1166 dyno info

[blowerbike]

--------------------------------------------

[67fire]

Is this a good time to interrupt and ask some questions?

I have a '79 GS1000 engine that I did a little work on:
(going on my fading memory...)
Weisco 73 or 73.5mm pistons (worked out to 1148?)
Andrews Products (S3?) cams .394/.394
S & W Race Springs (forgot the numbers) they were intended for the Andrews
S4 cams .424/.424 (still have them)
'81 GS 850 Cylinder head (bought it for the larger intake ports)
Manley custom made SS 38mm Intakes and 30mm exhaust valves
(took them 4 tries to get them right!) light porting by me.
29 mm Mikuni Smooth-bores
Yoshi head pipes into 3" single into 2.25" Glass-pack muffler (fairly quiet)
Andrews Products Hi-output coils
Solid copper core wires
NGK B7ES plugs @ .028 gap
Barnett racing clutch packs

It seemed to run better with the 34CV Carbs (?)

Any pointers as to what I "should have done?" (still can do?)
Street driven, never raced. Picture (click to enlarge):



Any guesses on HP?
Thanks for your help,

Eric

I am also thinking about getting my '79 GS1000S back on the road and would like to know which
of these parts I could use on that build or should I start from scratch?

[rapidray]

Raymond, your not worth it......

Who is "Raymond"? Ray.

[rapidray]

Is this a good time to interrupt and ask some questions?

I have a '79 GS1000 engine that I did a little work on:
(going on my fading memory...)
Weisco 73 or 73.5mm pistons (worked out to 1148?)
Andrews Products (S3?) cams .394/.394
S & W Race Springs (forgot the numbers) they were intended for the Andrews
S4 cams .424/.424 (still have them)
'81 GS 850 Cylinder head (bought it for the larger intake ports)
Manley custom made SS 38mm Intakes and 30mm exhaust valves
(took them 4 tries to get them right!) light porting by me.
29 mm Mikuni Smooth-bores
Yoshi head pipes into 3" single into 2.25" Glass-pack muffler (fairly quiet)
Andrews Products Hi-output coils
Solid copper core wires
NGK B7ES plugs @ .028 gap
Barnett racing clutch packs

It seemed to run better with the 34CV Carbs (?)

Any pointers as to what I "should have done?" (still can do?)
Street driven, never raced. Picture (click to enlarge):



Any guesses on HP?
Thanks for your help,

Eric

I am also thinking about getting my '79 GS1000S back on the road and would like to know which
of these parts I could use on that build or should I start from scratch?

What numbers did you degree the cams to? The 29 smoothbores, if jetted CORRECTLY, will make more power than the CVs due to more airflow. I also think the 7s are a hotter plug than that motor will like & would stick some 8s in it to start with. How much timing do you have in it? I would start at 34 degrees & go up from there if you can get GOOD gas. You should see somewhere around 120 at the rear wheel if it is all optimized & tuned correctly. Ray.

[TeamDar]

That is indeed a strange combination of parts. First of all 73mm will get you 1085cc and 73.5mm will get you 1100cc. A stock GS1000 head has 38mm intake and 32mm exhaust valves. A stock GS850 head has 36mm intake and 30mm exhaust valves. While you may have opened up the intake seat on the GS850 head to 38mm you have strangled the exhaust down 2mm from what a GS1000 had to begin with. You probably did raise compression since the GS850 head has a smaller combustion chamber. The 29mm smoothbores work great with the early style GS1000 head with only mild porting. The 1980 or newer heads with the larger intake ports are designed for 32mm (GS850) or 34mm (GS1000) CV carburetors. Putting 29mm smoothbores on the big port head is kind of silly. Throw a 1980 or newer 8-valve GS1000/1100 head on there with the stock valves and some 33mm smoothbores or 34mm-36mm flat slides and it will haul ass. Just my opinion. Dar

[blowerbike]

FYI...
34mm CV's moves more air than a 29mm mechanical carbs.

[67fire]

The 29's (if that is what they are? 33's ?) came NIB with the bike that I bought for a spare engine. I bought the '81 850 head to go with the 850 sleeves that I added to the initial 750 that it started life as back in '81. I traded the stock 26? carbs at a cycle salvage shop in MD. for the 34CV's from a 1000(?) as ,at the time, Suzuki was using the 32CV's on the 850. It made sense to me to go to the 34's. That engine, also ran the .394/.394 cams.
The '79GS1000S that I bought for the engine, had been raced at Sears Point by the PO and he had paid some famous guy (name escapes me) to build him the new engine. All that I did to the (long time in storage) long-block engine, was to take it apart and clean everything. Checked the ring gaps, honed, etc. Also opened up the valve reliefs .020 more (to be safer)
The cylinder head had the S & W springs (new) that I installed with the custom valves that were made for the 850 head (as I said prior, "fading memory") the valves were made to be 2mm larger (intake and exhaust) than the stock 1000 valves in the BETTER flowing head.
It also came with the NIB .424/.424 cams. As I thought that they might be a bit too much for a street bike, I used the .394/.394 cams that were in the previous 850 chain-drive bike. I still have the original 1000 head that was NOT improved upon for the GS1000S except for the new springs that were never ran after the re-build.
So, it is NOT my imagination that the 34CV carbs felt better with the larger valve ported heads? I will put them back on the custom head.
They were 73mm pistons, so that makes it a 1085? (The PO told me 1148)
So, I guess that I will bore the other '79 1000 into the larger bore weisco kit and find some 36CV's for it along with some new cams. I also will be looking for a newer cylinder head with the larger ports. Thanks!
Any cam recommendations for the GS1000S?

Eric

[67fire]

Also bare in mind that when I did these MODS, there were no computers and information was hard to find. I only replaced the 34CV's with the NIB 29's because that is what the PO was told to use by his engine builder so, I gave them a try. Yes, 29 IS SMALLER than 34. I NEVER would have thought that, without your "help."
When I built the 850 chain-drive, Suzuki was using the 32CV's and I was using the 34's! I am sooo surprised that it worked without your "help."

Now, if anyone wants to help with the camshaft choices on the new engine, I am all ears.
I have been reading of "Web" Cams being used on this site, are they still available? Any other manufacturers of cams for these bikes?

Eric

[posplayr]

http://www.webcamshafts.com/index_blank.html?pages/vehicle_search.html

Looks like webcams still produce 0.365, 0.395 and 0.418" lift for the GS1000 street

80GS1000 has a built GS1000 and I think he runs 0.395 that will take a stock 1150

[67fire]

Thanks for the link POS!
So, it looks like I could use the .424/.424 cams in the 1100 for the GS1000S with the under bucket shims and springs as they are basically the same profiles as the old Andrews cams.
More questions, can I mill the head .020 and bump the compression up closer to 10.50:1? and what is the largest size valves that can be put into another large port head?

Thanks in advance,

Eric

[posplayr]

Thanks for the link POS!
So, it looks like I could use the .424/.424 cams in the 1100 for the GS1000S with the under bucket shims and springs as they are basically the same profiles as the old Andrews cams.
More questions, can I mill the head .020 and bump the compression up closer to 10.50:1? and what is the largest size valves that can be put into another large port head?

Thanks in advance,

Eric

Hey Eric,
No ideas on those 8V tech questions. I'm strictly 16V and learning as I go. There are plenty of 8V guys here is you post for some recos on 8V perhaps in another thread to get their attention.
Jim

[67fire]

Then, perhaps, I will be asking you some questions on how to make some serious power out of my '83 GSX 750. Such as which cylinders (over-bore) will fit in the 750 engine. Perhaps build a short stroke big bore 900? Or something close.
When I made the 750 into an 850, I used the factory cylinders so as to not make the walls too thin by just boring the 750 cylinders. At the time, there was a 870 kit for it.

Thanks again,

Eric

[posplayr]

Then, perhaps, I will be asking you some questions on how to make some serious power out of my '83 GSX 750. Such as which cylinders (over-bore) will fit in the 750 engine. Perhaps build a short stroke big bore 900? Or something close.
When I made the 750 into an 850, I used the factory cylinders so as to not make the walls too thin by just boring the 750 cylinders. At the time, there was a 870 kit for it.

Thanks again,

Eric

Start with an 1100, you will get there quicker.

[rapidray]

Eric, an 1100 GS motor will be EXTREMELY difficult to get into that frame but a GSXR motor goes in fairly painlessly as they are, physically, very close in size. Ray.

[67fire]

I am sorry if I was not clear, I meant to say that I was going to bore the original 1000 motor to 1100 with the Weisco 73.5 kit and mill the head to gain a bit more compression in the GS1000S. Does that sound better?
I will still need to find a newer large port 1000 head and some 36 or 38 CV carbs for it though.
Also, would anyone have a source for the templates to paint it back to original paint style? I would like to do it a little different like a blue and gold or black and gold or even black and blue paint scheme.

Eric