Motor mount/insulator questions for a 1947 Dodge D25C

[RonJ]

My new to me 47 Dodge D25C (Canadian model) seems to be a hybrid following some of comments in previous posts.  I have replied to those but since they are a few years old they may not have a following.

Dodgeb4ya and others have provided great explanations.  Most of the photos do not load, I assume due to the time lapse.

My problem started with the proper fan belt rubbing on the upright that holds the front engine mount/insulator.  The previous owner installed a narrower belt to overcome this.  This skinny belt rides in the bottom of the pulley grooves which is less than ideal.

Looking down at the pulley on the engine I can see the groove is partially obscured and using a straight edge it shows that there is no clearance between the edge of the correct belt and the upright mount.

The real problem as I see it is that the engine has shifted a few degrees to the drivers side and is no longer perpendicular to the crossmember or the upright.  The car has never been in a collision but I thought after 75 years something else must be worn or broken.

It turns out that the often mentioned left rear mount is worn to the point where the bolt is near the back of the opening.  This would explain the shift off the engine to the left.  The other mounts of the same age are worn as well.

On both the left and the right rear mounts there is no lower rubber cushion.  Whether there ever was or not is unknown but the length of the “T” tube indicates there may have been.  The nut that goes on the bolt that passes through from the top has a bevel washer ahead of it and it tightens against the tube.  However the bolt itself is still loose.

Comments in some threads indicate that this is the case to prevent the rear from jumping out of position and that the weight of the engine and transmission simply holds everything down.

I’m thinking that since the T section seems long enough to accommodate a lower mount that there should be one there, even if it is just to prevent side to side movement of the bolt.

I have attached photos of the pulley and belt showing the proximity to the front upright engine mount and of the bolt and T tube in the left rear mount.

 

 

My questions are:

1)  What is the actual clearance measurement between the side of the OEM 5/8” belt and the upright for the front motor mount?

2)  While waiting for an answer from AB about the differences between part # L-348 and L-346 Rear Upper Engine Mounts as well L-347 and L-349 Rear Lower Engine Mounts as they all state they are for Dodge and 1947.  Does someone know which are the correct ones?

3)  Is L-338 Front Engine mount the correct one?

 

[Dodgeb4ya]

I have never seen a front pulley like that...looks cast? Maybe Canadian thing..IDK

Also that front engine  support has been out...also not bolted in with the factory "U" bolts and 5/8" nuts.

Generally about a 1/4"+ of belt clearance to the support plate is pretty common.

Cannot even come close to answer whats the right on re-pop mounts for your Dodge...

Todays after market mounts are sold as "They should fit and work" is about all your going to get these days.

The hardness of the rubber is critical for vibration free operstion.

Old NOS rubber can become very hard and not useable.

Edited December 21, 2022 by Dodgeb4ya

[RonJ]

Thanks for responding.  You are very observant.  Indeed, after I did some further cleaning the bolts holding the frame look non standard mostly because of the different flat washers used.  My parts book does not show the fasteners in the pictorial but does mention U Bolts and plates in a list.  I don’t have any other reference to what should be there.  I guess it’s not critical but it is a good indicator that there may be other issues.

The pulley looks cast and also seems original but what is interesting is that it has provision for a crank to turn the engine over.  There is an opening in the cross member that lines up but there  is no opening in the bumper.

The pulley groove does align with the water pump pulley groove and the generator pulley groove so if it is non stock, they did a good job of it.

I really to ponder how to get the quarter inch clearance or any clearance at all.

I’m also wondering now if the engine is not original and this particular engine had a different frame but with a similar front cushion.  75 years is a long time and many things could have been done.  I will try to correlate the engine number with the car serial number but I don’t think there is much information out there.  I read several times now that these Canadian cars are truly factory Frankencars with whatever parts were available on either side of the border.  So as one member told me it’s a Plodge, or some variation of a Chrysler, Plymouth and Dodge marriage.

here’s a closer photo of the pulley front and rear.

 

[RonJ]

With regards to the engine.  It appears it is a Plymouth engine based on the serial number on the block just above the generator.  See photo.

It does measure 25”.  These are not unusual for a Canadian car based on various groups.  The question now is the compatibility of the engine with the front upright mount if it is not the original engine or if it is the original engine as I was told, why is it set back far enough to cause the belt to rub.

Other than determining it is a Plymouth engine by the “P” prefix I have unable to find out anything else.  If someone in the group can help I would be grateful.

 

Number on the block is PI0C6262

 

 

[RonJ]

[Sam Buchanan]

P10 is US 1940 Plymouth but there may be something different with the Canadian cars.

[dpollo]

The engine pictured is from a 40 Plymouth and is a bolt for bolt swap except for two exceptions.  

1... it has a 4 bolt flywheel where the D25 had eight.   2, it did not originally have the cast damper which is correct for D25.

 

Dodge b4ya is correct, the bolts holding the front mount are incorrect however, the holes in the frame are slotted and the front mount can be slid backward so both the belt and also the timing cover can ride freely.   First, however, the rear mounts must be replaced.  In every way, these are the same as the USA Plymouth.   Easy to get, but often too hard.  In 1940, there was a lower doughnut moulded to fit.  Subsequent, or certainly post war years had only a slim rubber washer and sometimes only on the left side.  There is a large steel washer which goes under and if all is correct, it will contact the steel tube before the lower washer is put in a state of compression.   When all that is done, your D25 will run quietly and without much vibration.    These are only Frankencars in the minds of people who have chosen to ignore the engineering which made these very fine automobiles the best in the low price field.

[Dodgeb4ya]

Dave...is that cast damper a canadian only part?

Never ever seen one of that shape and type..

[andyd]

Ron...........I agree re the frankenstein comment.......BUT....they are built a particular way by Mother Mopar and for various reasons use the best of what was available..........here in Oz we have it even more..........lol........my understanding is that Canadian built cars used the DeSoto/Chrysler 25" engine and your statement that the engine is 25" long would confirm this statement........even if it does say P10......its a Canadian built Dodge which were Plymouth based with Dodge grilles etc and the DeSoto/Chrysler engine for economic reasons........here in Oz we sometimes had BOTH the 23" and 25" engine used in the same year depending on what gearbox you ordered installed in your new car..........lol...........I would strongly suggest you absolutely confirm the cylinder head length and/or stroke via the removable plug above cylinder # 6 to determine the exact size........regards from Oztralia...........andyd

[sidevalvepete]

6 hours ago, dpollo said:

 These are only Frankencars in the minds of people who have chosen to ignore the engineering which made these very fine automobiles the best in the low price field

Well said...the deeper I got into my rebuild, the more respect I developed for the team behind Chrysler Corp.

[RonJ]

Agreed that the holes for the upright support are slotted.  Interesting that the left side are as far to the rear as possible which would account for some of the engine misalignment to that side.  However since the engine and the mount move together it still doesn’t solve the clearance issue.

I will try to move the engine today.

[RonJ]

Also no disrespect to the cars or the engineering was intended by the term Frankencar.  It was only a summary of the initial build as described in various forums as well as any changes made during its 75 year life.  The fact that this 82 year old engine runs as smooth as it does is a testament to the technology of that era.

I have learned that I should really consider the 1940 Plymouth donor car that I have a lead on since the major components appear to the same as my car.

Its currently buried in snow so I cannot check the belt clearance issue.

[Dan Hiebert]

For whatever reason, your engine is off kilter (duh, you already know that).  It looks to be primarily due to the motor mounts both front and rear being quite worn out.  How it became so really isn't important, but one of those nice-to-know things.  Anyway, the front motor mount is a rectangular rubber block at the top of the front brace, and it is most likely just as worn out as those rear ones.  You'll probably find that the driver's side of the front mount is deformed / wallowed out / worn, allowing the engine to work its way akimbo over time.  Just the engine's torque will do that.  How the bottom of the front brace attaches to the frame is immaterial to your issue with the belt clearance.  I'd wager that if you replace both front and rear motor mounts, your problem will be solved.  The timing pointer thingy looks to bent, too.

Edited December 22, 2022 by Dan Hiebert

[LeRoy]

6 minutes ago, Dan Hiebert said:

 allowing the engine to work its way akimbo over time.  

Is akimbo anything like cattywampus? ?‍?

[Sam Buchanan]

[slatgrille]

....or put gas in a diesel and vise versa!

[Sniper]

Is it possible the harmonic balancer is installed backwards?

[DonaldSmith]

The fan belt should be in line with the water pump and generator pulleys. 

[chris 48 P15]

maybe something be wrong with bracket

plate 9-65-6

[RonJ]

It does not seem possible to have the pulley reversed since there is a crank handle fitting on it.

I agree that the pulley grooves should all be in alignment and they are.  
The problem showed up while I am trying to correct a poor 12v conversion where someone installed an alternator on a flimsy bracket which had the alternator not in alignment with the others, sort of an attempt to correct the engine offset by offsetting the alternator the other way.  I’m guessing the belt was still rubbing and probably came off, so the guy put a narrow belt on it to overcome this instead of solving the real problem.  I reinstalled the original generator on the original bracket to get back to a known starting point.  All grooves are aligned.  In one photo above you can see the pulley groove is partially obscured by the mounting plate.  Just going by the thickness of the engine side of the pulley I’m hoping to achieve 1/8” clearance but ideally would like up to 1/4” as suggested above.

The drawing in the last comment is the one I have in my book as well, and my mounting plate is that exact one.  That drawing does not show the Ubolt but the part 9-65-19 does show up in a list a few pages later on page 128.  The bracket is not bent or damaged when checked with a straightedge.

Its snowing like crazy at the moment but when I can get to the shop I will loosen the front insulator mount nuts (the rear ones are not doing anything), and try. To shift the engine a bit.  I can also loosen the bolts that fasten the upright and move it a bit, but since it moves in unison with the engine it may not make a difference to the pulley alignment.  My only points of reference are the rear mounting holes for the bolts and insulators.
I will shift the engine until those bolt holes are in the center of insulator holes and see what that does for the alignment.

All the comments so far have been valuable, increasing my knowledge and hopefully everyone else’s that sees the thread.

[Booger]

Catywampuss...whew. thought I was old!

[Dodgeb4ya]

You can wedge the bottom of the front support mount closer to the timing cover....giving more clearance for the crank pulley and belt.

I have had to do this many times on engine R&R jobs.

The weight of the engine on that front mount support tends to skid the two front mounting  pads  towards the front of the car.

Very slightly taking the weight of the engine off the support makes it easier to adjust it rearward if necessary.

Of course do all this after the rear mounts are replaced properly.

[RonJ]

That is a very interesting suggestion.  
I had pondered whether the support plate was truly 90 degrees to the mounting pads.  It is a difficult measurement to make and I don’t know the original design.  Assuming it is 90 degrees, the front insulator is certainly squashed with rubber bulging out the front which would indicate that the support plate is leaning backwards, pinching it and verifying your suggestion, that bottom of plate has moved forwards.

Noting that both rear mount bolts are near the rearmost side of the opening for the insulators, it also indicates the engine/tranny combo has shifted backwards which would pull the top of the front support plate back or force the bottom of the plate forward.   Seeing as how I need to remove that support anyway to change the front insulator, it will be an opportunity to verify if it is square.

Also thinking about the original design U bolt to hold it down.  A Ubolt would spread the forces that will try to distort the crossmember over a greater area than the small nuts and washers currently in there.  I have not seen a source for that Ubolt though so I may make a plate with two holes for the underside and continue to use bolts.

[Sniper]

3 hours ago, RonJ said:

It does not seem possible to have the pulley reversed since there is a crank handle fitting on it.

 

The crank handle fitting is part of the bolt holding the balancer on

[Dodgeb4ya]

Hank crank pulley bolt..