RKTek Drop in

[Norway]

So there are two different pistons...One set with the drop in kit, which includes the head. Another set of pistons are the direct replacement pistons??

I run a SLP Stage 3. Just wondering what would be best for me? I'm assuming just the direct replacement?

Kelsey has a drop-in kit with head +pistons. The pistons have a lower height from the wrist pin and up, effectively putting the top of the piston lower in th e cylinder. This increases port timing across the board but also lowers compression and increase squish clearance.

The head that comes in the kit is designed to make up for this by having domes sunk down into the cylinder. This would crash with stock pistons.

The replacement pistons are the same height as stock, hence will work perfectly with stock or other aftermarket head.

 

[grizzlytwin]

is it worth doing the pistons and head vs just the replacement pistions? For the extra cost is there a gain in performance worth while?

I am going to buy one or the other based on the reviews. My sled only has 175 miles on it but will do now vs later.

 

[wellfed777]

grizz
i think they're all saying the drop in kit for perfomance+ reliability

pistons only= reliability

 

[Boondocker82]

Sure wish someone would use this kit on the CFI-4 so I didn't have to be the Guinea pig but it looks more and more like I'm gonna be.

Sent from my EVO using Tapatalk 2

 

[poo18]

Can i run this drop in kit with an hps can on a 13 pro. Also what would this full kit cost to do and where does a guy order the kit. Thanks

 

[mtncat1]

no one will say for sure but the drop in kit is supposed to gain 10 to 12 hp on the top end. this is much more than any high compression head will give you.plus its on the top end not in the mid range.also i don,t think you get a choice on compression ratios.if run the rkt drop in kit you must run the head provided. don't be confused drop in kit is totally differant from the direct replacment pistons that rkt also sells.

 

[Washy]

I ran the PAR 13.1 head / HPS can on a completely stock 2012 163 Pro ( I have a 2.5 CE installed ) SLP 140-340 with 10-64 , secondary was stock , at Revey 5000-6500ft it was running 8150RPM,s , so the head and can made a 2 gram weight differents.

I ran my 2013 163 Pro with kelseys drop in kit and 13.5 head everthing else stock, in Revy today. Was too lean in non-ethanol so had to use it on the ethanol setting for the added fuel. going to need a controller
I had 68 gram weights in the sled and was pulling 8 to 8100 rpm. Odd time would hit 8200. 66 gram weights would have been ideal as kelsey recommends 8300 to 8500 RPM. I did not have 66 gram weights with me to try and I will probably change the primary spring. So far so good. 250 miles on the kit, 350 on sled.

 

[snobyrd]

I ran my 2013 163 Pro with kelseys drop in kit and 13.5 head everthing else stock, in Revy today. Was too lean in non-ethanol so had to use it on the ethanol setting for the added fuel. going to need a controller
I had 68 gram weights in the sled and was pulling 8 to 8100 rpm. Odd time would hit 8200. 66 gram weights would have been ideal as kelsey recommends 8300 to 8500 RPM. I did not have 66 gram weights with me to try and I will probably change the primary spring. So far so good. 250 miles on the kit, 350 on sled.

Did you hit det code? Also did u notice your track speed in powder on a hill.
Mine does 41-42 mph stock at 8200, I'm hoping to c some nice mph increase after I install my kit. I've got a boonie box ordered as well as a carls clutch kit, but 64 grm, I was thinking 68 gr but teck at carls said 64. I'm at 35-5000' in bc

 

[Washy]

Did you hit det code? Also did u notice your track speed in powder on a hill.
Mine does 41-42 mph stock at 8200, I'm hoping to c some nice mph increase after I install my kit. I've got a boonie box ordered as well as a carls clutch kit, but 64 grm, I was thinking 68 gr but teck at carls said 64. I'm at 35-5000' in bc

Yes I did hit the DET. I did not notice the track speed.

 

[live2beel]

With all of these diff. Drop-in kits out there, I wish someone would put them on a crank dyno. Stock vs drop-in on the same day same dyno. I woul like to see this on th 13 since it seems to have a little more punch stock than previous years. I have asked Rk-tek why he has dyno #"s for Doo & Cat on his website but nothing for POLARIS and he won"t reply. Just seems strange from a customers point of view.

 

[PaulAnd]

Mine---> 2010 cfi4, Rkt drop in kit stock compression domes, c3 belt drive--> 2:14 ratio, 7tooth avid, 153 track, carls helix, stock clutch's and springs, stock exhaust, no controller
just tried the 10-64's @ 1000 feet, 8600rpm @ 89 mph
aprox 500 miles on kit runs awesome

Thanks Norway

 

[Norway]

Mine---> 2010 cfi4, Rkt drop in kit stock compression domes, c3 belt drive--> 2:14 ratio, 7tooth avid, 153 track, carls helix, stock clutch's and springs, stock exhaust, no controller
just tried the 10-64's @ 1000 feet, 8600rpm @ 89 mph
aprox 500 miles on kit runs awesome

Thanks Norway

Any time.

89mph, cant be climbing??

 

[mountainhorse]

It is great that a vendor like VOHK will come on here to comment on his experiences with a product.

Please lets keep this thread on topic... if you have other products to talk about or want to make comparisons to other products...please start a new thread about that.

Thank you for helping me keep this thread on topic.


.

 

[RKT]

Still getting great reports from the drop in kit..

I appreciate all the feedback...

 

[Trxstr]

Piston clearance RKT drop in kit

Does anyone know what the allowable or ideal piston to cylinder clearance should be on the RKT drop in pistons on a 2012 Pro RMK 800?

 

[ditch1000]

Still getting great reports from the drop in kit..

I appreciate all the feedback...

Have your back ordered pistons come in yet Kelsey??? Are the backordered kits shipped out yet?? The pitfalls of a good product I guess....

 

[RKT]

Have your back ordered pistons come in yet Kelsey??? Are the backordered kits shipped out yet?? The pitfalls of a good
product I guess....

The back order was the result of a misplaced "order" email.. It is the 1st time this has happend and it will never happen again because I will follow up every order with a phone call instead of relying on the email system

To answer your question, the piston arrived in Cali today, so they will ship to me this week..

Sorry for all the delay... it was an unfortunate tunr of events that led to this.. It will never happen again...

 

[Trxstr]

Still getting great reports from the drop in kit..

I appreciate all the feedback...

What should the tolerances be for the drop in kit Kelsey?? 2012 pro RMK 800...

 

[RKT]

Still getting tons of positive results of this INEXPENSIVE kit that REALLY does deliver...

Thanks for all the feedback people...

 

[maxitout77]

I wanted to share my experience with Kelseys Direct Replacement Pistons. (IE pistons only, no head, can add that later)

'11 Pro, 3 turns oil screw. Im at 450 miles with these pistons. Although I cant say there is any more power or performance, I can tell you this is the best my engine has ever ran. It idles much smoother, builds revs quicker, and overall just feel much better than the stock motor. I have been able to jump back and forth from my '11 to a '13 and I can notifce the difference. I cant think of a better $360 I've spent on my sled.