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Yes, check that the pressure relief spring isn’t broken and that the plunger moves freely. I had a brand X go to zero oil pressure due to a tiny burr on the pressure relief valve plunger. My Pierce oil pressure relief valve spring had one pit of corrosion that likely could have caused the spring to collapse dropping the oil pressure. I found a near replacement that requires an extra shim washer. I had to buy ten so if you find you need one let me know.

Jim

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I still think these issues could be related to the start of Studebaker control and the new 8, unless the knowledge out there is that ’29’s and ’30’s had no more issues than previous years.

I know next to nothing about ’29’s or the Gemmer box, but it doesn’t stop me from speculating like everyone else on 200% of what I know. I don’t think the general excuse that all cars had material defects and quality control problems really explains this. If the Gemmer box bearing races are truly “pot metal” -a hard but brittle material that might wear well but prone to brittle fracture – it seems like an avoidable poor choice of material. Obviously much superior materials and quality control for bearing races and housings were available at the time, witness the Timken roller bearings used for wheels and differentials. Even the Fafnir spring shackle ball bearings seem to be more a problem of being a bit undersized and subject to attack by corrosion rather than being brittle or defective. They also were designed with a failsafe – if the balls crumbled the shackle pin was still trapped in a hard steel washer.

The comments that other luxury cars like Cord L-29 used the same basic steering gear doesn’t strike me as a roaring endorsement.

Pierce had to rely on outside vendors like Ross and Gemmer to supply steering gears, and it seems there may have been lapses in vetting the design and testing of these with the turmoil of 1928-29. One can imagine the chaos of crashing the engineering, management and process systems of two car companies together simultaneously with developing a completely new engine and car in a very short time while the staff is wondering what the organization chart is going to be over the coming year. It would hardly be surprising if with a very short fuse Pierce put the pressure on Gemmer to deliver something fast at reduced price to please the “new broom”. Any new design has teething troubles and issues that must be worked out, this is compounded by re-organization and compressed time schedules. My speculation.

Jim

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Poor metal in the steering gear and bad axles in 1929 coinciding with the takeover by Studebaker in 1928 and large increase in production. Coincidence or was this level of failure common at that time?

Jim

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Greg, I hadn’t thought about it but you are right, the jets are the same for both branches, so it doesn’t seem they were intentionally compensating for the difference in length with the jets. Reading a little further in the text where I found the distribution data (“Internal Combustion Engines” by Polson 1942) the main factor for the duplex manifold was to minimize the tendency of the heavy fuel drops to not reverse course as the different intake valves opened and closed. With an outside intake valve open it establishes flow down the length, then when it closes and an inside valve opens it forces the flow to reverse direction and the heavy fuel isn’t going to reverse with it, thus the outside cylinders tend to run richer than the inside cylinders if they aren’t split up.

Trying do all the inter-related calcs for airflow, AF ratio, heat loss would be very challenging. Better to just measure it. A thermocouple in the exhaust would be ideal, but just slapping one on the outside of the manifold and driving at a fixed condition long enough for the temp to stabilize would probably answer the basic question. Come spring I may do that on the Packard.

The change in airflow is simple to approximate without measuring for our purposes, at a fixed RPM it is going to be pretty close to proportional to manifold pressure. I tend to think in terms of fixed RPM, because I spend a lot of time trying to stay at 65 mph as I go up and down hills, so the speeds and cooling airflows are constant. Manifold pressure in turn will be pretty close to proportional to indicated horsepower =brake horsepower + engine friction. With sea level pressure at 29.92″, an engine cruising at 15″ vacuum has an absolute manifold pressure of 14.92, or approximately 1/2 of sea level pressure and 1/2 of mass flow.

Approximating the performance of the Pierce 385 Eight from the 323 ci inch Eight in the text book, at 2400 rpm and 60 mph (with an overdrive or tall rear end gear), the max indicated power will be about 158, friction hp 38, for a net max brake hp of 120. At 60 mph level road power will be about 45 bhp+38 engine friction hp = 83 ihp, and that should be around 14″ vacuum and is in the vicinity of a net 1/2 net airflow compared to wide open throttle.

Jim

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Greg, for some reason my full reply didn’t get uploaded, too much verbal diarrhea!

It would be interesting to measure EGT. Years ago I was researching valve seat recession and found that the exhaust valve temperatures at maximum speed and power were virtually unchanged from the 1930’s to the 1960’s. The reason is that low compression ratio increases exhaust gas temperature while high heat losses reduce it. Compression ratios increasing from 6 to 10 were offset by the lower heat losses of compact OHV combustion chambers after WWII leaving measured peak exhaust valve temps about the same at ~1300 to 1420 degrees. The peak gas temperature should be 100’s of degrees hotter than this.

My assumption that exhaust temp would go down at WOT is based on some data of various engines showing a valve temperature drop of 250 deg going from 15/1 AF ratio down to 12.5. I measured my Packard at 8/1.

In the ideal cycle the EGT is first a function of AF ratio regardless of throttle, maximum at stoichiometric going down richer or leaner regardless of mass flow (throttle/manifold pressure x RPM). In the real engine the EGT drops below ideal from the heat losses to the cooler cylinder walls, valves, exhaust ports and manifold. Higher mass flows have more heat loss but less temperature drop. Whether the EGT drops with increased throttle at constant RPM is a balancing act between the increased mass flow increasing temperature against the richer mixture cooling it after the booster opens. The actual change in mass flow between cruise power at fixed speed of 60 mph and max throttle is probably only on the order of 2/1, and my guess has been that the heat transfer of an engine with fixed coolant temperature and thick cast iron walls is going to have less effect on EGT than an 8/1 AF ratio – but that is just my guess and I could be proven wrong, it wouldn’t be the first time!

Meanwhile I found an interesting tidbit (well interesting to me anyway) of data from an early ’30’s straight 8 engine, probably a Chrysler Imperial engine. The measured variation in AF ratio at a low speed was as high as 16/1 on #2 and as low as 11.6 on #6. It probably would have been better at higher speed (I assume the low speed of the test was dictated by the limitations of the instrumentation). At any rate with that kind of variation one would risk valves cracking and seat recession on #2, and carbon fouling on #6. They were on different branches of the manifold with one branch averaging 14.4 and the other 12.8. The richer mixture was on the branch feeding #1,2 7 and 8, as would be expected trying to compensate for fuel dropping out on the longer travel length.

Jim

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John, I suspect you have some airplane experience since measuring and controlling induction temp is commonly done, particularly for supercharged aircraft engines. I don’t think it would work too well based on the outside surface temp of the intake manifold of a Pierce, since there is so much thermal mass in the cast iron manifold (wouldn’t respond quick enough to changing AF ratio) and its temperature is going to be highly influenced by the heat conduction from the block and the heat from the exhaust manifold. I think you would need a probe in the air flow itself downstream of the carb, and even then it probably wouldn’t tell you too much.

A big problem for long engines such as straight 8’s is the uneven distribution of the mixture from cylinder to cylinder. The fuel is still liquid mist when atomized at the carburetor and being heavier than air the centrifugal and gravitational forces on the drops as they fly around corners and along the length of the manifold effects the AF ratio at each cylinder. The heating of the intake manifold by the exhaust manifold and block help to vaporize the fuel along the way, but a huge challenge for these engines was trying to minimize the variation in AF ratio cylinder to cylinder.

Measuring the exhaust chemistry downstream of the exhaust manifold would only give an average of all cylinders, and one cylinder is probably running leaner than the others. As noted above, running leaner than stoichiometric is the most fuel efficient, but increases probability of lean misfire, maximizes exhaust temp stressing the valves and also provides the excess oxygen that promotes valve seat recession. Because of the cylinder to cylinder fuel distribution problem these engines were set up to run richer than stoichiometric to avoid lean misfire for the leanest cylinder at basic highway cruise power. Maximum power occurs richer than stoichiometric, and typically these engines were set up to run significantly richer than max power at wide open throttle to reduce knock and provide internal cooling. It also produces a lot of carbon from incomplete combustion that fouls the engine and was part of the reason for rapid wear leading to replacing piston rings and removing the head to “decarbonize” at ~15000 mile intervals.

The peak temperature one would expect in the exhaust manifold is not at wide open throttle but probably closer to the highway cruise position that coincides with the throttle position just before the carburetor “economizer” or “booster” valve starts to open up, dramatically richening the mixture for maximum power by dumping excess fuel to cool and prevent knock. Years ago I measured the AF ratio on my ’36 Packard EE-23 with a machine that you could put in the car and monitor while driving. I was a bit shocked to find the “booster” valve opened up at about 60 mph on a level road, and the slightest increase in throttle to go up a grade would peg the AF ratio to less than eight, the same territory one would expect of an aircraft engine at maximum takeoff power. I adjusted the “booster” to open a little later. Even so, I spend so much time at wide open throttle driving up hills at high altitude that the rich mixture always leaves carbon soot on the back of the car. I only worry about valve and exhaust manifold temps cruising down I-5, not climbing hills at wide open throttle.

Bottom line is I don’t think there is a proper AF ratio for these cars regardless of instrumentation beyond a bit of trial and error to keep them a little richer than the lean misfire limit.

I am reminded of my father who flew P-38’s in WWII on long missions where minimizing fuel burn to make it home was an obvious concern. They would slow the RPM way down, go to maximum cruise manifold pressure (throttle), and lean the mixture down to barely above the point of detonation (knock).

Jim

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Sir William: Yes, the Jag is a ’68 series “1 12” which means it has some Series 1 and some series 2 bits, makes it challenging sometimes ordering parts.

The picture was taken last year and the frame was about to be rolled in to re-mate the body to it. I just finished main engine assembly and will be working the transmission/free wheel/power brake assembly next in hopes of engine start in a few months.

Jim

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Yup.

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I am not sure how the factory adjusted them, but by posting how I have done it maybe someone who does know will chime in.

It is a bit of an iterative process because how the body sits on the frame effects the door alignment and so it ends up being a combination of bending the hinges and adjusting the body pads. First I assume the door should have a consistent gap with the body along the hinge side (fwd edge of a front hinge door, aft edge of a suicide door). The hinges can be bent slightly in a press to adjust this gap – a bit scary but I haven’t had one break yet. When those gaps are good the alignment of the latches and wedges is done by shimming the body pads to basically bend the whole body. My ’35 Club sedan has more shims in the middle and a lot of load on the front bolts at the firewall forcing a bend in the body that pulls the door latches/alignment wedges up at the center pillar.

I don’t know if this is how the factory did it. If not I am hoping someone will chime in that has the original, better method!

Jim

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Thanks guys, I feel pretty stupid at the moment, I was so focused on the broken screw head last Sunday I didn’t realize the great big cap screw with shim washer was what would have the spring and check valve. Duh! I have the big cap screw and spring removed now and soaking in solvent. A fair amount of sludge, I’m not sure yet if there is corrosion or wear.

If you guys think the function of the plug with broken head is just to seal a pressure check port then it seems like I can probably leave it alone and get everything cleaned up without trying to extract it. The idea of checking by turning the pump before installing in the engine is a good idea. Thanks!

Jim

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The ball in this first lifter was actually in pretty nice shape, no evidence of wear except the faintest scratches. Replacing it with a new ball didn’t help the leakage. Certainly that doesn’t mean the rest are good and I will check them out as best I can. Fortunately this car had relatively few miles on it and so far no evidence of any corrosion in the lifters.

Rather than build a complete valve body to insert into the plunger, my first attempt will be to cut & lap a new seat in the existing per the original, then fabricate a threaded insert to retain the ball instead of the cross pin. By cutting a new seat a bit deeper, the original cross pin to retain the ball might give the ball too much up and down motion, so I think that needs to be adjusted for.

The trouble and risk this entails is why I don’t take things apart unless necessary. The odds of it being better if messed with are not necessarily better than if left alone.

Thanks, Jim

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Greg, if you have a dis-assembled first design dis-assembled handy I would like to know if the seat is brass and conical- but not worth a lot of effort. I am pretty well stuck with dealing with what I have one way or another. My first pass at cleaning up the seat wasn’t good, looks like it has a defect right under the surface- although extremely hard to see because of the problem of getting light down the hole to see with a magnifier. I may end having to machine a new check valve seat to thread into this body to salvage it, and brass will be a lot easier to machine. In all likelihood even though it leaked a bit it would have been okay as is, but I have crossed the Rubicon now.

Fortunately the next three lifters seen in the picture passed the leak test easily and I won’t have to mess with them.

Thanks! Jim

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The good news is that it really is impossible to match exactly what a car was delivered with. I don’t believe the paint chips were accurate to start with, then they change with time even being protected. same goes with the paint itself, the pigments and mixes weren’t perfectly uniform and if you find someone who can mix the original paint code with original pigments there is no reason to believe they haven’t shifted with time. The best guide is probably paint protected such as being covered by upholstery, but this is simply closer – not dead accurate.

I have gone through over 10 mixes of hues and I can say that to really judge how it looks on the car you have to shoot parts of it on the car. It is amazing how two different colors can look indistinguishable on painted sheet metal samples, and look very different actually on the car. A color that seems wonderful in the can or on a small sample can look hideous on the car. This is amplified by metallics. What I have been doing is using the color books at the paint store, and for metallics have them change the metallic to substitute all the courser grade to the finest grade flakes to approximate the very fine iridescence of the original metallics (I have heard it was actually oyster shell, and the oyster shell deteriorates in the can over a few years).

I sometimes feel I am going blind trying to get a nice contrast (I am trying to approximate the lighter belt molding/modest contrast that were done on ’35’s)

At any rate, as said above, it is your judgement and taste you need to please in the end. Good luck!

Jim

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Tonight I did drive the pin out. There is no spring, and the ball actually is in pretty good shape, no corrosion but some microscopic scratches. Replacing it with a new ball bearing doesn’t stop leaking with air only, but the leakage seems minimal. It is very difficult to get light and magnifier down to look at the seat, but it is just cut into the plunger. It looks like it has some rough spots but I am not certain it is actually from wear or that it just wasn’t that well cut in the first place. It is a question whether it is actually good as new more or less and whether it is worth messing with all of them.

I will probably do as you did and find something to lap the seat with. I understand the Cadillac plungers need to have a new cap machined to get the height correct – seems like more work than polishing seats. Thanks, Jim

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Greg, thanks, I went through the same exercise reasoning the slot should be away from the thrust side, but curiously Packard did the opposite and I was wondering what I was missing. My ’36 Packard(with Egge pistons) has done fine so far (~20000 miles) with that seemingly backwards orientation. Now that I compare the original Packard and Pierce pistons they have a slight design difference that might explain. The Packard piston’s slot does not go all the way to the top of the skirt, Pierce’s skirt is completely slit. Where the Packard skirt is solid at the top I think corresponds with the highest side load when the piston tries to cock in the bore, so there may have reason to the madness.

Thanks for confirming – now I don’t have to pull them all out and recheck bearings!

Jim

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A very curious result in my K-S gas gauge UV exposure test. The fluid in my restored gauge suddenly turned to pale brown in the period of about one week after being in the gauge for a little over two months. That gauge has been protected in the garage without direct sunlight the entire time.

Meanwhile, the two UV test fluids sat in the direct sunlight for over a month with no obvious discoloration.

The fluid in the gauge that turned was probably about 20 years old stored away in a box inside its black light blocking sleeve until I pulled it out in July.

The fluid out in the exposure test was bought new in August.

One of the surprising things was how suddenly the color changed.

Perhaps age somehow plays a role?

Jim

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Ironstone is about the only show I go to. Beautiful grounds, old gold country area, laid back, a very wide range of makes and vintages, race cars but no hot rods more or less, and even has trailers, commercial and motorcycles. This year was the smallest showing of Pierces I’ve seen there, so a special thanks for driving your car up, it was great seeing it!

Maybe some year I’ll be able to drive mine there. Jim

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Thanks, have heard good things about the Atwater-Kent folks. Fortunately I think I have my original sending unit sealed and functioning properly (out of the car). I cleaned up the female ends by kissing with a Dremel conical cutting bit, some polishing compound between the new conical fitting ends and added the Teflon tape. Didn’t crank the fittings down too hard and now have the loss in reading down to 1 gallon in three weeks.

I like to make the originals work when possible, even if they don’t look factory fresh.

Jim

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Jim, yes they have, with multi-viscosity being one of the best improvements. My doomsday bearing failure scenario should be less of a concern now than when these cars were new, however my concern is all the details that go into an engine rebuild that can overwhelm the advantages of things like better oils.

My point of departure on this is that if this was 1935 and my car was factory fresh except for 1000 break-in miles, it should have no problem running at 65 mph with original gearing and all.

Further on the plus side, these engine designs were tested at max throttle and probably ~4000+ RPM, so even running at ~3000 RPM on the highway is significantly below their capability.

However, my Pierce engine was rebuilt by somebody in the ’60’s and about 50 miles were put on it before it was parked again for the next 50 years. All in all the bearing re-babbitting looks good but I can only determine how good the bond is by destroying it, and then I get to go through a few thousand dollars having someone else re-babbitt and line bore it, with no assurance it will be any better than what I have. One thing that is a reasonable assumption is that either way it won’t be as good as the original factory build, so taking precautions to compensate for the likely deviations from the original is what I am about.

My Packard has early copper-lead inserts that were notorious for problems relining. Packard had demonstrated them by running on the test track wide open averaging 92 mph continuously for 7 days and nights. My original inserts were serviceable but had worn the crank, so I hard chromed the crank up to standard and used the original bearings. Hard-chroming the crank weakens it, and I had aftermarket pistons that obviously hadn’t been tested in multiple engines at 4200 RPM as the originals had. For that reason I put in a high speed gear set to slow the engine down.

My Pierce has serviceable original pistons, good crank, a 4:23 rear end but a non-factory re-babbitt job. RPM at speed shouldn’t be an issue if I keep bearing temperatures down and don’t tempt fate by lugging at high load at high temperatures.

With the 50 miles put on it in the 60’s and acceptable but tight clearance my crank had significant drag (>10 ft-lbs) when the main caps were installed and torqued. Babbitt is forgiving, and that level of drag would have probably worked itself out with a good break-in, but I just finished hand-fitting each bearing and reduced the drag to 3 ft-lbs.

Bearing failures on babbitt rebuilds seem to be reasonably common. One of the papers was a by a Studebaker engineer who noted that just the presence of a copper washer in a cleaning solution dipper had disastrous results on a batch of babbitt. Is the guy re-babbitting today as meticulous and knowledgeable as the guy who did it at the factory day in and day out with a process engineer over-seeing? Maybe, maybe not.

As an aside, it is maddening that spell check insists on capitalizing “Babbitt””!

Jim”

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My google skills are lacking! Placed an order, 2.95/vial vs 18.75 plus S&H from C&E. Will be interesting to compare – if there is any difference at all.

Thanks Bill! Jim

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