GS1000 Cylinder Head Performance Upgrade Options

[rapidray]

It is also EASY for me to convert the round exhaust ports to "D" shape, I do it all the time. The benefit to the G head is bigger ports to begin with. Then the porting is less expensive for the customer as the time to turn a small port head into similar to a G is pretty involved. Ray.

[theDoktor]

Ray, a couple of technical questions about this head conversion: with Weisco 1085's in a 78 GS 1000 (8v), the piston crowns are relieved for just a single intake & exhaust valve. With the 83/84 GS 1100 head, are the valve reliefs in the Weisco pistons appropriate for the larger valves in the 1100 head? Does this conversion use the GS 1000 or GS 1100 cam chain? I assume they are a different length, but don't know for sure. What do you recommend for a mild street-oriented cam? In lieu of aftermarket cams, any recommendations on appropriate settings for degreeing the OEM cams?
I just may have to consider parting with my spare large-port GS 1000 head & cylinder block & go this direction instead.
Anyone interested in considering a trade for an 83/84 GS 1100 head? May have to consider parting with my VM29's too to finance some RS carbs...

[gs road racer]

Ray, a couple of technical questions about this head conversion: with Weisco 1085's in a 78 GS 1000 (8v), the piston crowns are relieved for just a single intake & exhaust valve. With the 83/84 GS 1100 head, are the valve reliefs in the Weisco pistons appropriate for the larger valves in the 1100 head? Does this conversion use the GS 1000 or GS 1100 cam chain? I assume they are a different length, but don't know for sure. What do you recommend for a mild street-oriented cam? In lieu of aftermarket cams, any recommendations on appropriate settings for degreeing the OEM cams?
I just may have to consider parting with my spare large-port GS 1000 head & cylinder block & go this direction instead.
Anyone interested in considering a trade for an 83/84 GS 1100 head? May have to consider parting with my VM29's too to finance some RS carbs...

you want a four valve GS1100 head in trade for your large port 2 valve GS1000 head? hmmmm maybe PM me

[Nessism]

Ray, a couple of technical questions about this head conversion: with Weisco 1085's in a 78 GS 1000 (8v), the piston crowns are relieved for just a single intake & exhaust valve. With the 83/84 GS 1100 head, are the valve reliefs in the Weisco pistons appropriate for the larger valves in the 1100 head? Does this conversion use the GS 1000 or GS 1100 cam chain? I assume they are a different length, but don't know for sure. What do you recommend for a mild street-oriented cam? In lieu of aftermarket cams, any recommendations on appropriate settings for degreeing the OEM cams?
I just may have to consider parting with my spare large-port GS 1000 head & cylinder block & go this direction instead.
Anyone interested in considering a trade for an 83/84 GS 1100 head? May have to consider parting with my VM29's too to finance some RS carbs...

The valves and cam chain are the same for the 8V 1000 and 1100 engines. Just so you know in advance, a 16V head will not fit on an 8V engine.

[theDoktor]

Ed, thanks for the info on the valves & cam chain & heads-up on the 16v head. Do you happen to know if my Weisco head gasket will still work with the 1100 head? My guess is that it will, given the same chamber & valve sizes.
I think I'll hold out for an 8v GS 1100 head. Thanks anyway for the 16v offer.
BTW, the cylinder block that goes with my big port head has a new sleeve in the #4 hole. Seems that the prior owner had a bit of a clutch issue- when he blew it up, it took a chunk out of the bottom of the #4 cylinder sleeve. All's better now.

[rapidray]

Doktor, call me at 714-356-7845 & I will be glad to help in any way I can. Ray.

[Nessism]

Ed, thanks for the info on the valves & cam chain & heads-up on the 16v head. Do you happen to know if my Weisco head gasket will still work with the 1100 head? My guess is that it will, given the same chamber & valve sizes.
I think I'll hold out for an 8v GS 1100 head. Thanks anyway for the 16v offer.
BTW, the cylinder block that goes with my big port head has a new sleeve in the #4 hole. Seems that the prior owner had a bit of a clutch issue- when he blew it up, it took a chunk out of the bottom of the #4 cylinder sleeve. All's better now.

I believe Suzuki uses the same gasket for both the 1000 and 1100 so I don't know why Weisco would be different.

[kochic]

I have the gs1000 and 1100 head gasket here, i can compare them today.
But from memory its only a camchain tunnel thing + the extra front bolt.
You can mix them.
Marc

[srsupertrap]

It is also EASY for me to convert the round exhaust ports to "D" shape, I do it all the time. The benefit to the G head is bigger ports to begin with. Then the porting is less expensive for the customer as the time to turn a small port head into similar to a G is pretty involved. Ray.

Ray,
Since the 82 GS1100G have a round port to begin with how do you transform it into a D shaped port? Welding?

[theDoktor]

Ray & all, what do you think of the small port head converted to the "D' profile with the port cleaned-up and matched. Proper valve job included, natch. Going for maximum port velocity & low to mid-range punch with good reliability. Fresh, matched springs with titanium keepers & collars. With 29mm Smoothbores & a set of mild cams, this might make for a nice street performance set-up. Thoughts, suggestions?

[Nessism]

Ray & all, what do you think of the small port head converted to the "D' profile with the port cleaned-up and matched. Proper valve job included, natch. Going for maximum port velocity & low to mid-range punch with good reliability. Fresh, matched springs with titanium keepers & collars. With 29mm Smoothbores & a set of mild cams, this might make for a nice street performance set-up. Thoughts, suggestions?

Stock retainers are fine for what you describe. Regarding the D profile, I think you would have to build up the ports short side radius with epoxy or maybe welding (not sure this is possible) which seems like way too much work and expense for an 8V engine.

[49er]

Welding is probably out because you would cause too much distortion. Most folk who have attempted this use an epoxy resin. It will eventually burn away though. How long will it last, a very good question?

My suggestion is keep an eye out for a later model head (83 onwards).

[BadBillyB]

Ray & all, what do you think of the small port head converted to the "D' profile with the port cleaned-up and matched. Proper valve job included, natch. Going for maximum port velocity & low to mid-range punch with good reliability. Fresh, matched springs with titanium keepers & collars. With 29mm Smoothbores & a set of mild cams, this might make for a nice street performance set-up. Thoughts, suggestions?

Titanium retainers are not suitable for street bikes IMO. The cams you are using will determine what kind of valve train parts you should use. You said you already have mild cams. What are they???....I wouldn't be so concerned with the "D" shaped exhaust ports as you can make the short side turn flat with a sanding roll. There is more to be lost/gained by how the valve seat area and ports are done. If you want max port velocity and low end grunt I would stick with the small port head and have it done by a pro, even if you have to pay a little more. Choose wisely here as I have seen very pretty port work done that had great flow bench numbers but didn't make any power...I have personally ported both the large and small port heads and agree, the large port head is easier to work with because of its size....And is perfect for drag race motors....Billy

[rapidray]

D porting the small port head requires NO epoxy or welding & will help the exhaust side flow a LOT! You also won't lose any bottom end or drivability. Titanium retainers aren't needed for a street engine unless it is a REALLY high performance or race engine. Put that money to use elsewhere. Ray.

[srsupertrap]

D porting the small port head requires NO epoxy or welding & will help the exhaust side flow a LOT! You also won't lose any bottom end or drivability. Ray.

Ray,
I am curious how do you convert the 82 GS1100G head with the round ports into a D port? I see a couple of those floating around the Forum.