Author Topic: Suggested Source for 10 over. Darrin Pistons and rings (Willys F-161)  (Read 1095 times)

52 Muntz

  • Newbie
  • *
  • Posts: 36
    • View Profile
    • Email
Ran into a wrinkle in my 161 rebuild.  I had what I thought was a complete NOS set of 10 over pistons. When they went to fit them it turns out I had 5 - 10 over and 1- 30 over. Aren't old cars fun.  In my surfing I can't find any 10 over pistons or rings. Any suggestions? Thanks.

MarkH

  • Hero Member
  • *****
  • Posts: 1083
    • View Profile
    • Email
Re: Suggested Source for 10 over. Darrin Pistons and rings (Willys F-161)
« Reply #1 on: September 13, 2018, 08:38:25 PM »
I've seen NOS ones turn up on eBay every now & then, usually larger oversizes. Swills and Walks carries pistons and Egg manufactures their version without the heat dam groove.
Don't know if you're looking for one or a set but unless you know you're buying the same brand & type you run the risk of having one a much different weight than the other five. I know Egg packages their sets all within a specific weight of each other.
Fully restored '54 Aero Lark
Rusty '58 Austin Healey 100-Six
Barely running'74 Chevelle Malibu

52 Muntz

  • Newbie
  • *
  • Posts: 36
    • View Profile
    • Email
Re: Suggested Source for 10 over. Darrin Pistons and rings (Willys F-161)
« Reply #2 on: September 13, 2018, 09:08:53 PM »
Thanks for the heads up. Never thought of the weight issue with different brand pistons.

r1lark

  • Sr. Member
  • ****
  • Posts: 380
    • View Profile
    • Email
Re: Suggested Source for 10 over. Darrin Pistons and rings (Willys F-161)
« Reply #3 on: September 14, 2018, 03:49:23 AM »
Is there a possibility that that one .030" oversize piston can be re-machined into a .010" oversize? If the 'odd' piston is the same manufacture as the other five, they probably all started off as the same casting.
Paul
Winston-Salem NC
Visit The Studebaker Skytop Registry website at:  www.studebakerskytop.com

MarkH

  • Hero Member
  • *****
  • Posts: 1083
    • View Profile
    • Email
Re: Suggested Source for 10 over. Darrin Pistons and rings (Willys F-161)
« Reply #4 on: September 14, 2018, 07:48:40 AM »
I've seen NOS ones turn up on eBay every now & then, usually larger oversizes. Swills and Walks carries pistons and Egg manufactures their version without the heat dam groove.
Don't know if you're looking for one or a set but unless you know you're buying the same brand & type you run the risk of having one a much different weight than the other five. I know Egg packages their sets all within a specific weight of each other.

Looks like I accidentally clicked "Change All" instead of "Ignore" in spell check yesterday.

To clarify...…….. Kaiserwillys.com and Walcks.com and Egge machine.
Fully restored '54 Aero Lark
Rusty '58 Austin Healey 100-Six
Barely running'74 Chevelle Malibu

52 Muntz

  • Newbie
  • *
  • Posts: 36
    • View Profile
    • Email
Re: Suggested Source for 10 over. Darrin Pistons and rings (Willys F-161)
« Reply #5 on: September 15, 2018, 12:27:46 AM »
MARK H - I was just about to search Swills and Walks thinking it was some great UK based parts hoard. LOL. Spell check is fun.
R1LARK I checked with the machine shop and machining the .30 down to .10 is not possible. They actually advised me pistons are not round they are oblong?? 
Oh well.  It appears another rebore down to 20 over and a new full set of pistons will be in order. Thanks for the thoughts guys.

r1lark

  • Sr. Member
  • ****
  • Posts: 380
    • View Profile
    • Email
Re: Suggested Source for 10 over. Darrin Pistons and rings (Willys F-161)
« Reply #6 on: September 15, 2018, 04:47:52 AM »
R1LARK I checked with the machine shop and machining the .30 down to .10 is not possible. They actually advised me pistons are not round they are oblong?? 

True, usually they are not perfectly round. Here is a site that has a discussion of this: http://blog.wiseco.com/pistons-arent-round-profile-and-ovality-explained

A general machine shop would probably not have the equipment to do this. A small specialty machine shop that has the capability to make pistons would be who you search out for this, especially one that is heavily involved in antique car engines. The bigger piston manufacturers would probably not bother with something like this.
Paul
Winston-Salem NC
Visit The Studebaker Skytop Registry website at:  www.studebakerskytop.com

joefrazer

  • Hero Member
  • *****
  • Posts: 4043
    • View Profile
Re: Suggested Source for 10 over. Darrin Pistons and rings (Willys F-161)
« Reply #7 on: September 15, 2018, 09:34:36 AM »
A friend had a Nash engine rebuilt and it disintegrated after about 2,000 miles. When we pulled it apart we found four of the six pistons were standard bore but the bores themselves were not well machined, one was 20 over and one was 40 over. The imbalance caused the issue and fortunately, my friend was able to recover the money spent on the "rebuild".