Low Cost / High Performance GS1100E Head work

[Nicholaschase29]

Here is some more information regarding Terry and his port work. I just got my head back and everything looks great. I would be interested to see a scanned copy of Jim's flow sheet (stock and ported) as it's hard to get an accurate number from your graph.

Here are a few pictures of Terry's work as well as a flow sheet. I still need to clean up the head. Thanks again!

[Katarat]

What the Busa guys dont understand is that they arent old people friendly, you cant ride the damn things. Im 66 3/4, have a bad back and I dont do water in engines or fuel injection. Outside of that you guys have a good Xmas. I may be old but I still like to go fast !

[posplayr]

What the Busa guys dont understand is that they arent old people friendly, you cant ride the damn things. Im 66 3/4, have a bad back and I dont do water in engines or fuel injection. Outside of that you guys have a good Xmas. I may be old but I still like to go fast !

Merry Christmas Wooodman, hope your not getting too much snow. My wife just headed up to Kalispel to see her folks at Swan Lake.

[posplayr]

Here is a comparision of the final numbers between Nicholas's head and mine. Mine has the 28mm 1150 backcut valves Nicholas's has stock 27mm back cut stock valves. Terry did some magic pulling out about 99 CFM at 0.35" lift to improve on the high lift performance of the 27mm valve and across the board improvment for the same valve. He said mine was a mild port . Looks like some excellent work you got there Nicholas.

[Nicholaschase29]

You can definitely see the improvement of flow down low with the 28mm intakes. In reality our valves are only open up around the .350 range for a fraction of the time that they're open (Jim with .348 webs and me with .355 G4's) so he has more usable flow - a good upgrade with the 28's.



Great work Terry - thanks again!

Jim - what program are you using to make the graphs? Just excel?
Thanks for making the comparison graph. Check your x values with my numbers. He got values at .370 and .4 for me. You have to plot a separate set of X values against my flow numbers.


Thanks,
Nick

[posplayr]

You can definitely see the improvement of flow down low with the 28mm intakes. In reality our valves are only open up around the .350 range for a fraction of the time that they're open (Jim with .348 webs and me with .355 G4's) so he has more usable flow - a good upgrade with the 28's.



Great work Terry - thanks again!

Jim - what program are you using to make the graphs? Just excel?
Thanks for making the comparison graph. Check your x values with my numbers. He got values at .370 and .4 for me. You have to plot a separate set of X values against my flow numbers.


Thanks,
Nick

Nick,
Just using Excel, I fixed up those couple of data points. I'm using the 0.340's cams not the 0.348's which have much more duration. I also added the stock numbers from my original head. and plotted intakes together and exhaust together. You head seems to have an intake resonance which is boosting the high light CFM. That should work well with a long duration (broad lobe) profile.
Jim

[posplayr]

It is springtime so just thought I would bump this thread for anybody thinking about muscling up an 1100/1150.

http://www.thegsresources.com/_forum/showthread.php?t=170253

http://www.thegsresources.com/_forum/showthread.php?t=171150

[fast pom]

I do get what CBXchris is saying modern bikes are cheap horsepower , but were is the fun in that you try to get an old GS750 to go quick talk about money pit.

[posplayr]

I do get what CBXchris is saying modern bikes are cheap horsepower , but were is the fun in that you try to get an old GS750 to go quick talk about money pit.

I think were mostly talking about old school 1100/1150 muscle

Anybody with a stock 1100 has gotta be thinking about it

[ronin1166]

My GS project has been static for FAAAAAR too long now.

But I'm getting a little time (and more importantly, spare coin;-) back lately.

Threads like this are giving me teh Major Wood...

IIRC, my DIY port cleanup is roughly 50% complete. Think I'll dig it out and have a look-see this weekend.
Decisions I need to make:
-- Stock or +1 in intake valves? My '83 Kat head has substantial core-shift, lots of undercut at the intake port/valve seat interface. I think +1 would chase it out smooth. But I already have a full set of NOS stock Suzuki valves...
-- Smooth/blend valve guides or not? Don't know how much this influences flow, but valve-stem support is a good thing...

FWIW, my build is similar to some described in this thread:
1166cc, Falicon Supercrank, Web .348 cams, APE springs w/ Ti retainers.
Tractable Street Monster in accordance with Pos' "personality" description.

.

[rapidray]

Ronin, one of my heads will get you 140 at the back wheel & 9.30 quarter mile potential with the parts you have listed. I speak from experience & have one here that DOES just that! Ray.

[ronin1166]

Ray,
Would that be with +1mm intake valves, or stock (27mm) GS1100?
Carb recommendations? Bike will be primarily street driven...on twisty roads...
Methinks I need to give you a shout sometime soon...

.

[posplayr]

Ray,
Would that be with +1mm intake valves, or stock (27mm) GS1100?
Carb recommendations? Bike will be primarily street driven...on twisty roads...
Methinks I need to give you a shout sometime soon...

.

You can look at the flow rate comparisions (first post) between two 1100E heads one with 27mm and the other with 28mm intakes). Terry got even more flow out of the 27mm head but at lower lift you can't beat the extra size.

[ronin1166]

Yeah, I saw that. Hard to argue with smaller-valve/high port velocity.
Still concerned about the effect of the core-shift undercut at the base of the intake-valve seats on my '83 Kat head.

.

[gearhead13]

How hard is it to do a valve job on a head with the guides cut at an angle?