19 replies to this topic

[BRAAAPF7]

I have RK Tek's first kit for the DD fix. Just wondering if there is more of a benefit to run the second kit with the helix over the first kit that i have?

[RK Tek]

Yes, there are several advantages to the new kit.. We have incorporated a couple of changes that allow for cooler running clutching and less belt slip..

The new kit is also much easier to adjust and install.

Both kits work well. but the new kit , from testing, shows better overall performance

[zx 800]

What is the differance in hp between your head vs the drop in kit. I know about the advantages of the single ring vs the dual. That the dual will not drop the hp like the single ring when heat soaked.

[RK Tek]

The drop in kit includes the head and a custom base gasket..

Basically, it was developed to address the heat-soaking issues that is present with the stock piston.
We took it a step further and custom machined the piston to have a geometry that also added some serious power gains. So the drop in kit, due to its custom piston design, will increase power output over an engine that is just equipped with our head.

Kelsey

[adrenalator8]

Kelsey:

what needles do you recommend for your 827 kit with porting.
I tryed the a needle shim and jetting the main up but couldn't keep it from scuffing the pistons after along pull across the lake "3000' "

I ran it with egts and the mids where really lean and I figured it was happening when I was letting off the throttle ,
Any ideas?

Thanks.

[Jeb]

I read how you heads perfom by using less fuel and better com chamber design. How do you incorporate this with the 600 sdi when we cannot change fuel flow?

[Simon R]

I read how you heads perfom by using less fuel and better com chamber design. How do you incorporate this with the 600 sdi when we cannot change fuel flow?

Better specific engine output for same quantity of fuel injected = better economy (faster engine acceleration, broader torque band will result in less throttle usage to acheive the same results).

Good Luck,

T.D.

Kelsey:

what needles do you recommend for your 827 kit with porting.
I tryed the a needle shim and jetting the main up but couldn't keep it from scuffing the pistons after along pull across the lake "3000' "

I ran it with egts and the mids where really lean and I figured it was happening when I was letting off the throttle ,
Any ideas?

Thanks.

What thickness needle shim are you using ?

T.D.

[adrenalator8]

I think it was a 0.030th shim,I had a really bad lean spot at around
7000rpm,i think these #'s are right it's been 3 years sence I ran it.

Cliff

[RK Tek]

The less fuel is a result of a higher combustion efficiency of the head..

Whenever you make ANYTHING more efficient... you need LESS "X" to make the same "Y"

In the case of the head.. the Stock DOO head is very inefficient. meaning it converts a smallpercentage of F/A mix into energy that contributes to the power. So you always have excess raw unburnt fuel surrounding the head and piston and this acts as a cooling agent and keeps internal engine temps lower and aid in preventing engine failure.. What it also does is greatly lower engine power .

My head designs have a much higher combustion efficiency and have much less raw fuel left in the chamber after combustion.. So, since it is combusting a higher percentage of F/A that is "thrown" at it.. it requires less F/A to have complete combusion.

In the case of the SDI..the head by itself shows great power increases. this is just simply becsuse the chmaber design is much better than OEM.. If you want to acheive the max power from the head addition, an EFI controller is needed such that fuel can be pulled at WOT..

827 guy.. We ride Summits.. I run stock needle I suspect you have an aftermarket can or exhaust system that is causing the failure not a carb only problem.. We have found that the aftermarket cans and exhaust will cause a instant lean condition.

Also, check the base of your cylinder near the bust port.. These will warp and cause an air leak and instant burn down when letting off the throttle..

We have also redesigned the piston to allow for much better resistence to seizure.

We also have a custom timing curve that pulls timinginthe lower rpms that seems to help in that area also

Kelsey

[adrenalator8]

Kealsy:

I ran the stock exhaust no can or pipe! This problem showed up in the first 40 miles so if it was the cylinder it was that way right out of the box??
I know that part of the first stick was from the nikki not adhearing well,when I pulled it apart there where flakes of nikki coming off that cylinder??
not sure why, could have been just bad bonding , but I had it redaone by Berniard in Quebec and the cylinder has lived fine after 2 more sticks.

I never had a problem with it out on the trail it was only on the lake.
It always stuck when getting out of the throttle.
as for the lean spot I just learned to drive around it ,
I was just wondering what you had come up with to help with the lean problem.

The kit made great power and was a blast to drive so later this winter I would like to put the cylinders on another block at do few tests on the dyno.

Cliff

[06MXZXRenegade800]

Ok, ill bite. Your heads are available color anodized. whats the options? :)

[06MXZXRenegade800]

aww, no PINK?!?! LOL

Gold sounds good. I was just wondering what kind of funky creations would have been available but i dont want or need anything fancy!

Kelsey, you better not sell that kit! It will be coming my way shortly if all goes as planned!!! lol




T minus 11hours and counting till payday :)

[BIGBLOCKTODD]

Yes, there are several advantages to the new kit.. We have incorporated a couple of changes that allow for cooler running clutching and less belt slip..

The new kit is also much easier to adjust and install.

Both kits work well. but the new kit , from testing, shows better overall performance

OK I HAVE A 2005 ZR 900 EFI IT HAS 85GRM DOLTENS 50-40 DOLTEN HELUX VFORCE REEDS 10.4 CLUTCH AND THE 06 BELT TORQUE ARM AT WHAT PERFORMANCE GAINS WILL I GET OUT OF THE RT TEK I MOSTLY TRAIL AND RACE 660 FEET IN THE SNOW

[machz69]

Hi there.... I have a 975 its 780 based... full porting..(race).. 670 rods..could get a one piece head that I could use my 809 top half (head)?. I dont want the head to cut so that it can only be run for 600'.. i will be running 2000'..

Thanks

[Garret 800HO]

I was just wondering if Kelsey still answers questions here?

Got a question aboot my RK tek computer upgrade... I love it, but wanna know more about it.. Doesn't say a lot about it on his site. Any way, if you still do, I'll post later what I needs to know!
Thanks!

Garret

[EASY]

I just bought an 05 rev 800/151 with the full RK drop in kit ( head, pistons, mpem upgrade) I ride in Golden and Revelstoke B.C.
Do I need to mix with race gas at that elevation??
how low can I go before I should consider mixing fuel??

Iam new to these kits so the more info the better, Even if it seems very basic to some of the guys who have been doing this for a while.

Thanks

(I have gone to the RK site, but that is not the info I was looking for unless I was looking in the wrong spot)

[adrenalator8]

I just bought an 05 rev 800/151 with the full RK drop in kit ( head, pistons, mpem upgrade) I ride in Golden and Revelstoke B.C.
Do I need to mix with race gas at that elevation??
how low can I go before I should consider mixing fuel??

Iam new to these kits so the more info the better, Even if it seems very basic to some of the guys who have been doing this for a while.

Thanks

(I have gone to the RK site, but that is not the info I was looking for unless I was looking in the wrong spot)

HI.

That kit is mostly designed to increase the efficiency of the engine,I don't think there was a increase in Compression ratio, so I would be inclined to run 92 octane, race gas would be a over kill and you would lose power.

I ran his 827 kit at seal level and never needed anything over 92 and it was in the 165HP range.

Hope this helps

Cliff Yeatman
advanced dyno