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W5 Cylinder Head Differences

Below is a photo of two W5 heads. The top one is marked W5A with a casting date of 8-23-27. The bottom one is marked W5A with a casting date of 5-17-28.
The combustion area depth, measured near the spark plug hole and on a centerline with the other spark plug holes, is .875 for the top and .968 for the bottom one.
Both heads measure a total thickness of 1.916.

Is the bottom head considered a later model "higher compression" version? And when were they first used?


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Do You own a car built by Durant? '23 Star Touring, '27 Star Coupe

Re: W5 Cylinder Head Differences

HI DON INTERESTING YOUR HEAD POSTING .IT WOULD BE INTERESTING TO CHECK THE CC VOLUME OF EACH HEAD MY GUESS IS DETONATION RUN ON AND BACK FIRING WAS EXPERIANCED WITH THE UPPER HEAD FROM CARBON DEPOSIT. AND THAT COMPRESSION RATIO IS ABOUT THE SAME BRIAN

Do You own a car built by Durant? 26 STAR 6 SEDAN

Re: W5 Cylinder Head Differences

That may well be. There is plenty of room to collect carbon on the top head, especially with the crappy fuel they had back then. Also, '27 was about the time Ethyl additive was being introduced for higher compression engines.

Do You own a car built by Durant? '23 Star Touring, '27 Star Coupe

Re: W5 Cylinder Head Differences

DON CHECK YOUR EMAIL FOR MY CORRECT PHONE #. I MUST BE SUFFERING FROM DETONATION IN THE BRAIN BRIAN

Do You own a car built by Durant? 26 STAR 6 SEDAN

Re: W5 Cylinder Head Differences

Hi Don, If you have vol 22 Feb 1998 number 4 of Durants Standard, page 21 has a small article on these heads. My car has the full chamber cast 601NB. The partial chamber cast 505A may have come later for higher compression ?? My car is a 25 Star Touring.
Hope this helps. Glenn

Do You own a car built by Durant? 25 Star

Re: W5 Cylinder Head Differences

I would guess the total volume is quite similar. What they give up over the piston, they take more over the valves. If the total volume is similar, the compression ratio would be similar.
Most likely, they made the change to improve "breathing" Flow to and from the valves would see less resistance for the head with the deeper part over the cylinders near the valves. Some old flathead blocks were also "relieved" to do this. Power depends on how easily you can get more air-fuel mixture into the cylinders, and likewise, push out the exhaust gases with less resistance.

Do You own a car built by Durant? yes

Re: W5 Cylinder Head Differences

HI CDMN NOW WE ARE TALKING LIKE HOT RODDERS .IDO NOT DELIEVE THE REASON TO INCREASE THE SQUISH OVER THE PISTON WAS TO IMPROVE PERFORMANCE.I THINK IT WAS TO STOP DETONATION AND TO STOP KICKBACK DUE TO CARBON DEPOSITS.THE PERFORMANCE THEORY I BELIEVE ON A LOW COMPRESSION ENGINE NOT TO BE IN COMPETITION ISNT VERY LIKLEY. REMEMBER THESE ENGINES WERE STILL BEING CRANKED BY HAND MUTCH OF THE TIME.FORD FLATTIES HAD VERY STRONG STARTERS VACUME ADVANCES AND CENTRIFICALE ADVANCE SYSTEMS TO HELP STARTING. JUST ONE MECHICANICS THEORY BRIAN

Do You own a car built by Durant? 26 STAR 6 SEDAN

Re: W5 Cylinder Head Differences

Don, Thanks for the onfo on the w5 head. I think I made a mistake as mine is a W8 head. It has a W8A 608 stamped on the head. The number on the gasket is 5626. It is still on the motor, but it looks more like the top photo. My distributor goes through the head between cylinder two and three.

Do You own a car built by Durant? 1930 Durant coupe 407

Re: W5 Cylinder Head Differences

My Dad raced the W5 Star engine in his midget in the late 30’s and my uncle said that the engines were well know for there endurance cause of there fully pressurized oiling system and design. He also stated they were plentiful and reasonable priced in junk yards and that my dad had installed Buick valves and went through the block in one valve area but forge heated it up and filled it with weld. He also said he welded up a stock cam to wide lobe and high lift as the tappets will adjust enough and there is plenty of room up in the head for the higher lift cam. They also milled the heads a lot he said and built headers and custom dual down draft carb manifold. My uncle also said he got fill checked a lot cause of the speed of his car. We have a number of articles about his racing and his car and being know as the father of a double set of twins. This information has led me to do a number of things to our engines to gain some more horse power. The quickest and most inexpensive thing to do is mill the head at least 100 thousands. Now Don your top head in your pictures is the head to mill and use as you gain the a lot more increase of compression cause the whole area is lowered down closer the piston head reducing volume the most. Also have a cam shop regrind your cam to more duration and higher lift. I have never had a valve hit the head yet. If you volume check your two different designed heads you will find they are almost exactly the same volume stock. One other helpful trick is to ream out all the ports in the block and manifold intake of course and exhaust and enlarge the holes in the gaskets as well and then polish everything. To go further bore the cylinder holes to at least 60 thousands and most blocks can take 100 thousands easily. Another horse power help is you also can specify a three ring piston instead of the stock 4 ring ones. That one extra ring cause’s a lot more drag and are not necessary. Next is to get a bigger new updraft carb that Frank Witkowski sells. Now after all this your bearings will have to be in good shape or repoured. You should also have your rods x-rayed for flaws and then peened for strength. You will be shocked at the horsepower gain. One other advisable thing these older continental engines need is a ¼” oil line ran over from the oil pressure gauge line and fitted on top of the timing cover as the chain is not oiled properly and continental did just that from the factory on all the W8 big four cylinder engines used in the Mason trucks and the 407 1930 Durant cars. We now are doing this to all 14L & 15L and W4 & W5 engines. Most of the time the chain and sprockets’ are chewed up and no good. Now the good news when all done the engine still looks stock on the outside. If anyone needs any help on an engine let Kenyon Machine Shop here in San Diego or me know and we will be glad to help you.
Faithfully Lance Haynes

Where Are You From? www.lancedurant.com

Do You own a car built by Durant? Only 5 now and lots of parts cars

Re: W5 Cylinder Head Differences

Lance,
That sounds like a lot of good information. You mentioned boring to .060" over. I did that on the W5 in my '23 and used stock size pistons from Chrysler or Desoto 6 cyl engines. These work with no modifications and actually have about 1/16" taller piston height. There is plenty of room for this extra height in the W5 and will help increase compression ratio also.
Now, if we could just find somebody to modify the crankshafts with counterweights!!

Do You own a car built by Durant? '23 Star Touring, '27 Star Coupe

Re: W5 Cylinder Head Differences

Lance,

Sounds like good Info...One question on the retrofited oil line going to the timing cover, did you put in an office restrictor to control the flow or is this line open? Bill

Re: W5 Cylinder Head Differences

Hi Bill.
We did use a reduced size orifice 3/32nd hole fitting on the cover that we brazed on. On another car we put a refrigerator ice maker line type needle shut off valve inline to restrict the flow and maintain sufficient pressure for all the bearings and the oil gauge. This change will give the timing chain badly needed oil. Later Lance Haynes

Where Are You From? www.lancedurant.com

Do You own a car built by Durant? Only 5 now and lots of parts cars

 

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