RK Tek performance head vs Slavens S3 vs cut stock heads

[BowHunter2400]

So recently I watched a YouTube video by Kyle (aka Dirt Bike Channel) on the new RK Tek head on his 2017 300xc. I had been set on a Slavens S3 head for my 250xc but now I gotta know which one is best! The RK Tek

is rather expensive compared to the S3 so I'm wondering if it really does deliver all that it claims!?! WHAT SAY YOU

BTW - Kyle has a great channel on YouTube and no I'm not affiliated with him just saying

[KPRacing]

The rm Tek head will be the better head.

The ridges do a number of things.

They help with mixing the mixture as well as the small peaks of the ridges give the harmonics (in all engines) a place to escape the engine structure. These harmonics happen to "ring" at a frequency the does "things" (too deep to get into) to the molecules that make up the gas. This physical "change" to the molecules along with the mixing effect are responsible for the power.

If the ridges could/would be made even more pronounced or peaked, power would go up even more.

[GASKICKER]

You should send Kyle a message about the differences as he has had both - on his 2015 he ran a Slavens and the 2017 has the RK Tek. Slavens is widely known among this group where RK Tek is very well known with sledheads.

I actually have the same question as you so hopefully someone with some seat time with both will chime in.

[superhero17]

I read somewhere that the two piece heads tend to vibrate loose over time and are more for race. Any truth to this?

[JCskylight]

Yeah, it would be great if someone with some actual experience with these 2 heads would chime in.  I'm in the market for something to increase the low end grunt and mid range.

I'm coming off a YZ with the Eddie Sanders 345 kit which is a serious grunt monster, big time.  The '17 300xc, which I recently bought, is somewhat weak down low, and that's with the Slavens Lectron Mule installed and a 51 tooth rear.  I'm wondering if the "sled heads" may prefer the RK tec head because it breathes better at higher RPM's.  Has anyone tried this head on a woods bike where grunt and mid RPM's rule ???????

JC

[KennyMc]

KTMTALK has a couple threads on it. In one I believe it was stated that Slavens verified the S3 is a stock head cut down and anodized. The RK tek head is actually a different shape based on your conversation with them.

[Chas_M]

9 hours ago, KennyMc said:

KTMTALK has a couple threads on it. In one I believe it was stated that Slavens verified the S3 is a stock head cut down and anodized. The RK tek head is actually a different shape based on your conversation with them.

 

I would think that this is not the case since the S3 is a custom design two piece unit.  The design may be similar to the stock head but certainly is not simply a 'cut down' stock head.

 

[KennyMc]

35 minutes ago, Chas_M said:

 

I would think that this is not the case since the S3 is a custom design two piece unit.  The design may be similar to the stock head but certainly is not simply a 'cut down' stock head.

 

Give him a call.  But my understanding is the shape of the head remains the same, where-as the RK head does not.

Edited February 16, 2017 by KennyMc

[DASFUEHRER]

I've had both. Had the sg3 on my 2013 300xc and I'm currently running the rk tech head on my 2017 300xc. Go with the rk tech head. They have a patent on that head for a reason. It gives the bike power everywhere! The slavens mule will only boost the bottom and some mid range. The rk tech head makes the 300 feel "4 stroke ish" meaning the power becomes more linear, and more of it! My .02. ?

[DASFUEHRER]

Here's a side by side comparison between the rk tech and the stock 17 head.

[JCskylight]

Thanks guys !  It's great to be able to get information from someone that has already experienced a particular product.  I think I'll go with RK-Tek.  I'll give them a call .  You can see just be looking at their head there is a lot of R&D that went into the development of the head.  Someone with a lot more education than me designed that thing, it's out there for sure !

JC

[ridindirty]

Very surprising seeing the RK TEK head with a metal finish like that, not expecting to see that. You would think it would be nice and uniform. Interesting...

[JCskylight]

At his point, I'm sure I'll go ahead and buy from RK-Tek.  I emailed Slavens last week asking about the S-3 head and never got a response.  If I can't get help about a product in order to make a purchase, getting help "after" a purchase seems doubtful.  I'm a little disappointed with Slavens, esp, after hearing guys on thumper raving about how much help they got from Jeff.  Oh well.   Appears the RK-Tek head is a more advanced head anyway.

JC

[Creeature]

The s3 is just an sx head...

[3pine]

Just put an RK Tec on a 300 Beta. More power bottom to top . Linear, Electric. A Dream come true motor. 

[hopsterj]

sorry for bringing this thread up again a bit later....

If one really wants to understand the RK Head, you need to talk to Kelsey at RK.

I very recently installed the S3 on my bike (2017 250xcw), and honestly didn't notice much difference from stock while riding it around (so, it's coming off asap), which has now led to this unfortunate and expensive experiment...today I ordered the RK head after chatting with Kelsey for over an hour...the guy understands 2 stroke engines probably better than anyone on this continent (he's candid and blunt, which is refreshing vs. the typical BS). The guy's a 2 stroke beast engine snowmobile guru....hmmm, sleds compared to bikes? my guess/gut tells me the guy knows his sh*t. Wish I would've gone this route to begin with.

It's amazing, give YouTube to a retailer and they make everyone think they need to drink their cool aid. Want an education in jetting and carbs also? Kelsey's a great resource. Personally, I'll go nowhere else from here on....no one else "boldly states" to refund/return the product if it's not to your liking....has to be good then.

Btw....S3 is in Spain, Slavens is a US retailer.  http://s3parts.com/product.html

Edited May 31, 2017 by hopsterj

[sbest]

RK looks like a variation on the Singh Swirl and knurled squish fad that went on 15 years ago. 

I've done a lot of work with 2 stroke head design. I had an aftermarket Blaster head with a similar finish. I really could not find an advantage. The chamber design looks to be more slanted toward high rpm output at the expense of low rpm. To be honest, as a machinist, it looks to me as if RK is just doing all the machining on the mill table to save costs.

[KennyMc]

RK looks like a variation on the Singh Swirl and knurled squish fad that went on 15 years ago. 
I've done a lot of work with 2 stroke head design. I had an aftermarket Blaster head with a similar finish. I really could not find an advantage. The chamber design looks to be more slanted toward high rpm output at the expense of low rpm. To be honest, as a machinist, it looks to me as if RK is just doing all the machining on the mill table to save costs.

Interesting article.....

https://pesn.com/archive/2005/10/13/9600187_Design_to_Improve_Turbulence_in_Combustion_Chambers/index.html

[peaceofwork]

kelsy is the best just ask him he will tell you - hes good at taking the time to explain his views and at least he answers his phone

[IanInCalgary]

On 5/30/2017 at 8:07 PM, hopsterj said:

sorry for bringing this thread up again a bit later....

If one really wants to understand the RK Head, you need to talk to Kelsey at RK.

I very recently installed the S3 on my bike (2017 250xcw), and honestly didn't notice much difference from stock while riding it around (so, it's coming off asap), which has now led to this unfortunate and expensive experiment...today I ordered the RK head after chatting with Kelsey for over an hour...the guy understands 2 stroke engines probably better than anyone on this continent (he's candid and blunt, which is refreshing vs. the typical BS). The guy's a 2 stroke beast engine snowmobile guru....hmmm, sleds compared to bikes? my guess/gut tells me the guy knows his sh*t. Wish I would've gone this route to begin with.

It's amazing, give YouTube to a retailer and they make everyone think they need to drink their cool aid. Want an education in jetting and carbs also? Kelsey's a great resource. Personally, I'll go nowhere else from here on....no one else "boldly states" to refund/return the product if it's not to your liking....has to be good then.

Btw....S3 is in Spain, Slavens is a US retailer.  http://s3parts.com/product.html

The S3 advertising doesn't say it improves performance so the S3 head is basically bling.  Someone on KTM Talk presented dyno graphs which showed performance of stock vs S3 heads - barely any difference.

 

The S3 head offered by Slavens Racing, however, does improve performance.  The Slavens S3 head is not the same as the S3 head available elsewhere.

 

Ian