RKIndyTek!!??

[Kestrel2126]

I just pulled my motor this summer on my '11, after 400 Break in miles, and right at 2000 under 8-12 PSI of boost. Last season, I was on the verge of doing the top end, but decided to throw caution to the wind and ride it til it blew. It never did, and I finished out the year. When I pulled the top end, I expected carnage. To my amazement, things couldn't have looked better (on the top end). Cylinders were clean, no stress cracks, good nicasil, and no scarring. Pistons were also in great shape. No scarring, great wash, no sign of DET, although the rings were definitely worn, they were not flaking.
Anyhow, I already new which way I was going for my top end, and sent the crank off to be rebuilt and balanced. I just found out the other day, that the motor was in fact getting close to grenading, but it was due to a lower bearing pin starting to walk out. I guess I got lucky on that, but was really surprised at how well the top end had taken the abuse.
So, this year, I'll have a fresh motor, that will hopefully be solid for another couple thousand boosted miles. And in a study of making two people that completely disagree (this is a major understatement), unknowingly work together, it will be on an Indy Dan bottom end, and an RKT top end. HAHAHA. Both of these guys are great to work with, are extremely knowledgeable, and build EXCELLENT products, regardless of their difference of opinion.
Dan rebuilt and balanced my crank, cleaned up the cases, balanced and shimmed my clutch, and checked and reinforced my cylinders. The motor should be in transit to me now.
Kelsey built me a custom head for my elevation and boost levels, as well as supplied me with a new set of matched forged pistons, to pair with the head.
I cannot wait to get this motor back in the sled and started getting my tuning dialed back in, so I can tear up the Colorado high country.
Thanks to both of these guys, for building great stuff, and at least on my sled, you can both get along!

 

[Vfrtrader]

Sounds like the turbos run cooler and don't have the problem the unblown boys are having.

 

[Reg2view]

Consider yourself submitted for the Nobel peace prize. An apology tour will surely guarantee you a win.

 

[ND]

Sounds like the turbos run cooler and don't have the problem the unblown boys are having.

You mean hotter......to make the skirts expand and take up that massive piston to wall clearance? .008" is insanely loose.

 

[RKT]

Dan rebuilt and balanced my crank, cleaned up the cases, balanced and shimmed my clutch, and checked and reinforced my cylinders. The motor should be in transit to me now.

Kestrel,, what exactly is the reinforcement you are mentioning..??

 

[Kestrel2126]

To be honest, I'm not 100% sure. My understanding it is a reinforcement of the cylinder skirts, but I'm not exactly sure of the process. Dan told me he would do this, then check the cylinders for round and good Nicasil. He also told me that this would not in any way effect the motors performance properties (porting, piston/crank clearance, etc). I liked the idea of this, as I have heard (and rebuilt one myself for a buddy) about a number of the '11 Pro's dropping cylinder skirts.

 

[Vfrtrader]

Quote:
Originally Posted by Vfrtrader
Sounds like the turbos run cooler and don't have the problem the unblown boys are having.

You mean hotter......to make the skirts expand and take up that massive piston to wall clearance? .008" is insanely loose.

No, cooler, more fuel runs cooler. No expansion, no scuffing of pistons, etc. But I'm no expert on the subject.

 

[Kestrel2126]

No, cooler, more fuel runs cooler. No expansion, no scuffing of pistons, etc. But I'm no expert on the subject.

Exactly

 

[philsummers21]

This is the route id like to go. Don't feel just pistons are the ticket. Id like to have the whole bottom end rebuilt and done correctly

 

[ND]

No, cooler, more fuel runs cooler. No expansion, no scuffing of pistons, etc. But I'm no expert on the subject.

I see what you're thinking, somebody would have to throw a wideband on a stock sled and see what the afr is and compare to the afr turbo guys are running. I'd imagine the turbo guys are running richer.
Problem is they're also making a ****load more power. On a four stroke when you around 35% of the energy from burning fuel is actually used to make horsepower, 35% goes into creating heat and the other 30% goes straight out your exhaust. In a two stroke the percent going out the exhaust is obviously going to be higher.
The point here is that as your power output goes up the heat created in the motor goes up substantially. even going from say 12.5:1 down to 11.8:1 I doubt that extra fuel is going to make up for the significant heat output increase going from 140hp to 200 plus.

 

[ND]

this doesn't transfer directly, but to give you an idea on piston to wall clearance, on the turbo 4 cylinders with high expanding 2618 slugs I'll generally run:
.0035-.0045 up to 400hp
.0045-.0055 400-600hp
.0050-.0060 600-800hp

My old car made 636whp, figuring 15-20% driveline for being AWD that's 760-790 at the crank. My piston to wall clearance was .0055". Walls and piston skirts looked great. Now I know a two stroke piston never gets a break to cool off, but .008" piston to wall clearance for a measely 140hp? That's looser then a hot dog down a hallway!

 

[philsummers21]

Any updates on this? Motor all back together and running yet?

 

[Kestrel2126]

I should have the motor on Wednesday (shipping mix up). I will post some pics/updates when I get everything back together.

 

[thmck]

Any updates on this? Motor all back together and running yet?

 

[BOHICA]

It may be on the snow tomorrow

 

[Kestrel2126]

Motor and sled are all back together. In addition to the motor work, I also upgraded from a standard Garrett 2860 turbo to a Tial 2860, as well as upgraded my EBC to the new model with TPS smart (linear boost level, based on throttle position). I got it on the snow today, for some break in miles. Everything runs great and feels really strong. We don't have much snow yet, so I can't really test, or tune for good riding conditions. Only issues I am having was a bog towards the bottom end, when in the throttle, then dropped it out, and went back in. I expected some of this, as the Tial is much more efficient, and paired with the head, I figured on being very rich. Other issue was an intermitent engine like that corresponded to a "Throttle stuck open" code. I am hoping that this is due to my new RSI throttle block not being properly adjusted, and not the EBC wiring.
Overall, It ran way better than I expected out of the gate, as I thought I would be way off on my fuel mapping. As far as the motor itself, everything looks and feels great.