Hi Dave,
I have not checked with Greg yet. I will send him an email.
Thank you,
Ken
Hi Peter,
Thank you for your insight. There is a Series 81 car close to me that I believe I can get for a song. The Radiator Shop is still looking mine over and I should know this week if it can be saved. We have one leak that I know of. Hopefully, we don’t have any others. I will let you know what I find out.
Peter,
Thank you for the lead. That one looks pretty rough to me. Do you know if a Series 81 from 1928, is the same as a Series 80?
Peter,
I completely understand you position. I was completely blessed by Bob when he made mine fit. Just a slight difference in the pitch can even make the cap not fit. It may fit one Pierce of the same model and not another one of the same.
I wanted to share a little of what I went through to get mine to where it fits today.
Thank you for helping me on my other projects. Was hoping I could help you with yours.
Ken
Below is what Bob sent me December 25, 2018
I should clear up a couple of details. The photos I sent you labeled Delrin, dog bone, stainless are of the three caps you own. If you look closely you will see a series of grid lines on the green colored back ground. These images are taken from an optical comparator display. The comparator uses a light and lens system to enlarge the item and project a shadow on to a screen. In this case the part was enlarged 20 times. Reading the grid against the shadow is how I took my measurements of the thread depth and angle. I used my phone camera and simply took a photo of the screen for each part.
My conclusion was the Delrin part was not cut deep enough leaving the large, oversize flat at the top (crest) of each thread. The thread angle and spacing were very good. The stainless part showed an irregular thread profile with poor angular dimensions.
The info you received from Greg Long is very helpful. He measured several caps and found a range of 2.030” to 2.045” This gives an average of 2.038”
George Teebay measured his cap and found it to be 2.032”
Paul Jacobs did not offer a measurement but stated his Delrin caps were made to fit his radiator neck. His (now yours) Delrin cap measures 2.040” as shown on my drawing.
One last bit of information I came up with is based on the dimension I measured off your radiator neck. This measurement inside the neck is called the minor diameter of the thread. I came up with 1.971” Doing some math, trig and geometry you can come up with a calculated major diameter (this is what you measure on the cap) I calculated a 2.047” diameter. This is larger than all of the caps but is still hitting pretty close. Going off the minor diameter and working backward is not the best way to go for several reasons.
In measuring your radiator neck, I did NOT take a series of measurements. Greg mentions his neck is 1.995” and brings up the question of roundness. I did not check roundness on your neck and should have done so.
Conclusion and Confusion: Somewhat surprised to see your neck at 1.971 and Greg’s at 1.995. This difference of .024” is a lot. If Greg’s is more typical (large) it would explain why Paul’s Delrin caps have NOT given him any reason to question size. Getting a measurement from Paul on the size of the neck he uses to qualify his parts would be interesting. We need to check your neck for roundness.
We know Paul’s Delrin cap does NOT fit your neck. Your neck is too small (or out of round) OR the Delrin part is too big. Betting your neck in NOT out of round, we should be able to machine down the thread on Paul’s Delrin part to get it to work.
Going forward—picking a dimension close to Greg’s average of 2.038” should work for your small neck and anything larger.
Paul’s comments on the “last photos—-” showing a damaged thread—-must be the photo of your stainless cap. He must have missed the caption titles and assumed all three photos were of his Delrin?
Greg is correct—the threads on the Delrin part are NOT deep enough (especially to fit a small diameter neck like yours)
Greg’s suggestion on making stainless caps with flat tops, etc. is interesting. I would like to see the photo of the cap profile he mentions.
The gas cap photo you show is interesting as it looks just like the Delrin cap. You mentioned your gas cap is not threaded and will not help us check any dimensions for your radiator cap.
This email is detailed but does summarize what we now know. Will check In with you when I get back in town.
Bob C.
Peter,
Nearly 3 years ago you and I were emailing back and forth about a Pierce Arrow Dogbone I bought on ebay. If you would like all of the information that Bob measured I can send to you.
Here is what my friend Bob came up with back then. I can email you everything I have if you would like. It was a lot of work to rework the dogbone. Bob went way out of his way to make it work for me. The Delrin Cap I bought off this site had the incorrect pitch for my Series 80. It was slightly off and Bob reworked that one so it would fit my Pierce. Below are the measurements that Bob came up with.
The Dog Bone that I bought on ebay is the 14 thread. It measure 2.095. I was originally thinking to grind the dog bone down and change
the pitch to 16 so I could use it on the Pierce. Bob did wind up cutting the threads off and putting a sleve on that worked great. I believe I have the correct measurements if you would like to have them please email me.
Ken
Steven,
Seems like a fair price.
Ken
Curtiss,
Thank you for sharing. I have never seen one before.
Ken
Mark,
Thank you that is perfect. Dave emailed me and he thought a Pierce Arrow member was going to have some made. If they are I would like to have one.
Thank you,
Ken
Hello Dave,
I am trying to see what the Insignia says. I can read Pierce Arrow and Motor Robe? I can’t read what it says below that. If anyone has a tag I would like to have one.
Thank you,
Ken
Karl,
That is a Beautiful Poster. It says a lot about the area.
Ken
Mark,
I agree with everyone this looks like a Fantastic Pierce Arrow, Congratulations!
Ken
When we bought our 25 Series 80 I couldn’t fit behind the wheel. I am also 6’2″ plus. I have a 32 inseem and size 12 I could barely fit through the door. I had to loose some weight. Now I fit in pretty well and enjoy driving. Greatful for loosing the weight and now the experience of driving our Pierce to shows.”
Jim,
We are sorry to see you leave. My wife and I bought our Pierce Arrow in Tucson
in 2016. I am glad that we made the trip there to pick it up. It has a wonderful history. It is the first car my wife authorized me to buy.
We both enjoy the Pierce Arrow Society and the friends we have made.
Ken and Twila
DC
Amen to that!
God Bless Everyone!
Ken and Twila
Curtiss,
I Love it. Thanks and Merry Christmas to all of you from Twila and Ken.
Hello All,
The Bug is for Saftey Glass. I had a set of Glass made for a Street Rod that I am going to show and they put the Bug on all the Glass in a visible area. It was to ovious so we had the Glass Company redo the Glass without the Bug. They were reluctant but we convinced them to do it. We didn’t want the Bug showing and distracting from the rest of the car. We saved the receipt incase we need to prove that it is Saftey Glass.
Tom,
Is your Passenger Glass the same as the Driveside? If so it should be easy to make the Glass. Use the Passenger side as a pattern.
Good Luck,
Ken
David,
Here is the 8 for $59 + nearly $10.
https://www.ebay.com/itm/1929-30-31-32-Pierce-Arrow-8-Collectible-Plate/303400917841
Al,
The weather was in the mid 40’s with snow in the foothills. Very unusuall for the area. We did experience light rain on the way home.
I gained 5 pounds on the scale when I weighed this monrning. Back on my diet today.
We really enjoyed the Buffet.
Yes, Happy Thanksgiving to everyone.
Twila and I went to Thanksgiving with the Indians at Chumash Casino in Solvang. We ate at the Buffet to our hearts content. Way to much food.
Ken and Twila