Flathead 6 engine number RF 20949 S - what's it from?

[LrudyD]

I've been looking for a Chrysler Flathead 6 and found one about 7 hours south of me.  It's already got a dual carb system and was re-built. When I asked the owner to get me the engine number, he gave me "RF 20949 S".  I have no idea what this is from!  Is it industrial? For a boat?  Can I use it in my '48 Windsor?

[LrudyD]

Okay, I did some digging around and found that this number is to a Chrysler Marine engine.  So, still wondering if it would work in a vehicle? The owner says yes, but... ?

[knuckleharley]

You will have to change the exhaust manifolds and put a thermostat in it,but AFAIK,that's it.

 

Some marine engines have governors on them,but that obviously doesn't apply to that one.

[greg g]

Conspicuous by it's absence is a bellhousing.  Do you currently have an engine from which to pull exhaust , bell housing and other auto related pieces?

 

Also some marine engines are counter rotating to offset prop torque steer.  Usual rule of thumb was starter in front of flywheel regular rotation , starter behind flywheel counter rotation. 

 

Buyer beware.

Edited October 15, 2020 by greg g

[DJ194950]

A picture of the exhaust will tell what is up with that.

 

Motor length at   least should give more clues.

 

A picture of the crankshaft aft end and number of holes in the flange plus a measurement of standout of the crank from the block will also some experienced people here supply with info as to changes required to make fit your app.

 

Overall if price is right and with some more info I wish Good Luck!

 

DJ

[Sniper]

7 hours south of you must be in old Mexico, lol.  I was in El Paso last week and I am pretty sure I could have gotten to Santa Fe in a lot less than that.

 

 

[LrudyD]

11 hours ago, Sniper said:

7 hours south of you must be in old Mexico, lol.  I was in El Paso last week and I am pretty sure I could have gotten to Santa Fe in a lot less than that.

 

 

It’s in a little town called Marfa, TX!  I was hoping for El Paso myself!

[LrudyD]

11 hours ago, greg g said:

Conspicuous by it's absence is a bellhousing.  Do you currently have an engine from which to pull exhaust , bell housing and other auto related pieces?

 

Also some marine engines are counter rotating to offset prop torque steer.  Usual full of them was starter in front of flywheel regular rotation , starter behind flywheel counter rotation.

 

Buyer beware.

Yep, I’ve got everything from engine back.  But, I’ll definitely ask about the rotation! Thanks!

[Sniper]

Well, shoot I was at the Federal Courthouse in Alpine a couple weeks ago.  Which is pretty much next door to Marfa.  So what is wrong with your old engine?

 

[Loren]

Just a wild guess I'd say it's a 23 inch engine (Plymouth/Dodge).

The reason I say that is because I don't believe Offenhauser made manifolds for a 25 inch Chrysler/DeSoto.

[knuckleharley]

Some big Dodge trucks from the mid-30's (2 ton and larger) and later had dual carbs and dual exhausts. Wouldn't they have been 25 inch engines?

 

Good luck finding one in a junkyard these days,though.I did see a setup for sale on ebay a couple of years ago,and the seller wanted "stoopid money" for it.

[TodFitch]

9 hours ago, knuckleharley said:

Some big Dodge trucks from the mid-30's (2 ton and larger) and later had dual carbs and dual exhausts. Wouldn't they have been 25 inch engines?

 

Good luck finding one in a junkyard these days,though.I did see a setup for sale on ebay a couple of years ago,and the seller wanted "stoopid money" for it.

 

If I recall correctly, those engines were much bigger than the 25 inch ones and specifically built for large trucks.

[Dodgeb4ya]

Twin carb 30" engines started in the middle of 1950 and continued thru 1955. Found only in the heavy 3-4 ton trucks.

Dodge also produced the 25" twin carb 265 engine starting in 1953 found only in the 2-1/2 ton "K" model trucks thru 1956 or 57.

Any of the twin carb engines are low production.

 

Edited October 16, 2020 by Dodgeb4ya

[knuckleharley]

3 hours ago, Dodgeb4ya said:

Twin carb 30" engines started in the middle of 1950 and continued thru 1955. Found only in the heavy 3-4 ton trucks.

Dodge also produced the 25" twin carb 265 engine starting in 1953 found only in the 2-1/2 ton "K" model trucks thru 1956 or 57.

Any of the twin carb engines are low production.

 

I know I saw photos of 1935 to maybe 1938 Dodge stake trucks in a junk yard that had two carbs and cast iron headers. This was probably 15-20 years ago,I was just assuming they were 251 cubic inch 25 inch long engines. Were such things produced,or was it likely to have been a conversion someone made

[Dodgeb4ya]

Absolute conversions...

No factory twin carb/exhaust trucks were offered till 1950. 

Twin carbs first started in the Dodge 377 ci. 4 ton model trucks.

The only 25" factory twin carb/ cast iron headers DT engine was the 265 starting in 1953. None before 1953.

 

Edited October 16, 2020 by Dodgeb4ya

[knuckleharley]

11 minutes ago, Dodgeb4ya said:

Absolute conversions...

No factory twin carb/exhaust trucks were offered till 1950. 

Twin carbs first started in the Dodge 377 ci. 4 ton model trucks.

The only 25" factory twin carb/ cast iron headers DT engine was the 265 starting in 1953. None before 1953.

 

Thanks!

[greg g]

Ellis developed their dual carb manifolds for 25 inch truck engines than made them for shorter blocks also.  I have seen a couple of the larger engines one was a 413 in a K series grain truck, the other was in a truck with a dump body.

[dpollo]

I suspect that is a 23 inch engine and it is pre war.  It has head studs and nuts.  Bolts were used on postwar engines.  If it is a prewar 23 inch engine , it will be a 201, a 218, or a 230.  Only the 230 had an eight bolt crankshaft flange which you will need.

Your car had a 251 originally which had a full flow filter which this unit does not have.

Your car needs the torque and power of a 251 to get it rolling.  a 201 or 218  would not do the job satisfactorily.

This may be the right engine in the right car, but your car needs a 251 or 265  (1946 to 1954)  or later.

[Sniper]

Pretty sure that engine has been gone thru since it left the factory, so the presence of studs holding on the head is probably not useful. 

[Dan Hiebert]

On 10/15/2020 at 7:55 AM, LrudyD said:

It’s in a little town called Marfa, TX!  I was hoping for El Paso myself!

Marfa!  I graduated high school in Presidio, Marfa was within our "stomping grounds" radius, right next door by west Texas standards.  If we wanted to watch a theater movie in English, we had to drive the 60 miles to Marfa to do so.  Can't go anywhere much in the U.S. from Presidio without going through Marfa first.  For as small as it is, there's actually some neat stuff to see (albeit not much of it) in Marfa.  I've been back quite a few times, it has become a lot like Taos since my HS days.

[LrudyD]

On 10/15/2020 at 6:34 AM, Sniper said:

Well, shoot I was at the Federal Courthouse in Alpine a couple weeks ago.  Which is pretty much next door to Marfa.  So what is wrong with your old engine?

 

Compression loss and found metal flakes in my oil when I was changing it. The po said it had low compression as well, so it’ll be a good time to try to get the original C38 for it.

[LrudyD]

Probably won’t get the Marfa engine. The guy started getting strange on the emails. I was asking questions based on all your suggestions, and his answer: “ I am telling you that this engine will fit, why will I lie to you or deceive you?”  Okay, that’s just weird. He wouldn’t get me a pic of the crankshaft aft end to see the bolt pattern, or the block length either, so, I’ll look elsewhere.

[kencombs]

7 minutes ago, LrudyD said:

Probably won’t get the Marfa engine. The guy started getting strange on the emails. I was asking questions based on all your suggestions, and his answer: “ I am telling you that this engine will fit, why will I lie to you or deceive you?”  Okay, that’s just weird. He wouldn’t get me a pic of the crankshaft aft end to see the bolt pattern, or the block length either, so, I’ll look elsewhere.

 

 

The Offy dual manifold almost assuredly indicates a 230/218 as I can find no indication that they ever built one for the long blocks.  Or, what looks to  be aftermarket cast iron header underneath it.

 

your car probably has a 251.  And, I don't think you would be happy with the torque loss of the shorter engine, even if it has the right crank flange.  The duals and carbs don't really effect the low end power, needed to start a heavy car rolling.