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32 DeSoto SC some questions about the motor.


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Posted

First of all it is running fine except for some oil consumption. We have had the car for 5 years and tour with it regularly.

This has resulted in roughly 7500 enjoyable miles. A quart of oil every 150 miles. Motor has 73,500 miles showing.

The car was restored about 25 years ago and was not driven much. I do not know if motor has ever been rebuilt. I was thinking either the oil consumption would either abate or get worse.

I still use non detergent oil with no additives. I do oil changes after every tour (500 - 700 mi.) Would adding Marvel Mystery Oil hurt or help?

Just did a compression test last week and got 80# on all 6 cylinders. It checked in the low 70's  5 years ago. What should my pressure be?

Car does not smoke but I feel it should have more zip.

What are thoughts on introducing some detergent oil.

 

Appreciate any suggestions

I may need to change my name

 

Touringcuda

 

Posted

Hi

 

As I also drive a 1932 SC (roadster ), the consumption of a quart in 150 miles would not seem to be  a problem.

 

As suggested, adding Mystery Oil could benefit the operation of the engine , most specifically as a protectant to the valves.

 

 

At 80# for your engine, you have reached the zip level.

 

Phil

Posted

The best thing you could do is get rid of non-detergent oil and put in a 5W or 10W-30 (40 might be better with that oil consumption) oil. The engine will be filthy everywhere inside running on non-detergent oil. The dirt (mainly combustion products, but also any dust that gets in etc.) is deposited where the oil stops on shut off and is not picked up again. It will be in the sump of course, inside the oil ways in the block and crankshaft, around the tappets and in the valve chamber, in the timing gear and all around the cover, in the ring grooves and so on. Your frequent changes are very good, but the oil does not carry much dirt out with it. You will have to remove the sump to clean it out first and make sure the oil pump pickup is not clogged with dirt.

 

In my mind, a quart per 150 miles is a lot. My 1930 Dodge 8 doesn't need any top-up between changes at 1000 to 1200 mile intervals and the level doesn't go down a noticeable amount. I am running a 5W-40 CI-4 rated (diesel) oil.

 

The formula to work out your compression pressure is given in this post and those referred to in it:

I expect your volumetric efficiency to be about 75% so if you know your compression ratio you can calculate the pressure.

Posted

First of all thanks for the response.

Our SC is a Four Door and 5 years ago I got a lot of excellent advice on this forum.

The first response from an actual owner means a lot because I did not know what normal oil consumption rates might be.

Before I would make the switch to detergent I need to drop the pan and clean the crud out. Have you done this on your car.

I know the motor is supported under the water pump. At the rear of the oil pan is a cross brace that I need to remove. There also is a support at the rear of the transmission. Will the front water pump support and the rear transmission support hold everything while I remove the cross brace at the rear of the oil pan? Clearances are close here (cross brace) and I cant tell if it is actually a support for the motor or a stiffener for the frame and a place to bolt the side trays. Floating power was new this year.

I have been wanting to drop the pan for a couple of years so this fall it will happen. The owners manual says this is annual maintenance.

 

As to the compression pressure any and all input is appreciated.

My searching on the internet for any and all information about the 1932 SC motor has educated and somewhat confused me and certainly generated many questions.

1932-3 DeSoto Complete Motor Specs Clutch Steering Brakes.pdf

If I attached this file correctly it shows my compression ratio at 5.35 and compression pressure at 90-95. I think it came from the restorecarsclassifieds.com  website. 

When we did the compression pressure test the motor was warm and we pulled all plugs but I forgot to hold throttle open. Somewhere I thought I read that the open throttle isn't mandatory with a six because there are intake valves open to compensate?

Should i repeat the compression pressure test?

My formula at 1000 feet elevation would be (14.16 PSIA) X (5.35 compression ratio) X (0.75) = 56.82 then add  28.86 for a grand total of  85.67      witch corresponds well with the  90 - 95 on the attached file for a new motor.

Could it be that bad oil rings or excess crud around them might be the cause of oil consumption??

Am I moving on the right track if I slowly introduce detergent oil to the motor after a complete cleaning of the oil pan??

 

I welcome any and all input.

 

Another spin on the subject is that I believe the 32 Desoto was one of the first with inserts in the mains. 

I purchased a 1928 - 1933   Desoto Master Parts List  reprint  off  E-Bay this winter and the inserts are listed.

 

Our DeSoto will be on the Glidden Tour in Hastings Nebraska week after next.

 

Bob

 

 

 

Posted

Based on those published figures, your Volumetric Efficiency is about 80%. So your compression pressure at 1000 feet elevation should be

 

14.7 * 0.8 * 5.35^1.3 - 14.2 = 90 psi gauge.

 

The owner's manual says to clean the sump annually because the oil (which was non-detergent of course) was poor (by today's standards) and the engine filled up with muck. It is not necessary with modern oils. I did clean mine, of course, when I replaced the rings. I can't help with the Floating Power system but you might like to look at the Taylormade's topic in the Dodge Brothers forum on Daphne, a 1932 DL with Floating Power - I expect they will be similar.

 

I have never done a compression test with the throttle open. Will it make a difference? Hmmm. We are compressing the air in the cylinder over a small number of compressions, not burning anything, so I can't see how it will make much difference. Mine takes about 4 compressions to peak on the meter.

 

If your engine has been rebuilt and then sat for a long time, my guess is that driving it a lot might reduce oil consumption and improve running, assuming it is in tune and so on. All cylinders at 80 psi is very good, though perhaps down a little. It should run well.

 

Once you refit the clean oil pan, fill it with 5W-40 oil. NO more non-detergent oil! Yes it will dirty quickly, but you are in the habit of 500 mile oil changes so do that a couple more times then go to 1000 miles. Some of the muck in the engine will come out in the short term and over time more will gradually be removed. It cannot harm the engine - the particles are very fine and the damaging stuff is heavier and will stay settled out. If it does damage anything, then it was metal and the engine was was already in trouble!

 

 

 

Posted

Looks like my next logical step is to clean the oil pan.

 

Can someone who has done this with the motor in the car advise me of the procedure? I think that by 1932 Chrysler and Dodge 6's were also into floating power and in 33 the Plymouth 6 also. They should be similar.

The cross member at the rear of the oil pan, does it support the motor or just reinforce the frame and hold the splash pans? 

There is little clearance there and I can't see if it is bolted or not. Probing with my fingers it feels like there may be a soft rubber support there.

 

 

Also does anyone know of a vendor that re-vulcanizes the (floating power) motor mounts?

Last year I had to unbolt and jack up front of motor to change my fan belt.

The fan belt wouldn't quite clear the brake line underneath because the rubber is becoming spongy.

 

Thanks again.

Posted

I have a 1932 Dodge Brothers DL (six).  I'm not sure how close my Floating Power set up is to yours, as the DBs seem to be something of an odd duck in the Chrysler lineup in the early thirties.  My car has a forward mount attached to the frame that has a rubber  mount on top that attaches to the motor under the water pump.  At the rear, there is a rubber mount under the rear of the transmission.  The rubber rests at the bottom of a metal support piece that surrounds the transmission.  This support  bolts to the X-frame with four bolts.  At the rear of the motor there is a support bracket that attaches to brackets on the frame.  This bracket has a flat rubber piece bolted on top that serves as a fusion for the motor.  The rubber is bolted only to the support, not to the motor.  Removing this support is a real pain in the neck, made more difficult by the presence of the leaf spring, attached to the motor, that extends from behind the support over to the passenger side of the frame and rest there in a rubber mount.  To get to the oil pan, you have to support the engine/trans assembly by the transmission.  Then you remove the cross support at the rear of the motor.  It will come free with the rubber pad attached.  If it's been on there for a while, it will take some fiddling to get it out.  Try to pull it straight down or it will rack and jam on the mounts.  With the support off, you have access to the spring that attaches with bolts that also hold on the bell housing cover.  After you remove the cover, you have access to the oil pan.  You my be able to access the pan bolts without removing the spring and bell housing cover - it's been awhile and I don't remember.

Make sure you reassemble everything in the reverse order you took it apart.  Forget anything and you'll have to take the support piece back off again.

 

My car has no "ears" attaching the bell housing to the frame.  The motor/transmission truly "floats" on three rubber mounts and does not touch the frame at any point.  I can post some frame off photos from my restoration if that would help.

Posted

Then and Now did a beautiful job doing all my mounts.  I'm posting from my IPad, but l'll access their contact information for you when I get home.

Posted

As far as the mounting system, here is how my 32 Dodge Brothers is set up.

 

Front motor mount....

IMG_6746.thumb.jpg.9337ae97a9a26f61afe178f3c5b5e049.jpg

 

Trans mount....

 

IMG_6758.thumb.jpg.640d9a25c4e42b0d0d6ab8b0152ae195.jpg

 

IMG_6774.thumb.jpg.87c943ba252bdf6f13bef50043346770.jpg

 

Mid motor support - before installing the torque spring.  I learned the hard way you have to install the torque spring before you put the support in.  Three bolts on each side

hold the support to the brackets.  You can just see the rubber mount and its metal support piece peeking out from behind the bellhousing cover.

 

IMG_7313.thumb.jpg.53cd2f2c824348b542f15004561a8bc1.jpg

 

Shot with the spring installed...

 

IMG_7318.thumb.jpg.818aa6667082325704868aef3bce49d4.jpg

 

I hope this is similar enough to your car to be of some help.

 

 

Posted

Sorry for the slow response.

The pictures are great. I have not been under my car since I looked at them but they appear almost identical.

Our car was restored in 1991. I know next to nothing about its history but it appears to have had caring owners previous to the restoration.

The fellow that restored it has passed but I do know where he lived in Pennsylvania. 

I definitely will be contacting Then and Now about my motor mounts. I wonder if they will be at Hershey?

It appears that you had the motor rebuilt. do you mind telling who did the work?

Is your 32 fully assembled yet? Your rear end gear ratio is similar to mine. Mine is 4.60 to 1. I have thought of possibly some sort of overdrive some day. 

We do a lot of touring but the scenery does look nice at 45 mph. 

The attached pictures were taken at Yellowstone Park. It was quite a climb from Cody. We followed a 32 Chevy 4 door as he struggled up the last steep grade into the park.

He turned around and went back down the hill and we went on and looped thru the park and saw "Old Faithful".

 

Thanks again,

I would like to stay in touch and hopefully share info about the cars. Our drive trains are for the most part identical.

We leave tomorrow for the Glidden Tour in Hastings Nebraska. When I return the oil pan will be on my list.

 

 

59b9ece5369a1_CodyHeritage2017132.thumb.JPG.81313707bf875a746f7de527af2e929f.JPG

 

 

Cody Heritage 2017 178.JPG

Posted

You're probably traveling too far north on your travels to Hastings, but we are in central Illinois if you ever want to stop by.  My restoration is about seventy-five percent complete, mostly just assembly at this point.  My motor was rebuilt by Loop 70 Motors in Columbia, Missouri.  New pistons, a rebore, new valves, valve guides and springs.  My crank and Babbitt bearings were in excellent shape - a real bonus as the 32 Dodge Brothers was the last Dodge to have the old poured Babbitt style bearings.  Not sure why, as I believe Plymouth  and DeSoto went to shell bearings in 32.  This was my first car, bought when I was 19 back in 1965.  I sold it to a fraternity brother in 1967 and bought it back from him four years ago.  In college I remember 45 to 50 was the comfortable cruising speed.  I haven't driven my car since 1967, so the memories are a bit vague, but I'm really looking forward to getting back behind the wheel as my restoration comes to its completion.

 

Have a great time at the Glidden Tour.

  • 2 weeks later...

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