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Suggestions About Engine Selection
https://www.slantsix.org/forum/viewtopic.php?t=40644		 Page 1 of 1
Author:  James_Douglas [ Tue Jun 15, 2010 6:19 pm ]
Post subject:  Suggestions About Engine Selection
Hello,

My name is James. I am an old MOPAR guy. I have had MOPAR big blocks, small blocks, and a couple of slant six's.

The slant six's were a long time ago in a 1960 Dodge Dart.

I am currently playing with 1940's Desoto's with Flathead 6's.

I have a 1947 Desoto Suburban which is a 140" wheelbase, 9 passenger, 4800 pound sedan.

We love this car, but the flathead is just not enough power as we intend on using this car to tow a trailer across the US. Well, it does have the power, but the current average driver in USA does not have the patience to wait for my acceleration.

I wanted to use an early Desoto Hemi, however, there is no way to get one in the 1946-1948 engine bay without having to change the steering over to a rack.

It then came to me that the old slant six in the old Dodge may fit without having to change the steering and this engine has about the same power as the stock small baby Hemi's.

If I were to go down this path, I would use a slant six with a Torque-Flight and a gear vendor overdrive. I specifically would use the 1961-1964 torque-flight with the rear pump and the 1962-1964 Plymouth round (in a straight line) push buttons.

I would appreciate any suggestions for which core engine would be best. I am looking for maximum strength and low end torque, not maximum HP.

Thanks, James

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Author:  ceej [ Tue Jun 15, 2010 6:40 pm ]
Post subject: 
You need the early crank for the early small register torque converter. For your application an early block should be just fine.
The BH is the favorite of racers, and can be found in the early 70's applications. You can install a bushing in the crank register to fit the early torque converter. There may be an issue with the ring gear on the converter. Somebody else will need to chime in. I haven't done one of these conversions personally.
Look for something in a 1971-1974 to locate a BH block. It isn't that critical though. It doesn't sound like you'll be trying to turn 6500 rpm with it, so shouldn't have strength problems with the three freeze plug blocks.

How heavy is the trailer? Might be a good candidate for a stroker for towing. Not much need to go hog wild with it, but a nice offset grind could give it a bit more grunt.

Two pennies :lol:

CJ
Author:  rustyfords [ Tue Jun 15, 2010 6:48 pm ]
Post subject: 
Welcome James....how about some photos of that DeSoto?

I love the huge orphan cars of that period.
Author:  kipamore [ Tue Jun 15, 2010 7:19 pm ]
Post subject: 
It would help to know the rearend ratio that's currently in it. I suppose it's pretty low at #4800 with the flathead. The Gear Vendors solves that problem, but it's a little expensive. The slant will move it, but you might be happier with a small V8. Or maybe a Jeep 4.0 inline 6. Or a blow thru turbo on the original motor.
Author:  sandy in BC [ Tue Jun 15, 2010 7:21 pm ]
Post subject: 
I have some DeSotos myself.....

You are right ....none of the V8s fit without a steering change. In my 51 hardtop I made new front frame rails and added a B car front subframe. That gave me torsion bars, power steering, a V8 , disc brakes and auto trans all in one go. Dont do the F body clip.....

The slant can be made to fit but is by no means a slam donk.....some radiator changes will be necessary. Motor mounts need to be madeup.....no Floating Power....

The slant 904 is about 1000000lbs lighter than a FH / Simplimatic....
Author:  olafla [ Thu Jun 17, 2010 1:25 am ]
Post subject: 
Hi, and welcome to the forum, James. I have a soft spot for the old flatheads myself, so over time I have gathered some links to manufacturers that still make high performance parts for them. As I understand from Sandy and the other posts here, there is a lot of work to transplant a newer engine into your car, so here are some links to powerboosting parts for the old one, just in case you decide not to convert to a slantsix. A little engine work together with these parts should push your torque and power figures upward quite a bit!
Langdon's Stovebolt Engine Parts have the Offy twin carb intake manifold, these beautiful cast headers, and even an electronic HEI distributor upgrade. At Wilcap Adapters you'll find adapters to put a GM (sorry!) manual or auto gearbox behind your flathead. I have no detailed knowledge about how the parts interchange between the different mopar division engines, but a good source for engine parts for Dodge flatheads is vintagepowerwagons.com. Whatever you decide to do, keep us posted.
Olaf.
Author:  Dart270 [ Thu Jun 17, 2010 4:29 am ]
Post subject: 
Sounds like a cool project.

I bet the GV OD will not fit the early rear pump trannys, but will fit '66-up. 904s are awesome.

Lou
Author:  4x4jimbo [ Thu Jun 17, 2010 7:04 pm ]
Post subject:  go slant
go for the slant!!! i have the 225 in my van with the torqueflight 3 speed though overdrive is a better idea .i can rip trees out the ground and it has plent of pickup and power.this isnt an average van though made for mudd
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