Datsun Roadster Forum-311s.org

Finally got a set of standard U20 rings & started installing them today. 2nd ring has a step in it. The data sheet with the rings says that the rings will either have a dot on the top side or say “top” on the upper side & that if there are no marks that the ring can go on either way. My second rings are not marked, so I assume which side goes up is not important. If that is true, does anyone have a suggested orientation for the 2nd ring?

Also, while checking end gap I found the top ring has 0.010” gap, which matches the minimum factory specs but the 2nd ring reads 0.007”, so I ordered a ring gap filer to take off the 0.003”.

Peace,
Pat

Usually the 2nd ring has a tighter gap because it sees less heat. I took a picture on the page which shows the ring clearances. It looks like your 2nd ring gap clearance is within specs.

That gap is too tight most have ,020 at least as it heats it will close
Cast iron or moly ?
Usually the stepped is the top, step on bottom / down side to let more oil into the ring groove
What's your piston to cyl clearance?

Sounds like the second ring is what’s referred to as a Napier ring and all of the ones I’ve seen the cut goes to the down side.
Dave

Sorry, I should have specified ring material. They are cast iron.

Looks like there are differing opinions as to which way the rings go, as well as gap so I'll contact Hastings Monday. Even though thy have discontinued these rings they should still have information about them in their system.

Peace,
Pat

I don't know if this would answer your question,....but here is a link to a video, on a Hastings website talking specifically, on which way to install compression rings. The video makes reference to "rings with a BEVEL "....is that what you are calling a "step" ?

From Hastings:
https://www.hastingspistonrings.com/tec ... h-ways-up/

Also:
Here are some FAQ's on this Hastings list. Refer to the following questions:

https://www.hastingspistonrings.com/tec ... faqs/faqs/
Question : Compression rings have an inside bevel - which way does the bevel go ?

ID bevel rings should have a dot to indicate the top of ring. Positive twist rings ID bevel up, whereas negative twist rings ID bevel down so be sure to check for the dot.

Question : I removed the rings from the box, which is the top ring and which is the 2nd ?

2nd ring has a DOT on the top and an inside bevel on the bottom – install DOT towards top of piston, check top ring for inside bevel, bevel install up, if no inside bevel, install either way in top groove.

Thanks, Mike, I'll check the videos. My second ring has an actual step, not a bevel.

peace,
Pat

Here is a photo of the 2nd ring.

Both the top & second ring have square corners on the inside.

That is a Napier ring, put the step down.
Dave

https://www.enginelabs.com/engine-tech/ ... otal-seal/

Follow the link for reference.

Thanks David. I appreciate your info. Have a great evening.

Peace,
Pat