Truck Flathead

mercjoe

mercjoe

Member
Hello eveyone.

Im wondering if this 8RT Ive been offered is a good candidate for a build. Since it comes with the 3 speed column transmission I thought it would be a good deal. It came out of a 1951 F1 truck.
Regarding the engine I don't think there should be big differences with a 8BA ( any important I should consider ? )

But more importantly I have no idea if these transmissions are any good


Thanks for any help
 

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The transmission should be fine. The gear ratios may be a little lower than a car, but if it's in decent shape, it should be synchronized in second and third (like the cars) and work fine for your needs. In fact, being a truck open drive, it could be an advantage (depending on what you want to use it in).
 
Water pumps, oil pan, and bell housing are the major differences truck to car engines. Carburetor air horns on trucks have a flange for the air cleaner clamp.
 
We hear a lot of tales about guys buying 2 or 3 engines before they stumble upon one without a severe crack. If at all possible the heads should be pulled and the decks and valve areas cleaned and inspected under good light. This still doesn't tell the whole story, but it takes the real bad ones outa the running. Now if it's a known and trusted 'pull out' running engine and you just want to get Ol Bessie out on the road by summer, then it might just fit the bill as is. Tell us a bit about the Ford it's going into and what your expectations (and experience) are.
 
Hi GB,

Im looking for a flathead for a future AV8 project. Still working on my current project but I'd like to start gathering stuff for the AV8.
The engine's owner just told me oil compression drops when hot, that's why he swapped for an y-block. At least he was honest. I really wanted this one but this a red flag


GB SISSON said:
We hear a lot of tales about guys buying 2 or 3 engines before they stumble upon one without a severe crack. If at all possible the heads should be pulled and the decks and valve areas cleaned and inspected under good light. This still doesn't tell the whole story, but it takes the real bad ones outa the running. Now if it's a known and trusted 'pull out' running engine and you just want to get Ol Bessie out on the road by summer, then it might just fit the bill as is. Tell us a bit about the Ford it's going into and what your expectations (and experience) are.
Click to expand...
 
Think about this : Bearings, oil pumps, even crankshafts and rods are readily available. Blocks are not. I would jump on a good running flathead, low oil pressure and all because of the probability of a good block. I posted on your thread the H.A.M.B. that I sold a good 8BA block. It was to a guy who had torn apart SIX engines with fatal cracks. "G.B."'s friends got lucky.

Don't reject this one out of hand so quickly. Price is a factor; but flatheads aren't cheap these days.
 
mercjoe said:
Hi GB,

Im looking for a flathead for a future AV8 project. Still working on my current project but I'd like to start gathering stuff for the AV8.
The engine's owner just told me oil compression drops when hot, that's why he swapped for an y-block. At least he was honest. I really wanted this one but this a red flag
Click to expand...

They all tend to drop somewhat when hot. How much of a drop is the question. I would use a mechanical gauge not solely rely on the stock, electrical one to determine oil pressure.
 
If you're thinking you're just going to "run it as is" - that is a different situation than one where you're planning on rebuilding it. If the price is fair, then it is probably worth a gamble - probably a better one than a lot I have taken. I always assume that I'm going to need to rebuild the engine - so set your expectations as such.

At least this one wasn't sitting outside or pulled out of a truck 50 years ago with the claim "ran good when pulled". Also, it has all the components of a running engine - so that is good.

The transmission is easily rebuildable and uses the same basic gears and associated components as a top-shifter 39 transmission. As noted, the open-drive may even be a plus for you.

How much does he want for it?
 
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Yeah, that"s true. It was removed running not long ago from its original truck and its all complete. It may be worth the shot. I guess I will get it.

Btw, Is it possible to install some adapter to make the transmission floor shift ?

Bored&Stroked said:
If you're thinking you're just going to "run it as is" - that is a different situation than one where you're planning on rebuilding it. If the price is fair, then it is probably worth a gamble - probably a better one than a lot I have taken. I always assume that I'm going to need to rebuild the engine - so set your expectations as such.

At least this one wasn't sitting outside or pulled out of a truck 50 years ago with the claim "ran good when pulled". Also, it has all the components of a running engine - so that is good.

The transmission is easily rebuildable and uses the same basic gears and associated components as a top-shifter 39 transmission. As noted, the open-drive may even be a plus for you.

How much does he want for it?
Click to expand...
 
I agree. Ill take the risk with this one.

Thanks Tub


tubman said:
Think about this : Bearings, oil pumps, even crankshafts and rods are readily available. Blocks are not. I would jump on a good running flathead, low oil pressure and all because of the probability of a good block. I posted on your thread the H.A.M.B. that I sold a good 8BA block. It was to a guy who had torn apart SIX engines with fatal cracks. "G.B."'s friends got lucky.

Don't reject this one out of hand so quickly. Price is a factor; but flatheads aren't cheap these days.
Click to expand...
 
mercjoe said:
Yeah, that"s true. It was removed running not long ago from its original truck and its all complete. It may be worth the shot. I guess I will get it.

Btw, Is it possible to install some adapter to make the transmission floor shift ?
Click to expand...

Two ways of doing this. They made "Floor Shift" conversion kits that bolted on the existing transmission, or you could find a '37 or later car or pickup transmission or case and use it. A complete transmission will bolt right up, or if the innards of the existing transmission are good, they can be transferred into the new case. I did this when I built my old '36 3-window. I had a good post war sideshift transmission, and transferred the parts into a '39 case I bought on Hemmings, using new synchronizers, bearings, and thrust washers. It turned out well.

Or, you can go completely upscale and buy a conversion kit from Speedway or Cornhuskers and install a GM T5 5 speed. (There are several ways of skinning this particular cat.)
 
Ill check the convertion kit approach first.
Thanks again !


tubman said:
Two ways of doing this. They made "Floor Shift" conversion kits that bolted on the existing transmission, or you could find a '37 or later car or pickup transmission or case
​
and use it. A complete transmission will bolt right up, or if the innards of the existing transmission are good, they can be transferred into the new case. I did this when I built my old '36 3-window. I had a good post war sideshift transmission, and transferred the parts into a '39 case I bought on Hemmings, using new synchronizers, bearings, and thrust washers. It turned out well.

Or, you can go completely upscale and buy a conversion kit from Speedway or Cornhuskers and install a GM T5 5 speed. (There are several ways of skinning this particular cat.)
Click to expand...
 
If you can afford to go that route, everybody I've ever known who put a T5 overdrive five-speed in one of our old hotrods had nothing but good things to say about it. Contact Krylon32 . . . he has been making complete transmission conversion kits for a couple decades, has complete kits, etc.. I've blown up a lot of 39 transmissions, it is a much better deal to go with a modern full-synchro and strong 5 speed.

Best of luck, keep us posted with what you find and how things are looking!

Take care,
B&S
 
"I'm looking for a flathead for a future AV8 project." This, from his post #6, which is why I thought an old Ford 3 speed might be a good fit.
 
I wish I could but cant afford a t5 right now.
I will try this one out first.and see how it goes.
Do you know which afapters are available for my transmission to make it floor ? And who carry those ?

Thanks for all the info and help


Bored&Stroked said:
If you can afford to go that route, everybody I've ever known who put a T5 overdrive five-speed in one of our old hotrods had nothing but good things to say about it. Contact Krylon32 . . . he has been making complete transmission conversion kits for a couple decades, has complete kits, etc.. I've blown up a lot of 39 transmissions, it is a much better deal to go with a modern full-synchro and strong 5 speed.

Best of luck, keep us posted with what you find and how things are looking!

Take care,
B&S
Click to expand...
 
mercjoe said:
I wish I could but cant afford a t5 right now.
I will try this one out first.and see how it goes.
Do you know which afapters are available for my transmission to make it floor ? And who carry those ?

Thanks for all the info and help
Click to expand...

I don't think anyone makes one specifically for that model anymore, but a google search might turn up something. You are probably going to end up modifying something that's still available or finding a used unit. They are available and show up on eBay or you could place a "Wanted" ad on the H.A.M.B. If you can find one, a Hurst shifter conversion is head and shoulders above the rest of them out there. Or, you can start having real fun and start going to swap meets, etc.
 
Thanks Tub

tubman said:
I don't think anyone makes one specifically for that model anymore, but a google search might turn up something. You are probably going to end up modifying something that's still available or finding a used unit. They are available and show up on eBay or you could place a "Wanted" ad on the H.A.M.B. If you can find one, a Hurst shifter conversion is head and shoulders above the rest of them out there. Or, you can start having real fun and start going to swap meets, etc.
Click to expand...
 
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