Fred's 2374 -> 2258 Engine Build Thread Options

[Ninja]

Heads up if you didn't know...

Rings can be made from different materials, and each has a different specific RMS (bore finish) to work properly.

I choose the rings before I have the bores finished and tell the machine shop what they are. I always send the new rings so the machine shop can check themselves.

The difference between cast iron and chrome steel rings; cast need ROUGH and chrome needs SMOOTH.

Important for the machinist to know!

Important for the machinist to ASK if he didn't know.

If he didn't ask would be a gigantic red flag for me...

[friethmiller]

Side clearance is CRITICAL!!!

When you measured .0025 difference in the thickness my first thought was, I hope one of those falls between .001-2 to the piston.

SO MUCH BS on how this stuff is fitting together for you!

Make you wonder if ANY of the critters supplying parts actually "give a shit" if the final engine will live.

I feel your pain!
(IMG:style_emoticons/default/ninja.gif)

Yeah Rick, the Hasting rings are suppose to work for these pistons but by the time I got the Piston to Cylinder Wall gap correct, the ring gaps increased by a magnitude of PI. No worries. There's plenty of things I can still do till it gets sorted out. I doubt this will cause much delay. It's just a shame about the side clearance, the Grant rings were around a .015" ring gap out of the box and could have certainly been opened up to meet the .017" spec. I did enjoy doing the head-to-head measurements. (IMG:style_emoticons/default/biggrin.gif)

[friethmiller]

Heads up if you didn't know...

Rings can be made from different materials, and each has a different specific RMS (bore finish) to work properly.

I choose the rings before I have the bores finished and tell the machine shop what they are. I always send the new rings so the machine shop can check themselves.

The difference between cast iron and chrome steel rings; cast need ROUGH and chrome needs SMOOTH.

Important for the machinist to know!

Important for the machinist to ASK if he didn't know.

If he didn't ask would be a gigantic red flag for me...

Interesting. I'm working with the JE rep now on what they recommend. I'll ask Eric (machinist) about the honing surface. They had my rings originally but not on the recent rework to hone them out for the pistons.

[Jack Standz]

We didn't use to have the knowledge and tools that are available today. Theories and hard research are now being exploited by those who know and pay attention.

Would send you some links, but am not able to right now. However, your machinist should use a profilometer. Powell Machine has some good YouTube videos that show how to dial in an aircooled cylinder bore/hone (jet ski or motorcycle engine, can't remember). Also, Lake Speed has some that discuss ring gap that are very good.

If you can set the gap where you want it, based on sound experience, that makes a lot of sense. So, patience pays if you can wait and regrind the ring gap to exactly where you want it. However, if you can't, those gaps are very probably ok. They aren't horrible and aren't likely to be an issue (refer to the videos where Lake Speed discusses ring gap - a tight gap can destroy things and gap, even if it seems excessive, doesn't automatically lead to excessive blowby or a meaningful loss in power).