Piston Ring Stagger

[billrigsby]

 

I cannot find this information anywhere

 

How do you stagger the piston rings

 

Top two compression rings 45° apart ?

3 piece oil, sheet says top and bottom 1" on either side of middle ring gap, but where to place that middle ring gap?

bottom cast oil ring 180° from the above oil ring?

 

I saw no ring gap above the piston pins.

 

 

Any thoughts?

[Dave72dt]

I'm surprised you haven't had more response.  Other than not having them all lined up in a row, there's a lot of personal preferences involved in an engine build including ring stagger. Mine on a 4 ring would be oil ring gap over the pin hole and 180 degrees for the next, 180 again for the next, another 180 and one more for the top ring.  On a 3 ring piston I still start with the oil ring over the pin and the top 2 rings 120 degrees apart from each other  and the oil ring gap.  Right way, wrong. way, who knows?  someone else does them differently, chime in.  Once again, you can contact tech support for their recommended stagger.

[Plymouthy Adams]

57 minutes ago, Dave72dt said:

  Once again, you can contact tech support for their recommended stagger.

 

I figured regardless of replies, him sending Hastings an inquiry would be his end go-to anyway.

[wagoneer]

Chrysler guidance is to stagger them 180 degrees apart so a failure in one doesn't mean a quick failure in the ring below. 

 

The oil rings "back each other up". I thought it was in the MTSC, but I can't find it at the moment. The gaps *should not* be aligned.

 

 

https://www.mymopar.com/downloads/mtsc/002.pdf

[kencombs]

I have always followed what I was taught way back when.  Two top compression rings 180deg apart with the gaps 90deg from the wrist pin.  3pc oil ring gap location relative to the others is not important, but the upper and lower scapers should be 180 apart and 90deg from the gap in the expander.  If two one pc oil rings are used, 180 apart and gap location relative to the piston unimportant.

[billrigsby]

I have sent them an email, this was the best I found online, three rings only, added my fourth.

 

With three different shop manuals, it is amazing how little information is in each.

I guess a lot is / was common knowledge?

 

 

 

 

[Dave72dt]

How were the rings staggered on the pistons you took out?  Were they the same on all the pistons?  Does your reference source explain why no ring gaps over the pins?  As long as you're getting info from the manufacturer, you should probably ask them about the thrust side of the piston.  Without knowing that, you could end up with all the ring  gaps on the wrong side of the piston.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Edited June 9, 2021 by Dave72dt

[billrigsby]

15 minutes ago, Dave72dt said:

How were the rings staggered on the pistons you took out?  Were they the same on all the pistons?  Does your reference source explain why no ring gaps over the pins?  As long as you're getting info from the manufacturer, you should probably ask them about the thrust side of the piston.  Without knowing that, you could end up with all the ring  gaps on the wrong side of the piston.

 

This engine was broken down so long ago I really don't know for sure, I do still have the pistons out in my crates I could dig them out and have a look.

 

That diagram came from Wiseco pistons, I'm not sure why nothing over the piston pin, I also heard this on the Flathead page on Facebook.

 

I did get a response from Hastings, they said what I have in my drawing is acceptable, as far as the thrust side of the piston it is my understanding there is a major and a minor thrust side and neither side should have a ring gap in that area, and again I do not know why.