Cylinder head ?

[Psycho1]

I was checking the cylinder head on my 90 Kat 600 and noticed the casting on number 3 intake runner plainly shows S-1 on it along with 12/CO. I looked for the dot everyone always refers to when talking about the S-1 heads, and can't seem to find one. From what I have been told, the Kat 600's normally had an S-3 head stock. Is this S-1 with no dot a standard Kat 600 head, or something done by before I bought it. PO claimed someone that worked for Team Suzuki did some modifications to the engine back around 1990-1991. Thanks

[HS2020]

S-1 is the GSXR Slingshot Heads. The S-2 is the GSXR Heads. The S-3 is the katana heads. At least that is what has been said on here a few times.

[Psycho1]

Yeah I remember reading that several times, but all mention of the S-1 heads refer to the S-1 on the casting like I have, along with a dime sized flat which I don't believe in on my head.

[HemiKat]

I dont really know what I have, but my head says S-1 on one carb port, and then has a dime sized raised spot on the other carb port.

Thats not really any help is it?

[Psycho1]

I've read the dime sized flat was supposedly on the cooling fins, not on the port. If it's actually on the port, I'll have to look again.

[kevin2502000]

Mine is on the cooling fins.

[HemiKat]

Mine is on the cooling fins.

Got a pic?

[kevin2502000]

I could if I was at home but I'm not so.......nope.........but there IS one on here somewhere...........

http://katriders.com/vb/showthread.php?t=104705

Not a pic but more info

[loudnlow7484]

"Dot Heads" have a dot on the side of the head, across the cooling fins (about the size of a dime).

the S-1, S-2, S-3 thing I can't personally verify. I can verify that both of the early 750 heads that I own that have the dot, and S-1 on them also have a dot with "17/C0" on it under one of the intake runners which corresponds to the part number of the head.

I would guess that the S-#'s probably have to do with when the castings were revised, and you can likely find these numbers on any head of the era. It's just rumored that the S-1 dot head is the best of them (would be the first version, if I'm correct about this).

[kevin2502000]

"Dot Heads" have a dot on the side of the head, across the cooling fins (about the size of a dime).

the S-1, S-2, S-3 thing I can't personally verify. I can verify that both of the early 750 heads that I own that have the dot, and S-1 on them also have a dot with "17/C0" on it under one of the intake runners which corresponds to the part number of the head.

I would guess that the S-#'s probably have to do with when the castings were revised, and you can likely find these numbers on any head of the era. It's just rumored that the S-1 dot head is the best of them (would be the first version, if I'm correct about this).

No need to be racist.........

[HemiKat]

I have two heads on my garage and both have dots of the outside of the fins. One is a S-2, and says co/17. The other is a S-1 but I could find my mirror to verify the date code.

That still doesnt help does it?

[Psycho1]

nope, but if I can get a pic showing the dot, I might be able to check something on mine. Wondering if possibly the dot was removed in an effort to hide the fact that it wasn't the factory head. OR as I mentioned earlier, maybe the S-1 CO/12 may have been a older version without a dot.

[Islandsteve]

Very interesting, I'm going to check mine when I get home tonight

[Psycho1]

Ok, ThAzKat took some pics of the dot, which are actually on the 750 cylinder blocks cooling fins, not the head itself. This leads me to believe the Dot means nothing other than maybe giving an assembly timeline for the engine as a whole, which may also mean a chance of having a little better cams in the S-1 head. The dot may also have something to do with bore capacity, since some cylinder blocks have a larger sleeve OD at the base where the sleeve fits into the block, as Arsenic found out while prepping his block for the bigbore kit. Another member checked both pre 600 engines he has, and they both have S-2 on the heads.

[kevin2502000]

Ok since I just took the pics I'm going to post them even though you already got your answer