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MarkAubuchon

V8 conversion for my 47 P15 sedan

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Just thinking out load.  what is the easiest small block mopar engine to install.  My car has a strong running 6, dual carbs, OD, discs, 8/34.  Probably upgrade to an automatic and  of course AC.  

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are you doing the work yourself or do you have a shop in mind to carry out your wishes...I ask for in truth, we can make suggestions that have worked well for our cases but your installer may well kick and buck like a bronc at the suggestions...if using a shop, it is usually best ot question their experience in this and see what they are comfortable in doing...as for the Mopar V8..the small block is usually taller and the big block a tad wider compared to each other but overall very little difference....you can fit either.  Personally I think the V6 should not be ruled out.

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Stop thinking out loud, go out and buy something with an automatic trans and add it to the collection. :)

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personally I have found the V6 and or the V8 with the NV3500 5 speed floor shift a very suitable power plant for the P15...it is not really thinking out loud...but I do restate the fact that if farming it out, talk directly to that sharecropper on the install

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Certainly a good swap and has been done many times in various configurations so you just need to sort out the details before you dive in. Troll through the search button and see what others have done.

Here are 2:

http://p15-d24.com/topic/22985-im-back/

http://p15-d24.com/topic/37426-360-magnum-nv3500-in-my-48-plymouth/

 

 

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Mark D, I did redo an 84 Z28, ttop, drove it for the summer, fun no pizzazz. Really like the old plymouths, just want to add a few comfort features.  As always I will do all the work in house.

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My only advise is something you don't want to hear. You already have a strong,good-running,hopped up inline 6 that will comfortably cruise at or above the legal speed limit anywhere in the country,so why fix it if it isn't broken?

If you need AC,it's as easy to put AC on the flat 6 as it is a V-8.

If you just GOTTA have a V-8,why not sell your car and buy one that needs a engine and transmission to alter? You can probably get a pretty nice price for your car,and the ones with no engines or transmissions usually sell pretty low,so you might even save a few bucks.

If you decide to make the swap anyhow,make sure you advertise your old engine and trans on the classifieds here. Someone will want them.

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On 11/12/2017 at 9:06 AM, Plymouthy Adams said:

are you doing the work yourself or do you have a shop in mind to carry out your wishes...I ask for in truth, we can make suggestions that have worked well for our cases but your installer may well kick and buck like a bronc at the suggestions...if using a shop, it is usually best ot question their experience in this and see what they are comfortable in doing...as for the Mopar V8..the small block is usually taller and the big block a tad wider compared to each other but overall very little difference....you can fit either.  Personally I think the V6 should not be ruled out.

Leave the Ply just the way it is.

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The OP says that he just want to add a few comfort features. In my world that would include enough power to keep up with any/all freeway traffic if the need arise. Adding something like an a/c pump to an L6 will just suck up hp that is already in short supply. The OP wants to install a small block so a late 360 Magnum is a good choice...in my little world I could easily stretch the definition of "small-block" since the EarlyHemi is closely related so maybe a healthy 392 is in order?;)   On a more practical side, there are plenty of rusted/wrecked Ram 1500 in the bone yards and as Plymouthy Adams suggests, some of the late v-6 are plenty stout if the electronics don't scare you off.

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2 hours ago, Plymouthy Adams said:

and be unhappy with it, surely you jest or you have made an offer to buy...?  if the man wishes to cut the car so be it..

Have a nice day crabby Adams.

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Hi...after reading your post and the various reactions my question for you is :

I would like to know what do you not like about your flathead 6?

l have done many engine swaps in my time...some worked out well and some did not...but always in the interest of upgrading...

More power, better acceleration, better gas mileage, parts availability...

All that being said...l have a 1934 Plymouth all stock with exception of 3.73 ford rear end...the acceleration is what you would expect from the stock engine and the car cruises easily at hi way speeds.

My current project is a 1940 Dodge D14.It has the original engine and transmission in stock form and runs well.   I put a 3.08 ford rear end and the car cruises easily just as the 34 does...

As a younger man l saw things a little differently....l have thought about an engine swap but have left the car as is...

So to repeat my question...what does your flathead 6 not do that you want it to

Also if you sell your engine l would be interested...although l am a long way from St Louis

Thanks...Tom

 

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Several years ago a friend with a very nice 47 coupe with a small MOPAR V8 and I with a stock 218, 3 speed, in front of a 3:73 rear axle, B3B truck drove together some 180 miles one way. We both filled up side by side at the start, then again side by side on the return drive. Our mpg was identical, I used 1/4 gal more fuel.  So I'm sold on the flathead six. 

 

IMG_1468.JPG

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So having noticed this thread since it was created has been interesting to see which way it would go.

So OP Mark is interested in a V8 swap, so be it, millions have been done, unless the car is super mint, rare and in preemo shape, not a big deal.

Having said this, staying with a Chrysler flathead 6 is my choice, but it's not my car or money so it's a moot point in reality.

The Chrysler flathead 6 cylinder engine with some drivetrain upgrades is more than up to the task of modern day driving and travel, not always the case for the Stovebolt Chevy or Ford Flathead V8s ( who can afford to build these anyways).

So whatever the OP reasons is or are, could include, a lot more power, doing burnouts, high speed driving, or false sense of a more modern engine being more reliable. Options for AC power steering whatever.

You could also be like the gazzillions of "Streetrods" across America and drop in a 350 SBC and a Turbo 350 or a T5 (many have used this half on a flathead 6) or a 700R overdrive automatic. Then when you go to carshows or cruise ins, you don't have to open the hood, as everyone else has the same powerplant so in essence its a cloned streetrod.

In all seriousness, your car, your money, your choice.

I have gotten to the point that those who want to swap out flathead 6s or install the competitors drive trains and transmissions is their choice and problem, not mine......

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5 minutes ago, 55 Fargo Spitfire said:

 

I have gotten to the point that those who want to swap out flathead 6s or install the competitors drive trains and transmissions is their choice and problem, not mine......

Same here. I just want to remind them to not scrap the parts they remove,and to give those of us who need them a shot at buying them.

Like many I started out as a fan of high-performance hot rods back in the 50's. The older I get and the less time I have left,the more I appreciate the "if it ain't broke,don't fix it!" mindset.

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5 minutes ago, knuckleharley said:

Same here. I just want to remind them to not scrap the parts they remove,and to give those of us who need them a shot at buying them.

Like many I started out as a fan of high-performance hot rods back in the 50's. The older I get and the less time I have left,the more I appreciate the "if it ain't broke,don't fix it!" mindset.

Well Knuck, there are those who must have Hi-Perf V8s in any old car or truck, and thats okay too, im just not 1 of those types.

But having said this, ain't nothing worse than an old dog of engine that can not keep up with the pack so to speak.

A well running flathead 6 230s, 251, 265 generally make enough power, the 201 and 218s maybe not as much...

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If swapping from a flathead to a V8 or 6 then I would add disc brakes upgrade suspension and swap rearend as well. 

But for me I feel happier driving my 39 with a flathead.  Although I swapped the original 201 for a 1950 218 and stroked it with a 230 crank. That was my choice. 

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4 minutes ago, Lloyd said:

If swapping from a flathead to a V8 or 6 then I would add disc brakes upgrade suspension and swap rearend as well. 

But for me I feel happier driving my 39 with a flathead.  Although I swapped the original 201 for a 1950 218 and stroked it with a 230 crank. That was my choice. 

Why is the V8 heavier, or what?

Brakes your choice to upgrade, the suspension is IFS and was far ahead of its time, add a shock relocation and no issues there...

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I’m just saying if I was going to put a V8 engine in my 39 I would go the whole 9 yards Fargo. I’m sure you know more about these cars than I do. I have seen bolt/weld on front end kits that include disc brakes and suspension. 

As far as weight. I have no idea what a V8 weighs or a flathead and if the suspension would need to be beefed up although to me it would be a consideration. Another one is if the frame can take the added HP? Could it possibly twist?

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There is another option for the P-15. I installed S6 with 904 and a 8 1/4. The S6 has 50 more HP than F6 and weighs less. It will produce much more HP with a few hop up procedures. Unlike some of the V8 conversions the engine bay remains stock. Your original radiator will keep you cool and you can use the stock steering column with a slight modification of the linkage on the auto. Check my swap out at //www.cascadepacificplymouth.org/ tech articles. One of the best things about this swap is it is not the norm as are everybody elses V8 swap.

Edited by bob westphal

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19 minutes ago, Lloyd said:

I’m just saying if I was going to put a V8 engine in my 39 I would go the whole 9 yards Fargo. I’m sure you know more about these cars than I do. I have seen bolt/weld on front end kits that include disc brakes and suspension

As far as weight. I have no idea what a V8 weighs or a flathead and if the suspension would need to be beefed up although to me it would be a consideration. Another one is if the frame can take the added HP? Could it possibly twist?

These frames are boxed and solid.

Frontend suspension is quite good.

Most V8s off center install to clear steering box.

Flathead 6s are heavy so most V8 swaps are not a weight issue.

I am not a proponent of swapping to disc brakes as a given.

Streetrods and all the creature comforts some must have especially AC in hot areas..

To each their own...

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1 hour ago, bob westphal said:

There is another option for the P-15. I installed S6 with 904 and a 8 1/4. The S6 has 50 more HP than F6 and weighs less. It will produce much more HP with a few hop up procedures. Unlike some of the V8 conversions the engine bay remains stock. Your original radiator will keep you cool and you can use the stock steering column with a slight modification of the linkage on the auto. Check my swap out at //www.cascadepacificplymouth.org/ tech articles. One of the best things about this swap is it is not the norm as are everybody elses V8 swap.

Hello Westphal, I think that is a good suggestion. I have a slant six that puts a lot of V8's to shame.  It runs so good, I can't see any reason to pull it out....  I am afraid that I can't do batter for my application, not to mention the great gas mileage I get.  I have a A833 OD behind it.  I just removed the 3.73's to put in 3.55's because I sheared the sure grip housing bolts and had to repair it.  Before that, I tore out the center of my clutch.  Don't underestimate the power of a slant six!  LOL

The engine is in my, huhummm, 1969 Valiant.  But if I ever hemi my Valiant, the slant is going into my 1937 pile of parts Dodge.  It will motivate me to do the project should I do the latter...

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An additional comment, almost without exception, when I open the hood, the comments are somewhat like this, "Wow, you kept the flathead six! That is cool!"  And when I reach in from the outside, push the start button and it immediately starts at idle, they are really impressed. Those are additional reasons I like my flathead. 

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   Not that anybody’s counting “votes” here, but I’m going to throw my 2¢worth in—simply put: I agree completely with knuckleharley (I almost always do, since we have a lot in common), pflaming (I almost always do with him, too [by the way—how did your surgery go???]), and Dale, Tom, Robert, Lloyd, and Bob, (these five gentlemen I’ve just encountered, but they share a common trait—common sense . . . and I do embrace that). Well, this ought to set off the others herein, but that doesn’t matter, either, because . . . . . . .

Edited by DrDoctor

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