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1926 Model TT Restoration: Engine/Trans Rebuild
https://www.waguns.org/viewtopic.php?f=148&t=98621
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Author:  Arisaka [ Mon Aug 12, 2019 4:03 pm ]
Post subject:  Re: 1926 Model TT Restoration: Update 39 - Valves and Head

Did a compression test on the model T cylinders, as I noticed it doesn’t have much power when climbing hills. Although climbing hills is always an issue with a T, my truck is lugging down pretty bad. This is a classic symptom of low compression. A new engine will put out 50 Psi or so for each cylinder. Mine were at 25 psi.

The typical cause of poor compression on a T is leaky valves, due to carbon buildup. Sometimes it is the rings, but usually the valves. New valves are $8 each, and if you put in new valves, the way to go is stainless steel. They are stronger and don’t carbon foul as easily.

Original Model T valves are two-piece, with a cast iron head and a steel shaft. New valves are one-piece stainless steel. Here is an example of a modern stainless steel replacement valve

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A valve job requires grinding of the valves and seats, and in extreme cases, installation of an seat insert. The valves are easy to get to. Just pull the head, and then the side cover plate.

Here is the head on my truck. Held on with 14 head bolts.

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The side plate is held on with a couple of bolts, and is located behind the intake manifold

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When you take the side plate and head off, you have access to the valves.

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Next step is to inspect the valves and then order up the appropriate replacements. Hopefully my current valves haven’t been ground too many times previously, and an oversized valve will work.

While I am at it, I will put on a high compression head. Original Model T heads run 3.8:1 compression. They were originally at 4:1 but were detuned to 3.8 because of the crappy gas available at that time. With new gas, I can run 6:1 heads and get a lot more power. And by a lot, I mean from 20 hp to 27 hp!

Here is the relationship between compression and power for a T:

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The 6:1 heads have a smaller combustion chamber, which provides the higher compression. They are also designed for better mixing of the gas/fuel mixture. Here is pic of a high compression heads (also called a “Z” head) and an original head:

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After the parts arrive, I will have to take the T up to my buddy’s place to get the valves ground and the seats in the block machined.

One thing about a Model T hobby, there is always something to fix!

Author:  RocketScott [ Mon Aug 12, 2019 5:03 pm ]
Post subject:  Re: 1926 Model TT Restoration: Update 39 - Valves and Head

Turbo!

Turbo!

Turbo!

Author:  MadPick [ Mon Aug 12, 2019 7:17 pm ]
Post subject:  Re: 1926 Model TT Restoration: Update 39 - Valves and Head

See? This is what happens when you half-ass a car restoration the first time through.


Spoiler: show
:peep:


:ROFLMAO: :ROFLMAO: :ROFLMAO:

Author:  Arisaka [ Mon Aug 12, 2019 8:41 pm ]
Post subject:  Re: 1926 Model TT Restoration: Update 39 - Valves and Head

MadPick wrote:
See? This is what happens when you half-ass a car restoration the first time through.


Spoiler: show
:peep:


:ROFLMAO: :ROFLMAO: :ROFLMAO:

Lol. This restoration may never end!

Author:  Arisaka [ Sat Jan 18, 2020 3:25 pm ]
Post subject:  Re: 1926 Model TT Restoration: Tow Truck Conversion

Decided it would be cool to convert the Model TT to a tow truck. So I checked out images on google. There are two main types of vintage tow booms: those meant for converted cars or pickups, and those mounted on heavy duty trucks like my Model TT.

Here is a typical light-duty boom, made by Weaver

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I actually found one of these on eBay for $2800. No thank you.

Here is a typical heavy duty boom, made by Manley

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There are several Manley models, with capacities from 3 to 5 tons. They are all hard to find, and I couldn’t locate one. Even if I could, it would probably run several thousand dollars. I figured I could build one for $500. Here is the model I chose to build:

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The first step was to build a mock-up out of 2x4 to see how it fit into my truck. Before I could do that, I needed some dimensions. There existed no dimensions on these booms online. So I found a pic of a boom mounted in a Model TT truck similar to mine:

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To get an idea of the scale of this pic, I printed it out and measured the wheel base on the pic. That was 10.75 inches. Then I went out and measured the real wheelbase on my truck, which was 123.5 inches. This gave me a scale for the pic of 11.49:1. Now I could measure the boom, multiply it by 11.49 and get actual boom size. That turned out to be around 6 feet. The boom angle was 45 degrees. With this info I was ready to build a mockup. Here is mockup #1

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I didn’t like the look of the boom extension, so I lengthened it. Here is mockup #2

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That looked better. After moving the boom fore and aft, it seemed to look best centered over the rear axle. I also checked that the boom would clear the garage door. Now I had what generously might be called a plan.

Next step will be gathering the angle iron, miscellaneous steel, pulleys, nuts/bolts and other stuff I will need.

Author:  MadPick [ Sat Jan 18, 2020 3:27 pm ]
Post subject:  Re: 1926 Model TT Restoration: Tow Truck Conversion

Oh, shit. This thread is back, to make me feel even worse about my mechanical abilities.

Hell, he's even using the Manley brand stuff. :frust:

Author:  RocketScott [ Sat Jan 18, 2020 3:51 pm ]
Post subject:  Re: 1926 Model TT Restoration: Tow Truck Conversion

How's that going to work with the machine gun mount?

Arisaka wrote:
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The logo on the side of the box is for the American Truck Historical Society, I'm a member

https://www.aths.org/

There's not a lot of traffic on their forum but it wouldn't be hard to track down the owner of that truck

ETA- I just posted over there to see if anyone knows the owner of that truck

Author:  Arisaka [ Sat Jan 18, 2020 4:09 pm ]
Post subject:  Re: 1926 Model TT Restoration: Tow Truck Conversion

Machine gun idea went away when I decided to not paint the truck olive drab. Instead I spent all last summer driving the old girl around and learning what still needed work, and how to upshift and double-clutch downshift those straight-cut gears without grinding a pound or two of gears. By the end of summer, I was half-ass decent at piloting the truck around. I found that the valves need a re-grind, and that I wanted to add a 270 cam and high compression head to give better breathing and more power. That work is on hold until my model T buddy can get to the valves in March. So I figured I would spend that time making her a tow truck.

Author:  AR15L [ Sat Jan 18, 2020 4:31 pm ]
Post subject:  Re: 1926 Model TT Restoration: Tow Truck Conversion

Arisaka wrote:
Machine gun idea went away when I decided to not paint the truck olive drab. Instead I spent all last summer driving the old girl around and learning what still needed work, and how to upshift and double-clutch downshift those straight-cut gears without grinding a pound or two of gears. By the end of summer, I was half-ass decent at piloting the truck around. I found that the valves need a re-grind, and that I wanted to add a 270 cam and high compression head to give better breathing and more power. That work is on hold until my model T buddy can get to the valves in March. So I figured I would spend that time making her a tow truck.

The truck is still black so technically you could hang a Thompson in the back window. :bigsmile:

Author:  Arisaka [ Sat Jan 18, 2020 4:35 pm ]
Post subject:  Re: 1926 Model TT Restoration: Tow Truck Conversion

I need a Thompson if the back window of every car I own!

Author:  AR15L [ Sat Jan 18, 2020 4:39 pm ]
Post subject:  Re: 1926 Model TT Restoration: Tow Truck Conversion

I just saw this. I have no idea how you missed it.

https://www.airporttow.com/museum

Author:  Traut [ Sat Jan 18, 2020 6:03 pm ]
Post subject:  Re: 1926 Model TT Restoration: Tow Truck Conversion

Hot Damn. The project continues! With the power increase from the valve job and a counterweight on the boom, we'll have wheelie hole shot videos to look forward to. This is one of my favorite threads. :thumbsup2:

Author:  Arisaka [ Sun Jan 19, 2020 12:07 pm ]
Post subject:  Re: 1926 Model TT Restoration: Tow Truck Conversion - updat

Spent some time thinking about design and dimensions. I think better with sketches.

First, a little trigonometry to figure out cradle dimensions knowing boom length and angle:

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Then some details of the boom design:

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Finally, the cradle design details:

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I have been keeping an eye on Craigslist and offer up for materials. Offer up had a lot of 3 x 5 x .255 angle iron for $100. But you had to take it all. So I now have about 8 times as much as I need.

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Hit Home Depot for nuts and bolts and spray paint

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Last year I got this hand winch off Craig’s list for 75 bucks

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eBay yielded these pulleys and snatch blocks. Most of them were frozen solid with rust. With a lot of penetrating oil I got them apart and dropped them in some Evaporust. Still working on them

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Going out to the garage now to cut, drill and make a whole lot of sparks. Here is my supervisor

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Author:  Arisaka [ Wed Jan 22, 2020 4:59 pm ]
Post subject:  Re: 1926 Model TT Restoration: Tow Truck Boom Fab

Been out cutting, grinding and drilling. First job was to cut some 3 x 5 x .25 angle iron into two lengths 79 inches long.

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These are the main boom arms. They are positioned next to each other in a triangle arrangement, with the base 24 inches wide and the tip end 9 inches wide. In the pic below, the boom is upside down, vs how it is positioned during use.

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I cut another piece of angle iron 24 inches long for the base of the boom.

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This was bolted to the boom arms with 6 3/8 x 1 inch bolts

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Next I drilled the boom arms for the cross members and pulley. I stepped up to the necessary 13/16 hole

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I burned up my old Makita 18v drill on that last bit. It was literally shooting smoke out it’s vents.

The first cross member is where the boom pivots on the vertical cradle support, which Is halfway up the boom, or 39 1/2 inches from either end. As you can see from the actual crane pic, this crross member looks to be 1 1/2 rod, threaded on each end.

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I didn’t have any 1 1/2 rod, a drill bit that big, or a die big enough to thread it. Instead, I used 3/4 inch threaded rod, inside some 1 inch sch 40 black iron pipe

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This gives the look of a beefy cross member, and allowed me to use stuff I had on hand or could pick up at ace hardware. Once bolted up, it looks pretty good, and I think it will be strong enough

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I forgot to mention that the performance goal here is to get a model T front axle off the ground using a hand-cranked winch. Since an entire Model T weighs less than 1200 pounds, the front axle probably weighs somewhere around 700 pounds. Just guessing here. My hand winch is a 4:1, and the pulley system I am planning to use has a mechanical advantage of 3. I will fabricate a longer winch handle to give me some more leverage. We will see later if it all goes as planned

The next cross member is where the horizontal arm of the boom extension bolts to the main boom. Here it is on the original crane. Look where that horizontal piece of angle intersects with the main boom arm.

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Here is my boom, with all those cross members installed

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The last job is to mount a pulley on the end of the boom. I need to fabricate a reducing bushing first, as the pulley ID is two inches, and the cross-bolt is a 3/4 inch grade 8 bolt. Here is where that pulley will go

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Later, I will disassemble the boom, clean it up, grind off any rough edges, and paint it with rustoleum hammered black paint. Then reassemble it.

Tomorrow I start on the boom extension arm assemblies

Author:  RocketScott [ Wed Jan 22, 2020 5:56 pm ]
Post subject:  Re: 1926 Model TT Restoration: Tow Truck Boom Fab

Nice work!



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