ring gap

[JLS]

what should I set the ring gap at on my stock rebuild 86 gn 3.8? Thanks

 

[earlbrown]

If you're planning on wailing on it, I like .006" per inch top and .007" per inch second ring.

 

[we4Mateo]

I've always ready .017"-.022" on the top and around the same on the 2nd, maybe a little looser than the top. I haven't set one up yet nor decided what I'm doing with mine. I may let the machine shop decide. But the .006-.007" sounds a little tight. Just make sure the gaps are on opposite sides.

 

[pacecarta]

.006-.007 might be a little tight but earl said .006-.007 PER INCH (.006X bore diameter).... to me that a little loose per most mfg specs for forced induction racing are around .0055 x bore(top ring) .0035 x bore (2nd ring)

 

[we4Mateo]

My bad. I know Earl knows what he's doing.

 

[earlbrown]

I run those numbers on my forced induction engines. In this case I err a few thou on the loose side.

All it takes is one good ring butting episode to pop a piston crown off and ruin an evening.

for those not well versed in speaking in 'thousandths'...


.0055 per inch on a 3.8 bore = .0209" gap.

.006 per inch on a 3.8 bore = .0228" gap.


The width of forearm hair is 2 thousandths.


So in this case you can literally say my end gaps are 'just a hair bigger"

 

[pacecarta]

not to split hairs but i did set mine at .0021

 

[bison]

.I agree with the above. Less gap will equal slightly less blow by but wont make more power. If you had an engine at .017 then opened and filed the rings to .025 you wont see anything but a little more blow by.

 

[m233roller]

Iv'e gapped rings from .018 top ring & .020 second ring, Iv'e done .020 top ring & .022 second ring, Iv'e done .022 on both rings & done .024 on both rings and have seen NO difference at all except the one with .024 ring gap had a tiny bit of blow by and all those engines had the crap ran out of them with many 1/4 mile passes too.

 

[JLS]

thanks guys, hey Mike this is John S from s.e. missouri bout to get this project put together finally lol