41 Plymouth SB Mopar Engine Swap

Lookin good Rock! Happy New Year!

 

Thanks, Glenn!

 

Happy New Year to you Rock!

 

Happy new year Rock,
As always you are moving right along... So close to seeing that front sway bar installed.
Have you thought about this kind of hose? http://www.speedwaymotors.com/Flexible-Radiator-Hoses,2495.html that is what I hope to use.

MobilDave

 

Hmm. I've mot seen those, Dave. They don't state the minimum bend radius and I'm going to need a tight one for that hose. I'll figure it out as i go along.

I will still have to remove the front clip at least one more time before its finished (probably twice). I'll get pics of that bar when I install it again.

 

Woo Hoo! It's looking like a car again! I got the running boards put on am modifying the underneath braces to make sure they support the boards properly.

Also, I have installed the front bumper. It is a 41 Dodge bumper and the mounts had it sitting about 12" away from the body. The Dodge had a tray that went on top of the mounts between the bumper and the body. i shortened up the mounts and made it sit about 4" away from the body. I like the "pointed" bumper. I think it works well with the car. What do y'all think?

(I'm excited now but I know I'll be disassembling stuff again soon. First, you have to make sure it all fits before you paint. Otherwise, you've got a mess on your hands. This all fits pretty well.)

I forgot to give props to Dan Babb (aka Danbabb) for coming by and helping me get the hood installed. Thanks, Dan!

 

I drove a 1941 Plymouth 2 door Plymouth coupe to high school. It was upgraded with a Chrysler "Spilfire" flathead six which was almost a straight "No Change" drop in. Needless to say, I loved the car then and still do today. Green with envy,

Specs

 

looks good rockable. my 40 front bumper is like that one. I like it moved closer like that, looks alot better than stock.

 

Thanks, Plow! My buddy wants me to make a tray and put it on top. What do you guys think?

 

I think it would look awkward in my opinion. I think it looks better closer(like you have it) and without the pan. Look how 40 fords are, the grille flows down like your plymouth, it would disrupt the look of the grille if a pan was put in.

 

I agree. I may trim the curved tips off, however.

 

Thats a tuff call there, I think it would look good both ways.

 

why so low in the frame? iam droping a 360 too. but to clear the dist. i need to push it up and to the front. is there something i need to know

 

If you notch the frame crossmember to clear the engine pulleys, and hammer clearance in the right side (passenger side) firewall to clear the head & valve cover you can keep the engine low and shift it to the right about an inch and a half or 2". That gives you a little extra clearance on the steering column and exhaust manifold, it keeps the engine low, and the 360 will look like it grew in there. An inch of clearance for the dist is plenty. Gene

 

I looked again today and there is no problem putting the distributor in and taking it out. It sits in the recess for the old six banger.

 

Rockable your doing an awesome job.I am in the middle of restoring my 1941 Chrysler royal but other than changing the running gear and cleaning it up frame wise I cannot imagine going into the depth that you are tackling.I am installing an La 318 in my car at present and was wondering if there will be an issue with offsetting by 2"? I tried using 3 different left exhaust manifolds but just cannot push the engine over any farther towards the steering box.One main concern I have is the angle that my engine will be at in regards to my Pinion.Can I run the drive shaft at 2 angles.I was reading where you offset by maybe 1.5 to 2 ' and over the length of the running gear you were only off by 1/2 an inch.My original rear housing was offset by 2" towards the passengers side and the ford 9 " that I am installing is prettty well centre.I know I cant drop the engine down so I am thinking if I havent room between the floor and the tranny to mount the shifter I plan on using and if I must maintain a minimum angle at the tail shaft then maybe my only alternitive is to modify the floor hump over the tranny.Sorry for cutting in on your rebuild thread.

 

Typicaly you move it right(pass side) 1 1/2"s & get the driver's ex man off of one of the boxy late 60s/early to mid 70s Dart/Valiants, it curls around the stearing column. @ least on the Plym/Dodges you will have to cut your inner fendes a bit. The 904 is tight to the floorboards.

 

I have purchased a set from a 1968 Barracuda and a set from a 72 dart and they both drive the engine over to the passengers side more by hitting on my column. Even if I lift the engine higher ,the engine will still hit on the steering box.Also I can only go up so high and still maintain my angle at the tranny tail as the tranny hits the floor.I am using a set from a 1968 charger 318 at present to do my mockup and I end up with a 2 " offset.Using the manifold in question is about all the steering box will allow anyhow as the engine is about 1/2 inch from the box and the manifold is 1/2 from the column

 

I've been working on this so long, I've forgotten the details. But, I believe I have about 1 1/2" of offset. Ideally, the rear should be offset the same. You are allowed a maximum of 1/2 a degree misalignment as I recall. Check it out and do the math. 2" and a centere up rear may put you over that. If you are outside of that, you may have a vibration and shortened u-joint life.

Thanks for the props. I'm enjoying the build. It's my first hot rod.

 

Hmm. Mine fit perfectly before I changed to a R&p. The Chrysler may be longer in that area and the angle may be different..

 

I am learning as I go with this rebuild so I will have to appoligize for the questions.I am editing this post at this time to correct my mistake.I have no idea why I thought I had a centered pinion on my housing .I actually have a 1 1/2 offset towards the passengers side.The original 1941 housing was about the same .Using the formula mentioned ,with this offset in the housing and 2" offset on the engine would It be close enough not give give me issues.I have no idea how to calculate it so this is the reason I am asking .Sorry for the inconvience and thanks for the help

 

just dicovered this thread and appreciate all the info,for sure!
Thanks!
RDR

 

Not trying to take over Rock's thread, but, You can have a u-joint angle up to a max of 30 degrees from straight. What you need to have the the front and rear U-joints to have opposite angles to keep the drive shaft balanced. The center line of the transmission and the center line of the rear axle pinion have to be parallel with each other but can be off set in any direction, up to the max 30 degree u-joint pivot. The length of the drive shaft has an effect on the u-joint angle, a shorter drive shaft will tolerate less transmission to axle pinion center line offset. Some offset is preferred over a straight line with no u-joint movement.

I have used a standard Mopar small block driver side exhaust manifold and cleared the steering shaft, depends on the car, and the engine height and offset. You can notch and box back in the front cross member to clear the crank pulleys without effecting the cross member structural strength. Generally, the lower you can get the motor, the better everything fits. I've built 4 of these cars. Gene

 

You might be mistaking steering u-joint max angle versus drive shaft angles.

 

Could be, I'll check that tomorrow. I have a couple drive shafts in the shop. Gene

 

Here's the poop on drivelines!

http://jniolon.clubfte.com/drivelinephasing/drivelinephasing.html

 

Thanks for the drive line info.Rock can you explain why you stated that you have to shorten one of your control arms to attain negative camber?Also I noticed that you were able to mount your engine higher than I am able to.Do you have lots of tunnel clearance using a std tranny.I found that when using the 904 auto in mine and the engine leveled that I am almost to the floor .

 

Well, I just couldn't get any neg. camber, so I shortened both of the upper control arms a little. Pretty simple. The cars were'nt designed to run negative camber because you don't want that with bias ply tires. I'm running radials and would like to have up to 1/2 degree. Not sure I'll have it but it will be better than positive camber.

I am not running a 904, so I can't comment on that combination. However, I did a lot of teardrop hammer work on my floor boarch to create tunnel clearance. In some areas, I definitely increased the height of the tunnel. I still may modify it further but it will work as I have it now, I believe.

 

Nice thread! It put pictures to my own thoughts of modifying my -37 Plymouth BC.

 

It's pretty much common knowledge that the right side of the firewall has to be dimpled to clear the valve cover. The Magnum 318 has a completely different shape than does the LA 318. Take a look at the pictures of both motors and give me a best guess on the possibility of not having to dimple the firewall if I use the Magnum motor in my 41. I'm thinking it may work without dimpling the firewall but anyone that has done this swap may have a better idea. I have both motors sitting here.