Mopar Flathead Engine Is It Still Practical For Modern Times?

[55 Fargo]

Hey all, after reading the thread on engine swap/upgrading. Some of the comments has sparked some question to the continued practical use of the "Chrysler Flathead" engine in today's modern high speed traffic world.

There are some on here who believe these engines might not be the best choice, and that some type of V8 is the best way to go, whether that be a SBC or strictly a Mopar only power plant.

Building and hopping up a flattie engine, can be a bit costly, and the HP increases are modest, but the "Kool" factor is still there.

I did start a Mopar flathead high performance thread a while back, and it was quite a lively thread, these engines can certainly be built, but the expense and return, might not be attractive to some.

I did buy a 318 LA engine this spring, it may or may not go into my 55 Fargo, time will tell, if not it will go into something else maybe my Son's fox body Mustang.....LOL

I personally cannot see why these engines, if in good tune, in a car or truck that has good suspension/steering and brakes, cannot be driven at fairly decent highway speeds, without going bankrupt in the process.

I do not resign to the notion, that Dakota frames or having IFS is a must, or without these, you cannot get along in today's traffic. I did speak to another Mopar guy a while back, he all but said the old trucks with stock drivetrains and suspension were of no use for modern use, and going modern everything but the body, was what is needed to drive anywhere in a decent time and in comfort.

I enjoy the feel and drive in my old truck, it could be better, and more power would be nice, I do not need a 300 HP plus V8 , but 175-200 hp would be a nice increase in power.

Anyway, share your thought and opinions on this topic, lets get it all out in the open, "Pro and Con".....

Edited August 23, 2015 by Fargos-Go-Far

[gshort]

Does it have to be a V-8? Why not a V-6? I am going the Dakota route. Have/had plans for a 360 in plant into the Dakota frame. After driving the Dakota home I have been seriously thinking of using the V-6.

The flathead was long gone by the time I got around to working on this truck. The rods were knocking and it had been pulled out 30 yrs ago. I debated dropping the V-8 into the original frame but for ride and safety I thought it would be cheaper to go this route.

[NiftyFifty]

You must remember that these trucks were never designed for today's highway speeds, and a lot of today's younger drivers aren't prepared for slower moving traffic sometimes. Your stock brakes and suspension aren't set up to make a quick stop at 68-75mph (twin highways) and although you can stick to the 55 roads, that starts to take the convince away. You also have to live with the fact some shops won't touch old engines like that, parts are harder to find when your in need on the road and even finding guys who are good with carbs is tough. Don't get me wrong, I really enjoy watching old guys faces light up when they see the flattie still under the hood and not a SBC, but if you have plans to use it as a long distance vehicle, or like to cruise at good highway speeds safely....then a v8 and IFS and upgraded brakes are more appropriate.

[Plymouthy Adams]

most folks who choose these older stock cars are in the slow lane to begin with and there is nothing at all wrong with this...also nothing wrong with other builds..it is basically a matter of choice...while the flathead can still be maintained with new parts..they are just usually not walk in and get handed over the counter when you enter any big box store..this sways some people to change and others...well many just have to have a HO engine and others yet have to make changes just because it is fun to do...this hobby can be like a bag of spice drops..a mixture of all things sweet..and if you like a bit of sour thrown in sure..drop in a SBC...

[55 Fargo]

You must remember that these trucks were never designed for today's highway speeds, and a lot of today's younger drivers aren't prepared for slower moving traffic sometimes. Your stock brakes and suspension aren't set up to make a quick stop at 68-75mph (twin highways) and although you can stick to the 55 roads, that starts to take the convince away. You also have to live with the fact some shops won't touch old engines like that, parts are harder to find when your in need on the road and even finding guys who are good with carbs is tough. Don't get me wrong, I really enjoy watching old guys faces light up when they see the flattie still under the hood and not a SBC, but if you have plans to use it as a long distance vehicle, or like to cruise at good highway speeds safely....then a v8 and IFS and upgraded brakes are more appropriate.

Well have driven hwy 59 north of Winnipeg to Grand Beach, and the Perimeter around Winnipeg, at 55-60 mph not much issue.The trouble with those smaller 2 lane highways is they are 100 kph posted, and some are downright busy, they should be twinned but the province is behind times, example Hwy 8 to Gimli, extremely busy at times.

Your area of Manitoba is lightly populated and with the exception of The #1 Hwy, you must experience relatively light traffic most of the time.

I totally agree that these trucks were not meant to drive 70+ mph, with the stock set-up....PS we are lucky in this area as traffic moves slower and is no where near as heavy as some other areas of this country and the USA.

Edited August 23, 2015 by Fargos-Go-Far

[Jeff Balazs]

My approach to this has led to some modifications. Better gearing and disc brakes on all four corners. I don't feel like there was really any choice on these upgrades as this will be my only vehicle until I kick off. With the 3.55 rear ratio it keeps up with the reasonable drivers on surface roads. But only a fraction of todays drivers maintain safe following distances.......so the better brakes I feel are a must.

 

As far as keeping one of these on the road goes I think one has to understand and compensate for what one is dealing with. Having a good set of spares and being able to do most of the work yourself is certainly a plus. I am not a fan of calling for a tow so I keep a pretty comrehensive set of spares and tools on board. And because this is my only vehicle and I plan on keeping it I will find and rebuild a spare engine. Also I have made many small modifications and upgrades to the basic package. Some of these were done to improve reliability and other have been made to make it easier to maintain and service.

 

Yes the old flatty could use a few more ponies. And no it will never be a hot rod. That is OK with me. What it is though is a sort of time machine. When I get in it I feel like every drive is an adventure and that is a feeling that has been gone for a long time with me. Would it be that way if it was a old body sitting on an all new chassis? I kinda doubt it.

Does any of this make any real sense? I am not sure if others understand any of it........and I am pretty sure I don't care if they do. I can't wait until it has been thoroughly tested (and it cools down some) to go out exploring. And if I am not going fast enough for some of the folks on the road ......  they will just have to get over it.

 

Jeff

[Plymouthy Adams]

I pretty much stay within the speed limit...just never in  a hurry it seems anymore..on the country roads between home and town most travels 10-15 over the speed limit...and come upon my butt at 55...well..wait till safe to pass...or leave home earlier....and if I am towing a car..say less than speed..I will pull over and let all go around me...it is only the safe thing to do..

[NiftyFifty]

I may have less traffic in Brandon then Winnipeg and area, but I have to travel 35 miles of 70mph highway to get to it first, and on top of that I like to do car shows, and those are spread all over and usually even further from home, and I have to take #1 to get to any of them anyway... So just booting around the perimeter and provincial highways would be easier then what I'm doing. It's fun to have the originality of the motor, but it's all in what your plans are for your truck, and where you plan to drive it too.

I created a custom monster, around a semi original engine, and I think that's where I went wrong...but at my age, I have lots of time to learn from my mistakes and do builds differently in the future

[55 Fargo]

I may have less traffic in Brandon then Winnipeg and area, but I have to travel 35 miles of 70mph highway to get to it first, and on top of that I like to do car shows, and those are spread all over and usually even further from home, and I have to take #1 to get to any of them anyway... So just booting around the perimeter and provincial highways would be easier then what I'm doing. It's fun to have the originality of the motor, but it's all in what your plans are for your truck, and where you plan to drive it too.

I created a custom monster, around a semi original engine, and I think that's where I went wrong...but at my age, I have lots of time to learn from my mistakes and do builds differently in the future

Well you could always sell this truck, and build another more suitable to your needs.

That way you can cruise at higher speeds to those car shows.

Yup we in the capital region have 800000 people and the drivers to deal with, yours is about 50000, but the Trans Canada highway is busy, I find this very light duty compared the bigger cities in Canada and the US....

I have no idea what I am going to do with mine in the future, but for the time being it will stay flathead.....

Edited August 23, 2015 by Fargos-Go-Far

[bluebanshee]

I feel comfortable at highway speeds on all the roads around here. The flathead doesn't have a ton of acceleration up a long hill but it will maintain whatever speed you were at before the hill. I did do a t5 swap, dual carbs, and have a pretty a pretty tall rear axle (3.27?) so cruising at 65 is not a problem. I've hit 71mph at maybe 2300 rpm, I dont recall exactly.Four wheel disc brakes and a dual port master cylinder seem completely adequate for stopping power.

[NiftyFifty]

Well you could always sell this truck, and build another more suitable to your needs.

That way you can cruise at higher speeds to those car shows.

Yup we in the capital region have 800000 people and the drivers to deal with, yours is about 50000, but the Trans Canada highway is busy, I find this very light duty compared the bigger cities in Canada and the US....

I have no idea what I am going to do with mine in the future, but for the time being it will stay flathead.....

Already the plan....although likely not build, cheaper to buy someone else's blood sweat and tears and make minor changes to make it mine. Maybe someday another PH, but I'm heading GM next round...I want to buy parts out of the book

[Dodgeb4ya]

A GM probably is best to move to. You can buy tons of Chineasy parts on line and even at 7-11 for a boring common street build.

[Jeff Balazs]

I may have less traffic in Brandon then Winnipeg and area, but I have to travel 35 miles of 70mph highway to get to it first, and on top of that I like to do car shows, and those are spread all over and usually even further from home, and I have to take #1 to get to any of them anyway... So just booting around the perimeter and provincial highways would be easier then what I'm doing. It's fun to have the originality of the motor, but it's all in what your plans are for your truck, and where you plan to drive it too.

I created a custom monster, around a semi original engine, and I think that's where I went wrong...but at my age, I have lots of time to learn from my mistakes and do builds differently in the future

Maybe taking a step back is the "Wise way tu" go for now? Sometimes we come up with a plan and it has a few flaws. Doesn't mean it is a totally bad plan.......just means it needs more thought and work. Unless you have unlimited time and money this was never.... ever going to be an easy project. We try something.......learn from it and come up with a solution. You are absolutely correct ,,,,,,, it would be easier to open a catalog and buy a kit. There are a fair amount of frustrating things about doing one of these trucks. In fact I am pretty certain the "M" in Mopar has something to do with masocisim.

 

I know I would do some things differently if I was starting again. Take a break.....mull it over.....most of the time there is a relatively easy solution. Just gotta give it some time.

 

Jeff

[NiftyFifty]

Yep, my truck has had 3 different configurations already in the last 6 years, and the last one got out of hand in the money department. A nice 62-65 GMC C-10 with a low ride look and a nice powerful engine would hit the spot right now. But I'll always be Mopar at heart, and not sure I would ever sell my Monaco, maybe only to buy one that was more pristine.

[59bisquik]

While I have only driven my truck a couple times, I am really excited about the flathead and the issues that come along with it.

I have been doing a frame off resto-mod on a 54 Ford coupe for the last few years. 302/AOD, rack and pinion, 8.8 with 3.55's and trac-loc, 4 wheel disc and planning on a mild custom with the bare steel look for the body. It still has a couple of years before its on the road.

With that being said, it should drive pretty close to a modern car and be reliable. But with the Dodge, I see a flathead, 6v and solid axles. I see it as a big yellow time machine. I want to keep it that way and couldn't fathom a chassis swap. To me, it's no longer a classic truck in my opinion. I am excited to be in the slow lane with my dual carbs and exhaust howling and puttering along at 55 to 65. The cool factor of a flathead outweighs the any modern high tech hotrod. I too think that that's part of the adventure of going somewhere.

That's not to say that disc brakes and seat belts for safety are a bad idea. I am just under the opinion that I wouldn't do anything that I couldn't easily return to stock like a front ifs clip for example. I do wish they made the front disc kit for these that I saw on a 30's rod years ago. It used the huge Buick finned drums, but actually had discs hidden inside.

Of course, to each their own and there is no "correct" answer. Just build the vehicle to suit your needs and intended purpose.

[NiftyFifty]

There is a kit for these trucks, works with stock 1/2 ton axle, search oust Rusty Hope or just disc conversion. Very easy and you can always go back to stock.

[55 Fargo]

While I have only driven my truck a couple times, I am really excited about the flathead and the issues that come along with it.

I have been doing a frame off resto-mod on a 54 Ford coupe for the last few years. 302/AOD, rack and pinion, 8.8 with 3.55's and trac-loc, 4 wheel disc and planning on a mild custom with the bare steel look for the body. It still has a couple of years before its on the road.

With that being said, it should drive pretty close to a modern car and be reliable. But with the Dodge, I see a flathead, 6v and solid axles. I see it as a big yellow time machine. I want to keep it that way and couldn't fathom a chassis swap. To me, it's no longer a classic truck in my opinion. I am excited to be in the slow lane with my dual carbs and exhaust howling and puttering along at 55 to 65. The cool factor of a flathead outweighs the any modern high tech hotrod. I too think that that's part of the adventure of going somewhere.

That's not to say that disc brakes and seat belts for safety are a bad idea. I am just under the opinion that I wouldn't do anything that I couldn't easily return to stock like a front ifs clip for example. I do wish they made the front disc kit for these that I saw on a 30's rod years ago. It used the huge Buick finned drums, but actually had discs hidden inside.

Of course, to each their own and there is no "correct" answer. Just build the vehicle to suit your needs and intended purpose.

I find these trucks steer and handle nicely if all is tight and in good form.

As mentioned, there are a few vendors who can supply you with a very straight forward front disc brake conversion, and it won't bankrupt you, Rustyhope, ECI, and Scarebird are a few.

Which engine do you have?, the 218 or 230, how do you find the performance change with dual carbs and exhaust, did you change the cam profile and shave the head too?

I love these old trucks, and it's a nice change from my Ram 1500 with a 395 hp Hemi with 6 spd trans, that truck is crazy fast, at least for me....

[59bisquik]

Mine currently has a 218 in it with dual carbs and exhaust. It is an industrial motor and is otherwise stock. Obviously never been to the dyno, but the seat-of-my-pants meter says it feels a bit peppier than stock.

 

Down the road, I will rebuild the 230 and put it back in with the dual exhaust and carbs and add a cam and shaved head. The 230 lost compression in #5 and we found a running 218 in an airport tug. It was an easy swap and got us up and running again for the time being. 

 

Who knows, once I get the back of the frame and bed cleaned up, pull the overloads off the back as well as a few leaf springs all the way around to lower the altitude, I might just have a head milled and swap it on. I do have a spare head...

Edited August 24, 2015 by 59bisquik

[pflaming]

We just completed a 9,000 trip across the USA. With the exception of Bear Tooth Pass in Montana there was no road my. 218 truck with the 3.73 rear axle would not have been quite adequate. Winnipeg was no worse than where I live, but I'm not in the Bay Area or the LA basin. Current road construction basically eliminates excessive grades and has all curves slanted to soft specifications for driver ease and traffic flow.

In three different trips. I drove a '50 Plymouth, a 60 rambler American, and a '59 Renault Dahfene from central Nebraska to California and back in the late 50's and early 60's. There were no freeways then. For the roads we have today I see very little stress on the old suspensions, given disc brakes, radial tires, and up to par front suspensions and rear springs. No V 8 for me. Do like the longer, larger flathead and overdrive.

Edited August 24, 2015 by pflaming

[Jeff Balazs]

While I have only driven my truck a couple times, I am really excited about the flathead and the issues that come along with it.

I have been doing a frame off resto-mod on a 54 Ford coupe for the last few years. 302/AOD, rack and pinion, 8.8 with 3.55's and trac-loc, 4 wheel disc and planning on a mild custom with the bare steel look for the body. It still has a couple of years before its on the road.

With that being said, it should drive pretty close to a modern car and be reliable. But with the Dodge, I see a flathead, 6v and solid axles. I see it as a big yellow time machine. I want to keep it that way and couldn't fathom a chassis swap. To me, it's no longer a classic truck in my opinion. I am excited to be in the slow lane with my dual carbs and exhaust howling and puttering along at 55 to 65. The cool factor of a flathead outweighs the any modern high tech hotrod. I too think that that's part of the adventure of going somewhere.

That's not to say that disc brakes and seat belts for safety are a bad idea. I am just under the opinion that I wouldn't do anything that I couldn't easily return to stock like a front ifs clip for example. I do wish they made the front disc kit for these that I saw on a 30's rod years ago. It used the huge Buick finned drums, but actually had discs hidden inside.

Of course, to each their own and there is no "correct" answer. Just build the vehicle to suit your needs and intended purpose.

I am pretty happy with the way mine rides and steers. It is a 3/4 ton with the 116" wheelbase and I think this makes for a the nice ride. There is room for a bit of improvement ....maybe better shocks...but honestly it is OK the way it is.

Seat belts are easy and I have upgraded the lighting and visibility because I think this makes good sense.

 

Jeff

[55 Fargo]

I am pretty happy with the way mine rides and steers. It is a 3/4 ton with the 116" wheelbase and I think this makes for a the nice ride. There is room for a bit of improvement ....maybe better shocks...but honestly it is OK the way it is.

Seat belts are easy and I have upgraded the lighting and visibility because I think this makes good sense.

 

Jeff

You know Jeff, I gotta concur.

These trucks ride pretty decent when the springs and suspension and all of there parts are in good well maintained condition.

My 55 108 wb, is lighter, but still rides very nicely on a smooth surface, maybe going over railway tracks and down rutted gravel roads she is a bit of a beast.

I do not agree that the frame and/or front clip must be changed to be safe and comfortable. I would agree those changes are superior, but the stock set-up is not in itself inferior.

I fully believe the weak spots are the following, #1 the brakes, #2 the differential gearing, #3 the transmissions, not that the latter 2 items are weak, they are just designed for slower moving work......PS it ain't never going to ride, handle or power like my 2015 hemi Ram truck, and why would I want it too.....

Edited August 25, 2015 by Fargos-Go-Far

[pflaming]

I too concur with Jeff. Now I removed the next to the bottom leaf from all four springs which softened the ride, lowered it's stance, and made it less top heavy so that it corners quite well considering. It has 15 inch radial tires so It rides quite nicely and with better seats will ride even better. Prior to the fire, I drove it to 48 dodger's BBQ and back a drive of some 320 miles with no significant fatigue.

The steering is very tight and it tracks like a train. With disc front brakes and a 3:73 rear axle I am very comfortable on the freeways, yI travel with the truckers and pass them with ease if I so desire. An overdrive is waiting to replace the std three speed.

In short, I like my truck and drive it whereever I want to go. I am still detailing since the fire, but I am back on the road, the second time around was harder than the first but I'm getting there.

Fully Practical? Maybe not, dependable and comfortable yes, it can be.

Edited August 26, 2015 by pflaming

[Jeff Balazs]

For sure the gearing needs to be addressed. We can all easily agree on that one.

As far as a safe top speed goes it should easily cruise at 65-70. Much beyond that and I think you are pushing what is reasonable.

One thing about running one of these engines in traffic is that they do need to be in a good state of tune. There is no over abundance of power so however much it makes...... It all needs to be present and accounted for. I really like my Pertronix ignition set up. I can't speak for the rest of you but the various sets of points I tried before converting this distributor were more that a bit fiddly and seemed to go out of adjustment quickly. That went bye-bye with this modification and I would not go back. I would not hesitate to suggest this mod to anyone who has had the same experience with the stock set up as I had. And it is hard to beat that 40K spark.for quick starts.

 

Jeff

 

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[55 Fargo]

I too concur with Jeff. Now I removed the next to the bottom leaf from all four springs which softened the ride, lowered it's stance, and made it less top heavy so that it corners quite well considering. It has 15 inch radial tires so It rides quite nicely and with better seats will ride even better. Prior to the fire, I drove it to 48 dodger's BBQ and back a drive of some 320 miles with no significant fatigue.

The steering is very tight and it tracks like a train. With disc front brakes and a 3:73 rear axle I am very comfortable on the freeways, yI travel with the truckers and pass them with ease if I so desire. An overdrive is waiting to replace the std three speed.

In short, I like my truck and drive it whereever I want to go. I am still detailing since the fire, but I am back on the road, the second time around was harder than the first but I'm getting there.

Practical? Maybe not dependable and comfortable yes!

image.jpg

Hey Paul, you ever do a "burn out" with your truck. Kinda like the body finish, it kinda grows on you after a spell...

[pflaming]

Burn out? Just once on a Saturday night at a night street drag. I am thinking of putting a spark plug on the end of the tail pipe, etc. . . .

The exterior has not been detailed, just a quick clean. When it is resandrd then sprayed with a number coats of clear with a good gun, then buffed out, it will be a head turner. It will be a "vongough" on wheels! So thanks for the support, to be continued

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Edited August 26, 2015 by pflaming