I learned something cool at NHRA Gateway today

[jeffgs]

I ran into PSM Steve Johnson's mechanic today and i had to ask how close was his motor was to the original production GS1100 four valve and was surprised to learn the basic "short block" is actually pretty similar but the head would obviously be an extremely modified version of that basic design, or like a high port 17 degree sbf head verses what i would normally run, a 20 degree version.

Anyway i had read some interesting tech info on that head design and it centered on the combustion design, as if it were a triumph of engineering. So anyway it just added another brick to solidifying my appreciation for this very special motorcycle

 

[blowerbike]

the cases is the only GS part used in PSM today.

 

[850 Combat]

When it was new, I read in the contemporary motorcycle press that the 16 valve TSCC Suzuki GS1100 head resembled the Cosworth DFV cylinder head. The DFV was probably the most successful pure racing engine ever, if you include the Indy DFX version. It won F1 races for 16 years or so, and CART races for about a decade.

 

[GregT]

When it was new, I read in the contemporary motorcycle press that the 16 valve TSCC Suzuki GS1100 head resembled the Cosworth DFV cylinder head. The DFV was probably the most successful pure racing engine ever, if you include the Indy DFX version. It won F1 races for 16 years or so, and CART races for about a decade.

It resembles the Cosworth head of the same period only in that they are both 4 valve...If you have a look on the underside of a 4valve GS, GSX or GSXR head you'll see a patent number. Basically this patent covers the design of the 4 "pockets" the valves sit in - and also the shaped ridges around the pockets.
The Cossie layout is very plain with no ridges or pockets. According to Prof Gordon Blair at a talk he gave here some years back, modern F1 combustion chambers consist of the valve cutaways in the piston and absolutely minimal squish clearance everywhere else.

 

[jeffgs]

I was hoping for this.

i am going to study more on it soon, i get into the engineering of it a lot. I was beat down early for being consumed with runner size and valve lift. Now i am into the stabilization of the detonation and flame speed and coverage. A lot of small tire radial racing limits the port size and valve angles and it is amazing what you can get out of a cnc 225 head on a large small block. By focusing on quench and stabilizing the mixture on the border of the piston to prevent it pre detonating we have been able to safely add more tune with a single plate.

Which brings me back to the production Suzuki head and what a winner it was. I was impressed by Honda bolting a CVCC head on a sbc just to shut G.M. up. I often get mocked at work for extolling the benfits to the combustion chamber when using multiple valves and cams when hotrodders still want cam in block

 

[rapidray]

The 16 valve FACTORY Suzuki head is a VERY good design. Unfortunately, the NHRA requires the Suzuki Pro Stock engines to use the stone age 8 valve design head. They can use either the Vance & Hines head or the Ward Vortex 2 head. The 16 valve heads are illegal in NHRA Pro Stock & is just the STUPIDEST crap in the world. It's the same with them not allowing fuel injection on the Pro Stock cars!!
Ray.

 

[jeffgs]

Well they did the same to he Harleys this year. i sorta understand from a competative stand pointt for one team will runaway based on a number of things.....but it has been the complaint that there should be a component of allowing them to bring the best their manufacturer has. After the whole Warren Johnson deal with the DRCE head and the Buddy Ingersol turbo Buick debacle i have felt for sometime there is more to how they govern classes i.e. i think there is more lining of pockets that turns the rulebook. Remember NHRA is where Ford turned to when the babies at Chrysler whined until NASCAR banned the SOHC motor.

I am sorry I have been pretty commited to stop bad mouthing but I get the frusteration.

 

[GregT]

The 16 valve FACTORY Suzuki head is a VERY good design. Unfortunately, the NHRA requires the Suzuki Pro Stock engines to use the stone age 8 valve design head. They can use either the Vance & Hines head or the Ward Vortex 2 head. The 16 valve heads are illegal in NHRA Pro Stock & is just the STUPIDEST crap in the world. It's the same with them not allowing fuel injection on the Pro Stock cars!!
Ray.

No argument from me on the Suzuki 16V heads - two points : the Britten motorcycle which i'll assume some of you have heard of, used a chamber shape VERY similar to the (patented) suzuki one. Even the 5 valve version used the pockets and ridges we're familiar with. That team could have copied any head shape they liked - they had access to cossie bits to look at i know - but they copied the Suzuki layout....because it works.
And second....locally i hear roadrace car teams here moaning that spectators cars in the car park are using higher and more modern technology than they're allowed to use in the race cars....So tech limitation rules are becoming more common, darn it (this site won't let me say what I really think....)

 

[Guest]

locally i hear roadrace car teams here moaning that spectators cars in the car park are using higher and more modern technology than they're allowed to use in the race cars....So tech limitation rules are becoming more common, darn it (this site won't let me say what I really think....)

That's because racing has become about entertainment first and development second or not at all (in the case of Nascar). BTW, are you the same Greg T from the M-C Chassis Design list?


Mark

 

[BadBillyB]

I guess I was one of the lucky ones, because I ran P/S motorcycle back in the 80's when 95 percent of the motor was factory Suzuki parts. Back then it was all about what you knew about motors and not how much money you had. I had less than 5 grand in my whole bike, but got to run with the big boys at the Gatornationals (my home track) back in 1985.....You could be competitive with off the shelf parts if you had a good cylinder head/cam combo and a decent chassis. This will never change....Byron Hines himself couldn't figure out how in the hell a GS1000 "L" model ended up in the staging lanes on Sunday for eliminations. Back then we ran modified dirt bike carbs and spoke rims.......(fast forward 30 years) The average guy now is stuck being a spectator. There's a reason P/S motorcycles are only seen at NHRA events, and it's all about $$$$$$$....And who do you think is making it ???......This will never change..... George Bryce from Star Racing sketched out on a dinner napkin, a cylinder head design that could have rocked HD's world and is currently being sold as the "Monstar" head in a joint effort with Mitch Brown. NHRA shot this design down and made the Harley guys go back to 2 valve configurations. This is why the Suzuki guys are still running 2 valve motors......Doesn't make sense to me at all. What are they going to do when all the GS1150 cases are all gone ????........Then will it still be a Suzuki????......Billy

 

[Guest]

I heard v&h purchased the last 200 cases that Suzuki made about a year or so ago