Fellas,

In the relatively near future I will be replacing the rings in my high compression ka24de. I would like to know if there are any of you out there that have had any experience with doing such a thing. I'm running after market flat top pistons in the engine. I will not know specifics about any over bore info until I open it up, as I purchased the motor from an individual that didn't even know it had flat top pistons in it.

What sort of tips and/or suggestions would do you have that may help with the replacement?

Is there a brand name that you would recommend?

What about procedures that may be out of the norm that might be beneficial in the enhancement of reliability?

Or, would I be better off to have a machine shop do this for me?

Things to keep in mind:
If you post a link that I could have found with Google, more than likely I've already seen it AND I'm looking to drive conversation here...tell me what you know.


Also, I have no fear of doing the job and considering that I paid $100 for the engine I'm well ahead of the curve in relation to the monies spent

Lastly, the motor will see boost.

Thanks.

 

Unless you've got a forged sohc piston in that motor it won't do very well if your tune is spot on. Disassemble, measure cylinder bore / out of round. Hone accordingly and re-assemble with oem or whatever brand rings your pistons are.

 

Ill post pix once the pistons are out. There are pix of the tops of them im my build thread. Little to no dish but no "fly" cuts. They are aluminum for sure...but that's all I could figure out. I will break the rings in NA before having it fitted and tuned for boost.

Ill know more once I break it down.

 

That's what we are thinking they are.
they are flat, with a slight "step down" that might only be a couple of pennies widths deep.
Only reason they were discovered was because of an unplanned head gasket job

You mean, unless the tune is spot on? or are you saying that even with a spot on tune, it won't do well?


There in lies part of the problem. We've not been able to positively identify the pistons. The only marking on them is a "ST" engraved in the center of them.
Thought they might be old SuperTech pistons, but after spending a good bit of time talking with a rep over there, we are certain that they are not SuperTechs.
Hoping to find some sort of model numbers or something on the underneath side to be able to identify them.

In the meantime, without knowing the exact brand of the piston, what would be the recommended process?
Is there any "use this ring..." or "do it this way..." to be better safe, then sorry?

my thoughts are, unless the pistons can be identified, to have a machine shop measure it out to know how thick/wide the rings need to be, then track down the right sized ring.
I just honestly don't know what makes a good ring, good. or if all of them are pretty much the same or what. low tension, versus standard tension. "normal" ring sets versus those "total seal" doo dads. and all that jazz.

 

Here is a link to the pix in my thread...just page down and they are hard to miss.

https://www.tamparacing.com/forums/n...-hatch-20.html

PS: Empire is my co-pilot, partner in crime, or turd in my pocket on this build...hence his 25 cents. Why .25? Have you ever seen him add just .02? LOL.

 

yeah, that post was at least 25 cents. you should see some of the other ones when i toss in a whole dollar... really getting your moneys worth then. lol

- The turd in rhart's pocket

 

For future reference, that phase is a term of endearment. My dad used to say that when ever I would refer to anything as "we" when working on one of my projects. Great times.

And that link holds a dollars worth...Hehehe.

 

Am I understanding correctly that you are running a 11:1 motor thats turbo charged?

 

As crazy as it sounds Tom. Yes, but the plan is to supercharge the KA. Low boost, of course. Its going to take an excellent tune. Intecooling, the whole works. I've been sitting on the supercharger for a while now. With Empire's assistance we've worked out a pretty solid plan with the idea of a mild build approaching 300hp and similar torque numbers. The fun aspect of the build being the achievement of an insanely flat torque curve.

But first the rings.

 

I wouldn't bother with a S/C set up. Especially on a 4 cylinder when turbo charging it is so easy. S/C steals hp to make hp. Turbo turns wasted power into hp. It's a no brainer.
I ran high compression on my DSM's for many years. It's completely doable but it won't like pump gas at all and. You will have to keep the boost down and run such minimal timing the high compression will be negated. To take advantage of the high compression you will need to convert to E85 or use methanol injection. Personally I recommend a progressive meth injection setup.