Curiouser and curiouser, said Alice.....

[Carla]

Hi, Go, and thanks for the reply.....

Broken rings seldom make noise, but they will damage the piston and the bore. Sometimes, albeit very uncommonly, the top of a piston will break off, or the piston itself will break, leading to a horrible noise.

In the case of this '34 engine, tho, everything inside the engine looked good.......very nearly perfect, in fact, except for the damaged oil feed pipe for the timing chain, and the excess wear of the chainwheels.

The cause of the rap noise is still a mystery. Any part striking another part inside an engine with sufficient force to cause a noticeable rap or knock noise really must leave some evidence in the form of a wear or damaged spot somewhere......or so one would think.

I'm reminded of a bit of folklore from many years ago.......in the old coal mines, sometimes the coal face, or the rock formations in the mine would shift or move a little bit, creating a knocking sound. This would warn the miners of a possible collapse of the mine shaft. In the folklore, the knocking was the work of 'tommy-knockers', the ghosts of lost miners who were knocking to warn their living colleagues.

So.......maybe I've got a left-over tommy-knocker who lost his position when his mine was closed down, and decided to take up residence in my engine?

cheers

Carla

[Go Fleiter]

When I broke some of the piston rings 1999, a couple of parts got into the cylinders makin sme noise like holding a skrew driver into the rotating Fan blades. Other rings must have been broken years ago with no problems at all. Greetings! Go

[plym_46]

I had a noise in my P15 engine.  I had just had the crank turned and did the bottom end due to scored crank at the main seal area.  The engine showed 50 lbs of oil pressure, cylinder walls looked fine, top of all the pistons looked great.  It developed a noise on acceleration that was troubling.  I was going to pull it and do a complete rebuild when I fond a p28 engine and decided to put the money into a 230 rather thant the 218.  I did not pull the engine down after removal, and it sits on the stand in the garage as it was pulled.  I suuspect it was either pin bushings or piston slap as the engine was quite at idel and at cruising speed, but step on the gas to climb a hill and there it was (it was not spark knock)

When the 230 was disassembled, every piston had one if not two compression rings that were broken. This seems to be a common fault reported by quite a few people who pull thier engines down, wonder if that may be the source of some noise???

[36 Ply]

Carla-

I went out to the garage and consulted my 1949 Hollanders (reprint).

It mentions that a 33-48 Dodge passenger engine should fit a 33-48 Plymouth; no modifications are mentioned.

It also notes that a Plymouth 35-36 fits a '33 by switching flywheel housing and motor supports and drilling holes in them.

Several Dodge and Plymouth engine swaps, of various years in the '30s and '40s? that were sent in to Hollanders by wreckers are mentioned,? but the year 1934 is not mentioned specifically.

Regards,

Pat O'Connor

[Carla]

Hi, David,

Thank you for the reply, and the idea.

I put the crank back in the '34 engine, and fitted up the oil transfer tube 'wrong way round' as you had, even tho my memory was that it had been fitted correctly. (I could have mis-remembered, of course)

As you mentioned, with the tube fitted wrong way round, there is indeed a clearance problem with the counter-weight next #4 rod journal. On our '34 engine, with the tube snugged down, the counterweight did the most slightly 'tick' on the tube, just the barest touch. There was no shiny wear spot on the tube or the crank, tho, so that hadn't been the problem.

I did find another error in the previous rebuilder's fitup of the engine, tho, one which rather surprised me. The keyseat for the front pulley, or vibration damper, was continued back farther than on later engines, leading the' rebuilder' to, apparently, believe that the crank timing sprocket was keyed thereby. With it so assembled, of course, the timing marks could not line up with the crank at #1 TDC, so the 'rebuilder' just used the timing position which 'seemed right'. The 'rebuilder' apparently just didn't notice the Woodruff keyseat in the crank for the timing sprocket which, when used correctly, would position the timing sprocket correctly.

That Woodruff key may not be easy to find, so I shall probably have to make one, which won't be all that difficult.

Now, this leads to an interesting question.......the engine seemed to run 'normally' except for the 'rap' noise.....but the cam timing had to be 'out' by some little bit, with the crank sprocket mis-located as it was.

I can't visualise this cam timing error, which had to be very slight, considering that the engine seemed to run well, as creating a condition leading to the 'rap' sound......

So, I suppose that about all I can do is to re-assemble the engine, taking care to examine every moving part as it goes back together. With the head studs removed, and the top of the block cleaned, I shall be able to sweep the piston tops with an indicator, relative to the block surface, to see whether the replacement pistons protrude above the block at TDC.......but I doubt I shall find any problem there, as the head gasket showed no signs of being struck by a piston, nor did any of the pistons show a wear spot at a top edge.

Oh, well.......its got to be there somewhere.....just have to keep looking.

I have to admit that, the more I think about it, the more tempted I am to just crate and cosmolene the '34 engine, and fit a later model engine......we've several engines here which might be candidates for the '34, amongst which is a '53 Ply 218, which may be in pretty nice condition.

Actually, the primary reason I'd fit a later engine isn't so much to get a bit more hp, (with that 4.3 back axle, cruising speed on the road is limited to 50-ish, maybe 55 at the most, I'd think, no matter which engine.....but a bit better pulling power on hills wouldn't come amiss)......I'm thinking more of the tendency of some of the '34 engines to.....apparently....have a localised overheat problem at the back of the engine, since they haven't the water tube of the later ones. That, coupled with the too-thin upper casting section of the head, leading to head cracks, is a serious nuisance.  (we've got three '34 engines here, the original one from our '34 and two others, with one uncracked head amongst the three engines.

The idea, of course, is to have the '34 on the road as an everyday-use car, with a reliable engine, but to take great care to preserve the original engine and other related components, so that the '34 could be put back to exactly original at some point in future......My partner and I won't be here forever, the '34 will doubtless out-live us, and some later owner may well be ever so particular about exact originality.....having all the original bits and pieces neatly stored away in crates, in a good coating of mil-spec cosmolene, will deal with that.

I've seen a few '34's with later engines, using the '34 bell-housing with the starter housing milled away for clearance.....I've been told....if I remember this correctly, that there is an element of chance.....of 'dumb luck' if you will......in casting variations of later blocks, some of which protrude more than others in the area which fouls the starter, so that the starter can be milled enough for clearance to operate with some engines, but not with others......does anyone here have any experience with that?

I'm trying to remember what I was told, years ago, about the particular combination of flywheel and clutch needed for this conversion.....something about using an early 8-bolt flywheel, which has the smaller bolt pattern for the smaller original '34 clutch, as the later, larger clutch won't clear the bell-housing.......or one has to use a later flywheel, and re-drill for the smaller clutch.....does anyone here remember those details?

There was another, and better, way to fit a later engine to a '34, which I'd seen done, years ago.....but I don't remember much about the details......If I remember correctly, a spare '34 cross-member was cut on either side of the bell-housing, and the centre section of a '35 cross-member welded in, with suitable re-enforcement plates, so that provided the setup for using the '35 mounts  and bell-housing, with, of course, the '35 gearbox and handbrake assembly.

Does anyone here know anything about that conversion.......and.....its the ultimate 'long shot' but worth asking.....would anyone know of a '34 which had been converted that way, then re-converted back to original, and the conversion parts might still be in existence?

I realise that all this talk about building up a reliable engine for the '34 may seem a bit 'silly' in the context of so many of these cars which are kept as carefully preserved antiques and display cars, so they don't ever see much service on the road.....but I'm thinking in terms of reliability over, say, a 2000-ish mile round trip up to deal with some property we own up near the Canadian border....and the '34 engine's lack of the better cooling of the later engines, along with the possibility of another head crack, does worry me.

Might we do better, for our needs, to get the '34 engine done up nicely and keep the '34 dead original as it now is, then think of selling the '34 and replacing it with, ideally, a late '30's, probably a nice'37-'39 Chrysler Imperial, (if we could find one) which would  be a nicer road car in some respects?

cheers

Carla

[David Pollock]

I had the crankshaft reground  for my 37 Plymouth back around Christmas 68.  It was uncommonly cold as I experienced my wrenches sticking to my hands. Reassembled everything and put it back in the car.  A sharp metalic knock, new to the engine was present. Seemed to be near #4 but did not short out or anything like that. Took the engine  out again and checked all the pistons. Put a new pin bushing in #4 and reassembled it.   Wait!  I see a shiny spot on the counterweight next to #4 cylinder. Turned the engine and the weight just kisses the oil transfer pipe. Took the pipe off and it had a corresponding mark.  Turned the pipe end for end, and there was no clearance problem. Seems the way that looks right for the pipe to go is wrong. I just about made the same mistake  on another 201 ten years later. Thank heavens for the persistance of memory. Incidentally, that same 37 engine is still running almost 40 years later!

[chetbrz]

My advice is to fix what you see is broken irregardless of your feelings about where you think the noise might be coming from.? I have been surprised more then once over the past 35 years of working on mechanical devices.? ?Never let your knowledge stand in the way of success.

My 2 & 1/2 cents,

Chet?

[57plymouth]

The timing chain could have been slapping the inside of the cover.

Are you sure it wasn't valve noise? 

[Carla]

Well, I got the engine out of our '34 and got it pretty well thoroly dissected....

This engine seemed to run well, showed good oil pressure on the gage, wasn't overheating, and all those good behaviours generally.....but....it had this engine noise when we got the car, and finally, all these years later, I'm getting around to working on it.

It had a 'sharp rap' or 'knock' noise, which sounded like a bad wristpin (gudgeon-pin) bush or possibly some sort of piston slap. It was definitely a 'metal striking metal' noise, not a spark rap. I couldn't isolate the rap to any one cyl by shorting plugs in turn......

Once it was apart, it was apparent that the engine had very little mileage on it since it was rebuilt.....it had been bored .060, crank ground .010, and it generally seemed unworn.

The crank looks good, the inserts, both main and rod, look good, with no evidence of the sort of wear which could cause any sort of knock...

The pinfit feels good on all the pistons....none are loose/shaky enough to have been a piston pin rap sound. I didn't see any marks on #3 and #4 pistons to indicate they'd been hitting the dist shaft.....as I remember, that was a little detail with some Dodge truck engines, having to put clearance flats on oversize pistons to clear the dist shaft when at BDC. The '34 engine being short stroke, I wonder whether there is a clearance problem there at all.........guess I have to do a bit of dummy reassembly there and have a look.

There is, I suppose, a possibility that one of the pistons could have been hitting the head gasket......I'll have to do a partial reassembly to check for that.

I did notice some scoring on the piston skirts, at right angles to the pins......that seems curious.....not enough piston clearance when hot?....the oil squirt holes in the rods were clear, so there should have been adequate cylinder oiling.

We don't have any useful history on the engine.....apparently, a previous owner had it rebuilt, and it knocked from the time it was assembled.....now, just why that knock wasn't found and corrected by whomever it was who was working on the car at that time is difficult to understand......

I have to admit that its bothering me.......if some part was loose enough to do a medium loud rap, or some mis-assembled part was striking something it shouldn't, there should be some obvious looseness, or wear marks.......and I'm not seeing anything out of the ordinary, so far......(except for one minor nuisance.....badly worn timing chain and camshaft chainwheel, the little oil squirt tube at the very front of the main oil gallery, which squirts oil on the timing chain had been damaged by being struck on the tip, hard enough to close it.....I can't imagine a loose timing chain causing a rap, tho.)

Has anyone seen this problem?

Any ideas?

cheers

Carla