orillia from my place, I stopped at the home of my riding buddy @totalfool in London ON about 2.5 hours from Harrow for the night. The lower photos my "rig" in his driveway.
Model T - engine-trailer.jpg


Model T - engine-trailer-LONDON.jpg


The whole trip to Orillia took until about noon the next day and the little trailer rode along like a champ! When I arrived at Morton Starter & Alternator (Owner Gord Morton is a well-known Model T expert) we lifted the powertrain off the mount and I had a little look around his shop (photos below).

You will note the photos of the old Ford block (not sure if it is a Model A or a T like mine - they are quite similar) with the three silvery main bearings - the silver stuff is the babbit that has been poured at 800 deg. F as a molten liquid - using special molds that bolt in-place. After pouring and cooling, the babbit bearings are line-bored to size using special tooling and then the crankshaft is fitted, rods and pistons installed etc. etc. The whole babbit process and the special tooling is the reason I needed to job-out this rebuild as I do not have any of that technology in my arsenal and I don't plan to do this again.

.....to be continued....
 
Last edited:
Model T crankshaft failure and rebuild....PART 2

To make sure that this is a one-time failure - not to be repeated, I finally secured a forged 4340 steel crankshaft (i.e. modern materials and manufacturing) that is a drop-in fit to the Model T block. This crankshaft is made by SCAT Cranks (the same folks who make hi-perf cranks for your small-block or big-block hot-rod rebuild) and it will NEVER break - ever.

The original T crank is a 3-main bearing affair that was made from forged steel and it is a known weak point in the engine with several very visible design flaws. The three main bearings (modern 4-cylinders have five main bearings) allow a good degree of crank flex, and while the engine produces only 20 HP - it is a 2.9-litre unit (~177 cu.in.) and that power is made at very low 900 RPM (about the same as the idle speed on our XS650s) with a "red line" of only 1600 RPM - it is fairly torquey. The compression ratio is quoted variously as 3.82:1 up to 4.5:1 (our XS650s are about 8.4:1 and many modern engines run at 10:1 or higher). The peak engine torque is about 80-83 ft-lbs, so the T has good hill-climbing ability - albeit slowly - and takes off from a stop reasonably smartly.

All of the above means that the tiny little main journals on the stock crankshaft are under a fair bit of stress (they very are small for an engine of this capacity - only about ...1" - 1-1/8" diameter I'd say). The most common failure mode is torsional-shear (i.e. a twisting-off motion) either between cylinders 2 and 3 or right at the back end of the crankshaft where the flywheel flange is located. That is where my crank failed - and it is a nice clean break (see the photo below and zoom-in on the centre of the crankshaft). Also of note: there are no web counterbalance weights on the original crank and that makes the engine vibrate - A LOT - which also puts more stress on all of the parts. Henry was big into cost-cutting - and that is fine...but...only 103 years old and it breaks? Geeezzzz...

The new SCAT crank was danged expensive - below is an advert for a brand new Model T crank back in about 1923 - and I paid nearly 400x ( :yikes: ) that amount in CDN dollars...so this had better frickin' work.
Orig_Model T crankshaft advert.jpg


The typical failure point is at the RH end of the crank where the large flywheel flange joins the much smaller #3 main bearing journal.
NOTE: there is little or no radius at the transition from a smaller diameter crank main journal to the much larger diameter flywheel mounting flange section. Design details are called "stress-risers" in modern engineering parlance and every undergrad knows to avoid them at all costs. I guess when Henry and his boys were designing the Model T engine in about 1907-8....such things were not as well understood. Anyhow - the $7.25 price ( :wtf: ) makes me weep. Modern cranks have a big radius at each change of cross-section and these points are always polished to eliminate micro-cracks that can grow into big failures (....like mine did :cussing: ).

The photo below shows the snazzy new SCAT crank in its box - note the counterbalances on each crankpin web which will result in much smoother running and less stress on the bearings and note the polished transitions between the bearing journals and the crank webs. The new crankshaft is made out of the same high tensile strength steel alloy as the cranks in modern cars. This alloy has a yield strength of well over 100,000 psi (about 750 kPa) - which is at least 4-5 times stronger than the original Model T crankshaft, plus it has much better geometry with larger journals as well as properly radiused and polished section changes to eliminate microcracks.

As I said - it should not break - ever.
Scat Crankshaft_1.jpg


The photos below were taken at the engine rebuilder's shop yesterday. It depicts the flywheel-end of the crank looking forward with the engine upside down. The generator mounting flange is visible on the left side of the block as are the cam-timing and generator drive gears way up at the front of the engine. You can also see the block-mounted camshaft (it is a flathead engine) down inside the left side of the upside-down block.

NOTE: the silvery twisted-off crankshaft end, the safety-wired castle-nutted rod-bolts, and the cute little sheet metal oil "dippers" scoops on each conn-rod to aid with lubrication (no oil pump in a Model T - thanks Henry!). The dippers are an aftermarket enhancement that many original Model T owners added back in the day after having problems with main and rod bearings.

Orig_CRANK.jpg


...and here is the flywheel-starter ring gear and magneto assembly - the broken-off crankshaft flange is still stuck in the centre of the flywheel hub and you can see the silvery-looking twisted-off stub of the crank ( :poo: ).
Orig_FLYWHEEL.jpg


The engine rebuilder has inspected everything and he tells me that all is well with the block, pistons and rods, the cylinder head, camshaft and valves. So, the only engine part that must actually be replaced is the crankshaft itself. He has looked over the transmission bands (it is a two-speed planetary gearbox) and he will replace the bands with modern kevlar-lined units that should not wear out for many miles - if ever.

He tells me that he may be able to line-bore the existing babbit out to fit the larger journals on the SCAT crank - or he may need to pour new babbit - we will see about that over the next couple of weeks.

So - aside from the brutal cost of the new crank, I got off pretty lightly on this little fiasco.

Pete
 

Attachments

  • Scat Crankshaft_box.jpg
    Scat Crankshaft_box.jpg
    293.7 KB · Views: 21
Last edited:
Model T crankshaft failure and rebuild....PART 2

To make sure that this is a one-time failure - not to be repeated, I finally secured a forged 4340 steel crankshaft (i.e. modern materials and manufacturing) that is a drop-in fit to the Model T block. This crankshaft is made by SCAT Cranks (the same folks who make hi-perf cranks for your small-block or big-block hot-rod rebuild) and it will NEVER break - ever.

The original T crank is a 3-main bearing affair that was made from forged steel but it is a known weak point in the engine. The three main bearings (modern 4-cylinders have five main bearings) allows a good degree of crank flex, and while the engine produces only 20 HP - it is a 2.9-litre unit (~177 cu.in.) and that power is made at very low 900 RPM (about the same as the idle speed on our XS650s) with a "red line" of only 1600 RPM. The compression ratio is quoted variously as 3.82:1 up to 4.5:1 (our XS650s are about 8.4:1 and many modern engines run at 10:1 or higher). The peak engine torque is about 80-83 ft-lbs, so the T has good hill-climbing ability - albeit slowly - and takes off from a stop fairly smartly.

All of the above means that the tiny little main journals on the stock crankshaft are under a fair bit of stress (they very are small for an engine of this capacity - only about ...1" - 1-1/8" diameter I'd say). The most common failure mode is a torsional-shear (i.e. a twisting-off motion) either between cylinders 2 and 3 or right at the back end of the crankshaft where the flywheel flange is located. That is where my crank failed - and it is a nice clean break (see the photo below and zoom in on the centre of the crankshaft). Also of note: there are no web counterbalance weights on the original crank and that makes the engine vibrate - A LOT - which also puts more stress on all of the parts. Henry was big into cost-cutting - and that is fine...but...only 103 years old and it breaks? Geeezzzz...

The new SCAT crank was danged expensive - below is an advert for a brand new Model T crank back in about 1923 - and I paid nearly 400x ( :yikes: ) that amount in CDN dollars...so this had better frickin' work.
View attachment 257919
The typical failure point is at the RH end of the crank where the large flywheel flange joins the much smaller #3 main bearing journal. NOTE: there is little or no radius at the transition from a smaller diameter crank main journal to the much larger diameter flywheel mounting flange section. Design details are called "stress-risers" in modern engineering parlance and every undergrad knows to avoid them at all costs. I guess when Henry and his boys were designing the Model T engine in about 1907-8....such things were not as well understood. Anyhow - the $7.25 price ( :wtf: ) makes me weep. Modern cranks have a big radius at each change of cross-section and it is polished to eliminate micro-cracks that can grow into big failures (....like mine did :cussing: ).

...and here is the snazzy new SCAT crank in its box - note the counterbalances on each crankpin web which will result in much smoother running and less stress on the bearings and polished transitions between the bearing journals and the crank webs. The new crankshaft is made out of the same high tensile strength steel alloy as the cranks in modern cars - with a yield strength of well over 100,000 psi (about 750 kPa) - which is at least 4-5 times stronger than the original Model T crankshaft, plus it has much better geometry with larger journals and well-radiused and polished section changes than the original part.

As I said - it should not break - ever.
View attachment 257917

The photos below were taken at the engine rebuilder's shop yesterday. It depicts the flywheel-end of the crank looking forward with the engine upside down. The generator mounting flange is visible on the left side of the block as are the cam-timing and generator drive gears way up at the front of the engine. You can also see the block-mounted camshaft (it is a flathead engine) down inside the left side of the upside-down block.

NOTE: the silvery twisted-off crankshaft end, the safety-wired castle-nutted rod-bolts, and the cute little sheet metal oil "dippers" scoops on each conn-rod to aid with lubrication (no oil pump in a Model T - thanks Henry!). The dippers are an aftermarket enhancement that many original Model T owners added back in the day after having problems with main and rod bearings.

View attachment 257914

...and here is the flywheel-starter ring gear and magneto assembly - the crankshaft flange is still stuck in the centre of the flywheel hub and you can see the silvery-looking twisted-off stub of the crank ( :poo: ).
View attachment 257915

The engine rebuilder has inspected everything and he tells me that all is well with the block, pistons and rods, the head, cam and valves and so the only engine part that must actually be replaced is the crankshaft itself. He has looked over the transmission bands (it is a two-speed planetary gearbox) and he will replace the bands with modern kevlar-lined units that should not wear out for many miles - if ever.

He tells me that he may be able to line-bore the existing babbit out to fit the larger journals on the SCAT crank - or he may need to pour new babbit - we will see about that over the next couple of weeks.

So - aside from the brutal cost of the new crank, I got off pretty lightly on this little fiasco.

Pete
Great story @MaxPete. Hope you get her back together quickly. Were the pictures of the engine on the trailer taken inside your snazzy new shop? Did I miss photos of the completed structure?
 
Yep - that is the new barn - but it is so cluttered and has such a lot of my buddy's stuff that I really don't want to show it right now.

Once the engine and trans are back together, I will nip back up to Orillia and get them and put the vehicle back together - hopefully in the early spring.

P
 
Except for that slant four, and wasn’t the OHC six a Pontiac? Yes, V8 were all the same.
IIRC, the OHC six was a 250, using the same dimensions as the Chevy 250. We used to use the Pontiac rods in the Chevy 250's that we raced back in the 70's.
 
I know practically nothing about Cars and less than that for Old Fords
Just thinking out loud here .. What i hear a service of the valve train is more or less always done when opening an engine
In this case i suppose some springs and push rods . Usually not expensive
Even if they look good maybe an idea to replace ..
Perhaps some of the car guys have an opinion
 
So - aside from the brutal cost of the new crank, I got off pretty lightly on this little fiasco.
I'm sure the bill for installing the crank and all the other stuff he has to do will not be cheap. But then you are not playing with a old Jap motorcycle. What you are doing does not hurt the value of it at all. May even increase it's value because you've fixed a known weak point.
A guy I worked with years ago told me "If you smoke cigars don't complain about he price of matches".
 
I know practically nothing about Cars and less than that for Old Fords
Just thinking out loud here .. What i hear a service of the valve train is more or less always done when opening an engine
In this case i suppose some springs and push rods . Usually not expensive
Even if they look good maybe an idea to replace ..
Perhaps some of the car guys have an opinion

Indeed Jan - but getting at the valves and re-surfacing them is not a difficult task and it was likely just done a few hundred km ago - at most. With modern engine oils and fuels, the valves and other engine internal parts should be fine for many years to come (these vehicles are only driven a few hundred km/year).

The crankshaft failure was due to design flaws and metal fatigue which is a cumulative thing built up over millions of thermal and stress cycles the crank has experienced over the last 100+ years of operation. It would have been good if the crank had been replaced when the vehicle was restored in 2008 - but it wasn't so...oh well. As I said above, this new crank is total overkill so that bug in this good ole' Model T has been well and truly squashed.

I'm sure the bill for installing the crank and all the other stuff he has to do will not be cheap. But then you are not playing with a old Jap motorcycle. What you are doing does not hurt the value of it at all. May even increase it's value because you've fixed a known weak point.
A guy I worked with years ago told me "If you smoke cigars don't complain about he price of matches".

Right-on Greg - I bought it knowing that there would be tinkering (I enjoy that) but not knowing that a major engine failure was right around the corner. As you say though, the value of the old Ford has gone up because the next owner won't need to worry about the crankshaft.

I have found in the Model T community, that many people consider themselves to be caretakers or custodians rather than owners because the newest Model T is a 1927 and so there is nobody alive now who bought one new - and yet the cars just keep on chugging along. There are more than 50,000 Model Ts reportedly still operating on the world's roads and that number is going up each year as cars are pulled out of barns, rebuilt, and put into service. The basic design is extremely robust, very simple and easy to work on and parts are readily available from multiple suppliers.

Like with our XS650s, virtually every part is available including body and chassis sheet metal and electrical and mechanical parts - many of which have been updated with better designs and modern materials - and part costs are pretty reasonable. The SCAT crankshaft is clearly an exception - but I was given for free - an original 1924 crank which had been magnafluxed and should be sound - and I could have used it in this rebuild, so I made my own bed on this one.

Anyhow, I will enjoy this sweet old piece of history - and then it will pass along to someone else who will undoubtedly enjoy it too....etc. etc.

Pete
 
Last edited:
Yes Sir this is something I have not understood ..The big Expensive cars today that dont last more than 15 years or so
VOLVO dealer Prices are starting at $ 40 000
Where are the small VW Beetle / Citroen / Fiat / Trabant even Aluminium ---Glass Fibre .More thought through design Would not need to scrap virtually any car. People are unemployed and have time to repair.

Not my field but I would be surprised if that not would save the environment Clear as day is that a say 40 Hp 3 Cylinder Car has far less emissions than a big car Nothing preventing them to be hybrids either as far as I know.
Not even out there to buy.
 
Yes Sir this is something I have not understood ..The big Expensive cars today that dont last more than 15 years or so
VOLVO dealer Prices are starting at $ 40 000
Where are the small VW Beetle / Citroen / Fiat / Trabant even Aluminium ---Glass Fibre .More thought through design Would not need to scrap virtually any car. People are unemployed and have time to repair.

Not my field but I would be surprised if that not would save the environment Clear as day is that a say 40 Hp 3 Cylinder Car has far less emissions than a big car Nothing preventing them to be hybrids either as far as I know.
Not even out there to buy.
Jan, I fully agree, would make far more sense economically and environmentally if the manufacturers did what they are fully capable of doing - build durable cars. Which could last much longer - like houses, they could last forever or at least as long as the owner requires. They could be smaller, lighter, much more frugal. Both the materials used to make them but also the running costs and fuel consumption. But they don't. They tell us, it's not what the public wants. I don't know what the public wants of course.

But I always wonder if what we want is what we are told we want?

Bigger, better, faster, newer, more expensive.

Are these notions now outdated?
 
Jan, I fully agree, would make far more sense economically and environmentally if the manufacturers did what they are fully capable of doing - build durable cars. Which could last much longer - like houses, they could last forever or at least as long as the owner requires. They could be smaller, lighter, much more frugal. Both the materials used to make them but also the running costs and fuel consumption. But they don't. They tell us, it's not what the public wants. I don't know what the public wants of course.

But I always wonder if what we want is what we are told we want?

Bigger, better, faster, newer, more expensive.

Are these notions now outdated?
These were some of the reasons I decided to buy a 2006 Ford Ranger this spring. I'm sure I paid too much for it! It was from down near Washington DC and looking under it looks like if it was a Central New York 2006 would have looked in 2007! Also only has 72,000 miles on it two wheel drive four cylinder and 5-speed manual trans. Only options would be AC and CD Player. Hoping it's the last vehicle I buy.

Then again wife bought a new left over 2022 Can-Am Spyder and has a one year old Nissan Rogue!
 
Back
Top