by Charles Gayman. Courtesy of the Walter P. Chrysler Club. See their magazine for more photos and new articles!
Originally printed in the April 1976 WPC News.
At a Southern California Region car show in 1974, Mr. Gayman found out for the first time that he had 1951 Suburban body #1!
This is an account of a one-owner car that never did get “run down,” but was generally well-maintained, and from time to time, was upgraded, from the owner's view, at least. Its present state is not yet perfection, but it's High Reliability mechanically. And it's not a show car, but a daily work horse that we are very proud to be seen in. This car's case history is more one of evolution than restoration. I hope some of the upgrading will be of interest and applicable to your pet project.
We bought this car from Art Frost of Glendale, California on November 30, 1951, at a very satisfactory discount from the $4278 sticker price. It was delivered in very poor condition, but I quickly decided not to rely on the warranty, unless something serious developed. Three unsatisfactory trips to their service department convinced me that “I'd rather do it myself.”
The first night we had the car, it ran low on oil, due to a porous weld in the Purolator. Fortunately, I had been watching the oil gauge, and no harm was done. Many trim parts were incompletely attached, but I found enough screws in a sack under the rear mat to complete the job. The rear shocks were not attached to the rear axle and the shipping clamps were clanking on the frame. Many other unsatisfactory items appeared for nearly three years.
Now I cite this sad situation not out of bitterness or anger, but to make a point.
I still had faith in the integrity of Chrysler Corporation engineering and instinct told me that I had a most extraordinary automobile, well worth debugging. So my “restoration” started on a brand new car less than 24 hours old. I had long preached that there's no such thing as a “lemon” - just certain parts of any new car might be citric.
Well, in spite of a doubtful start, patience and some hard work have turned this machine into the most satisfactory car imaginable. And it's been so rewarding, that I try to continue the policy of improvement whenever maintenance is required.
From Day One, we loved the car's spacious comfort, its ride, precise steering, excellent braking and many convenience features. Its relative economy for such a large car was impressive.
On the other hand, its power was only marginally satisfactory, and it had an acute heating problem in desert and mountain driving. This became increasingly critical from Spring to Summer in 1952. I brought in the dealer, who didn't help matters, and the factory, who did. They furnished me a finer mesh core which helped about 5 degrees. And then I made a fan shroud as on some later Hemis and used a 6-blade Dodge Truck fan when the weather went over 100 degrees. This fan is P/N 567087.
This kept me out of trouble until we bought a 15 foot vacation trailer coach, which grossed 2200 pounds. This was in 1955. I had a radiator shop make a radiator assembly, using my top and bottom tanks on a thicker core for a Chevy Truck. Again, a marked improvement was obtained. One time, on returning from a vacation trip to Colorado and Oklahoma, we encountered a hot spell between Kingman and Barstow. The official weather temperature was 118 degrees. With our luggage rack loaded and the trailer behind, our 8400 pound GVW made it with only a pint of water added. I saw more licensed and abandoned automobiles on that one day on “66” than in all my other vacation trips totaled. So you might say we had won the battle.
This car has accumulated over 175,000 miles and has never let us down. And we have had only two flat tires, one in 1953 and one in 1964! And this car has pulled the trailer over every major mountain pass in Colorado, some many times. It has crossed the tough run from Tuba City thru Kayenta, Mexican Hat, Bluff and Blanding to Cortes, several times when it was soft sand and washboard roads. It has been out to the Totem Pole on the floor of Monument Valley, and up to Dead Horse Point, all with the trailer. Is it any wonder that we love and admire this car? And no problems that I couldn't fix quickly, such as generator brushes or a fan belt.
I am a hard driver, but try not to abuse a car. I've found that if these old flat head sixes are put in good condition, with good oil in the crankcase, and coolant not allowed to boil away, they will run forever and turn in a fine performance record. Now these are precautions that any car deserves, old or new. However, the key to retaining adequate coolant during severe desert driving is having a beefed-up cooling system, and kept CLEAN, too.
In 1960, after 82,000 miles, I decided to rebuild and upgrade the engine. Originally, it had the following specifications:
The original crankshaft had a defective thrust face, so I pulled the engine out of the car and completely disassembled it on a low bench in the garage. All the freeze plugs, all the oil gallery plugs, everything removable came out. and the block, head and other parts were boiled 48 hours in an Oakite tank. It was surgically clean. I bought a “ten/ten” undersize reground crankshaft with a 1/4”longer stroke and a set of rods to match. The crank was a hardened one. Not trusting anyone, I washed the oil passages myself before assembly and checked journal and crank pin clearances with Plastigage. The rods had the bolt heads recessed into the forging to clear the camshaft.
The cylinder block was bored .030” oversize, nominally. I ordered a set of .030” oversize Sterling Conformatic pistons, recommended for Dodge Truck or heavy-duty passenger car service. These are solid-skirt cam-ground pistons, with invar struts to control expansion. They have three ring grooves, which reduce friction and heat and increase torque thereby. A third valuable feature is the steel liner in the top ring groove, which greatly increases the life of the top ring lands. This was a weak spot in these engines in high torque service.
Of course, the engine got new rod, main, and cam bearings, new timing chain and sprockets, new water tube, new seals and gaskets, etc. The valve seats were redone including 75 and 15 degree stones to clean up passages and control seat width. The head was planed .035” to raise the compression somewhat further than due solely to the displacement increase.
So now, the engine has the original block and head, original camshaft, pushrods, springs, and all but two of the original valves. It also has new tappet screws. If I ever rebuild it again, I will replace all this, on general principles.
With raised compression, thinner webs between cylinders, and hard service, I am bitterly opposed to putting head gaskets on dry. I have used Gasgacinch with no ensuing problems. Also, the machinist should be cautioned not to chamfer the top of the cylinder bores more than the barest minimum to ease ring entry. The object is to retain the fullest possible area to support the thin gasket webs.
On the other hand, the bottom of the head will have more flat area than necessary. The sharp edge here should be radiused with a small high speed rotary grinder to eliminate “hot corners”. Rough spots in the head chambers should be snagged off also.
I am also opposed to putting freeze plugs in dry. I coat the inside of them well with 3M 8001 Super Adhesive, also the edges of the holes in the block. After setting them with a drift bar, put a little more around the outside edge. Two freeze plugs should be put in the rear hole. Drive each one separately, and check to see that the second one will not touch the bell housing.
When this engine was assembled as far as mains, rods, rings, pins and pistons, it could be turned easily on the bench by two hands grasping the crank webs. It was free when new, and never got much looser. It broke in quickly, and by 150 miles, I was driving the car at 70 for a few miles at a time.
The way this engine turned out removed all incentive to convert over to a V-8. It has been a dandy. And its increase in performance has been accompanied by an increase in durability. I still can't believe it's a flat-head six.
The new specifications of this engine are:
Operation above 3600 RPM is avoided in the interest of long engine life, especially with such a long stroke. But continuous full throttle operation on upgrades at 3200 presents no problems.
Ten years and 85,000 miles after the major rebuild, I disassembled the engine in 1970 for a ring and valve job. Less than .007” of cylinder wear was found. This is rather remarkable, considering the work this engine has done. Part of it attributable to a Marvel Mystery Inverse Oiler. Another factor is the engine's oil consumption which in hard driving is 500 miles to the quart. A third factor is a hot thermostat, 180 degrees. (Since the car often runs at 205 to 215 towing a trailer in the desert heat, this thermostat does not impair cooling. And it improves matters in the winter. ) And the car is never driven hard until it is up to 180 degrees.
Some years ago, I took a test setup with accurate reference standards to a parts house and selected two Stewart-Warner Temperature gauges. One was selected to be accurate at 212 degrees for engine temperature. The other was selected to be accurate at 100 degrees, for weather temperature. The sensing bulb of the latter is located between the grille bars, shielded from both the sun and the radiator. It has always agreed with official weather reports on the radio within one degree.
This gauge installation helped me determine my original heating problem and it has kept me out of trouble since, and even provided peace of mind. A 210 reading in cool weather would be cause for panic, but after climbing a grade in 110 degree weather for half an hour, it only brings a benign smile.
This car runs beautifully on any good regular gas. However, I put in half a tank of ethyl when passing through low elevations such as Death Valley or the Salton Sea areas. But its performance is definitely superior at high elevations with regular.
Incidentally, any car loses power at high elevations, It is particularly apparent towing a trailer over Loveland Pass, nearly 12,000 feet, although low gear is more than adequate. But the surprising thing is that the car has no difficulty maintaining high speed with the trailer at high elevation on nearly level ground. The decrease in wind resistance is so pronounced at 10,000 feet in the high Colorado Valleys, that it will run at 70 easily, even up a slight grade. And the compression pressures are so reduced that the engine smoothes out like a perfectly balanced turbine.
About ten years ago, I installed a larger oil pump, P/N 1314607. It maintains pressure at slow idle immediately after driving 70 on a freeway. This is good insurance for severe operation.
A compression check with this engine shows about 130 pounds/sq. in. This is relatively high with an L-Head engine. It should not be compared to the readings from a Valve-in-Head engine, which enjoys a thermodynamic advantage.
About 14 years ago, my M-6 transmission suffered a broken snap ring in the oil pump. The broken ring had milled a groove in the pump chamber, which did not allow it to develop adequate pressure at low car speeds. After studying my shop manual, I rebuilt the transmission, using some new parts and some from other transmissions that looked better. It has run over 75,000 miles since, with no problems, whatever. These transmissions are not for hotrodding, but with reasonable patience and understanding, they do very well. Incidentally, 10W is the originally specified lubricant, but I believe ATF would be all right. Don't use 80 or 90 gear oil!
Another item that has had a major overhaul is the steering gear box. It leaked lubricant rather badly when the car was young, and had become sloppy. Part of the problem was the box being loose on the car frame, but I went clear through it anyway, including installation of a new tube-and-worm and a new roller-tooth assembly. All new seals and small parts were installed also. I noticed that the bearing surfaces for the tube-and-worm, cups and cones, were pitted. In 1970, for my last ring job, I had the left fender apron off, and decided to check the steering again. Again, I found the same pitting situation, but merely removed paper shims and reset the roller tooth to factory pre-loads.
I was certain that this had not been due to improper adjustments, and concluded that this pitting was electrical in origin. The horn relay coil is energized when its low potential end is grounded thru the horn ring assembly at the top of the tube-and-worm. But the current doesn't really return to chassis ground until the current flows across these roller bearings to the steering housing. The damage to the bearing surfaces arises from the fact they can't make good electrical contact, not if the lubricant is doing its job, which is to separate metal surfaces with a micro-thin film. But it's so thin that the potential gradient is very steep, even with only 6 volts, so the contact is completed at the first place that, by chance, breaks down electrically. And you have an arc-marked part. So no wonder that the bearing surfaces become eroded and eventually the adjustment is no longer correct.
Lacking a lathe, it seemed that it would be too difficult to devise a mechanical fix. So I got an engineering buddy at Lockheed, named Dave Hill, to help me. Dave is a transistor circuitry expert and he devised a circuit to handle the horn relay current. We even included a damper diode to snuff out the inductive kick when the circuit is opened. So now the transistor handles the horn relay current and we merely beep the base of the transistor, which is only a few milliamperes, a very light non-inductive load. The simple unit worked 100% immediately and never has given one speck of trouble. And after four years, the pre-load seems perfect.
Now I love to see old cars restored to original appearance, and I certainly have no fault to find with those whose principal delight is toward this end. However, I get my kicks out of lengthening the time span between mechanical overhauls or even adjustments. High Reliability and Extra Long Service Life are the names of my game.
Incidentally, the lubricant level in the gear box has hardly dropped at all, it has taken only about an ounce in 11 years. The fabric-lined bushing at the upper end of the steering column was replaced years ago; the new one does not seem to be developing any wear.
In 1970, I obtained a new pin and bearing kit for the steering balcrank, complete with seals, and installed it with the prescribed pre-load. This car steers more precisely than any other car I have ever owned, including newer ones. While the car is rolling, it steers easily, but parking can be quite an exercise, even with a gear ratio giving 5 1/2 turns, lock-to-lock.
I've never measured the turning circle of this car, but it's exceptionally tight, especially for such a long wheelbase. And the steering geometry must be exceptionally good, it's the only car I've ever owned that didn't have peculiar front tire wear.
We had trouble with impact breaks on two of our first set of tires at 18,000 miles. Before replacing them, I had Parker's in Glendale true all 5 wheels. They were near the limits of factory tolerance for wobble and eccentricity. And since, they've stayed perfect for over twenty years. The best money I ever spent! Combined with regular lubes on wiped-off fittings, well balanced tires, the result has been that the original kingpins are tight, and the front suspension is virtually perfect.
Several years ago, it was necessary to raise the front end, since it had dropped to the lower limit of factory allowance. That was an excellent chance to inspect all bushings. A neighbor made me some 5/8 thick aluminum spacers on his lathe, which raised the front end 1 1/4 inches, near the upper limit. New silencers were made from gasket material. The lower ends of the coil springs were potted in their perches in the lower control arms, using silicone rubber, to exclude rubber and dirt. This bonded well to the clean parts. New rubber parts were installed in all tie-rod ball and sockets.
The metal parts were given one-quarter turn to present new bearing surfaces.
When the car with its clean, tight, newly painted front end was driven into a large local wheel alignment shop, its condition created quite a bit of interest. They had to bend the steering knuckle support on the right side to restore camber adjustability with double leeway. Done cold, of course. This car steers perfectly at any speed up to 83, which is not its top speed, but is much faster than I'm generally willing to drive it. There is not the slightest tremor in its handling.
This car came with 15 X 6 “L” Safety Rims, having a 5 bolt pattern on a 6 inch bolt circle, and uses 9/16 X 18 L & R bolts. They are the same as on later Imperials. The original tires were 8.20-15 Rayons. All since have been either nylon or polyester. Present tires are L78-15, bias belted. They were bought before radial tires were commonly available in materials other than rayon.
L78-15 tires are rated at 700 revolutions per mile. Since this car has an axle ratio of 4.11, the engine in high gear turns 2900 turns per mile. At 60 miles per hour, this corresponds to 2900 RPM. 3600 RPM operation corresponds to 75 MPH. These tires are rated at 1970 pounds load at 32 psi pressure. This Suburban, with a full tank of gas but otherwise unloaded, weighs 4800 pounds, very nearly divided among all four wheels. For ordinary driving around town, I inflate to 26psi.
Transmission ratios are: Direct is 1:1, Direct Underdrive is 1.75:1. In low manual range, the higher gear is 2.04:1, and low Underdrive is 3.57:1. When this latter ratio is multiplied by the axle ratio, the result is 14.7. This is the number of engine revolutions per wheel revolution.
This explains why the car pulls the trailer through deep sand so well, but it doesn't explain why it doesn't dig itself in, like every other car I ever owned. This must be a property of the rear springing and shock absorbers.
Based on an allowable 3600 RPM maximum for the engine, the maximum permissible speed in Direct Underdrive is 43 MPH. In Low Manual Direct, it's 37 MPH, and in Low Underdrive, it's 21 MPH. Incidentally, reverse gear in this car is 3.99:1.
The third member in the rear axle has never given any trouble. It does not have a “scrubbing block,” as found on some higher-powered cars, but it simply depends on generous construction.
The present performance of the car in high gear would justify a change to a 3.73 axle ratio, particularly in view of the higher fuel costs recently. But the admittedly limited flexibility of the M-6 transmission cancels most of this thinking, particularly since a lot more trailer-towing is planned.
The wheelbase of the car is 139 1/2 inches. The front tread is 57 1/4 inches. The rear tread is a wide 63 inches.
Front and rear wheel bearings were replaced once, at about 130,000 miles. The 3 U-Joints and center bearing were replaced at about 140,000 miles. The center bearing is cushioned on a DPCD front engine mount (6 cyl. flat head).
The brakes have 12 inch diameter drums, and have been turned only once, for about 4 or 5 brake re-linings. The lining area is 201 square inches. They might be considered marginal for stops under panic conditions above 55 MPH, but are OK for a driver aware of their limitations. My trailer's brakes do at least their share.
The oil seals at each wheel have been replaced at each lining change. The wheel cylinders were replaced with new genuine Wagner-Lockheed ones in 1970, also the brake hoses. The master cylinder was last serviced in 1961 but still seems OK. The Brake Booster (Servo Unit) has never given one speck of trouble in 23 years. It was original equipment incidentally.
The rear suspension is presently aided by Delco Air-Lifts, inflated to 70 psi. The rear springs should be re-arched and the rubber bushings should be replaced on general principles, so as to secure a net gain of 1 1/2 to 2 inches without the Air-Lifts. They then would be used merely to compensate for load changes.
The seat backs and door panels in this car are in very good condition and are original. The bench and back cushions have been recovered with Naugahyde tailored to have fewest seams and maximum durability. The original upholstery was pleated and gorgeous, but repeatedly “tore along the dotted lines.” The headliner and rope moldings around the doors need replacing. This is on the agenda.
The front and middle seats are identical; both are on tracks. The rear seat back is part of the bulkhead separating the trunk. In normal position, it is a 9-passenger car, a bit substandard for three adults in the rear, but OUR children loved it, so do our grandchildren. The middle seat can be scooted to the rear a few inches to make a spacious 6-passenger car. Or it can be left in the center of its travel, and the rear seat back can be folded down to enlarge the luggage area. Or it can be scooted forward to make a 3-passenger car and the rear seat will unfold a second time to give a luggage space over 6 feet long. At one time we used chaise pads with a trunk platform to sleep two adults remote from any normal accommodations. Two children could sleep on the seats, and the baby on the rear shelf under the window. However this didn't last long and led to the trailer.
The luggage rack was an “included extra” on these cars. I have replaced the original slats with heavier ash, of clear stock. They have been soaked in clear linseed oil for weeks. The steel rails have been replaced with stainless to end plating problems. Screws and cup washers are stainless, with nylon cup washers.
The car has been repainted to original colors, Morocco Brown Poly (lower) and Samoa Beige Poly, formulated in Acrylic Enamel, and covered with several coats of clear Acrylic. A protective strip with a vinyl insert has been added at the “belt line” of the car, to protect against the door bangers. I would rather have this non-original feature than a lot of nicks and maybe a broken nose.
We are considering installing air-conditioning and maybe power steering. Any other car we could find would be a “come-down” in most respects.
We wish every member could enjoy his car as much as we've enjoyed ours!
If you bought a new automobile today, how much confidence would you have in its ability to complete a nearly trouble-free 5400 mile trip with a trailer, returning in condition all read to go again?
Our 1951 DeSoto Suburban covered itself with glory in August and September of 1975 when it made just such a trip. Very little special preparation was done in advance, other than lubrication.
Twenty-four years old and starting with over 178,000 miles on the odometer, it pulled our vacation trailer coach through desert heat and over mountains, from Burbank (adjoining Los Angeles) to St. Paul and Minneapolis via Tulsa and home again, with numerous side trips. Moreover, it arrived home ready for encores. How's that for engineering integrity and dependable durability?
In July, my wife and I had booked an extended rail tour into Mexico and our consciences hurt us. Our daughter in West St. Paul had been imploring us to visit her family and we felt guilty about heading off the other way.
Our son foresaw a chance to take a two-week vacation in August and help us drive. We all wanted to make just one more sentimental journey in our all-time favorite automobile. And we wanted to visit my wife's family in Tulsa, including an aunt nearing 90. We kicked around the idea of flying, but our desire to see the country-side and my confidence in our car won out.
While our son was convincing his mother it wasn't sheer madness, I started grooming our trailer. It seemed to be the doubtful part of the plan. And, fortunately, it didn't need too much, mostly cosmetics.
We had bought the Suburban new in 1951 and the trailer new in 1955. Prior to this Oklahoma/Minnesota trip, our Suburban had towed the trailer nearly 50,000 miles. This, in itself, might be some kind of record. The car now has nearly 185,000 miles on the odometer, and the only work ever done on the rear axle has been one replacement of the wheel bearings and replacement of seals when relining brakes. The so-called “third member” -the gear assembly - is still quiet and is apparently good for many tens of thousands of additional miles. This should not come as any great surprise, however. This is still the same basic rear axle design that often ran 200,000 or 300,000 or more miles in taxicab service in the forties and early fifties. Chrysler Corporation can be especially proud of this design and quality control in manufacture.
To get back to our preparations, our son helped in the trailer grooming with a lot of muscle and rubbing compound. We put on two new tires and worked on brakes, electrical, hardware, and caulking. Preparations on the Suburban included a filter and oil change (10W40), checking lubricants in fluid drive and transmission (ATF), rear axle and steering gear (both 90), and lubing all fittings, including 3 U-joints, also front and rear wheel bearings. Oiling the distributor and a drop of oil at each end of the generator completed the lubrication. A cleaned set of spark plugs was installed. Our Suburban has a coolant recovery system added. The coolant, half glycol and half water looked clean and had been staying at normal level, so nothing was done internally to the cooling system.
The standard four-blade fan was replaced with an old Dodge truck fan, P/N 567087, for extra cooling while trailer-towing in desert and mountains. A 180 degree thermostat prevents excessive cooling on downgrades or at night. These items constituted the only mechanical work done; we started out with all else “as is”.
Before we got too far from home, I thought we ought to give the rig a change to prove it would “hold together” for thousands of miles at the legal 55. The second day out, near Williams, Arizona, I let it roll up to 68 on a gentle upgrade. The faster it ran, the better it acted, but we limited that test to two miles, even though it was still accelerating. I felt that any rig that ran so beautifully at 68, couldn't fail at 55.
Our son did about 80% of the driving going east to Tulsa and north to the Twin Cities. One day we drove over 600 miles. Not bad for a flat head six moving 8490 pounds, gross vehicle weight!
I had packed about 60 pounds of spare parts including complete engine gaskets, electrical spares, hoses, seals, carburetor, fuel pump, water pump. axle shaft, and even a good used set of engine bearing inserts. Also, there were many miscellaneous small parts, sealants, lubricants, etc. Also, our tools weighed probably 50 pounds. As it turned out, we didn't need a single part on the entire trip. But can you imagine the look on a parts man's face if I had gone in to ask for any of this stuff for a '51 DeSoto!
Now I'll tell you about the minor trouble we did have. And this was an easy, “labor only” job. On our last day's run into West St. Paul, we had six or eight instances of the engine dying at a stoplight. However, it would restart promptly and run beautifully again. This dying was accompanied by an unreliable, delayed downshift from direct to underdrive. At our daughter's house, on a hunch, I checked the governor points on the side of the transmission, and sure enough, they were oily and blackened. After cleaning the switch assembly and polishing the contacts, the problem disappeared. (This treatment more recently cured a similar problem on my wife's '53 hemi-head DeSoto. This operation will be part of any tune-up henceforth. )
We planned our eastbound August run to avoid the Barstow-to-Kingman bake oven in the hot afternoons. As it was, we encountered 108 degree weather but had no heating problems. We even made the round trip without adding coolant.
In passing, I should add that we also had no tire trouble. Our Suburban has had only two flat tires in all its life - one in 1953 and one in 1964. The trailer had one in 1957. On some trips, we have encountered 118 degree weather, and one shouldn't start out in remote, hot areas without very good tires.
On the main highways, there were few grades that we did not pull in direct (high gear). The longest was eastbound in Arizona from Ash Fork toward Williams, where we ran a stead, easy 35 in underdrive for about two miles with no heating problem.
Our son had brief but satisfying visits in Tulsa and West St. Paul. Then he flew home from MSP to LAX to get back on the job. My wife and I relaxed and enjoyed more extended visits. I did all the return trip driving plus numerous side trips and it was all sheer pleasure.
At times we ran into violent rainstorms and cool weather. It is good to report that both the car and the trailer stayed dry inside. Our heater, wipers and brakes behaved perfectly, and there was not the slightest ignition problem.
We found that a large segment of our population is highly appreciative of older cars, especially when they have been well-kept. We had many compliments and expressions of interest in our Suburban. I backed the trailer and car into a double parking space in downtown Gallup and immediately drew a small crowd of local bank employees and business people. The police wouldn't let me add any coins to their parking meters. I had to raise the hood, run the engine, show the interior and answer a jillion questions.
While we were staying with our daughter, we drove the Suburban southeast toward Red Wing to meet the Freedom Train, en route to Minneapolis. I am also a rail fan, and am nearly as enthusiastic over that beautiful GS-4 Lima steam locomotive as our Suburban. We “raced” alongside of it back to Hastings, Minnesota, as we had done many times years ago with its brethren between Ventura and Santa Barbara, when we had a 1941 De Soto.
Half the town had turned out at Hastings while this huge ex-SP locomotive was serviced. When we parked about a hundred feet away, our Suburban drew its own appreciative crowd. All along the trip, friendly strangers took pictures, many times.
When we got back to Flagstaff, we decided to take a scenic loop side trip. We drove south to Sedona in Oak Creek Canyon and spent the night there. Next day, we drove up Schnebly Hill. This is a spectacularly scenic unpaved road. Actually, it's little better than a jeep trail, steep in places, winding, gullied, bumpy and rocky. This took us into some of Arizona's most beautiful back country. Mountains, lakes, streams, wild flowers, and tall pines. Of course, we had the trailer and picnicked along the way. We came out on Interstate 17 and turned north to Flagstaff.
The confidence we have always had in the ruggedness and mechanical integrity of this husky car has allowed us to explore a lot of highly scenic back country with a trailer; places that many wouldn't venture into in the average car without a trailer. And it has always brought us home safely, and in great comfort and in elegant style.
We have toyed with the idea of buying a new Dodge van or mini-motor-home. But whatever motor vehicle we buy is going to have an awful tough act to follow.
The early portion of our stay in West St. Paul coincided with the National Chrysler Car Clubs meet in Detroit. I deeply regretted our inability to modify our itinerary and attend this once-in-a-lifetime gathering. Considering we had already covered some three-fourths of the distance, the disappointment was particularly acute. There were simply too many interlocking family commitments to allow revision of our scheduling. However, I thought of Sherwood and many others of our Southern California Section and wondered how many had been able to make it. I would like very much to have been able to display our 1951 DeSoto Suburban and show the Chrysler Corporation one of their all-time most appreciated automobiles!
The 1951 DeSoto Suburban is a one-owner car and is owner-maintained except for body and upholstery work. Its performance and reliability are believed to be well above average for any car anywhere near its age in terms of original characteristics. It is not a restoration but a preservation job with a few changes intended to give increased durability and a moderate performance increase.
As examples, the cooling system has a specially-made high-efficiency radiator core. Half glycol is used to raise the boiling point. This coolant and an added recovery system, in combination, practically eliminate rust and corrosion. A seven pound cap further raises the boiling point and gives added protection against loss of coolant, as compared to the original 4 pound cap. An added fan shroud increases fan efficiency.
The L-Head Six Engine originally had 3.437 bore and 4.5 stroke, giving 250.6 cubic inches displacement. In 1960 the owner rebuilt it using a hardened Chrysler Industrial Engine crankshaft having 4.75 stroke. Of course, a shorter set of rods was required to match. Heavy duty rod and main bearing inserts were used, for added durability.
The cylinders were rebored to fit a set of Sterling Conformatic pistons, nominally .030 oversize. These pistons are intended for Dodge Truck service. They have solid skirts with invar struts to control expansion. The top ring lands have steel liners to extend piston and ring life. The pistons have 3 rings, as compared to the original four. This trades some increase in oil consumption for a reduction in friction, heat and wear.
The boring and stroking resulted in a displacement increase to 269 cubic inches. This, plus a planing of the head by .035 has resulted in a compression ratio increase to about 7.65 as compared to the original 7.0. Regular gas is definitely superior above 3000 feet elevation, but half a tank of ethyl now and then is advisable at low elevations such as Death Valley or the Imperial Valley, or in extra dry weather below 1000 feet. The increases in displacement and compression ratio, combined with the reduction in piston friction have resulted in a highly gratifying improvement in performance.
The cam is original. The only parts replaced in the valve train are two new valves, new tappet screw, new cam bearings, timing chain, and sprockets when the engine was rebuilt. The oil pump has been replaced with a higher capacity unit, P/N 1314 607. It maintains good pressure when idling, immediately following hard operation in the hottest weather.
Many other items on this car have received Tender Loving Care over the years, but mostly, it has been on a one-time basis. Fix it perfectly, eliminate any possibility of early failure, and its genuine built-in integrity lets it run forever.
The transmission was rebuilt about 15 years ago and seems perfect yet.
The front suspension and steering are an absolute delight. The car is steady, precise, and without a tremor at speeds way too fast for the good of the engine. (It is mentally redlined at 3600 RPM, which is about 75 mph in Direct.) Since the car lacks power steering, however, parking is quite an exercise.
Many technical aspects of this superb Suburban are covered in greater detail in the Southern California Region's “Free Wheeling News,” Vol. IV, No.3, postmarked Oct. 1974. Anyone contemplating a major rebuild on a Chrysler Corporation L-Head Six might well profit from it.
An excellent historical article on DeSoto Suburbans in general, with particular emphasis on the 1948 models, appeared in July August 1974 issue of Special Interest Autos, a publication of Hemmings Motor News.
See our DeSoto section and DeSotoLand.
Chrysler CEO Al Gardner
Dart DDCT: fun, funky orange car
All Mopar Car and Truck News
Chrysler 300 Letter Cars
The Engine Cleanup Committee