9 replies to this topic

[m9a3r5i7o2n]

V-8 Engine Oakland-Pontiac 1930-31-32
After two years and four months of trying to get enough information about the Oak-Pon engine I have finally got the Shop Manual, the Fundamental Pamphlet and the Instruction for the Owners in CD form which is one tough job in total. Just procuring one is difficult as the Pontiac Oakland International Club doesn’t seem to be very well manned by professionals. POIC needs to have people just in the , “Cars before the 1955 V-8 engine” division. Even after joining the POIC it is almost impossible to get books out their library. Maybe moving to Florida is the answer.
After getting all this information I have to stick even more firmly to my original statement that Cadillac and Buick were worried by the Oak-Pon engine and put a lot of pressure on GM management to force Oak-Pon to drop it.
One of the things that took me a long time to understand was the spark plug placement in the “L” head engine. It was situated in the an area above the parallel plane of the cylinder head itself and not similar to later “L” head engines. This may have accounted for the peculiar horsepower curve between the 190-31 V-8 and the Pontiac of 1932. Also there was a change in the compression ration that accompanied the spark plug change from a 18mm “Metric” to the more modern 14mm “Metric” style. Both of these types of plugs I have in my possession and making double size sketches of them to clarify my assessment of their worth. One thing very noticeable is the 14mm must have been much less expensive to manufacture and also more efficient in usage. Another item when comparing this plug with modern plugs one can’t help but notice Plugs are not much different from the 14mm plug. Whether AC was the first to do this I doubt but compared to the old demountable plugs the total price must have been about ¼ the cost.

The place where the plug sat when looking from the side view was a Trapezium. I have as yet not been able view the 1932 Pontiac head but it seem to have a lower horsepower RPM than the Oakland head and still puts out 1 more HP , a peculiar happening. There is one somewhere in Montana but I haven’t been able to view it as yet.

After putting the books and the pamphlets on a series of CDs, and if anyone is contemplating putting 413 pages on CDs I advise them to have plenty of time as old manuals are a jockeying of pages to get them to look like something worthwhile. Using anything beside a flat scanner is useless and the result is an even worse result than what you started with. Finding an original set of Shop Manuals is impossible but had someone of sold me one or even loan me one now I could correct all the mistakes made in this one, altho it is a serviceable result. It took 6 Cds of the RW 70MB Data type. I haven’t added up the total of MBS but it is much lower than this as none of the CDS are full.
Probably more to follow, M. L. Anderson

[Ray Bell]

Nice to see you back, Marion, and nice to see you're still on the trail of this interesting engine...

But why the change of identity?

I've been interested to hear from you because I've become very interested in the Simca Vedette family of engines, particulary as used in the Brazilian cars at the end of the sixties.

e.mail me at raybell@racingphoenix.com if you'd like some further detail...

[Arthur Anderson]

Hi Marion!

Welcome back.

Interesting treatise on the spark plug placement on the Oakland/Viking V8's. I have always pretty much imagined that combustion chamber design was as much as "by-guess-and-by-God" in even the late 20's and early 30's, certainly up until Charles "Boss" Kettering's laboratory created a workable glass porthole in a cylinder head to allow actual, visual observation of the flame pattern upon ignition, and certainly before the advent of computers.

Even with a growing base of data that had to have been circulating around S. A. E. and their overseas counterparts regarding the design of combustion chambers, I would guess that all of it pretty much was gathered from months, if not years, of creating varying designs, making prototype cylinder head castings, installing them, and noting the readings on the dynamometer.

Of course, the now-pretty much discarded idea of valves being placed at rather oblique angles to the combustion chamber, nearly horizontal in a Vee-engine (also used in the Auburn-Lycoming V12, and I believe also in the Pierce-Arrow V12 (both of which engines survived in production well into the 1960's powering American-LaFrance and Seagrave fire engines respectively) must have had some deleterious effect on the power output of this engine (as it must have in the two V12's I mention), due to the rather great volume of the combustion chamber, and an (by later flathead standards) extremely odd-shaped chamber at that.

Art

[marion5drsn]

COLD
G1
G-1 ½
G-2
G-2 ½
G-3
G-3 ½
G-4 =K-4
G-4 ½
G-5 =K-5
G-6
G-7 = K-7
G-8 = K8
G-9 = K-9
G-10 = K-10
G-11 = K-11
G-12 = K-12
G-13
G-14 = K-14
HOT

After studying this sparkplug situation for some time and drawing sketches of them from G6 to G14 a lot of little things become very apparent . An actual group of eighteen plugs in all.
# 1, The sparkplug design group at AC was working overtime to come up with plugs easier to manufacture. One can’t help but notice that the rolled over area to hold the insulator in position was much cheaper to do than the two piece body of the K series. Also the effort to get rid of the small brass terminal at the top of the plug by making it integral to the center electrode. This with no threads needed to screw the terminal onto the plug. A small thing in comparison to the complete car but a cost reduction never the less. Also the amount of machining was reduced by eliminating the unnecessary angles, different radii and outside diameters on the plugs.
# 2, The older plugs were of a very narrow heat range and the newer plugs seem to have a larger heat range. That is the old G series versus the newer K series see above. They dropped the colder plugs below K-4 a reduction of four plugs.

The AC group may have been copying other manufactures but the advances were larger than likely at any other time at AC. After making the 14mm plug with .500” reach on the 44,46 etc series only small changes seem to have occurred this was about 193? .

M.L. Anderson

[Arthur Anderson]

Wasn't the Champion K-4, even though a 2-piece plug (an inner plug, with machined steel ferrule, an an outside hex-head plug into which the inner was threaded from beneath, done this way? I have some OEM Champions of this model in a lock N store, but haven't even cracked open the carton since I sold my last Model A Ford some years ago. Champion's K-4 was the OEM plug for the Model A, and I believe the Model B 4-cylinder as well.

Art

[marion5drsn]

Art; Tracking down the old AC G-series plugs is a job in itself, I wouldn't even consider trying to track down other plugs altho the owners of the old Oakland V-8 do use Champion D-21 plugs. I believe I will see if I can find someone who will sell me just one Champion D-21 to compare it to the original G-12 used the Oakland V-8. This plug was 18mm and was listed as a .500” reach but had an extended skirt to project the firing electrodes into the combustion chamber by .075”. It appears to me that just what the engine needed was a very long extended plug similar to the Denso Extended KJ20CR11. But plugs of this type were not in use or possibly not even thought of at that time.

I am still working on the possibility of finding a 1932 Pontiac V-8 cyl. head which used the AC K-12 14mm .375” reach plug and also see if the head had a more “modern” combustion chamber. I would bet that it hasn’t a “buried” spark plug!
That weird horsepower curve came from somewhere.

M.L. Anderson

[marion5drsn]

I have finally purchased a Champion D-21 sparkplug for $2.86 and the way I see it is not the correct sparkplug for the old Oakland V-8 engine as it does not have the extended or projected firing tip by .075”. The .075” may not sound like a lot but it is a ton in the measurements on a sparkplug. It also has a flat ground electrode and not the round electrode of the G 12 of the old Oakland. A significant improvement. A .875” hexagon instead of a 1.000” hexagon.

Next step is an AC C-88.

M.L. Anderson

[m9a3r5i7o2n]

The best picture I have seen of the 1930-31-32 Oakland-Pontiac V-8 engine.

http://home.comcast....landVEight.html

M.L. Anderson

[Ray Bell]

I'm hoping to do better than that in the near future, Marion...

The car that I photographed and which started you on this quest is going to come within the ambit of my stories about classic cars for a local magazine. At that stage we should get the engine well and truly exposed, probably get shots of spare engines and parts.

[m9a3r5i7o2n]

Ray Bell states;
I'm hoping to do better than that in the near future, Marion...

The car that I photographed and which started you on this quest is going to come within the ambit of my stories about classic cars for a local magazine. At that stage we should get the engine well and truly exposed, probably get shots of spare engines and parts.

Ray;
#1- One of the big problems of getting good pictures of the engines etc. is that the owners never seem to get the idea until the whole project is put together and then it is too late to get a picture of the Synchronized Vibration Dampener. It is almost impossible to really see the Synchronizer after the engine is in the car. The radiator, fender, frame and some other stuff is in the way. Make sure that he understands you want pictures of the project at “ALL” stages of assembly!!! Of course the Synchronizer is the main place to get a good picture. From my judgment the radiator must be out of the way and it wouldn’t hurt to get some pictures before the fenders were in place.

# 2-If you can also get pictures of the camshaft and rocker arm cage that also is very interesting.

# 3- I have a very good picture of a rocker arm lying of a table and it really shows the details.

# 4- One of the places that I believe the factory didn’t do right is the end of the valve lash adjusting screw. They should have placed a flattened ball in a cup so the rocker arm was always striking the valve end with a flat instead of a radius. Pontiac did this on some of the later side valve engines.

#5-See if you can get him to give you a ride in the car only if the Synchronizer is working properly, I rode in one and was surprised at how well it rode.

#6-I have never seen a good picture from the top of the engine. It would take two pictures to do this properly as the air cleaner is in the way of a large portion of the engine.

#7- Most people do not understand that the control of light is the most important thing in getting good pictures, that is why I was surprised when I received the Arnold Landvoigt picture of the engine with the hood still on the car. He must have got it with the sun shining into the engine area just when he took the picture. In addition to using a flash it must have been well back lighted somehow! I am writing him today to ask him just how he did it.
M.L. Anderson