[Psycho1]

Thanks for the pics Kevin. In those pics it does look like the dot is on the head not the cylinder. It's hard to make out exactly where the break between the head and cylinders are, but it looks like it might be in the gap between the cooling fins right below the dot.

[kevin2502000]

Thanks for the pics Kevin. In those pics it does look like the dot is on the head not the cylinder. It's hard to make out exactly where the break between the head and cylinders are, but it looks like it might be in the gap between the cooling fins right below the dot.

It is definitely on the cylinder.

[loudnlow7484]

It is definitely on the cylinder.

It is definitely on the head....... I have a head (just the head) in my garage... the dot is on the head. I just came in from out there, otherwise I'd run out and take a picture.... but be assured, the dot is absolutely, 100%, positively on the head.

[kevin2502000]

It is definitely on the head....... I have a head (just the head) in my garage... the dot is on the head. I just came in from out there, otherwise I'd run out and take a picture.... but be assured, the dot is absolutely, 100%, positively on the head.

Hmmmm..... I will have to take a better look tomorrow.

[mreedohio]

couple pics of the dot on thazkat's 750

[600toStart]

[loudnlow7484]

Hmmmm..... I will have to take a better look tomorrow.

I'll save you the trouble.......

just the head, with the dot.....

[kevin2502000]

Ok Thanks I believe you now, looking at 600tostarts it also looks to be on the cylinder but it must be right at the mating surface as shown on your pic.

[HemiKat]

Both my S1 and S2 heads have the dot...anyone have a head without the dot? Just curious.

[Psycho1]

The S-1 head on my 600 doesn't have the Dot.

[600toStart]

We must get to the bottom of this!

[loudnlow7484]

Only 750 heads would have the dot, and only pre98 models. The original "dot head" was the 88-89 GSXR750 head (short stroke 750). So as long as they kept that casting, they should have the dot. If you're saying that the S2 head also has the dot, then they obviously kept the dot regardless of any other changes. I can't personally verify that the ports are any different on an S1 vs S2 vs S3 head...... it's all just word of mouth. Unless somebody here has a flowbench we can toss the heads on, I doubt we can really know for sure. The best I can come up with is that, in theory, the earlier the head, the closer it will be to the original casting of the 88-89 GSXR head.

If there is anybody that can tell about the performance differences on here, it would probably be Suzukiray. I believe he uses the dot heads on old 4 valve GS race motors, so he would be after the best flowing heads.

The 98+ 750 head, so I hear, is a pretty close clone of the either 90 or 91 (I can't remember which) GSXR750 head, which is about as good as it gets for the long-stroke 750's. There was a guy on one of the GSXR boards that was using one, upgraded with Yosh titanium parts and GSXR cams.

[Psycho1]

I'm just thinking my S-1 may be from an 86/87 GSX-R750 or something pre dot. Then I don't know what the difference would be between that head and the S-1 with the dot as far as the valves and ports.

[loudnlow7484]

I'm just thinking my S-1 may be from an 86/87 GSX-R750 or something pre dot. Then I don't know what the difference would be between that head and the S-1 with the dot as far as the valves and ports.

The 86-87 head would have smaller ports. They came factory with 29mm flatslides, so the ports would match up with that. Any GSXR head would also have a distinct gray color to it, unless it was repainted to match. I'm not positive that the early 750 head's valves would clear the smaller bore of a 600, but then the whole 750 top end can be swapped onto the 600 bottom end (or the 600 block could be resleeved to accept 750 pistons). If you suspect that parts may have been mix-n-matched on your engine, there may be no way to find out exactly where they came from. Suzuki wasn't always so big on stamping part numbers on everything...... funny how something like connecting rods (which could be more easily identified by measurements and construction) are stamped with their part numbers, but a more complex item like a head isn't.

You could pull the head off, and measure the valve sizes, check the combustion chamber volume, get some port measurements, and measure your bore (to see if a 750 top end was swapped on), and then MAYBE you could figure out where the parts came from.

[Psycho1]

Yeah, the cylinders appear to be somewhere around a stock 62mm-ish bore still. Cooling fins on the S-1 head stick out a little further than the cooling fins on the 599cc cylinders. The head appears to have been shaved, and is black with no grey paint underneath. The head should have been put on sometime in 90/91, so it would be older than that.