Sweetx99 Posted September 19, 2023 Report Posted September 19, 2023 (edited) Looking for help with an engine swap for my P19 2 dr. I have found a 251 military 25” motor, but was wondering if anyone knows if my bellhousing from the 218 currently in the car would work? New to these cars so please forgive my ignorance, any advice is welcome. thanks mike Edited September 24, 2023 by Sweetx99 Quote
andyd Posted September 19, 2023 Report Posted September 19, 2023 Welcome aboard the best mopar forum..........no offence but why do you want to install a 4cylinder GM engine in a mopar?...........apart from anything else what did you intend to do about not having a parking brake any more using the GM install.........whats wrong with the original engine?..........your choice but its an unusual one........andyd 1 Quote
D35 Torpedo Posted September 19, 2023 Report Posted September 19, 2023 (edited) Usually people do engine swaps to gain performance, not lose it...I assume you already have the engine, and you want to use it... you will need to cut the car up and weld mounts in, change wiring, and get a custom driveshaft made. A simple swap would be for an original engine. A great engine to swap would be a jeep 4 liter engine, and the junk yards are full of them. They have seven main bearings, and are fairly bullet proof. I've seen them with half a million kms, no oil pressure, whipping doughnuts at 5500 rpm all day. Performace parts are abundant aswell. Edited September 19, 2023 by D35 Torpedo 1 Quote
Curt Lee Posted September 19, 2023 Report Posted September 19, 2023 Not to throw any extra stones, but the Iron Duke is not a well-regarded engine even among GM enthusiasts. Mother MoPar didn't bless us with large engine compartments, either... a Slant Six would be my late model engine of choice if the flathead would not work at all. And even those aren't simple one-day jobs. 1 Quote
Plymouthy Adams Posted September 19, 2023 Report Posted September 19, 2023 (edited) I will say but one thing...the six is barely adequate for the job and less than for some applications like interstate running....the 4 banger is going to be such a disappointment. I know it is likely your choice because you already have it on hand to use. BUT the same work is involved basically on most swaps....I would recommend a more modern engine with a bend in the middle even over the dated and beloved /6. I kept mine Mopar..bent in the middle engine with all the modern features....you would not believe me when I said how cost effective this swap was. This car drives so sweet...and in the south, the AC is most welcome...5 speed floor shift Edited September 19, 2023 by Plymouthy Adams 1 Quote
Los_Control Posted September 19, 2023 Report Posted September 19, 2023 My thoughts were what torque does the 4cyl produce? vrs the flathead. Neither one has much horsepower, it is the torque that does the work. So many times I have taught myself the lesson that free is not always cheap .... I just wish I would learn it. ..... Assuming you already have the 4cyl engine. I have heard of all sorts of engines stuffed into these old cars, big blocks, hemi, small block, 6 cyl ..... diesel ..... never a 4cyl .... hey who, is your car to do as you wish. I'm not even a purist .... I have a 350 sbc with a manual 5spd in my chebby truck, is a kick in the pants to drive it .... I would stuff it in a Dodge. Or possibly a Ford 300 strait 6, wonderful engine .... A Dakota V6 .... The only time I could think of installing a 4cyl is if in the aftermath of a nuclear war and just using whats available. .... My 2 cents. Quote
SteveR Posted September 19, 2023 Report Posted September 19, 2023 I wonder how well a 2.5-engine will push around that 3070-pound car. As they say, torque is everything. Quote
Sweetx99 Posted September 20, 2023 Author Report Posted September 20, 2023 12 hours ago, Plymouthy Adams said: I will say but one thing...the six is barely adequate for the job and less than for some applications like interstate running....the 4 banger is going to be such a disappointment. I know it is likely your choice because you already have it on hand to use. BUT the same work is involved basically on most swaps....I would recommend a more modern engine with a bend in the middle even over the dated and beloved /6. I kept mine Mopar..bent in the middle engine with all the modern features....you would not believe me when I said how cost effective this swap was. This car drives so sweet...and in the south, the AC is most welcome...5 speed floor shift Thank you all for the replies! This would be awesome, the magnum V6, just not sure how you accomplished its install? You did the brake booster as well as the trans, how much did you have to cut out and any mounting advice? again, thanks, as this is my first attempt. Quote
Sweetx99 Posted September 20, 2023 Author Report Posted September 20, 2023 11 hours ago, Los_Control said: My thoughts were what torque does the 4cyl produce? vrs the flathead. Neither one has much horsepower, it is the torque that does the work. So many times I have taught myself the lesson that free is not always cheap .... I just wish I would learn it. ..... Assuming you already have the 4cyl engine. I have heard of all sorts of engines stuffed into these old cars, big blocks, hemi, small block, 6 cyl ..... diesel ..... never a 4cyl .... hey who, is your car to do as you wish. I'm not even a purist .... I have a 350 sbc with a manual 5spd in my chebby truck, is a kick in the pants to drive it .... I would stuff it in a Dodge. Or possibly a Ford 300 strait 6, wonderful engine .... A Dakota V6 .... The only time I could think of installing a 4cyl is if in the aftermath of a nuclear war and just using whats available. .... My 2 cents. I was looking for a simple solution to get this car running and driving. The 6 cylinder flathead is stuck, so its got to come out. Not having a lot of room, thought the iron duke might work. I read yours and the other comments and agree with all. So if anyone has done this, and has some real world install build info, please do get in touch. My window to get this done is 90 or so days, so the sawzall is out and ready! 11 hours ago, Los_Control said: My thoughts were what torque does the 4cyl produce? vrs the flathead. Neither one has much horsepower, it is the torque that does the work. So many times I have taught myself the lesson that free is not always cheap .... I just wish I would learn it. ..... Assuming you already have the 4cyl engine. I have heard of all sorts of engines stuffed into these old cars, big blocks, hemi, small block, 6 cyl ..... diesel ..... never a 4cyl .... hey who, is your car to do as you wish. I'm not even a purist .... I have a 350 sbc with a manual 5spd in my chebby truck, is a kick in the pants to drive it .... I would stuff it in a Dodge. Or possibly a Ford 300 strait 6, wonderful engine .... A Dakota V6 .... The only time I could think of installing a 4cyl is if in the aftermath of a nuclear war and just using whats available. .... My 2 cents. Quote
Plymouthy Adams Posted September 20, 2023 Report Posted September 20, 2023 Being realistic, even with me being retired and all that, I cannot evade, escape or deny daily life events so I will say there is no way I can or could build the car I did in 90 days..... 1 Quote
Los_Control Posted September 20, 2023 Report Posted September 20, 2023 Always different complications going with a motor swap. .... The magnum V6 is a awesome choice .... you will need to build a wiring harness to work with the computer. Not to mention all the mounts & drive line. Same time you could get a old sbc 283 with a automatic trans and the old school horseshoe engine mount & adjustable trans mount ... run a carburetor Much easier installation .... would it be done in 90 days? Problem is, if you set a 90 day time limit ..... then you have no clue what engine to start with .... then you ask on a forum what engine to use ..... It's not going to happen. You have a 90 day time limit, you are confident and posting to tell us exactly what you are doing .... not asking for guidance. Just saying, be realistic in your abilities ..... I'm confident you can do it .... just not in 90 days. So what changes in 90 days? Take your time, have fun and get er done! 1 Quote
soth122003 Posted September 20, 2023 Report Posted September 20, 2023 You said the flathead is stuck, so out it comes. If you only have 90 days, you might be better off unsticking the flathead. I mean it's your car and do with it what you will, but IMHO it will be easier and faster to unstick/rebuild the flat head in 90 days than to swap in a different engine. (unless you go with another flathead) Joe Lee 4 Quote
Sweetx99 Posted September 20, 2023 Author Report Posted September 20, 2023 1 hour ago, Los_Control said: Always different complications going with a motor swap. .... The magnum V6 is a awesome choice .... you will need to build a wiring harness to work with the computer. Not to mention all the mounts & drive line. Same time you could get a old sbc 283 with a automatic trans and the old school horseshoe engine mount & adjustable trans mount ... run a carburetor Much easier installation .... would it be done in 90 days? Problem is, if you set a 90 day time limit ..... then you have no clue what engine to start with .... then you ask on a forum what engine to use ..... It's not going to happen. You have a 90 day time limit, you are confident and posting to tell us exactly what you are doing .... not asking for guidance. Just saying, be realistic in your abilities ..... I'm confident you can do it .... just not in 90 days. So what changes in 90 days? Take your time, have fun and get er done! Hello and thank you so much for the reply. I really like your 283+automatic. Carb with zero electronics work perfect. My concern was after viewing some engine swap vids, they mention moving the motor over an inch or so due to space issues. The rush is an event I would like to make in February. If I could find a good running flathead 6, I would go that route and change up the trans etc. Im no Bad Chad, but I believe I can get it done. But need to get a motor. Wonder if there’s a non electronic v-6 that would work. Thanks again, appreciate the comments! Quote
Sweetx99 Posted September 20, 2023 Author Report Posted September 20, 2023 35 minutes ago, soth122003 said: You said the flathead is stuck, so out it comes. If you only have 90 days, you might be better off unsticking the flathead. I mean it's your car and do with it what you will, but IMHO it will be easier and faster to unstick/rebuild the flat head in 90 days than to swap in a different engine. (unless you go with another flathead) Joe Lee Thank you so much for the reply! I thought about that, heard it was an expensive rebuild. I will be removing the head shortly, have the pan off and looked at a few bearings, seemed ok. Not sure yet why its stuck. That would be the best idea, keeping it stock. Gonna take another look at that option, unless I can find a super running flathead for sale. Quote
soth122003 Posted September 20, 2023 Report Posted September 20, 2023 This guy is a bit extreme but the principal is sound. Use marvel and tranny fluid and let it soak, trying every few days to break it loose. Pulling the head and using heat can help. But the time frame is usually a few days to a few weeks to get an old flathead running. Unless the engine is really broke. (rod, crank, pistons or walls crack) But the visual of the crank by removing the oil pan or removing the head should tell you that. https://www.youtube.com/watch?v=ZKFMSH0G9bI Joe Lee 1 Quote
SteveR Posted September 20, 2023 Report Posted September 20, 2023 BTW 6 cylinders sound sooo much better than little 4 poppers. Quote
Sniper Posted September 20, 2023 Report Posted September 20, 2023 straight 6's sound like tractors, lol. Quote
Sniper Posted September 21, 2023 Report Posted September 21, 2023 If I was going to swap in a different engine I would go with a 318. Because I have one and not a 360 on the stand, lol. There is actually an article I uploaded to the tech section that details that swap. But be warned, some of the parts suppliers are out of business. Quote
SteveR Posted September 21, 2023 Report Posted September 21, 2023 (edited) In my 37 Plymouth, I have on it a Glasspack from the early 70s. I doubt there is any fiberglass in it anymore and it sounds pretty throaty. The other day while waiting at a round-a-bout a boy racer with his little 4 banger revved his engine thinking he was pretty cool. I then revved my engine. It put him to shame but they laughed not expecting this 86-year-old to sound so good. Edited September 21, 2023 by SteveR Quote
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