Re: Collapsed skirts on used pistons
Posted by Troy Taylor On 2016/12/26 17:48:15
I was going to hold off saying anything until things were a bit further along, but I can never keep a secret plus a blending of the minds and experience is key.
I have been playing for a while on the possibility of piston work for Packard. With the many different and really old Pre-War's we have been working on many of the Studebaker Pistons are not available and we turned a set for our Big Six and Special Six.
In light of the recent issues with Egge and the 374, we started looking at this. Egge will consider a run of 374 pistons for us at 200 sets bare minimum. Of course at repair rate, size variation, and taking up space on a shelve, as Fred has pointed out from the Business aspect, it really is not cost effective to peruse.
I recalled having a used set of Jahn pistons that I removed from a 374 two years ago. I compared the two pistons in measurements and the differences were in Jahn having a High Dome and Egge has an extended skirt.
Moving forward, For Packard, we have cast what I am calling a semi-universal blank. In its design for flexibility, one blank was given Extra stock. It can be machined to a bore ranging from 4.000 inches to 4.312 inches. This will allow flexibility to cover both 352 and 374 and a nice oversize range for each.
Plenty of meat on the dome for different options. The pin height is set 2 5/16 from bottom as cast and will machine 374 2.070 pin Hight. In addition the mold can adjust to allow the cast to adjust machine pin bore higher or lower by 5/16 inches making it versatile in applications.
We are "Playing" with turning a set to put into a 374 on the floor. This will be a low priority in the shop trying to get cars ready for the spring shows but will keep updates coming. We really need to look at total costs and if it makes sense.
Feedback is welcome, don't beat me up too bad
Attach file:
(258.33 KB)
(200.40 KB)
(32.35 KB)
I have been playing for a while on the possibility of piston work for Packard. With the many different and really old Pre-War's we have been working on many of the Studebaker Pistons are not available and we turned a set for our Big Six and Special Six.
In light of the recent issues with Egge and the 374, we started looking at this. Egge will consider a run of 374 pistons for us at 200 sets bare minimum. Of course at repair rate, size variation, and taking up space on a shelve, as Fred has pointed out from the Business aspect, it really is not cost effective to peruse.
I recalled having a used set of Jahn pistons that I removed from a 374 two years ago. I compared the two pistons in measurements and the differences were in Jahn having a High Dome and Egge has an extended skirt.
Moving forward, For Packard, we have cast what I am calling a semi-universal blank. In its design for flexibility, one blank was given Extra stock. It can be machined to a bore ranging from 4.000 inches to 4.312 inches. This will allow flexibility to cover both 352 and 374 and a nice oversize range for each.
Plenty of meat on the dome for different options. The pin height is set 2 5/16 from bottom as cast and will machine 374 2.070 pin Hight. In addition the mold can adjust to allow the cast to adjust machine pin bore higher or lower by 5/16 inches making it versatile in applications.
We are "Playing" with turning a set to put into a 374 on the floor. This will be a low priority in the shop trying to get cars ready for the spring shows but will keep updates coming. We really need to look at total costs and if it makes sense.
Feedback is welcome, don't beat me up too bad
Attach file:
(258.33 KB)
(200.40 KB)
(32.35 KB)
This Post was from: https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?post_id=186143