Changes to 8 Cylinder Engine from 27 to 30

[alsancle]

Does anyone know the basic difference between the straight 8 engine from 27 to 30? My understanding is that they are more or less the same with tweaks to boost the horsepower each year. Is that correct?

thanks, A.J.

[28StutzCabriolet]

A.J.

As you say, there were small changes in the engine over time. From memory: The main change came with the introduction of the of the optional 'Challenger' engine that came out in mid late 1927. The bore was increased from 3 3/16" to 3 1/4" over the earlier engine and the cylinder head was new with larger ports and redesigned valve gear. The intake manifold was significantly changed as well with a redesign by 'Swan'. (I believe.) It is noticeably larger than the 1926 and 1927 and is made in two parts. The carburetor, a dual throat updraft Zenith on all models' was increased in size and an accelerator pump was added at that time. The material on the earlier carburetors and the earliest of these larger ones was made of brass. About the time 'Challenger' engine was made standard on the 1928 'BB' cars, the carburetors were changed to potmetal. These have been the curse of restorers as they began to go bad even while Stutz was still in business. The 28' 'BB' engine also used an air cleaner and had a larger generator than earlier cars. There were optional compression ratios too. The 1929 model 'M' used essentially the same engine as the 28' 'BB', however the bore was enlarged again to 3 3/8" and the valves were made larger. The crankcase breather moved from the right rear to the left front of the engine. I have forgotten which, but I know that some engines (the earliest?) had cast aluminum valve covers. Others are pressed sheet metal. My 28BB has a sheet steel valve cover.

Hope this is useful.

Brian

[alsancle]

Thanks Brian. I have located a relatively complete 27 chassis and engine and I was wondering how many of the parts would interchange to use on my 28. The asking price is 4k which I did not think was unreasonable.

A.J.

[28StutzCabriolet]

A.J.

I am sort of in the same boat. Although my car is complete, the frame is heavily pitted and I would like to upgrade to a better frame if I can find one. I have been offered several 1926 and 1927 frames, but I have passed on them. I am not an expert, however I believe that there are more differences than similarities between 27 and 28. For example, the brakes would be different unless the 27 chassis was updated to the 1928 style Bendex brakes. (People usually changed the whole front end and rear end...) The 1928 transmission uses a transmission lock that is in the center of the gearshift knob. The 27 has the lock at the base (I think.) The front fenders are different, so the holes in the frame for locating the fenders are probably in the wrong place. The radiator and shell would be the same except for the bolt-on water outlets. It all comes down to the engine and whether it is a 'Challenger' or the earlier engine. The photo attached in the previous letter is of a 1928. If the engine has a good Zenith updraft (in brass) with the accelerator pump, that in itself could be worth $1500 to $2000. I would also want to know what the rear end ratio is. It is stamped on the backside of the rear end housing, just to the inside of the spring perch. If you can not find it there, pull the four bolts off the end of the worm (not losing he shims. The rear end ration is stamped on the end of the worm. Most are stump pullers. Mine is the lowest: 5 to 1.

By the way, what kind of 28' BB do you have? Mine is a Phillips bodied convertible coupe. Original colors: emerald green with silver moldings with green stripes and black fenders. Green leather upholstery in the front and in the rumble seat.

Regards,

Brian

[alsancle]

Brian,

Hopefully it is a challenger, although I will probably buy it either way - I seem to only regret the stuff I don't buy as opposed to what I do buy :-). Somebody was going to build a race car out of it so they rear end is some kind of two speed setup with heavy duty hydrolic brakes. Fortuntely I don't need any back end parts.

My car is the "Schumacher Special" from a previous thread. Check out www.townisp.com/~alsancle for pictures and history.

The numbers stamped on the right rear axle housing of my car are as follows:

On top, one of the following CV0, JV0 or GVC. On the bottom, 349. Do you have any idea what those mean? I do know that 2.7 turns of the drive shaft result in 1 turn of the wheel.

A.J.

[pughs]

The aluminum valve cover was used up to engine number 85502 with the stamped cover used thereafter.

Steve

[Ivan Saxton]

The 1927 AA parts book I have shows the change to 3 1/4" bore came after engine#84860. The change from SV5D to 105D was after "approx" engine 85500, which corresponds with when Steve says the valve cover changed from Aluminium to pressed steel. The book also specifies different heads for each type of valve cover. This could have been due to difference in ports and inlet manifold. One head I have has different ports for different exhaust crossflow for intake heating, but I have no idea whether it is early AA or later M series.

The aluminium cover can definitely be used on the later BB head, because Bill Kerr used one on his lowered shortened "hotrod" because he liked it better.

You might pick the change point to the "Challenger" engine from a BB parts book through the change in camshaft number. There was a very noticable change in valve timing, but none of them was very good by our modern standards. It is possible to regrind the better camshaft to get some overlap. However once you change the valve timing to give better breathing you certainly have to make bigger venturis, and doubtless change the jet sizes too. I suspect the carbs may not necessarily be well matched to modern fuel, and who knows what the composition was then or may vary now. In the 1970's we had the man who was service manager at Barlow Motors in Melbourne to one of our regular meetings of the Stutz Owners' Register. He told us that they expected 17 miles/Imperial gallon of the big sedans around town. I think you would be happy if you got that now. One of about a dozen of bronze replica 105DC carbs I made up for people a few years ago was for a Lancia Dilambda, which had an extra feature which gave better economy. When I need to make carbs for my own cars I'll do this. There is a lot of "knife-and-fork" work in copying all the detail and making them functionally accurate. When I measured the length of orifice of original jets they varied surprisingly. I dont know it this mattered, but I made mine all identical. Incidentally, in the 1960's, you could still detect trace of black enamel finish on some diecast 105DC's. I had a bronze 105D for one of my cars, but there was detail difference that I reckon was better on the diecast ones; so when I started making replicas I let that one go without regret.

There are differences in the cylinder block castings, and also the main bearing caps. M series have a pair of cast gussets from the back of the block onto the bellhousing, if that description makes sense. The cores for the water jacket changed as the bore increased, reducing the gap between the cylinders.

Engine 91845, with casting date 26th of March 1928 has a single strengthening rib on the centre main bearing cap. Geoff Ringrose told me his engine, which was close to mine, BROKE the cente main cap when he was out on an event.

Engine 92335, cast 9th of May 1928 has a much stronger centre cap with two strengthening ribs. So the company must have encountered the problem, even if it might rarely happen. Perhaps this may be a clue to why the car failed so unexpectedly in the match race with the Hispano at Indianapolis. If a main bearing cap broke, and they had to keep going, it would be pretty much inevitable that there would be reduced oil pressure and conrod bearings would eventually start to fail. The white metal big ends are OK with scratch tinning of the dural rods with pure tin, but the grip is tenuous at worst, and I have peeled original whitemetal linings out with a pocket knife. You only can guess whether the bond was not perfect always, because they had not the methods of testing that we may today, or whether it deteriorates with age. If the bearing comes loose it ca lock or drag on the crankpin,and bend the rod which will eventually break and ventilate the crankcase. I have seen the consequence of this where some idiot drilled a few 3/16th holes into the rods and poured the big ends without tinning like the practice in some big old stationary engines. I really have much greater faith in these alloy rods when I saw what a pouding they could take before one failed. The only ones I would never use personally are the later rods from M and L series, which have steel caps. Every one of these that I have is crcacked from under the inner side of the bolt heads. Now the book strictly says that you should tighten the bolts with a spanner 6" long. (Even this could give a big variation of tension between operators). Now on a steel conrod, a correctly tightened bolt is stretched within its elastic limit.

An alloy rod is much softer that the steel, so the elastic stress is in compression of the alloy. When they changed the cap to steel they reduced the length of alloy to compress by about 60%, which introduced a new problem.

To revert finally to blocks and main bearings, my DV32 engine #DV30004 is a BB pattern block cored for 3 3/8"bore with "SPECIAL" cast on the left of the block upside down. Casting date is 27th of June, 1928; earlier than two late BB engines I know. Main bearing caps are all massive; possibly 3-4 times as strong as standard.

Now if you read the Stutz chapter on Stutz in John Bentley's 1950's book "Great American Automobiles" he quotes a company statement that they tested cars for two years before the DV32 model was introduced. It is likely that the DV32 was pretty much designed before Lockhart blew his tyre at Daytona. And far from copying the J Duesenberg as people in the past have suggested, it is certain that Stutz were running DV prototypes round town at the same time as the very first J model.

[Walter_b]

I have what I think is a 1929 Stutz or maybe a late 28 as it is titled. I was told its a BB 5 pass. sedan,but its a 2 dr. Its in very good codition--Would really like to sell or trade it. I live in Sun City, AZ. Thanks,Walter

[alsancle]

Walter,

Post a picture and I'm sure somebody can help identify the year. The BB is 28. You can tell for sure by the serial number which if not on the title can be found by removing the rear bumper and looking at the right frame horn where the bumper mounts. The engine has a number stamped on the plate attached to the valve cover. As engines maybe swapped this is not always full proof but thats easier to look at then taking off the bumper.

A.J.

[Walter_b]

A.J., Thanks for your reply, I tried to put a picture on the picture post. I will check to see if it is there. This car looks completely original and almost perfect. The number on what looks like the overhead aluminum cam cover is 89827. It has lots of other numbers on it, on the fire wall - engine, etc. It's been very hot and rainy here in AZ, but I will get out tomorrow and crawl around the car some and see about getting some more numbers. Walter

[K8096]

Looked at your picture in the photo gallary. Your car is definately a 1928. It has early style radiator shell, bumpers, 1928 only headlights too. Should be short wheelbase of 131". I don't know what Stutz called that body style, but it's basically a two door sedan. What kind of money are you talking?

[Walter_b]

This car is in really good condition and drives very well. I think $35K is more then a fair price. I would entertain a trade on a another pre-war, late 30s, early 40s. If anyone has any interest my phone number is 623-972-0072, my cell is 623-698-3001. Thanks. Walter

[John B]

I am possibly interested, please e-mail me at fabricator813@yahoo.com