RkTek 858, who still have them?

[Sunvang]

Are you shore it was not detonation , do you use a timing key with his kit , does his kit with different piston and cylinder shim change the port timing? your piston looks alot like this one

Pretty sure there was no detonation yes. I used the offset timing key yes.

I see the similarities with you piston, but what is strange is that the damage is not consitent. One piston had ehaust port damage, one had intake side damage.

 

[gunnerthesnowman]

Pretty sure there was no detonation yes. I used the offset timing key yes.

I see the similarities with you piston, but what is strange is that the damage is not consitent. One piston had ehaust port damage, one had intake side damage.

Is the off set key a + or - on the timing , how many degrees ? are you running a fuel box with this kit?

I run a 870 BB, what i found out with mine ( as you can see with the piston ) was that i can run more timing in low end and on top end then my stock 800 motor ( with piston kit/with cylinder shim) but the 870 BB takes less timing and more fuel in the mid range , its a good thing to know what you pipe back pressure and temp. is doing

 

[Sunvang]

Is the off set key a + or - on the timing , how many degrees ? are you running a fuel box with this kit?

I run a 870 BB, what i found out with mine ( as you can see with the piston ) was that i can run more timing in low end and on top end then my stock 800 motor ( with piston kit/with cylinder shim) but the 870 BB takes less timing and more fuel in the mid range , its a good thing to know what you pipe back pressure and temp. is doing

I believe it was a +3 on timing, and the fuel controller was Boondockers. I have used a BD box numerous times before on previosu turbo builds, so i choose that over the PC.

I used a air/fuel ratio to tune it, and according to that, I was running richer than I usually run my turbo sleds.
But i did not use exhaust temp so cant be sure.

 

[gunnerthesnowman]

I believe it was a +3 on timing, and the fuel controller was Boondockers. I have used a BD box numerous times before on previosu turbo builds, so i choose that over the PC.

I used a air/fuel ratio to tune it, and according to that, I was running richer than I usually run my turbo sleds.
But i did not use exhaust temp so cant be sure.

OK , my A/F was running 11.5 when she died ( have data log ) pulled 2 -2.5 degrees of timing in the mid range ( had to added fuel as after pulling the timing caused it to run leaner in mid range).
I would not relie on the stock knock senser with my BB , as your engine sound could of changed from the factory setting.
If you rebuild it you may want to try it with out the +3 degree timing key

 

[Sunvang]

OK , my A/F was running 11.5 when she died ( have data log ) pulled 2 -2.5 degrees of timing in the mid range ( had to added fuel as after pulling the timing caused it to run leaner in mid range).
I would not relie on the stock knock senser with my BB , as your engine sound could of changed from the factory setting.
If you rebuild it you may want to try it with out the +3 degree timing key

Not rebuilding this kit again. When it was running well, I dont feel it ran well enough to risk another blown engine.

 

[gunnerthesnowman]

Not rebuilding this kit again. When it was running well, I dont feel it ran well enough to risk another blown engine.

Thats to bad , when i was looking for a piston kit for my Pro 2012 800 motor , i looked a Kelsey's kit , I did not like the fact the the pistons were shorter and was not using anything to adjust the fuel

 

[N.A84]

Plugs looked dark and good, and a/f numbers were low.


My theory is that the balance of the piston is screwed up when they shim the cylinder up, without using longer rods. The pistons gets top heavy, and starts wobling back and and forth, causing the cracks.

But Mtntk have been using shim since 2008 and i have heard some impressive mileage numbers of their kits.

 

[diamonddave]

Plugs looked dark and good, and a/f numbers were low.


My theory is that the balance of the piston is screwed up when they shim the cylinder up, without using longer rods. The pistons gets top heavy, and starts wobling back and and forth, causing the cracks.

But Mtntk have been using shim since 2008 and i have heard some impressive mileage numbers of their kits.

Remember the MTNTK Kit is using a stock "sized" bore.

I love the Wiseco story though...Sorry to see you guys going through the pain. This motor seems to do as well as it can with the stock sized bore.

 

[N.A84]

Remember the MTNTK Kit is using a stock "sized" bore.

I love the Wiseco story though...Sorry to see you guys going through the pain. This motor seems to do as well as it can with the stock sized bore.

Crap, my bad. I was thinking on the fix kit for a sec lol.

 

[geo]

Just info.

Original "fix kit" uses the theory that taller piston will rock less in the bore (hence need for spacer, not to change port timing). This "theory" has been around long enough and successful enough to be copied more than once.
Not saying you need one as Poo has made physical and engine management changes that have, IMO, made this a non-issue but I think there are other benefits to the design.

OP, my only comment, if you had no engine management issues, that's just brutal. Sorry for your luck.

 

[mnsledder1]

858

mine lasted 11 miles no help from Kelsey Do not buy this motor! 2013 800 Bad fuel controller bore job flaked off both pistons stuck complete failure Kelsey blamed Boondocker and plating company offered no help charged me another 500 for pistons just so I could sell the kit then had to buy new cylinder and pistons on top of this complete 4k dollar mistake

 

[N.A84]

mine lasted 11 miles no help from Kelsey Do not buy this motor! 2013 800 Bad fuel controller bore job flaked off both pistons stuck complete failure Kelsey blamed Boondocker and plating company offered no help charged me another 500 for pistons just so I could sell the kit then had to buy new cylinder and pistons on top of this complete 4k dollar mistake

11 miles..? Damn, that is just sad.