Ford ring spec

[Bajajet]

Have to re-ring my Ford 502. Bore is 4.39 (.030) over. Forged pistons. What should the target ring gap be?
Thanks

[Moneypitt]

A good base line is .004 per inch of bore. Most ring manufacturers will have their perfered gap listed with the paperwork that comes with the rings. Also some pistons (Hypertunic sp) require different gaps. NA and blown have different specs as well as automotive vs marine use. Check the ring box for specs..........MP

[Jet City]

The 4.390 (460) rings I have list .004 per inch as a minimum end gap, 4.390 x .004 = .0176 min.

[Moneypitt]

I can't believe someone hasn't jumped up about marine use!!.......Increase the gap for marine use a bunch. Combustion chamber temps go to the moon, the ring temperature soors, but, the marine use cylinder around them has the whole lake/rivrer to keep it cooler than if it were the truck you pull the boat to the "water" with...For this reason, you might want to consult the ring manufacturer as to the recomended gap "for marine use"........................MP

[Bajajet]

Should have rings this morning. I'll see what the instructions say for marine use and give them a call if it isn't clear. It seems that the last set were around .022-.024. That was 2 years ago though. Maybe my memory is way off but those numbers stick in my head.

[Jet City]

I can't believe someone hasn't jumped up about marine use!!.......Increase the gap for marine use a bunch. Combustion chamber temps go to the moon, the ring temperature soors, but, the marine use cylinder around them has the whole lake/rivrer to keep it cooler than if it were the truck you pull the boat to the "water" with...For this reason, you might want to consult the ring manufacturer as to the recomended gap "for marine use"........................MP
You already mentioned it, I think your advise of getting the Mfgr recomended gap is good. If I had to guess I would say .006 per inch for a .026 gap (top ring) and .028 for 2nd ring, I seem to recall my engine builder recomending .006 for my upcoming N2o build, I'd think marine would be similar, this is for forged pistons, hyperuetectics are another story.

[Bajajet]

Just got off the phone with F/M tech. He recommended (for marine) the Drag/Oval track spec .045 x bore dia for top ring and .055 x bore dia for second. What do you guys think?
:confused:

[Moneypitt]

How about .0045/.0055 X bore dia......Not .045/ .055............MP

[Bajajet]

Read what I mean not what I type :smile:
Switching gears here, anyone have a better suggestion than a printo-seal for an intake gasket? I have heard of them sliding around and getting pulled into the intake ports.
Thanks

[Squirtin Thunder]

Read what I mean not what I type :smile:
Switching gears here, anyone have a better suggestion than a printo-seal for an intake gasket? I have heard of them sliding around and getting pulled into the intake ports.
Thanks
I use them all the time, intake and head. Good stuff !!!

[Jet City]

Read what I mean not what I type :smile:
Switching gears here, anyone have a better suggestion than a printo-seal for an intake gasket? I have heard of them sliding around and getting pulled into the intake ports.
Thanks
I prefer Mr Gasket ultra seal, but I have not had problems with Fel-Pro's.

[SmokinLowriderSS]

I'm happy with the fel-pros I put in last winter.
The .005" per inch of bore looks good. Should put you right in mid-range for the factory ring gap specs. Anything a fair distance above minimum is good and should be safe. It's those folks who forget the differences in expansion as mentioned above between cooler than normal cylinders and hotter than normal (or fast-heating from a sudden WFO throttle blast) that get in trouble with rings closing up entirely and things getting torn up.