Cylinder head questions

[Doc Brown]

I have seen a S3 cylinder head set for the 2018 EC 300.

Am I wrong or should that fit also my 2019 EC 300? As far as I know cylinder, head should be the same. No clue about the ignition systems and if they are relevant.

There are three inserts, silver, black and red, no clue which one does what, but the dealer's description says: standard, standard+, and standard++.

Anyone here who can widen my horizon please?

 

[TGM_OFFROAD]

I have seen a S3 cylinder head set for the 2018 EC 300.

Am I wrong or should that fit also my 2019 EC 300? As far as I know cylinder, head should be the same. No clue about the ignition systems and if they are relevant.

There are three inserts, silver, black and red, no clue which one does what, but the dealer's description says: standard, standard+, and standard++.

Anyone here who can widen my horizon please?

As far as I know it should also work for the 19. The head inserts are same design as factory head less squish so higher compression. Standard is same as stock, standard plus is high compression which If I remember was still about 2mm of squish with the stock base gasket and the ++ is even higher compression with about 1.8mm squish, again if I remember correctly. The domes are not reshaped as far as I can tell. I prefer the rk tek to be honest but both seem like good options.

 

[hannesd]

why would you buy the S3 head with inserts if you still need to put them on the lathe to decrease squish? you can just aswell put the orginal head on the lathe, or even cheaper, just put a smaller base gasket on and be done.
and IF you should screw up the original head, THEN you can still find another head aftermarket or original...right?
we all know someone who knows someone with a lathe, right?
if you're worries about compression going uptoo much with the thinner base gasket, measure volume with oil and piston in TDC and verify with other measurements from fellow members.
just my 2 cents guys...

 

[Doc Brown]

Thank you guys, my questions have been perfectly answered.

 

[Jakobi]

Hey Doc.

Back on my 2010 model, I used the black insert with a 0.5mm base gasket.. It gave me 1.25mm squish and waaaay too much compression. Had the insert cut to give more volume and she was a very nice engine after that.. All up cost a lot more than just having the stock head worked though.

 

[dANbOT]

For me, at elevation.. the high comp insert and base gasket adjustment got my squish / compression ratio bang on. More expensive, but zero turnaround time. I feel like the S3 head also translated to some extra cooling.

 

[Doc Brown]

Thank you guys!

@Jacobi

That's strange, the compression should only be raised but not be too high. Is it possible that S3 sent you a wrong insert? dANbOT's worked obviously well...

 

[Jakobi]

I was on a 250 too.. they run higher comp than the 300's out of the box to start with. It's the same as trying to close the squish up with the stock head simply by removing base gaskets alone.. You push the CR through the roof.

Higher octane fuels, and altitude both allow greater compression ratios too.

S3 head insert combustion chambers are some volume as stock.

 

[Undertow]

For GP300 -18, I switched from stock head to S3 and high comp insert (the medium one that came with the head).

Stock head had wayyy too much compression. Pinged every time I closed the throttle. S3 head made it a lot smoother to ride with nice fuel economy.

 

[Doc Brown]

I was on a 250 too.. they run higher comp than the 300's out of the box to start with. It's the same as trying to close the squish up with the stock head simply by removing base gaskets alone.. You push the CR through the roof.

Higher octane fuels, and altitude both allow greater compression ratios too.

S3 head insert combustion chambers are some volume as stock.

Changing squish by altering base gaskets is a very bad and unprofessional way to do it imo. I agree as S3 says that their inserts are same volume as standard head.

 

[Doc Brown]

For GP300 -18, I switched from stock head to S3 and high comp insert (the medium one that came with the head).

Stock head had wayyy too much compression. Pinged every time I closed the throttle. S3 head made it a lot smoother to ride with nice fuel economy.

Another strange thing. Must be a quality issue, none of my 2019's (both 300's) pinged on deceleration...

 

[taylor146]

Hi, I suffered from decel ping/ knock on my 2018 300 that I couldn't seem to jet out. Checked the comp ratio and it was 13.85:1 std. With high sqish. Fitted the S3 head with highest comp black insert which reduces comp to 13:1 with reduced squish which cured my running problems. I have been told that the std 19 head is lower comp STD. I'm in the UK and suspect that different fuels across the world will have different effects .

 

[Doc Brown]

I have been told that the std 19 head is lower comp STD. I'm in the UK and suspect that different fuels across the world will have different effects .

That's indeed interesting. I only heard that the EC 300/19 head is different vs the EC300/18 head.

Fuels are high quality over here, I can run 95 which we call "super", 98 "super plus" and 101 "power". The latter one is incredibly expensive so I don't use it.

Has anyone with a EC300 tried the cylinder head of the GP model? Allegedly it should be "better" whatever that means....