Hello, Plymouth folks,
Well, I've just now been through a bit of a "learning experience", and I'm having to be in a bit of a "mea culpa" state of mind......so, thought I'd share the experience, as a good example of the famous old truism "Do as I say, not as I do"
Bob's '41 engine ran today, with only a return spring on the carbie in lieu of the correct throttle-linkage.......but it has problems, and will have to come down again.
Why will it need to come down again?.......well, I made some mistakes, it turns out. When Bob brought the engine over to our place, after getting it back as a "completely rebuilt" engine from a "professional engine shop", I really knew that I should have stripped the engine down completely and done a complete correct assembly "from scratch" instead of just correcting a few obvious errors.
Particularly, I didn't verify that the oil galleries in the block were certainly clear and clean, nor did I have the crank out, inspect and the mains, and fit the new main shells, taking care that the crank turned over freely when the main caps were torqued down.
The engine was really too tight for a Dodge/Ply six, which I didn't like, but I'd seen engines which seemed a bit tight smooth out nicely after a few minutes run time, so I was willing to give that one the "benefit of the doubt".
We got the various and sundry peripheral parts found, cleaned up, etc, and got the engine in the chassis.......and there I made my first mistake. I left the head off, with the idea of cranking the engine over with no compression load until the gage showed oil pressure, indicating that we had oil in the galleries and going to the bearings. I asked Bob to kick the starter and tell me when the gage showed good oil pressure. After a relatively few turns, he said " I see pressure on the gage".
Consider my mistake here.......that car had been in storage for six years, and I had never seen it run. I had no way to know whether the dash oil gage was any good, and I didn't check it by temporarily fitting a known good oil pressure gage.
Consider my next mistake.......not only should I have temporarily fitted a known good oil pressure gage, but I should have spun the headless engine over with the starter quite a bit more than I did, and checked the dash oil gage reading at the fast cranking speed against that of the known good gage. I didn't do that.
It turns out that the dash gage is no good. It swung full high when the engine first cranked, and stayed there. It now reads 80+lbs whether the engine is running or not, which, you may understand, is "a really bad failure".
I have no idea as to whether the engine ever developed any oil pressure. Presumably, it would, but I don't like not knowing for a certainty.
The next major mistake I made was to fail to communicate adequately with Bob when we started the engine for the first time. The 6v battery we were using was nearly dead, so we jumped the it with 12V from another vehicle. Bob was holding the throttle whilst I kicked the starter from inside the car.
I didn't adequately discuss the starting procedure, and Bob held the throttle open to keep the engine running up at somewhere around 1800-2000 rpm when it first fired. I came out and around the engine, and tried to pull the engine down to 500-ish or so, but Bob kept pulling it up to high revolutions, saying that he'd been told to do this to "break in the cam".
Well, the engine ran smoothly on all six for a couple of minutes time, and then developed a rather nasty "rap", along with a dramatically excessive amount of oil smoke from the road draught tube and oil filler cap.
So.......I don't know just what happened in that engine, but its something really bad......the "rap" is somewhat intermittent, and varies with engine speed, but its a loud nasty rap.....enough to be much more serious than merely a tappet adjustment.
Did I lose a bearing from oil starvation? Did I crack a piston or break rings from the over-speeding when the engine first fired?
I've never heard such a nasty bad rap when starting a freshly-refitted Dodge/Ply six......but all the other ones I've done were started much more gently, by spinning them over with the head off til the oil pressure had been up surely long enough to get a full supply of oil to the bearings, then putting the head on and firing them with the throttle position at a brisk idle......500-ish rpm or so. They would start at a brisk tick-over and I would let them run for a couple of hours time, to allow the wearing surfaces to gently bed into one another.
Well, live and learn........ now, there's nothing for it but to have the engine out again, strip it down to the bare block, and inspect all the pieces.....I'll let you know what we find.
cheers
Carla
Wow. Thanks for sharing... thats one positive from your last falls ordeal - your sharing and teaching people like myself who are just beginning their first engine rebuild. Hope the damage was manageable.
Ryan
Carla:
You certainly went to a lot of trouble to make sure the engine was circulating oil before you started it, but I think there are other, positive methods of making sure the initial start is 'wet'. I have done a lot of engine rebuilds, and very many years ago I failed to pre-prime a new oil pump on a newly rebuilt Austin Sheerline engine. The pump siezed immediately the engine fired, sheared the drive, and the engine started dry. By the time we realised there was no oil pressure - too late!
Since that time, I make sure every new oil pump is rotated and oil fed into it so that the rotor or gears are thoroughly wet. In addition, whenever I assemble an engine I use 'white grease' liberally. I coat timing gears or sprockets and chain, seals and seal surfaces, cam bearings/journals/lobes when the cam is installed, lifters, cylinder walls, pistons, rings and ring grooves, and after checking bearing clearances, all main and rod bearings and journals. This procedure has kept me out of trouble, but it is time consuming.
I have heard of, but never used, a engine pre-oiler that involves a pressurised container with a line connected to the oil? pressure guage outlet or filter pressure outlet on the block. Then a couple of litres (quarts) of oil are pumped through the system. After the buttoning up is completed the oil level is topped up and the engine started.
Brian
What an awful feeling when a new engine sounds so bad. Just a quick note I always do when rebuilding any engine is to use Lucas Oil Treatment as I build it. At least I have a little time to catch a low oil pressure problem. I hope it is a minor problem and you get it running soon. Good Luck
Dennis
I'm just now getting back to this engine project, after having to wait for the crank to be re-ground, and the rods reconned, this time by a reliable specialist shop. It took a while to identify a suitable shop, as the old line engine shops here in the south bay area have all closed down over the past decade or so. The shop we selected is one up in Hayward, whose primary business is that of building mega-dollar racing engines, commonly based on the 'small block' Chevrolet V8. I had a look through their facility, and was quite impressed with their equipment, and the work they are doing.
Fortunately, I was able to get the engine's owner to authorise the further cost of having the crank, flywheel, and pressure plate balanced together. This may seem a bit 'over-kill' as the factory balance of the old Dodge/Ply sixes was generally pretty good, but, on the other hand, its 'cheap insurance' for a smooth-running engine.......well, not cheap, really, but after all the other work going into this engine, I'd just feel better about knowing the balance was surely good.
I'll weight-match the pistons, and each end of the rods, myself. (this is a simple, easy job, involving a simple pan balance scale graduated to a tenth of a gram, and bringing the weight of each component down to match the lightest one. A simple frame can be easily improvised to hold one end of the rods, whilst the other one is on the scale pan, all that matters is to hold them exactly uniformly)
The block will have to be totally stripped to bare casting, and thoroly cleaned, using a rifle cleaning rod and bore brushes/patches to surely verify that the oilways.....the long holes drilled in the block casting.... are totally free of any grit or sludge. When the engine goes together, all its components....and the assembly area, tools, etc., have to be 'really clean'....a shell bearing which runs with .002 clearance, that is, .001 on each side, will be damaged by a teeny-tiny bit of grit thats no bigger than that .001. (for perspective, a human hair will run .0015 dia, in the case of really fine-haired people, to .003, with .002-.0025 being most common.....the old machine shop spec of a 'red hair' means .002)
Here is a really important 'do as I say' item.......back when I was doing engine work commercially, I ran across several engines which had lower end failures at very low mileages after 'complete rebuilding' by a 'professional engine rebuilder'. The problem was one of common practice, years ago, in which a rebuilder would 'hot-tank' a block, and consider that the hot caustic bath would have adequately cleaned out the oilways.
They didn't consider it necessary to physically clean the oilways with a cleaning-rod, which, in my opinion, was a major mistake. In some instances, sludge buildup in the oilways would clog the oilways solid, and the Oakite or other caustic material wouldn't completely dissolve and remove the sludge in some parts of the oilways. This problem, I suspect, would have been exacerbated by the common practice of running really cheap, low-quality 'grocery store oil' in the old engines, by owners who simply didn't know the difference, or didn't care. That stuff forms a grade of congealed sludge which needs to be seen to be believed.
One of the worst examples of that particular problem I've seen was a '40's Chrysler 251, a commercial rebuild, which had bearing problems. On pulling the engine down and checking the oilways, I found them so thoroly clogged with hardened sludge that I couldn't get a rifle brush though the drilled holes...... I had to use a little air drill-motor and long 'aircraft drills' to literally drill out the sludge.
(An obscure oddment you might possibly find in some of those old engines would be a set of the 'Thexton oil chokes', a widgetty bad invention which restricted the oil flow to the cam bearings, to send more oil to the mains....bad idea.....another obscure oddment, which could destroy a Chrysler engine quickly, is the idea of removing the filter assy. and plugging off the full-flow filter lines cos you can't get the correct filter elements for the full-flow system.....yes, that works, but there is a little special plug hiding in the block which must be removed to bye-pass the full-flow ports. Now, how's that for some truly trivial trivia?)
Well, getting Bob's engine back together will be straight-forward, now, albeit after a nasty economic loss, and many hours of lost working time.
The 'post-mortem' on his engine revealed a couple of really simple errors, which track back to some really bad work by the so-called 'rebuilder' who took a lot of Bob's money to allegedly 'rebuild' his engine. I say 'errors' but one detail was apparently overtly dishonest, in my opinion. Bob had been billed for, amongst other work, 'reconditioning' the rods. The alleged machinist did fit new wrist-pin bushings but didn't do the rod bores....maybe he considered that to be 'reconning' the rods? The #1 rod bearing failure after just a few minutes run time was basically a rod bore error/alignment problem. The secondary problem, which would have had that engine losing bearings far sooner than should be, was that a lot of dirt and grit had been left in the oilways.
So, why am I telling you all this?......on one level, its a 'mea culpa'.....as I said earlier, I really 'knew' that engine should have come completely down, and have been completely inspected, to find the 'weevils contained therein', but I 'gambled'.....partially, I suppose, cos Bob was so unhappy about having paid so very much money to that alleged 'rebuilder' and really wanted to think that his engine would be alright.
The 'moral of the story' is, of course,.....'do as I say, not as I did'......it seems that there are 'engine mechanics' these days who are accustomed to throwing modern engines together 'quick, cheap, and dirty' fashion, and really just don't understand the detail work necessary to fit up an engine correctly......which is just not going to work on these old sixes.
So, if you are an 'average owner' and need to have an engine done up, how can you keep from being 'taken' as Bob was?
Thats a really good question, isn't it?.......well, is the development of, say, some sort of 'guide-book' for evaluating prospective engine machinists and engine shops, and showing the 'average owner' how to have some realistic chance of correctly specifying and inspecting engine work, a worthwhile project for an 'old car club' organisation?
cheers
Carla