DavidMc

Jon, Would you care to elaborate on what you mean by " heat soak" issues as opposed to vapor lock . I guess you are talking about what happens when the car is stopped after a hot run and will not restart until it cools, due to what I would have called vapor lock. I am interested to know how it differs from vapor lock. It is my understanding of what we are all talking about here is fuel that cannot be pumped due to the formation of vapor bubbles in the fuel lines. If vapor is forming in the carburetor float bowl then the situation is different and the venturi probably draws off either pure vapor ( with insufficient energy to keep the engine running) or a mixture of liquid and vapor causing that jerking effect that happens some time.

Joe, No problem plumbing a return line back the tank but how do you determine the size for the restriction orifice needed in that line to ensure that the return flow never starves the feed to the engine? The attachment to post #13 deals with this but its not simple. I have learnt a lot form the information being exchanged here and the attachment from Spininghill regarding the effect of ethanol on RVP is particularly interesting and surprising.

I had a restoration project years ago that had one of those devices fitted, I never figured out how it worked but it was not correct for the car so I replaced it with the correct Stewart Warner vacuum tank. It would still be interested to know how they work.

Some interesting information here but keep in mind that Tom’s original question was for ideas that work particularly the use of additives. More comment on this would be of interest. However picking up on some of the information, one of the main ideas that comes up every time vapor lock is discussed is avoidance of ethanol containing fuels and yet we learn that ethanol has a higher boiling point than the lowest boiling point fractions of gasoline which would lead you to conclude that ethanol fuels would be less likely to cause vapor lock. Are we just biased about ethanol because of its other negative effects? My experience has been that it makes the problem worse but there is no doubt it is not the sole cause, any fuel will vapor lock in my cars under the “right” conditions. There is no practical way, when you are experiencing the problem, to experiment with different fuels, you go for what you hope is the best available. Another comment that resonates with my experience is “……..fuel from the pump “dead-heads” against the metering device on the engine, waiting to be used. This is a hot environment, and the fuel gets hot while it waits to be used” There is fuel in the engine bay moving very slowly through to the engine. It is subject to high under hood temperature and radiant heat from the exhaust manifold. The low flow rate allows plenty of time for the fuel to get hot. The stored volume in the engine bay is large especially on car with vacuum tanks. A solution is to fit a pump that keeps the fuel in circulation back to the fuel tank. Ideally we want all of the fuel not flowing to the engine to be flowing back to the tank but there- in lies the difficulty. The fuel flow rate to the engine is very variable over the range from idle to full power at high revs, but the return flow to the tank will be at a fixed rate. That fixed rate needs to be restricted so that it does not starve the engine under any condition - with some margin for error. This idea is discussed in great detail in a much earlier thread: http://forums.aaca.org/topic/213513-modern-fuel-vapors-and-a-54-bentley/?page=2 A problem with assessing vapor lock cures is you cannot try something then drive the car down the road to see if it works. The car may drive well for a long time until the conditions tip it over the edge. I have friends who have made some change that they are convinced has cured their vapor lock but they rarely drive the car. Some long time later it is typical to find that what they thought was a fix did not work. It’s a difficult issue and one that generates differing opinions a bit like the “what is the best oil to use” subject. When the weather is very hot and I am on tour my best fix has always been to add as much kerosene as possible, I don’t know why it works but does.

Tom , In answer to your question about additives I have found adding kerosene reduces vapor lock, I haven’t tried Marvel Mystery oil as it is not available here in Australia. Others have reported improvements with Diesel fuel but when I tried Diesel, it made no difference. The problem with Kerosene is you need to dilute the fuel with at least 10 -15% for it to be effective and if all of the conditions are against you nothing works and I have tried everything. I have relocated the fuel line away from the exhaust system, fitted heat shielding, fitted a bypass electric pump removed the engine trays to allow more cool air around the engine, raised the leading edge of the hood to allow more air flow into the engine bay. But on a hot day when in stop start traffic or on a long climb none of the above are sufficient and a wet rag around the carburettor is needed but that is very temporary . I have been on tour climbing and had to keep wetting the carburettor every 100 feet or so- not fun when there is no overtaking lane and traffic following. Fuel is made up of many fractions with varying boiling points and the lowest boiling point fractions boil at very low temperature. Adding kerosene does not change that but even though the theory may be unclear it has on many occasions been the only way I could keep running. Again I do not dispute the theory but I have found that octane rating makes no difference but 10% ethanol certainly does and must be avoided in hot weather. In winter my cars will run perfectly on any fuel including 10% ethanol and, incidentally they run fine on 10-15% kerosene and I suspect would run fine on 100% kerosene once hot. My cars are Packards of the 1920’s. I have restored three and driven them all extensively over the last 30+ years and they have all vapor locked under the same conditions. Stop start traffic & long climbs. This is not a new problem. I have copies of letters written by the Packard Motor Car Company to its dealers regarding the problem. The first was written March 17 1930 headed “ Boiling Gasoline”. Some quotations from that letter are interesting: “The combination of high operating temperature together with blended fuel including very volatile fractions has in some cases caused trouble through the boiling of fuel in the vacuum tank, the carburettor and the line connecting these two units ……” A minor modification was suggested in the letter. However, a further letter was sent to the dealers some 16 months later dated July 31 1931 advising that the previous modification needed to be replaced with a more drastic change where the carburettor float bowl needed to be fitted with a vent connected to the intake manifold. In that letter Packard referred to the above letter and stated in part: “It will be well for you to read this letter again because the situation has become even more serious. The gasoline on the market today is more susceptible to vapor lock than the fuel of a year ago and the corrective measures at that time are not adequate today. The problem of high volatility fuel is far worse today that it was in 1931 as modern fuels have become increasingly volatile which is not a problem for the cars of today as they operate with fuel under high pressure where the boiling point is far higher. The problem seems to worse on some cars no doubt due to the proximity of the fuel system to heat. The Packards have the vacuum tank over the exhaust manifold which combined with high under hood temperatures makes the problem worse than on cars where these conditions do no exist. It is quite possible you will not have a problem particularly if you can keep away from hills and keep the car moving to keep the air flowing through the engine bay. Good luck with your tour, let us know how it went.

Regarding the rubbing issue, there is an adjustment bolt/stop on the hub . This can be adjusted to prevent rubbing on full lock at the expense of a slight increase in turning circle. I don't think you will have a problem with the slightly wider tire.

Rick, Your Maxwell seems to be coming along very nicely,. I don't think you can check the band linings without major dismantling but I would expect yours to be fine otherwise you would run out of adjustment.. although I have no experience with heavily worn linings, hopefully others can advise. I am not aware of a published valve clearance I set mine at about 0.010", I don't think its critical just so long as there is clearance at all times. The adjusting nuts are easily accessed. The original axle bearings are large Hyatt rollers and they have no inner or outer hardened seats they simply roll on the inside diameter of the axle housing and the outside diameter of the axle neither of which are hardened so if they have not been regularly lubricated the housings and axles wear. When I got mine it had huge play of 1/16" - 1/8" up and down movement of the wheel. I sleeved the axle housings along with new axles to take modern bearings. If there is no play in yours then that is a big bonus but you will still need to make sure that the planetary gears are lubricated as Frank has said. This is where there are some differences between the models. The planetary gears are encased in a sealed housing that is lubricated separately from the bearings and ring and pinion gears. On ,my AC the planetary housing has two halves bolted together so it can be stripped for inspection , but I think Frank will confirm that on his LD the case is riveted together so it cannot be stripped. . Whatever the design of yours the rear axle unit needs to be checked to ensure everything is lubricated and if your lucky not badly worn. David

The larger section tires will probably fit the wheels however if the car has side mounted spares you need to make sure the wider tire will fit in the well. I would talk to the tire suppliers.

Rick, Where to start, firstly when it comes to photos Frank is the man, he photographs everything as he goes. I bought mine from US as a "fully restored car" expecting it to need some minor work however it had been nicely cosmetically restored but very little had been done mechanically. The cylinder bores were heavily corroded and so I had a full engine rebuild carried out, sleeved the bores back to standard, new aluminium pistons from Arias (with oil rings), A model Ford connecting rods, crankshaft ground and new babitt bearings.. The original connecting rods have a hinged big end and they are very heavy, the A Ford rods are interchangeable with minor work, half the weight and have a conventional 2 bolt big end cap. Modern oil seals were fitted at the front of the engine and rear o the transmission, taking care to ensure that oil grooves allowed oil into the bearings. The transmission wasn't too bad, the bands had been fitted with new linings made from wooden segments as original and the final drive clutch plates were good. The previous owner had converted the universal joints to modern needle roller units using a kit that is (or was) available in US. The rear axle was a disaster and it has been a major problem for years, I have lost count of the number of times I have had it apart and it still makes more noise than I would like. I had a new ring gear and pinion made, the previous owner made new axles, I have fitted new modern axle bearings and thrust bearings. Replaced the original pinion shaft brass bush with 2 modern roller bearings and modern oil seals are fitted at the pinion shaft and on the axles at the wheel hubs. The rear axle design on these cars is awful to use polite language! Getting the pinion to ring gear alignment correct, under load is difficult to say the least. The ignition system uses a 6v AC dynamo (LV magneto) with coil points and condenser for running and a small 6v battery for starting. It s a waste spark system, both spark plugs spark on each stroke. The original carburetor can be made to work, mine has a modern Amal. That's a quick summary of the main issues over the last few years work on the car, I am happy to share any details that may arise with yours which hopefully will not require anywhere near the amount of work mine required. Photo attached. Mine is a 1912 AC which was the last of the 2 cylinder models. Its mechanically the same as the AB and very similar to others with the 4.5" bore and virtually the same as those with the 4" bore. The body however is very different. David

Rick, In my experience overfilling from excessive use of the drippers is not a problem, the oil will build up in the transmission and leak out, I have never drained off excess oil even after driving with the drippers running excessively. Due to the slope of engine/transmission to the rear, excess oil will be at the rear of the transmission, mine has a small screwed plug in the transmission cover towards the rear, it also has a small filler tube in the top of the engine, they can be used to insert a wire dipstick, neither of these are original. The plug at the rear is worth having as this where most of the oil accumulates . The engine oil level on mine is always very low, which used to worry me but it is obviously not a problem and is normal. It is interesting that your car does not leak a lot, I have done everything I can to reduce leakage including modern oil seals to the front and rear bearings and a seal where the shifter shaft enters the transmission case and it still leaves a small puddle when standing. It was much worse before these modifications. If mine was not leaking I would be worried that it wasn't getting enough oil. David

Rick, If your car still has the original pistons and rings it will not have any oil rings so a little smoke is normal . The following comments in the instructions for the 1911 AB, about the operation of the drippers, would apply to all of the 2 cylinder models: "Never feed less than 20 drops a minute through each oiler. No hard and fast rule can be laid down as to the exact amount of oil to feed. Probably the best plan is to regulate the flow until a light blue smoke is seen coming from the exhaust then cut down the supply to a point where the engine just does not smoke" I have oil rings in mine so it does not smoke. The use of oil rings is a topic on which opinions are divided. David

Rick, Firstly I love your car it looks like a great unmolested survivor. When I first got mine in about 2008 I spoke to Penrite about the appropriate oil and bought some of what they recommended at considerable expense then it was pointed out to me by a Maxwell owner that these cars get a constant oil change as they drive - marking their trail as they go, and any modern oil is vastly better than what was around when they were built. So I now run whatever multigrade engine oil is on special at the supermarket and make sure the drippers are dripping well, (when I can see them). The drip rate is specified in the early Maxwell literature (20 drips / min?) but in my experience it is impossible to achieve, it varies widely depending on engine speed etc, I adjust mine often when driving and lubrication seems fine. So long as the oil flow keeps up with the oil loss. Mine has now done at least 6000 kms on this oil since I rebuilt the engine and it still has excellent compression. David

As Friartuck says " The intent here is not to cook the battery...." Keeping to a maximum of around 8 amps also prevents cooking of the generator. On my first project may years ago I set the third brush to give about 15 amps (maybe more it was a long time ago) and the generator eventually overheated and solder melted out around the commutator. . Once it was repaired and the set to about 8 amps it has never given a problem. There is no cooling on those early.generators

Rick, you will need both ignition and fuel set right for starting, because the engine is more forgiving when already running. The model AA will have the 6V low tension magneto (Splitdorf model H), a fixed (not trembler) dual output ignition coil and condenser, and points in the back of the LT magneto. Do you have this original equipment, because the arrangement of your car will determine the response. Check the ignition first. With the plugs out, ignition wires connected and lying on the barrels (jugs), a quick flick of the starting handle over top dead centre should produce healthy sparks at the plugs. If not, rectify this first. The ignition system is quite fussy about the components. Do you have the original block coil and plate condenser encapsulated in the switch box on the dash? Under the lid of the switch box can you identify 4 copper strips that come up from inside the box to screw terminals? Two of these strips connect to the ignition coil, The other 2 are the connections to the dry cell battery which is mounted under the seat. The ignition is easy to fault-find and if set up correctly, the carburettor then is not troublesome, it may just cause rich running. So let me know what we are facing. Looking forward to hearing from you. Frank

Rick, Thanks for the feed back on the clutch, glad it is working. I flood the carburetor then turn it over 2-3 times with the ignition off then set it on full retard , battery on, and it starts easily (most times!). However I gave up on my original carburetor and have fitted a new Amal motor bike carburetor. I have the ignition timing set at about 2-3 deg before top dead centre which gives a 35 deg BTDC fully advanced. It runs best at full advance. I have a friend with an LD who has persisted with the original carburetor and now has his starting very well. I will pass your question on to him and he may be able to offer some help in setting your carburetor. David

Rick, As you know, top gear drives through a multi plate clutch, low and reverse gears use bands. The plate on the top of the transmission needs to be removed to access the clutch from inside the car. The fingers that depress the plates to engage the clutch are pivoted on a star shaped piece threaded onto the output shaft and are held in place by two set screws with lock nuts. There are a number of machined flats on the threaded shaft to receive the set screws. The fingers bear on a hemispherical nose and they need to ride over the round part just onto the cylindrical part to engage top gear when the gear lever is in the top gear position. With the top of the transmission removed and the gear lever in neutral, the set screws and locknuts are loosened so that the finger assembly can be rotated on the threaded sleeve. Turn the finger assembly so that when the lever is moved into top the fingers ride over the ball shaped part just onto the cylindrical part. It will need a firm shove when the adjustment is correct. When tightening the set screws, the finger assembly may need to be rotated a little so that the screws do not bear on the thread of the output shaft. When engaging top on the road the engine revs need to reduce to around idle speed before the clutch will engage, at least that is the case with my AC. I hope that makes sense, some trial and error may be required . David

This company offers a reproduction Packard voltage regulator, they were not very responsive when I tried finding some details. It would be good to know if anyone has used their product. http://www.mykmlifestyle.com/

Mal, No problem and while we are at it how about a ride in your '41. David

Tom, Glad you enjoyed the ride in the '29 Packard in Sydney, I wish I could do the same for Kristyn's dad. David

The spark plug is a 1/2 inch tapered pipe thread. This is the same as used on the Model T Ford, the ones in my 1912 Maxwell AC are Champion 25, readily available from T Ford parts sources. The Maxwell Yahoo site contains a wealth of information on questions like this if you scan "Conversations". https://groups.yahoo.com/neo/groups/maxwellbriscoeowners/info

We call them Welsh plugs here in Australia, no idea why.

Try this supplier. I have not tried them and have heard mixed reports. http://www.classicandvintagebulbs.com/

This company makes some lap rail hardware see pages 16 & 17 http://www.antiqueautotophardware.com/2016%20Catalog.pdf

The hood profile looks similar to the Packard which is probably what made you think its a Packard, if you post the photo in the "Photo & Video Forums" under "What is it" you are sure to get further comments.

I believe it is a 1926 Buick