Flathead 6 to Flathead V8 swap?

[Cooper40]

I'm wondering if it's possible to swap a flathead v8 into a 1949 Plymouth with a flathead 6 in it? I don't know much about whether the motor mounts are different or the transmissions are different or any other things like that. Enlighten me!

 

If it's too hard, I'll just swap a flat 6 into it. Anything I need to be aware of with swapping another flat 6 in? Would the transmissions be the same? And the motor mounts?

[kencombs]

 

First of all, a flathead v8  would most likely be a Ford, vastly inferior to the Mopar.   Cool engine but not super reliable.   Hard to find good ones due to  block cracks.  Expensive to rebuild.  Second, everything is different.

 

Any Mopar flat six can be used, but larger 25" head versions require some oil pan/front crossmember work and radiator relocation.  Use your clutch housing, clutch and trans, no need to change the whole thing.

[Ivan_B]

36 minutes ago, kencombs said:

Hard to find good ones due to  block cracks.

+1; I would not consider swapping one old engine with a different but also old engine, given the overall circumstances of this project. One of those working OEM engines for sale on the forum might still be available.

[Plymouthy Adams]

This is what many here do not see or consider and in truth rarely related in the thread, MANY USE WHAT IS ON HAND OR BEING MADE AVAILABLE with little regard to practicality and solely based on the keeping it low bucks.  This type thread is as bad as many click bait articles on the internet coupled with well intentions of most first time new owners with few skill sets, few tools and often no room to tear the car down for this type operation.   Sadly we can only hope they get up to speed quickly before another car is sent to the scrapper.....it is never to me the question of stock or mod, it is the fact you finish what you started.  

[Los_Control]

3 minutes ago, Plymouthy Adams said:

MANY USE WHAT IS ON HAND

I will agree 100% .... use what we have and lets keep the cost down.

 

As far as installing a flathead V8 .... I wonder if @Cooper40 is aware that Mopar never made a V8 flathead?

So naturally it would turn into a bigger job Different radiator, Ford flatty has 2 water pumps with 2 upper radiator hoses. New motor mounts, transmission & mounts and modify or make a new drive line.

 

I have thought about it a lot since I actually have one ..... Terrible idea.

[Ivan_B]

1 hour ago, Plymouthy Adams said:

MANY USE WHAT IS ON HAND OR BEING MADE AVAILABLE with little regard to practicality and solely based on the keeping it low bucks

I would suggest a more balanced approach. Trying to save a few $ by attempting to make something out of sticks and dirt might be counterproductive in relation to the original objectives. Time and labor are very valuable. In fact, this is the main production resource\asses for the overwhelming majority of the population. Instead of using it unproductively, attempting to do something one is not capable of, we can always sell it on the market and generate some income to pay others to do things for us that we cannot do ourselves.

 

Back to the original topic: a more modern V8 + transmission + driveshaft + rear end (if available cheap and local) could be a more realistic scenario, assuming that you can safely fit it into the car. Although, I still would not recommend it.

Edited May 6 by Ivan_B

[Cooper40]

Thanks guys for educating me lol. I didn't realize that only ford made a flathead v8. Definitely won't be doing that haha. I'll definitely be looking for flathead 6s. I don't want to put in a newer v8 because I want to keep this more or less in the time period of the car. 

I'll keep looking around my area. I have seen some pop up on here too. 

[Doug&Deb]

Cooper what is the issue with your engine? If it needs a rebuild consider doing it yourself. I did mine last year and I’ve never done anything like that before. Yes I’ve had some issues due to my low skill level but I’ve gotten through it and learned a ton. 

[Cooper40]

@Doug&Deb You know I keep going back and forth on rebuilding it myself. That's what I was thinking originally.  I think it spun a rod bearing. The crank is damaged and needs to be ground down. Some of the cylinders are pitted from rust and they all have big ridges on the tops from high mileage. I did have it running last year but not for long. Bearings need to be replaced. It does seem like a good project and I would learn a ton  Definitely something I'm still thinking about as I haven't really decided what to do yet.

[Los_Control]

4 hours ago, Ivan_B said:

I would suggest a more balanced approach. Trying to save a few $ by attempting to make something out of sticks and dirt might be counterproductive in relation to the original objectives.

Oh shucks, you know the damn internet 🤣🤣🤣  ..... did you know Adobe houses were built with sticks & Mud? Here is a photo of a 2 story 4 bedroom house 2 car garage being added on to a 100 year old Adobe house in Old town Albuquerque. ..... It was built out of sticks and mud and perfect condition.  The adobe walls were 12" thick and very economical to heat/cool .... We built the addition to match it with 12" walls ..... Later I did convert the original adobe house portion into a work out room and a apartment.

Sticks and mud works really well together.

 

 

 

 

 

 

 

[Los_Control]

6 minutes ago, Cooper40 said:

I think it spun a rod bearing. The crank is damaged and needs to be ground down. Some of the cylinders are pitted from rust and they all have big ridges on the tops from high mileage.

DING DING DING we have a winner!!!!

 

Of course it needs to be rebuilt.

I simply could not afford the machine shop bill or the parts bill that comes afterwards.  ..... Or the 6 month turn around for a machine shop.

 

What you can do is clean the crank the best you can, install some new bearings and use plasti gauge to measure .... shim if needed.

Throw on some new rings.

 

Depending on how well you clean & measure the crank & shim as needed .... dictates how long the new bearings last.

New rings on a old cylinder may not seal .... They are a spring and we collapse them to install them .... they spring back to seal .....

Depending on how badly things are worn .... If you are lucky it might let out a puff of smoke when you leave the traffic light. ..... Who knows how many months or years this will last..

 

The point is it will get your car running again and you can concentrate on other repairs. ...... The stage you are at right now is disturbing and others have mentioned it.

It is where the average man gives up and the car sits and eventually ends up in the scrap yard.

 

I'm saying stick a few hundred $$ in it for bearings, gaskets, rings.  .... If the car ran before you tore it down, it will only run better when new parts are installed.

It may only last 6 months or 6 years .... But you bought time to fix the other issues and drive the car. Then prepare for the future replacement.

 

A rich man would just yank it out and rebuild it .... We are not all like that man and have to work with what we have.

[QEC]

Weekend driveway rebuilds done by a novice are likely to last about as long...

Swapping in a later v-6/v-8 is not a weekend job for a novice either, however, the cost to do a proper rebuild may not be much different than the labour to install the later unit. And, last I checked, the pik-n-pull yards have some options, along with wrecks on Craigslist. 

Just some food for thought.

[Ivan_B]

2 hours ago, Los_Control said:

It is where the average man gives up and the car sits and eventually ends up in the scrap yard.

Typical sunk-cost fallacy example, in my opinion, as applied to practical everyday situations. And many people encourage it, for various reasons. Don't give up, they say... It's a great learning experience, they say (yeah, right, of what not to do)... Given the circumstances, this car was likely a mistake in the first place. As mentioned, I had one just like it, many years ago back in college. I was lucky-enough to quickly realize that it was not at all what I expected, and get rid of it until it became a major trouble.

 

1 hour ago, QEC said:

Weekend driveway rebuilds done by a novice are likely to last about as long...

I agree. And people would find an excuse for everything: well, at least I had so much fun; I had such a great learning experience; I did it all by myself, and so forth 🙄

 

Cooper, are you working or still in school? Many retired fellas are really happy to spend their days in the garage with great aspirations, that's all. They are in a different situation in life. Some of those projects go on for decades and are later passed on as an unwanted inheritance, which the relatives have to dispose off. Don't you have other, more important things to do? Keith Did an engine rebuild, on the tube. Ask him how much time and money it took. If you get an old engine, odds are, it will be in similar condition as your current one.

This is the last time I am saying this, I promise , but until you got too deep into this mess, get rid of it, save some money, and get another car which you can readily enjoy. Let someone else, who has the proper means, etc., to work with this one.

 

Edited May 7 by Ivan_B

[Loren]

It is expensive to rebuild an engine, there’s question about it.

It is expensive to restore a car as well, no question about that either.

Museums do not restore cars ( unless it is very special one ) they go out and buy the very best example of the one they want to display and when they find a better one they sell the first.

I grew up with Ford products and around Ford V8 race cars. I even have an autographed picture of Henry Ford in my office. So I’ve been around them all my life. Any restorer who knows their stuff will tell you the V8 block is way too complicated, way too heavy and came from the factory with cracks as standard equipment. They pick up more in time too. Henry Ford was such an authoritarian that he dictated what his engineers would do. A lot of the problems the V8 had were designed in by Ford himself and not corrected until after he died. It has been said that the Ford Motor Company hadn’t made a profit since the Model T. Because it was not a stock company it didn’t have to report profit and loss ( until 1956 when they finally sold stock….because they needed the money ) Henry Ford did whatever he wanted to do whether or not it was any good. For example Henry dictated that the water pumps would be in the cylinder head and since the V8 had two heads it would have two pumps. Why? Because he said so. And of course they overheated…a lot, until Henry was dead and they moved the pumps to the block and then they got rid of the flathead altogether.

Chrysler actually had engineers who did engineering. Walter Chrysler didn’t try to engineer his cars, he had professionals do it. Thus if you want to rebuild a Chrysler made flathead six you won’t have to pick the best block out of a dozen candidates. They already had features like exhaust valve seat inserts which pre-unleaded fuel cars need now days. The water distribution tube everyone hates, directs coolant right to exhaust valve. The guys who designed these engines did us old car nuts a real service. Even my Dad who loved Ford products said ( from experience and observation ) if you drove a Plymouth within it’s limits it would last forever. I would needle him a little and ask him how Lee Petty ( and others ) could be so successful with a flathead Plymouth. He gave me an honest answer they were lighter, they got better mileage in fuel and tires and made fewer pitstops. Petty just drove and stayed out of trouble. So would I put a flathead V8 in a Plymouth? In a word, no. A Chrysler 251 or 265, of course! ( Ford V8s were only 239, even the smaller DeSoto 237 would be better ). That is my humble opinion on the matter.

 

[Sniper]

Thing is the Ford flathead V8 really didn't make any more power than the Plymouth  of the same year.  I mean in 1951 the Ford 39 V8 made 100hp, my 51 218 made 97. 

 

A major reason the Ford V8 had cooling issues was the exhaust runner.  The exhaust valve is in the lifter valley and the port has to run to the outside of the block, thru the cooling jacket to exit, all that heat gets dumped into the cooling system.  Having the two center port's siamesed didn't help either.  The mopar flathead exhaust valve is located right next to the block side and has a very short run out of the block.  Each exhaust port is separate.

 

Ford exhaust port cutaway

 

[Plymouthy Adams]

14 hours ago, Los_Control said:

Oh shucks, you know the damn internet 🤣🤣🤣  ..... did you know Adobe houses were built with sticks & Mud? Here is a photo of a 2 story 4 bedroom house 2 car garage being added on to a 100 year old Adobe house in Old town Albuquerque. ..... It was built out of sticks and mud and perfect condition.  The adobe walls were 12" thick and very economical to heat/cool .... We built the addition to match it with 12" walls ..... Later I did convert the original adobe house portion into a work out room and a apartment.

Sticks and mud works really well together.

 

 

 

 

 

 

 

 

 hopefully any time I see Stick and Mud associated with house building, it will be the last names of the contractors.  👷‍♂️

Edited May 7 by Plymouthy Adams

[greg g]

Plymouthy, Chrysler actually did make flathead v8's, in France when they bought Simca.  Several models of Simca cars and a commercial vehicle or two were powered by liscence built Ford v8.  Chrysler continued production after re engineering the blocks to deal with their well known deficiencies.   I believe they manufactured these engine well after flathead 6 engines were quit in the US.  The simca Vedette got the flathead Ford v8 through till 1961.  So a Flathead V8 in a Plymouth isn't a far stretch.  Run what changes brung.

https://www.motortrend.com/news/simca-ford-flathead-v-8s-until-1961-found/

 

Simca of Brazil may have stuck with that powerplant till 64 in a Model called the Esplanade.

 

Edited May 7 by greg g

[Sniper]

It's clear that the authors of that article know doodlysquat.  Chrysler was building Hemis for the war effort, long before Duntov made his setup.  I present to you the Chrysler  IV-2220

 

https://en.wikipedia.org/wiki/Chrysler_IV-2220

[Plymouthy Adams]

I was going to post that point myself Greg but would have just been repeating myself.....but the limit was only to the French Connection as they had bought that piece of pie as part of the European market entry not to mention the Rootes group where even under Chrysler direction was installing Ford OHV V8's under the hood, and Pentastars on the fender.......hybrid a new term my fanny....!!

[Los_Control]

We learn something new everyday,

5 hours ago, greg g said:

Plymouthy, Chrysler actually did make flathead v8's, in France when they bought Simca.  Several models of Simca cars and a commercial vehicle or two were powered by liscence built Ford v8.

Still a stretch since it was a Ford engine ...... was this the V8 60?  .... Either way it is still a Flathead.

 

I love the old saying .... "Speed kills, drive a flathead and live forever"

 

With the valves in the block it is a poor exit plan for a air pump to move air. Then top it off with the 2 middle cylinders sharing a exhaust tube. Then the cooling is a issue as both banks are individual or separate from each other .... coolant only circulates through one side and not the entire engine  .... 2 water pumps, 2 T-stats .... the water pumps double as motor mounts.

Mine is a 1951 8BA, actually has a decent distributor .... the older engines had the dizzy mounted on the block below the fan .... You actually used a machine on the work bench to set up the points .... what a total pita. .... Adjust the valves on a stock V8 is a incredible process ..... shim or grind .... there are aftermarket adjustable lifters, not factory.....

 

Sorry to say Greg I did not click on your link to see what Chrysler did with it ..... Anything they did to it is basically putting lipstick on a pig.

Impossible for Chrysler to fix such a mess .... they could change it enough to call their own though.

 

This one has been worked on, crank is turned 10/10, stock pistons with zero ridge nice bores. Some new valves were installed .... it was rebuilt then the truck was parked.

Will be a nice runner someday ..... since I picked up a nice 318 I no longer entertain the idea of installing it in my Dodge   🤣

 

Like a Harley Davidson, flathead V8 just has a very distinct and pleasing sound I love em.

 

 

[Loren]

11 hours ago, Sniper said:

Thing is the Ford flathead V8 really didn't make any more power than the Plymouth  of the same year.  I mean in 1951 the Ford 39 V8 made 100hp, my 51 218 made 97. 

 

A major reason the Ford V8 had cooling issues was the exhaust runner.  The exhaust valve is in the lifter valley and the port has to run to the outside of the block, thru the cooling jacket to exit, all that heat gets dumped into the cooling system.  Having the two center port's siamesed didn't help either.  The mopar flathead exhaust valve is located right next to the block side and has a very short run out of the block.  Each exhaust port is separate.

 

Ford exhaust port cutaway

 

I’ve talked to guys that had a Ford flathead 6 ( yes they made them ) and they said they could out run a V8! One of the telling facts is that while Lee Petty was winning NASCAR races against the new Olds Rocket 88 overhead valve V8s, the Fords and Mercurys were nowhere to be seen.

[Loren]

9 hours ago, greg g said:

Plymouthy, Chrysler actually did make flathead v8's, in France when they bought Simca.  Several models of Simca cars and a commercial vehicle or two were powered by liscence built Ford v8.  Chrysler continued production after re engineering the blocks to deal with their well known deficiencies.   I believe they manufactured these engine well after flathead 6 engines were quit in the US.  The simca Vedette got the flathead Ford v8 through till 1961.  So a Flathead V8 in a Plymouth isn't a far stretch.  Run what changes brung.

https://www.motortrend.com/news/simca-ford-flathead-v-8s-until-1961-found/

 

Simca of Brazil may have stuck with that powerplant till 64 in a Model called the Esplanade.

 

Just to add a little clarification, the V8s Simca made were V8 60s, which replaced the “Model B” 4 cylinder. The flathead usually found in Fords and Mercurys we are most familiar with were V8 85s. ( which is what they were called when they were both made at the same time ) We are familiar with the Duntov designed Ardun hemi heads for the V8, but did you know the Brazilians produced the Simca V8 with similar heads? I have no idea ( and I am not suggesting it ) if the Chrysler engineers were influenced by the Ardun V8 heads. Duntov went on to greater fame helping the Corvette become a performance sports car ( his major contribution was putting Ed Cole’s Chevy V8 in them ).

If you’ve been around them the Ardun heads are also known as “Over done” heads.

Another V8 factoid is that the French military had a vehicle designed around the Ford V8 and contracted to have them made long after Ford phased them out.

The Simca wasn’t the last Ford engined car made by Chrysler. We recall the Sunbeam Tiger V8, but that’s another era.

[RobertKB]

51 minutes ago, Loren said:

I’ve talked to guys that had a Ford flathead 6 ( yes they made them ) and they said they could out run a V8! 

I’ve heard also that the Ford flathead six was a superior engine to the Ford flathead V8. One old farmer told me that he and other area farmers would pull the flathead V8 from their bigger farm trucks after a while and put in the Ford flathead six. I’ve heard it was a really good engine with no Henry Ford influence. 

[Loren]

After the Model K disaster Henry shied away from sixes. The implication was that sixes were not good. The truth was HIS six was no good.

The fact that the Ford Motor Company could engineer and build a good six if Henry stayed away is all the proof you need that he messed things up.

It’s said the company was run by a “Mad Hatter” before the war. After the war the government stepped in and installed Henry ll to save the company because it was too important. 
The Ford 8N tractor was a candidate for an engine swap with the flathead six. You can still find them once in a while. An outfit called Funk Brothers put them together.

Needless to say I have flathead six Plymouths but no Ford V8s. 

[Doug&Deb]

Just to add one more consideration. I belong to several Facebook flathead 6 groups and although they are for any vehicle powered by a flathead 6 there are far more Mopar owners. Our engines are much easier to use as daily drivers than most others.