Inliners International Forums General Discussion Engines Flathead Dodge question

Since a stock '59 Flathead Dodge six developes 135 hp @ 3600 RPM, and 205 lbs of torque @ 1200, I wonder what RPM range folks who soup 'em up normally run 'em at? Seems to me that you could cruise with a 2,400 lb car at some pretty low RPM.

Let's say that the engine is rebuilt with 8:1 compression ratio, a little porting and maybe a "3/4" cam, electronic ignition, dual Holley-webber carbs and headers. What would a reasonable RPM range, at highway speeds, be?

Also, would the above modifications bring the engine close to 200 HP? Or, is that an unresaonable guestimate?

Well, your rpm at cruise speed is deterimined by your axle ratio and tire size. This site will help you determine that: http://www.drivetrainsuperstores.com/calculate.asp

Once you know what you have you can plug in a gear ratio that matches the majority of the speeds you drive the car to get a desired rpm. Its really a trade off. Crusing at 65 with rpm's around 1900-2100 with good low end performance would call for an OD trans.

If you stay with stock trans, then you are limited in what you can do. Pick your cam based on how your car will be driven (Street,highway,etc). Over caming will result in being unhappy with how your car performs.

With a hotter cam, a higher compression ratio may be called for. The cam maker can help you choose a good overall cam for your engine specs and type of driving you will be doing.

Thanks for the feed-back. The combination I was thinking of would be building the engine, connecting it to a S-10 5-speed and then gearing the rear end to put me in the RPM range best suited for the torque curve. I realize that the cam and engine modifications I use will determine the best torque range. Your calculatins of 1900-2000 RPM, at highway speeds, sounds like a great range for economy with a 230 Dodge.

Dennis;
I have basically the setup you are talking about except I up graded to a “big block” 251 CI Desoto engine. I have installed a reground cam from Earl Edgerton. 260 degrees duration @ .410” lift both intake and exhaust. Dual Carter B&B carburetors and a split exhaust manifold. This combination is coupled to a T-5 five speed over drive transmission from an S-10. I have installed a 3.55/1 differential from a Dodge Charger. My engine is fresh and has about 10 hours run time on a test bench. I hope to have this car (1948 Plymouth) on the road this spring. I anticipate my 65 MPG cruising RPM to be about 2000 with 215-75R 15 tires. And I should have gobs of low end torque. I know people who will turn these flat 6’s in excess of five grand for short time periods. But I don’t think they would hold up long at this speed. I have posted lots of pictures at the following URL.
http://photo.starblvd.net/DonCoatney?st=album&pg=0

Don Coatney

Man, haven't seen one of them in a while! Aren't the Chrysler and DeSoto engines longer than the Dodge/Plymouth engines? Seems like that would be a big deal to swap to a "big block".

What are the problems you've encountered with the swap?

The reason I've been thinking of a 217/230, instead of a 251, or 265, was because of the availability of speed parts. I haven't seen anything for a Chrysler for DeSoto for years.

Dennis;
It is somewhat of a challenge to drop a big block flat 6 into a P-15. I had to make modifications both to the harmonic balancer and the front frame cross member to make things fit. I also had to modify the radiator bracket and reverse it to get the radiator in. And I had to notch the fenders and hood to accommodate the radiator. Had to re drill the front engine mount. Everything from the rear engine mounts back does not require any modifications. I am going to run an electric “pusher” cooling fan and I had to make brackets to install it.

There are as many HP enhancement parts available for “big block” flat 6’s as there are for small blocks. A guy by the name of George Asche in Pennsylvania will custom modify your stock intake and exhaust manifold for dual or triple carburetors and a true split on the exhaust. He does excellent work and also will sell you rebuilt carburetors if you so elect. If you are interested I will dig up his phone number as he is not on the web. Earl Edgerton in California can do a re-grind on your cam to what ever profile you want. And Earl also casts new finned aluminum heads for both big and small blocks. There are several people who are now making custom exhaust headers for both big and small blocks.

My engine is from a 1953 Desoto. I have installed Chevy pistons and Chevy stainless intake and exhaust valves in the engine. Earl’s cam and George’s manifold. There were a few modifications to the bell housing to bolt up the T-5. And I made a custom pilot bearing mount to replace the pilot bushing with a bearing. I am now in the process of installing disc brakes. I bought the basic kit from PLYDO in West Virginia and the rest of the parts came from the corner auto parts store. If you went to the link I posted there are lots of pictures of what it takes to get to where I am on this project. If I can help you out in any way let me know.
Don Coatney

Thanks for the info, Don.

I'm not presently working on a MOPAR project, but like to have notes and contacts, prior to starting anything. I've been compiling info for some time on Chevy sixes, but have nothing on MOPAR flatheads. I would appreciate the addresses of the parts folks you mentioned.

I high school, back in the 50s, I had a friend who had a '53 Plymouth. He had tripple carbs, milled head and a split manifold with dual exhausts. I drove a '51 Flathead 6 Ford with similar modifications, but he out-ran me with ease. I always wanted to build a Dodge, or Plymouth, flathead to see if I'd get as big a kick out of it as he did.

I cut and welded exhaust manifolds for dual exhausts for years. More recently I've learned to weld up my own tube headers. It's time-consuming and slow, but I'm retired and have the time.

Dennis;
George Asche can be reached at the following.

George Asche Jr.
R.D. 1
Venus, Pennsylvania 16364
(814) 354-2621

When you call be prepared for a long phone conversation as George has lots of information to share. Pictured below is the engine he has installed in his 1929 Desoto. George has owned this car for over 50 years. The engine is a 265 CI big block with a 3 speed over drive transmission. I had the pleasure of taking a ride in this car last summer. George wound this engine to over five grand on more than one occasion during this ride. In the early 1950's George raced this car on Daytona beach and ran over 140 miles per hour.

Here is a link to Earl Edgerton.

http://www.edgycams.com/

When I sent my cam to Earl he told me it would take 3 weeks. And he delivered as promised. It was a pleasure to work with him. Hope this information helps. I also included a picture of my engine. The engine is actually running as this picture was taken. Too bad you can not hear it.
Don Coatney





[This message has been edited by Don Coatney (edited 12-30-2003).]

Don, thanks so much for the info. I couldn't find Venus on the map, but will try to call George Ashe tonight. I live in Danville, PA and may go see him, if he's open to visitors.

Man, 5,000 rpm on a big ol' engine like that sounds like a lot! Must have a stroke of about a foot!

Good shot of the engine, too.

Dennis;
Venus is near Oil City. Here is a couple more pictures of George's stuff. If you get a chance drive up and see him. Make sure you tell him hi for me. And yes there is a dual charging system on this car.
Don Coatney












[This message has been edited by Don Coatney (edited 12-30-2003).]

[This message has been edited by Don Coatney (edited 12-30-2003).]

[This message has been edited by Don Coatney (edited 12-30-2003).]

I talked to George this morning. He is a store house of information, just like you said. Nice fellow. He remembered you and said he enjoyed your visit. I'm going to ride up there, some day, and visit him. He said he would be happy to visit and share MOPAR information with me. Thanks for the contact.

Glad you got a chance to talk to him. It will be worth your while to pay him a visit.
Don Coatney

Don:

GREAT PICTURES!

I've flown airplanes with fewer guages on the instrument panel...

Which leads me to this question; what is the object that looks like the open end of an aluminum can just to the right of the steering wheel?

Its an empty drinking cup w/ a wire handle.



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There is a story behind this drinking cup. While George Asche was taking me out for a spin in this Desoto Roadster he made the comment that people have often told him his car has everything but the kitchen sink. He then reached over and grabbed what looks like a chrome emergency brake handle and gave it a couple of pumps. Then he pulled a sliding brass sink from below the heater controls. Turned on the small brass spigot located dead center in the dash and proved to me that this car does indeed have a kitchen sink.
Don Coatney

Don, I noticed that your exhaust manifold has two outlets, but they don't seem to be split, or baffled between the cylinders. Did I miss something?

A while back, I welded up a second flange on a manifold for a guy with a flathead Studebaker. He didn't have that "Jaguar" sound until we removed the exhaust again and put a baffle in to seperate the front three cylinders from the rear three. After that, it sounded as good as any Chevy with Fentons I'd ever heard.

I normally cut a piece out of the manifold and weld up each end, like those shown on Goroge's photos. The Studebaker owner didn't want me to do that, though. That was more difficult to do.

Dennis;
George Asche split my manifold. The hear riser baffle inside the manifold is welded shut so there is a true split.
Don Coatney

Looks good that way. It's probably stronger, too.

I noticed George didn't have any heat to his intake manifold.

I've been heating my Chevy intakes with water, to keep 'em from freezing up. It helps the driveability in the summer, too.

Don- When are you going to get high tech and post an MP3 sound clip on that engine? I want to hear it again, need all the motivation I can get out there in the great white north. 8 below this morning, 2 feet of snow out of the last storm, but I got a heater from Santa to keep my fingers warm...

Your arch race rival, Pete




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Check out the restoration of my '50 Plymouth here:

http://home.rmci.net/blueskies/plymouth.html

Pete;
Glad you finally got some heat for your stable. Don’t need any here in the Boro. It was in the 70’s yesterday. Bit cooler today but no snow. I do expect a phone call once you get that jalopy of yours fired up. It will probably be the only chance I have to hear your #2 engine. You however will have a chance to hear my engine again as I will be leading the big race and you will be behind me.
Your Arch Race Winning Rival
Don Coatney

This is great. Its like watching the Discovery Channel's Biker Shootout last night! Who's going to be the winner?

I've kept tabs on both your buildups and now know all your speed secrets. How do I get into the next race challenge? It's going to have to be held in California though. I don't allow El Plymino in the snow!

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Stuck in the 50's
1951 Ply Concord truck
1954 Nash Rambler 2 dr
http://www.picturetrail.com/elplymino

At this rate, I'm going to have to put skis on the front and a big track on the back of my '50, more snow predicted today....

This photo was taken from my front door new years day, durring the last storm which dumped about 24" in about as many hours.

Pete





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Check out the restoration of my '50 Plymouth here:

http://home.rmci.net/blueskies/plymouth.html

BRRRRR My hats off to you guys...It's been in the upper twenties here and this Texas boy is freezing. I built a 53Ply. for my little brother in the mid sixties(cam, 2carbs,bore and mill work)it beat up more than it's share of bent8's, But Ya'll hav'm looking soooo good. I been watching the progess too and I believe ya'll have come up with some performance combinations that will be really impressive. I would love to hear them Run...Paul

Pete: Terrible! I could never live in that stuff.
Here's a picture of me taken from my back yard New Year's day. Thats me sitting down and a couple of the girls from next door. I had to come inside because I got sunburned. Ouch! Don



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Stuck in the 50's
1951 Ply Concord truck
1954 Nash Rambler 2 dr www.picturetrail.com/elplymino

[This message has been edited by 51 El Plymino (edited 01-06-2004).]

[This message has been edited by 51 El Plymino (edited 01-06-2004).]

Man, you really know how to hurt a feller! I'm originally from Florida, but live in Pennsylvania, now. This is the only time of the year I miss FLA, though.

What have you done with your plymouth pickup, lately? That is such a neat purchase.

A 265 crank is the speed equipment that I'd like to locate for my 25" Mopar. Improve the oiling, balance the internals, upgrade the camshaft. The 265 will run strong with good torque. Lighter modern pistons would also be a good idea.

I have considered a turbocharger. I think 6 pounds boost would work if the block was built right and the head was o-ringed. Each pound of boost will increase the power output about 10 percent, with the greatest increase being in the mid-range. A turbo motor would not have to run above 3,500 RPM to have a significant power increase.

I have the ideas, I don't have the money

Dennis: I haven't done much more than some cleaning, parts buying and thinking about what I want to do with the motor. I've got a general idea where its going (rat) but my imigination is way bigger than my wallet!