what happens if your ring end gap is to tight?

[bansheejoel]

i know ring end gap is a big deal ofcouce but i was wondering what would happen if it was to tight? check out these pics, my ring end gap is supposed to be .008-.033" on a engine i built and it was .009" and i think i should have filed them down a little because i think they were putting alot of stress on the cylinders. The polished spots are where the coating is wearing off (normal) but you can see where all of the stress was only on a small amount of the piston. BTW the engine has 1.6 miles on it. top two marks are where the powervalves are and the bottom two marks are on the outer edges of where the exhaust port is

 

 

Edited January 14, 2009 by bansheejoel

[Snopczynski]

Whats the exhaust port width on the cylinders?

[jbooker82]

If they are to tight then when they heat up it can cause them to bind and catch a port wich will really mess things up.

[AKheathen]

i know ring end gap is a big deal ofcouce but i was wondering what would happen if it was to tight? check out these pics, my ring end gap is supposed to be .008-.033" on a engine i built and it was .009" and i think i should have filed them down a little because i think they were putting alot of stress on the cylinders. The polished spots are where the coating is wearing off (normal) but you can see where all of the stress was only on a small amount of the piston. BTW the engine has 1.6 miles on it. top two marks are where the powervalves are and the bottom two marks are on the outer edges of where the exhaust port is

 

 

what are the piston clearances/ jugg square? why did you tear down after 1.6 mi?

[bansheejoel]

what are the piston clearances/ jugg square? why did you tear down after 1.6 mi?

 

I tried to get the piston clearance but im not sure how to do it. I tore it apart because i was hearing a wierd clunk sound and i found the pistons looking like this. I think the clunk sound was coming from the ring catching the bottom of the exhaust port b/c there is some small dings in there now......i think i should have filed the rings a little bit because the end gap was only .001 over the minimum spec.

[AKheathen]

I tried to get the piston clearance but im not sure how to do it. I tore it apart because i was hearing a wierd clunk sound and i found the pistons looking like this. I think the clunk sound was coming from the ring catching the bottom of the exhaust port b/c there is some small dings in there now......i think i should have filed the rings a little bit because the end gap was only .001 over the minimum spec.

did you re-chamfer the edges of the ports? you use a t-mic and measure the bore 360 degrees top to bottom. then measure the piston the same with a caliper gauge. also, measure the t-mic in the caliper gauge to ensure accurate readings.

[AKheathen]

if you don't have access to the gauges, you could put a coat of oil on the bore, heat the piston up to about 400 degrees, and drop it through the jugg in the proper orientation. then, with the measured ring and cold piston. set the piston on a flat surface with the ring installed, and the gap up. compress the ring with the corresponding feeler gauge in the gap, and measure how far the ring sticks out past the piston.

[bansheejoel]

did you re-chamfer the edges of the ports? you use a t-mic and measure the bore 360 degrees top to bottom. then measure the piston the same with a caliper gauge. also, measure the t-mic in the caliper gauge to ensure accurate readings.

 

sounds good. I have inside mics and a digital caliper so i will have to give that a try...thanks man.

 

all the ports looked like they were relived but it is a nickacil bore and i didnt want to do much grinding on them.

 

Its going to the shop tommarow to get diamond honed and checked out. Its bullshit, the pistons, rings, and cylinders are all new OEM parts that i payed huge money for......like 4 mill cub money for lol cylinders were $569.99 each and i needed two and pistons were over $150 each ::

[AKheathen]

sounds good. I have inside mics and a digital caliper so i will have to give that a try...thanks man.

 

all the ports looked like they were relived but it is a nickacil bore and i didnt want to do much grinding on them.

 

Its going to the shop tommarow to get diamond honed and checked out. Its bullshit, the pistons, rings, and cylinders are all new OEM parts that i payed huge money for......like 4 mill cub money for lol cylinders were $569.99 each and i needed two and pistons were over $150 each ::

jeez, nickle is some hard stuff. was it plating, or high nickle sleeves?

[lt1bird]

I did the same...my gap was only .008.....I was told it was ok but I filed to .012...... didnt want to take a chance...

 

also make sure the rings were number side up....

[fastrthnu]

when I do gap, I use a feeler gauge which are cheap and stick the ring square in the bore right before it overlaps any ports (about 5/8" from the top) and measure the gap. The minimum gap is already set for heat torrerance. Its alot safer to make it just a hair bigger though. The gap has a specific direction on each ring it should face (usually one opposing the other), and you ports all need to be chamfered. The tollerances for heated cylinders/piston clearances should be in the specs they come with where a feeler gauge can also be used to check without heating.

[bansheejoel]

when I do gap, I use a feeler gauge which are cheap and stick the ring square in the bore right before it overlaps any ports (about 5/8" from the top) and measure the gap. The minimum gap is already set for heat torrerance. Its alot safer to make it just a hair bigger though. The gap has a specific direction on each ring it should face (usually one opposing the other), and you ports all need to be chamfered. The tollerances for heated cylinders/piston clearances should be in the specs they come with where a feeler gauge can also be used to check without heating.

 

 

thanks your the help everyone