Loren

When you look at a HyDrive engine there is a relief valve on the oil pump in addition to the one in the block. It makes you wonder why they put that there. Could it be that the Torque Converter generated its own pressure? Aside from people forgetting to drain the Torque Converter every engine oil change, I wonder what the engine longevity is vs a standard shift. HyDrive has always fascinated me being the ultimate FluidDrive. If it added to the life of the engine that would be another reason to find one. (one of my modern cars needs to have a transmission oil change every 70,000 miles. The car lets you know its time when the transmission slips going up a hill in high gear. After I had the dealer do the service -once, I only got 55,000 miles and it was slipping again. I talk to a number of friends in the trade and they said, "Nobody drains the Torque Converter". Needless to say I now do that service myself)

James brings up a good point about anti-freeze. The main reason the "Green Police" don't want it on the ground or down the drains is that it is poison. Pets (and animals) are drawn to it as it is sweet to the taste. A pan sitting on the garage floor is a very real danger to pets. There are however safer alternatives. Anti-freeze for solar hot water systems that is labeled Non Toxic might work in engines. I've never tried it but I know with a little shopping you can find non toxic automotive anti-freeze. You will pay a high price for it however. An old buddy of mine told me how they used to keep Model T Fords from freezing up in the Northern Wisconsin Lumber Camps. They took thin lubricating oil and filled the radiator with that. In the spring after the last frost they replaced the hoses and the oil with water. We've all seen radiators with milk chocolate colored water circulating in them. I attended an Allen Test School and they were explaining how electrolysis occurred, motion, dissimilar metals and water. They claimed a radiator could generate a measurable electrical current and that current was eating away at the iron (or aluminum) of your engine. At the time I drove a well used 1958 F100 with a 223 I block 6. To test their lesson I clipped my volt meter ground clamp to where the radiator cap mounted and held the positive in the center of the water with the engine running. The old Ford put out 12 volts! Needless to say I quickly added radiator maintenance to my 'to do list' on the pickup!

160 is an appropriate thermostat for a 49. 180 should really be used in a pressurized cooling system. Everybody knows water boils at 212 at sea level without any more than atmospheric pressure. No matter how much heat you put to a pan of water it will stay at 212, until you run out of water. The water evaporating cools the pan and keeps the water at 212. Use 50/50 coolant and the boiling point goes higher. Add a pressure cap and for each pound of pressure the boiling point goes up 2 degrees. So on the cars I used to work on the red area of the gauge was where the coolant boiled, 265 degrees! According to the factory 264 was okay. There’s a few things one needs to know about cooling systems: When you shut down an engine it gets hotter. The coolant is no longer circulating. When you’ve boiled off coolant the temp gauge will read lower because it is no longer covered with coolant which it needs to read correctly. Air in a cooling system will prevent it from working correctly. Robinaire (among others) makes a device which places your cooling system under vacuum, then if the vacuum holds you can open a valve and fill the system from a tube in a bucket. This gets all the air out and is useful for vehicles with complex hard to bleed cooling systems. Some times a mechanic will drill a small hole in a thermostat in order to induce a flow past the wax bulb. I used to do this when I noticed that engines would get hot well before the thermostat opened. The coolant under the thermostat was stagnant and didn’t get hot when the car sat idling. I’ve seen temp gauges peg before the thermostat opened. Just a small hole stopped that problem. Anti-freeze is made from the same chemicals as brake fluid and smells exactly the same when burned in the engine. A white cloud following you in addition to the smell is a good indication of a blown head gasket or a power brake master cylinder leaking. I once had both happen to the same car.

Remember you’re getting “a pig in a poke” You have no idea if they are any good. To me they looked like they’ve been under water. The seller wants $1,000 each, not sure that will happen. The last one I bought on ebay, I paid $475 and it turned out to be in good shape (and it looked better than those). The safe thing would be to offer $1,500 for all three and hope you can get one good one, or make one good one out of the three.

I started to work up two chokes using the second boss for a second sessons automatic choke on the exhaust manifold, after noticing that Plymouth had moved them in the past. A friend told me it was unnecessary as you only needed one to start the car. So….there’s another vote for a single choke. Sure is a lot simpler.

Having spent several decades in manufacturing I can tell you drilling holes in metal isn’t as simple as you might think. Engineers talk about the diameter vs depth ratio and the types of drills required to achieve deep holes. The problem is getting the chips out of the hole while drilling. Deep hole drills have one cutting surface (your typical jobber drill of course has two) made of carbide brazed to a tube that looks like a quarter pie sliced cut out of it when viewed on end. The tube is connected to a high pressure pump which forces coolant out of a hole in the carbide. The coolant literally blows the chips out of the hole. ( what I am trying to describe is called a “gun drill” if you’d like to google it) What the various diameters are may be a function of how they drilled the holes. It must be remembered that Plymouth and Dodge made their own engines in their own factories and thus could have used very different methodologies. I have only dealt with Plymouths and never noticed the different diameters. I am thinking it can’t make much difference. It could be that it was done as a two step process with two different drills. The larger diameter for clearance of the second drill on a rapid approach. Even with a gun drill there are limits to how much torque can be applied to the drill with chips coming out of the hole. Finishing with a smaller drill makes sense in that case. The hole that I am impressed with is the one running the length of the block. I am not sure boring out the holes would be of much value. The more volume the pump has to fill on cold start up is more time the bearings are not getting pressure.

If you take a look at the cam bearings you will see two sets of holes. One set is smaller than the other set. I will let you ponder that a moment. The oil pump is on one side of the block and the oil galley is on the other, it takes a cross over tube to connect them. The oil passage doubles back with thru holes to the other side. Now look at the crankshaft. The front main feds oil to cylinder #1 and the rear main feds cylinder #6 all the other mains feed two cylinders each. If you were to guess which rod bearings might suffer from oil starvation, you’d say #2,3,4 or 5. But theres more, because the rods are fed by one hole drilled in the crank, there is a timing issue as to when they get a full shot of oil. 40 lbs of oil pressure does a good job of lubrication and the pump has enough volume, especially when you consider what Chevrolet gave their engines. Pressure to the mains, cast iron pistons and dip fed rods! Many after market parts makers have noticed on OHV V8s that the oil goes to areas where it really isn’t needed. Smokey Yunick made oil pans, timing covers, valley covers and rocker covers out of clear plastic so he could study where the oil was going. He started putting restricters in the oil lines to the cam bearings and lifters as a means of directing more oil to the mains & rods. In our case that is why the cam bearings have two sets of holes. Standard practice is to use the small holes on number 2 and 3 cam bearing. The front bearing feeds the timing chain and one rod bearing. There is no rear bearing as the cam runs directly in the bock and feds only one rod bearing. I talked to one old boy who said they used to cut a short piece of lamp wick and insert it in oil galley and push it over to the cam bearings as a used car lot fix for worn bearings. I don’t think I’d recommend that but you get the idea.

You are not mistaken at all. In fact you are right on the money. The 49 has 4 bolts holding the upper A-arm pin while a 55 has only two and very likely is wider and the A-arms longer (if not mounted in a slightly different spot). That is the fly in the ointment. Right about where you would want to drill the hole for the upper shock mount is almost exactly where the pivot pin passes over the spring seat. It could be done if you are willing to saw the pivot pin near the bolt bosses and weld on a flat bar with a hole in it for the shock mount. Of course that means a disassembly of the front suspension. Sounds like a whole lot of work to me. It could be done and it really is an elegant solution if you need to do that much renovation to your suspension. In my case the car has only 38,000 miles and doesn't wander. My front shocks were worn and so I've replaced them with new stock ones. In the mean time I think I will be on the hunt for someone who has replaced the front frame clip. If I have to do that much work, I want to clean and paint every piece. The ideal way to do it would be to get a front clip that you can turn over and find the perfect spot for the upper mount, drill it, modify the upper pin with the flat bar and transfer the hole to the bar. Then when you trade pieces on your car you can use the pin as a drill jig. The lower A-arm might benefit from welding spots to bolt the plate to the bottom for the lower shock mount. Since I have lots of other high value projects I think I will put this one on the back burner till I get a front clip.

After considerable effort I got the coupe into its new garage/shop. The neighbors told me they hadn’t seen the door open in 5 years. I now know why. I will be rebuilding the door. Once inside I pulled the front wheels and did some brain storming. First off I rejected the Ford F1 mounts. Plymouth uses a boxed frame and the pick up used a channel frame. Not surprising as pick ups were cheaper than cars back in those days. Plymouth even though a low priced car was built to a higher standard than pick up trucks. Boxed frames being inherently stronger can also be lighter or at least made from lighter material and that is the case here. For several reasons I rejected bolting the F1 mounts to the frame. I looked at the possibility of using fabricated mounts as well. I didn’t like that idea either. Welding to a frame is done all the time I know and folks will question my sanity when I mention my objections to doing it. If you weld across the frame member, if it is going to crack, that’s where it will crack. The rule has always been if you must weld, it should lengthwise or better yet use rivets. Rivets or bolts can use doubler plates which is difficult with welding most of the time. So I am not keen on relocating the upper mount….still. I did more research on the 55-56 shocks. You can order them front all the regular suppliers but….since there is only one outfit making them they are out of line price wise. I don’t want to experiment with pricey parts I have no use for if it doesn’t work out. That said, the concept of mounting a second shock inside the spring (like the 55-56 Plymouth) sounds appealing as you only have to drill three holes. I found two shocks which might work but I am going to do more measuring. The first came on the 1975-80 AMC Pacer. Don’t laugh. The second one will require a plate to mount it on the bottom of the lower arm. This shock has been fitted to nearly all the GM brands at one time or another, Fords, Studebakers and interestingly the 1961-72 Volvo P1800, which means you have all sorts of great choices in shock brands such as Koni, Bilstein, KYB etc. So that is the latest in my thought process. When I get the dog gone door rebuilt, I will be able to do a test drive.

One key in the deciding if it is a Continental or a Chrysler is the location of the distributer. Chrysler on the side Continental on the top of the head. This way in one quick glance you can tell.

You scored my friend! On eBay there is a guy with lots of throttle switches which will work (non-stock but the same type) for $6.25 (I bought 10) They were made for the government and had International Truck P/Ns. For the relay you can use a Bosch Square type that go for very little ($5.00 or less). The 12 volt version is very common as the alarm and stereo guys use tons of them. I found a German made 6 volt version on Amazon.com for I think $8.00. PM me for the pin numbers to the stock wiring. As for the Lock Out Cable I would go to my speedo guy and have one made for less than the ones that say "Overdrive" on the handle or www.vanpeltsales.com for a reproduction. Van Pelt sells the solenoid and the governor if you can't find a better price on eBay. Also, take the speedo gear out of your old transmission and put it in your new Overdrive, they fit. Then your speedo will read correctly. If you have a short wheelbase Plymouth you will have to shorten the drive shaft and make an extension rod for your e-brake (absolutely necessary to have a working e-brake on an Overdrive car). However, if your old gearbox is the long version (same length as the Overdrive) then don't worry it just bolts in. You will really appreciate the Overdrive in a Plymouth!

This is exactly why I trust the factories engineers over my version of what passes for engineering. The notion of using the 55-56 design along with the original location seemed to cover the engineering issue but not the supply issue. The thread from 2015 never got to the point of identifying the right shock. It seems the fellow closest to a solution couldn't say exactly what he was using. "Original" meant what was on his car when he got it but not necessarily what was OEM stock. So...we don't have an answer as yet. I have a new set of OEM spec shocks and I have ordered the short F1 mount from Speedway. The only way to prevent bottoming is to remove the spring from one side and measure the wheel travel at the mounting point of the shock. I might even drill an old shock to release the oil and any resistance. The idea being is to avoid any binding or tweaking of the shock. Hopefully I can generate enough data to pick the right shock.

Easy. The between the A-arm set up was a clever Chrysler innovation to improve the longevity of the shocks, which it did but...all choices in engineering are compromises. When the speed limits were 45-55 mph it made a lot of sense. At 65-70 mph not so much. We have to remember what we think is an "improvement" is just a compromise with different goals. The 1955-56 compromise kept some of the short travel long life goal but added better road holding. Now we have a different set of goals, better handling of course with future access to replacement parts at reasonable prices. From my research there are limited choices for stock shocks, limited choices for the 1955-56 design, so I have to make a decision (or a compromise if you will). Right at this moment I am leaning toward the F1 mount. What would cinch it would be to know the right shock to use. Any suggestions?

I am loathe to make changes to Chrysler's designs. I figure the engineers know a lot more than I do (It doesn't take much imagination to reach that conclusion. lol) When I remembered the 55's characteristics and it seemed like a great idea to use that update, but...those are not real common shocks either being two years only. The stock set up was not made for "spirited" driving to be sure. It was made for long service and wear. One of the great charms of the Plymouth. I am softening to the idea of the 1948-52 Ford F1 upper mount (www.speedwaymotors.com has reproductions in two lengths) because of the availability of a better selection of shocks. The modification is something that could have been done during the time period that the car was made so there is that. While the shock travel is more than the 55-56 design (and much more the 49-54) I would expect similar or better characteristics. Now to find the right shock.

My P17 was the lightest and cheapest of the MoPar cars. That's why they were raced in NASCAR's early days. Lee Petty proved they were capable of finishing a 500 mile race ahead of the Oldsmobile V8s. Petty was in racing as a business and he was all about the numbers. Petty did some smart shopping in the Chrysler parts bin to be competitive. In a 1954 interview he said he used Imperial wheels, tires, springs and shocks and the old photos seem to prove it. My coupe came without a front sway bar so I got one. Big improvement! I went shopping for stiffer shocks and found there is only one part number for all the MoPars now. I guess we should be glad there is something available. For off road racing two shocks are better than one stiff one (and three were pretty standard). So rather than go the relocation route with something available and stiffer, I thought what about a second shock? Finding a place for additional shocks is always a challenge however. But I seem to recall that the 1955-56 Plymouths & Dodges used a shock mounted inside the spring on the lower control arm to a simple hole in the frame near the upper A-Arm pivot. That would allow you to keep the stock shock and add another one without a whole lot of drama. I also remember my Mother's 55 rode very good and seemed to handle nicely too. So here's a question, has anyone seen this or done this? I'll be darned if I can get the search function to find a post on this.

Have you changed the gas cap? Most you can buy now days are not vented and are so labeled (at least they used to be). Your car should have a vented cap. A quick check would be to loosen it and take a drive.

Love your Chrysler! I agree with on Steve. He’s been very helpful to me.

0.002? I hope we all know the width of an average human hair is 0.004. As a rule of thumb once a head gasket is torqued down I have found them to be roughly 0.055 thick, or enough to loose the difference of 0.002 in. What is of note is when you get a crankshaft ground, the machinists have this nasty habit of trying to clean up the bearing surface with the least amount of material removal. A 0.010 divot in the journal becomes a 0.020 undersize crank journal if ground on center. So they use a little trick whereby they kick the centerline over to grind only the side that has the divot. The result is less stock removal and all journals the same size BUT, and you knew there is always a but, you could end up with a crankshaft with 6 different strokes! Rarely are the effected cylinders given longer strokes. The machinists don’t care because most mechanics do not have the means to accurately measure the difference. Besides the pistons rock in the bore at both ends of the stroke making it even harder to measure. Since there isn’t much you can do to change machinist behavior, this is one of those things I’ve stopped worrying about. Besides if the piston clears the head with no gasket, it will certainly clear with a gasket. Something one should worry about are the valves. You absolutely should check to see if they clear after milling the head or getting new valves or seats or a reground cam. I hope I didn’t spoil your day.

That's what I call imagination! I'd walk across a parking lot to see that. Chevy V8 not so much. I've known guys with 240, 260, 280Z cars and they were all reliable long lasting engines. Surrounding one with 1950 Plymouth iron is a major improvement (to the engine. Datsuns were shall we say somewhat light weight). One guy I knew put about 250,000 miles on one in a surprisingly short time. Kind of reminds me of what the Cuban "Automovilistas" were forced to do when the original engines in their cars wore out. Maybe there's a name for your car, "El Cubano" It certainly will be the only one like it (outside of Cuba) and that accounts for something! I like it! Thank God you didn't choose another boring Chevy V8!

Barney Navarro was also the guy who built the Rambler 6 that qualified for the Indy 500 many years ago. How many times have you heard Rambler and Indy 500 mentioned in the same sentence? Ed Winfield was famous for out running Arthur Chevrolet’s 16 valve DOHC Frontenac Model T, with a flathead Model T. Chevrolet made the comment, “I see it but I don’t believe it!” Timed speed 122 mph on a board track. The secret was the “Two up, two down” crankshaft which made the intake pulses 180 degrees apart and his “Hooker” roller cam. Tommy Thickstun, the designer of Plymouth manifold we like so much, was a student of Winfield’s 180 degree theories regarding manifolds. If we look at compression ratios over the last 100 years, the trend has been upwards until the 1970s when smog regulations forced a temporary drop. World War ll brought high octane fuel into popular usage and compression ratios followed. The L head engines were not made for good high octane fuel and could not take advantage of it. In fact there is a limit to how much compression you can get from a flathead. At a certain point they can’t breathe because you’ve made the combustion chamber too small. Navarro had an answer for that. The 6-71 supercharger. One of the guys who worked with Barney on it was Tom Beatty. I knew Tom much better than I knew Navarro. He had one of the early P 38 drop tank Lakesters with a blown flathead V8. That lasted until he started putting so much boost to it that he pushed the crankshaft out the bottom! Anyway, with electronic engine controls and turbocharging compression ratios are unheard of high now. Engines have grown smaller, more powerful and economical because of compression ratios. Supercharging or turbocharging used to mean you had to have lower compression to control detonation. No longer. Direct injection (like a diesel) keeps detonation under control and it makes for a denser charge. (The fuel doesn’t displace air in the intake charge) knock sensors assist and offer an extra layer of protection. I suspect we have reached the high water mark of gasoline engines. Electric cars seem to be gaining the edge. Still there is something about the sound of an engine that gets the blood pumping.

I was leafing through an old Hop Up magazine from December 1952 and I came across an advertisement placed by Barney Navarro. Navarro knew what he was talking about as he made the best cylinder heads for the Ford V8 and was a pioneer in the use of the GM 6-71 blower on gasoline engines. What he was saying is universal for all gasoline engines, COMPRESSION is what makes horse power. Not Cams, not Carburetors, not Ignitions. One of his good friends (and mentors) was the great Ed Winfield who was a manufacturer of carburetors and the guy who taught most of the successful cam grinders how to grind cams. He could not have gotten away with saying this if it wasn't true (in fact this issue of Hop Up has an article he penned entitled "The truth about Cams" which Winfield approved). Anyway, Cams, Carburetors and Ignitions all work in support of the almighty Compression Ratio. You can if you want add them to a stock engine but nothing makes one come alive like Compression. Barney's ad used this logic to sell his cylinder heads and he made the case that adding Compression was a really economical way to get more power. So.... Think about it. When you go to make some big modification to your stock/original Plymouth, what is the cost benefit ratio? More importantly what does that mod do for your car and is it worth doing? Changing a rear axle won't add 1 horse power. (changing the ratio might bring up your highway speed but you can do that with an Overdrive or a ratio change, which is much easier with the stock axle) Changing to Disc Brakes can actually take away horse power through drag. (you do know those pads are always in close contact with the rotors and if they weren't you would be pumping the brakes every time you stop) Just sayn'

Well I don't say this very often, but you should do your Mustang swap.....and sell the 265 engine to me! I'd happily pay to get rebuilt. A Windsor was a pretty nice car for a small Chrysler. Looks like you have a pretty nice example and I am envious!

Decades ago I remember a magazine article that explained how piston rings are made. They are cast. From what I remember the photos looked like they were investment cast under vacuum. There is one exception, DEVES brand rings are cut from tube stock. Oddly some of the best engine replacement parts can be sourced from India of all places. Piston rings, bearings and pistons are all very high quality. I once did work for a company that made truck parts among them pistons. They closed their plant and sold the real estate because they could "buy" better quality pistons from India, cheaper.

I have to toss my 2 cents in here. When I was in college I had a 49 Special Deluxe that got ZERO maintenance. I rode nicely and never gave any trouble. My friend had a 68 Ford Torino GT (which was 2 years old at the time). His car squeaked from the front suspension every time it moved. EEY EEY EEY. It sounded like two teenagers on an old spring mattress! It was so embarrassing, he did a lot of walking. Now the Plymouth had metal to metal bushings in its suspension, but the Ford had full rubber isolated suspension. Yet the old Plymouth was silent and so was every one I have ever seen. SO...before you "modernize" your Plymouth you might want to consider this. Just sayn'

I love automobiles, always have. My view of what makes an "interesting" car is far different from most people. I spent a lot of my youth as a dealer mechanic, so my view is effected by that. My cars tend to be period correct within 5 years and are what a dealer mechanic would build for themselves. A dealer mechanic would put the best stuff from the MoPar parts book on their car, usually the lightest car with components from the bigger cars. That focuses on what was possible in the day. That I find entertaining. If I were doing an engine swap in my Plymouth it would be a 265 Chrysler flathead 6. (got one almost ready to go in my Suburban) Or if I really got kinky perhaps a Perkins Diesel as the factory did. (and only because the factory did and I happen to like diesel engines) It pains me greatly to hear folks doing "swaps" of well designed original components and in the process creating new problems for which they have no solutions. I've seen cars that could be driven and enjoyed laid up seemingly forever with projects that were well beyond the skills of the owners. It just seems to be a word to the wise that if it isn't broke don't fix it. Keep it simple. You'll get to enjoy more time with your car in motion. There is a certain "charm" to an old car. Seems a shame to change a car so much that it no longer has that charm. If one wants a car to perform like a Mercedes, perhaps they should buy a Mercedes. Sure seems like a lot less work. I mean just sayn'. A 49 Plymouth is never going to drive like a modern car or even a premium car of its era. That's what you sign up for when you get one. That's the charm of it. That's what I love about it. I want the best example of what it could have been back in its day. I want the car Lee Petty drove to work everyday. That's what seems like fun to me. Call me a purist, but do not call me an engineer, I don't qualify or pretend to.