AMT Double Dragster Engine Option

[Lunajammer]

The two Chevy engines can be built either inline or as twin mills side by side with potvin blowers. I'd like to build the rail dragster with one engine, but I hate to break up the pair of Chevys in case I want to keep them for another project. That leaves the Chrysler engine which also comes with the kit, but the instructions don't show that option with a potvin blower.

My questions is, though the instructions don't show it, can the Chrysler engine be built with the potvin blower using the Chevy mounting plate (Item #68) or would that be incorrect? Or is there another way the Potvin can be correctly used with the Chrysler?

LINK TO INSTRUCTION SHEET

Edited November 15, 2015 by Lunajammer

[Force]

The Potvin blower setups are for the Chevys but you could use it on the Hemi if you want to, but the intake manifold would probably not fit on the Hemi so most likely it has to be modified, the tubes could also be too short.
Otherwise the Hemi comes with a regular blower setup.

[Ace-Garageguy]

Haken is right about the Chevy manifold for the Potvin setup not fitting on the Chrysler.

The Chrysler is wider between the heads and has entirely different port spacing. The blower will probably have to go farther forward on the Chrysler too (the drive mount for the old Hemi is typically longer than the Chebby unit) so you'll possibly have to lengthen the tubes from the blower to the manifold.

A little scratchbuilding or modifying stuff you may have in your parts box should get you there, though. One approach would be to start with a simple one-piece manifold for the Hemi (that has the port-runners laid out right, and the right width) and file the top flat, then put tubes on the front of it to reach your blower tubes. That would represent a manifold design similar to what the kit gives you for the Chebbys. 

Two-piece manifolds were the most common for setting up a 392-family Hemi with the front-drive blower. Start with the "log" style intake manifolds that come in the kit, and file off the mounting plates for the carburetors, then run additional tubes forward to hit your blower tubes. You'll be going for a look like in the pix below.

Here are some Potvin / Hemi setups for a guide. Notice the blower-drive mount / timing cover length.

                                        

    

                                                                                                         

Here are a couple of SBC front-drive blower setups for comparison...

The point is, you can use the timing cover that comes in the kit for the Chrysler engine, file it flat, and mount the Chebby / Potvin blower drive to it, OR, if you want to save the Potvin drive, you can make up something that looks about right from the rear cover of a parts-box blower (also flied flat on the rear side, and mated to the Chrysler timing cover).

 

Edited November 15, 2015 by Ace-Garageguy

[62rebel]

That shouldn't be hard to do with the log manifold from the reissued '53 F100 kit, a little sanding and cutting and Bob's your uncle. I have two DD kits in various stages of build, including one with the dual blower setup from the '53 Studebaker in the Fiat coupe...

[Ace-Garageguy]

That shouldn't be hard to do with the log manifold from the reissued '53 F100 kit, a little sanding and cutting and Bob's your uncle. I have two DD kits in various stages of build, including one with the dual blower setup from the '53 Studebaker in the Fiat coupe...

I just pulled the Double Dragster kit off the shelf and it comes with a pair of log manifolds for the Chrysler. I'd forgotten just exactly what was in the kit. 

[62rebel]

dang, it did. so much stuff in the box I missed them!

[Lunajammer]

These are great answers and I appreciate the reference pics Bill.

So it's got me wondering... I've got a spare 409 from the 59 El Camino. I haven't pulled it out the check, but would it work for me to use that with the Potvin chevy manifold and just hang onto all the DD engines?

[Ace-Garageguy]

These are great answers and I appreciate the reference pics Bill.

So it's got me wondering... I've got a spare 409 from the 59 El Camino. I haven't pulled it out the check, but would it work for me to use that with the Potvin chevy manifold and just hang onto all the DD engines?

Glad to help.

No reason not to use a front-blown 409. I've never seen one, so it would be very interesting in its uniqueness. Not ALL front-blown setups were Potvin anyway, so even if Potvin didn't make a rig for the 348 / 409, a good machinist / engineer could.

The intake manifold for the DD Potvin-Chebbys might fit a kit 409, but I kinda doubt it. The port-spacing for a 348 / 409 is similar to the port spacing of the SBC, but the heads are probably farther apart.

You can make up either a one-piece intake manifold as I suggested for the Chrysler, or build a pair of log manifolds. A little more work, but definitely doable.

 

348/409 intake manifold port-spacing: 

 

 

 

Edited November 15, 2015 by Ace-Garageguy

[Ace-Garageguy]

 

 This is really getting annoying. Something here won't allow me to post additional information. I'm getting "post too old to be edited" and "404 ERROR. We can't find the page you're looking for" messages.

 

Let's see if this will go through.

Edited November 15, 2015 by Ace-Garageguy

[Bernard Kron]

I thought I'd show this motor for a Studebaker Bonneville streamliner I started a few years back but haven't finished. The basic 392 is from the AMT '53 Studebaker kit but there's no reason you couldn't used the one in the Double Dragster. The blower casing, nose drive, manifolds and tubing are all from the MPC Carl Casper Undertaker kit (the rest of the Undertaker motor is pretty awful, unfortunately...).

Edited November 16, 2015 by Bernard Kron

[Mark]

The Round 2 MPC Cosmic Charger dragster includes a newly-tooled Potvin blower drive setup; that one should work, and taking those parts out of that kit won't leave it unbuildable. 

This won't be of any help unless you could track down the parts...AMT did include a similar setup for the Chrysler display engine in their '61-'62 Buick Special wagons.  The same display engine and trailer were then used in the '63 Nova wagon.  The Nova wagon was later butchered into the Boss Nova (using the Chrysler engine to power the car).  Unfortunately the Potvin setup wasn't included in the Boss Nova because in that kit, the engine is right behind the driver, and that setup wouldn't fit.  So you'd be looking for fifty-year-old parts.  It wouldn't be tough to scratchbuild/kitbash a convincing setup anyway.

[Ace-Garageguy]

One more try...I've been bumped off the site and locked out the last two times I've tried to post this.

I looked in the El Camino kit to see what you'd be up against doing a front-drive 409.

The top-mounted blower manifold is easily converted into a front-drive manifold by adding forward-running tubes.

You can use the oval-case GMC blower in the kit, just mounted on its side in the front. The injection from the kit will work too.

You'll have to file the water pump / timing cover flat, and make up a blower-drive extension from an old parts-box blower rear cover.

You'll also have to make up an airbox / popoff valve and tubes to run up to your manifold.

All in all, not too hard, and really unusual.

[Lunajammer]

The front drive caught my eye when scrolling through the amazing reference site George Klass Remembers. I know so little about the subject to barely follow what you're saying, but you've certainly excited me about it to research it much more deeply. I like the idea of the front blower on a 409. Over the years I've inherited several well stocked (but trashy) parts boxes I might get away with replicating the shapes, but I need to learn it to do it right. You guys are an inspiration and as always Bill, your contributions are immeasurable.