Basic cost to overhaul a Flathead V8

moonshine runner

moonshine runner

Senior Member
Hey all,

This questioned has probably been asked here before, and I know there are a lot of variables, but could someone give me somewhat of an idea of what it cost to overhaul a Flathead V8 ?

This is in my 47 Super Deluxe.

Thanks!!

Kevin
 
Walt Dupont is probably the most prolific builder on the barn, and can give you a close estamate, depending on what you want done on the rebuild. O how bad the original engine is.
When I was building engines the average 276 engine went between 3500 and 4500. Recently a stock rebuild by a local shop went for a little over 4K, but I'm not sure of that.
 
V8COOPMAN said:
Flattys may be cool and maybe even romantic, but they ain't inexpensive to do any more. Plus, ya can't just drop one off at ANY ol' engine rebuilder's shop and expect that they SHOULD know what they're doing with one, either. DD
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Makes total sense DD.

Thanks!!

Kevin
 
Ol' Ron said:
Walt Dupont is probably the most prolific builder on the barn, and can give you a close estamate, depending on what you want done on the rebuild. O how bad the original engine is.
When I was building engines the average 276 engine went between 3500 and 4500. Recently a stock rebuild by a local shop went for a little over 4K, but I'm not sure of that.
Click to expand...

Thank you Ol Ron!!

Kevin
 
Moonshine Runner - assuming you are limiting the rebuild to a 239 short block only (with intake and exhaust manifolds plus oil pan and oil pump and water pumps included), and your block is of sound mind and body and not cracked and/or filled with mold sand, and you are pulling and reinstalling the engine yourself, and using all NOS bearings, valves, etc., you can get away with $2,400-$3,000 MINIMUM with an experienced, seasoned and qualified builder. If you want a turnkey job for the whole shooting match where you install an entire rebuilt engine (including carb, generator, starter rebuilds, distributor rework/setting, etc.) and you plug and play do not be surprised by a $5,000+ number.

I can personally vouch in 2014 on a 59AB for the former number, as well as the 30+ days to get the years of grease out from under my fingernails...

Since you are going for the whole Monty do not forget the radiator boiling/rodding and other ancillary costs (hoses, stats, etc.) as well - don't want to recontaminate a clean block.
 
len47merc said:
Moonshine Runner - assuming you are limiting the rebuild to a 239 short block only (with intake and exhaust manifolds plus oil pan and oil pump and water pumps included), and your block is of sound mind and body and not cracked and/or filled with mold sand, and you are pulling and reinstalling the engine yourself, and using all NOS bearings, valves, etc., you can get away with $2,400-$3,000 MINIMUM with an experienced, seasoned and qualified builder. If you want a turnkey job for the whole shooting match where you install an entire rebuilt engine (including carb, generator, starter rebuilds, distributor rework/setting, etc.) and you plug and play do not be surprised by a $5,000+ number.

I can personally vouch in 2014 on a 59AB for the former number, as well as the 30+ days to get the years of grease out from under my fingernails...

Since you are going for the whole Monty do not forget the radiator boiling/rodding and other ancillary costs (hoses, stats, etc.) as well - don't want to recontaminate a clean block.
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Len47Merc,

Many thanks! Hey, I love your car! A lot of what you mentioned has already been done by me. Radiator has been rodded and cleaned out by a reputable old time radiator shop in Joplin.

I did a basic rebuild on the generator awhile back and it's charging good and I've got all new hoses on the car so that may save some expense. Oh, and new stats and new water Drake water pumps.

Kevin
 
A lot of variables in your request. But I will give you my estimates. In the last 4 years I have rebuilt a 41 221, 59ab, 50 8ba, 52 merc. I have to have my local machine shops do the hot tank, magna flux, crank grind, bore/hone. Then the parts: All new bearings, pistons, rings, water pumps, valves, guides. I do all the assembly (butt ground the stems on the last build, adj. on the first 3). So I have $1600 to $1900 in parts and shop services. Now this is just a hobby and not a business. Add $500 if you are lucky to find a rebuildable block. Buyer has to use his bolt-ons, carb, generator, starter, dist., etc.
Add $2/ hour for my labor.:D
A good rebuilder might add $2000 for his labor.
Okay, so there is my guesstimate.
John
 
oldford2 said:
A lot of variables in your request. But I will give you my estimates. In the last 4 years I have rebuilt a 41 221, 59ab, 50 8ba, 52 merc. I have to have my local machine shops do the hot tank, magna flux, crank grind, bore/hone. Then the parts: All new bearings, pistons, rings, water pumps, valves, guides. I do all the assembly (butt ground the stems on the last build, adj. on the first 3). So I have $1600 to $1900 in parts and shop services. Now this is just a hobby and not a business. Add $500 if you are lucky to find a rebuildable block. Buyer has to use his bolt-ons, carb, generator, starter, dist., etc.
Add $2/ hour for my labor.:D
A good rebuilder might add $2000 for his labor.
Okay, so there is my guesstimate.
John
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Many thanks John!! I appreciate that. I am just trying to get some sort of idea.

Oh BTW, I just put a fresh rebuilt carb on the car so a lot of the components have been replaced.

The engine may or may not need an overhaul but just feeling the waters. I had a compression test ran on the car and most cylinders were 75 to 80 with one down around 62.

Now, since it don't use oil or smoke and seems to have fair power, myself and a mechanic who just did some work on it believes it could just be valves caused most likely from todays cruddy gas, but I am by far no expert so I don't know for sure.

Kevin
 
I would love to have your machining costs,I just did a 99a engine,new 4in crank,new EGGE pistons,all nos ford rod floaters,new mains.
Machine shop costs to balance crank and rods etc,bore and hone block,resurface two cast iron heads, resize the rods and fit new bushes.reface flywheel was $3750.00.
I,m still picking myself up from the floor.
Lawrie
 
I've seen complete, fully reconditioned engines for up to $10K here in New Zealand in recent times. Of course, that was the asking price, whether they got it I don't know.
 
I think you have your answer. Assuming you have a 59AB in your '47, compression should be running 100 psi min and ~115-120 psi/cylinder for a motor in good running condition. Recall tells me the original spec for 79As and 79Ms is 120 lbs - check Van Pelt's website for confirmation of my old-timer's memory. My '47 was untouched with 37K original miles on it before I had it rebuilt and all cylinders were above 110 lbs even then and overall they varied from 110 to 123 psi (too high a variance). I pulled it to replace the main seals and found one main/journal was a bit more than iffy so, given the 'book' states the motors were intended by Ford to be rebuilt after 25K I figured I was on borrowed time anyway and went whole hog.

If you are not concerned with a re-builder that may not be local to you feel free to reach out for a recommendation.
 
49r said:
Easy to spend $10K rebuilding a complete engine in NZ.
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Same here in Massachusetts. (Maybe slightly less, I had to disassemble two junk engines to finally find a good usable block.) That includes rebuilt water pumps, distributor, coil, newly poured babbit, magnaflux block and crank, bore and hone, square deck block, soda blast, jet wash, polish, new valves and rings, assembly, balance, paint.
 
Put a half quart of Marvel Mystery Oil in the gas tank for a few tanks of gas and drive it for about 500 miles. After that use 1/2 pint with every tank of fuel. You could drizzle about a pint down both sides of the carb while running before the start of driving. I have seen plenty of engines with a little lower compression than yours run good for a lot of years. I would also run Castrol 20/50 in your engine. G.M.
 
if it starts good,idles smooth dont smoke and has decent oil preasure run it.some times a valve job can cause more harm than good.
 
All the above are good honest answers. However, I think the advice given in the last two posts; from GM and Jake should be heeded.
 
G.M. said:
Put a half quart of Marvel Mystery Oil in the gas tank for a few tanks of gas and drive it for about 500 miles. After that use 1/2 pint with every tank of fuel. You could drizzle about a pint down both sides of the carb while running before the start of driving. I have seen plenty of engines with a little lower compression than yours run good for a lot of years. I would also run Castrol 20/50 in your engine. G.M.
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Thanks GM,

That is exactly what I am going to do. Going to get a new set off points in then going to shoot the MMO to the car and drive it.

Kevin
 
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