1150 or 1100 head? is one really better?

[katman]

Does anybody have real numbers on any increase of an 1150 head over an 1100? is there any?

I know the 1150 cams are almost identical except one of the cams has less lift than the 1100.

lets hear the real deal, hard numbers. who has done the dyno thing with the both for comparison?

[Big Jay]

The 1150 has a larger intake valve, so it will flow more, however, the main thing is the potential. It has bigger intake seats and can take a 29.5 mm valve vs 28.5 for an 1100.

Jay

[Silvermachine81]

The 1150 has a larger intake valve, so it will flow more, however, the main thing is the potential. It has bigger intake seats and can take a 29.5 mm valve vs 28.5 for an 1100.

Jay

Does APE have a kit available with all the small parts required for the transition?

[katman]

but is it enough flow to feel a diff? is it that much diff to do a swap.

I know for draggers it is but for the street? skipin the cheese burger and beer a few nights a week would gain more HP and save you money.

I would like to see some numbers if anyone has them. Just out of interest.

[Richie]

my opinion is either one will work, in my experiance for the kind of power i need to make by the time you do all the work to it, like i use it cost $3500 or so, or around 5 g's for one like we use now, but at this point there is no advantage to have an 1150 head over an 1100 head, except its faster to take the valve cover off (less bolts)..richie

[Road_Clam]

Generally speaking simply adding bigger valves will no yield significant gains on the street. Bigger valves, in theory does mean more top end flow, BUT at the cost of lesser vacuume "signal" from low to mid range operation (where a typicall street engine spends a lot of it's time). Like modding anything, you need to step back and look at the whole engine, not just bigger valves. To get those added bigger valves to really reach potential you need a bigger carb venturi, and a good free flowing exhaust. A seasoned race engine builder once commented to me "an engine is simply an air pump" Allowing more air to be passed in only one area of the combustion process, won't always yield true gains. So basically, don't add a performance big valve head, and expect it to make more power when you running a stock GS airbox with a paper filter (simply a comparative comment).
Rich

[RacingJake]

This is what somebody told me;

80 for the GS1100, 85 for the 1150, 95 for the early GSXR1100's, measured at .350" lift. Bone stock heads.

But if your going turbo the 1150 is a stronger head, thicker? Lecroy will know for sure.

To swap all you need is 1150 studs and nut's and a electric tach since the 1150 has no tach gear on the front. If you have a choice between heads I'd do the swap.

As for drag racing all our good runs feel slow But the 1150 head should give you 5 mph increase in speed.

[rosco15]

I did the switch last winter. I've changed alot of things, but I can give you a rough idea of what it did on the track. I had an 1100 head that I had a +1 ss valves in it. Some really mild proting that I did. Ran a best of something like 10.11 @ 128. Switched to the 1150 head. The only thing I did to the head was put in the ss valves out of the 1100 head and rounded off the short side radius. It was running in the upper 9.80 range at like 133. Ran a bigger cam for a while and ran as fast as 135 mph, but the 60' was *@%^$*@%^$*@%^$*@%^$. Finally put the smaller cam back in and went from a 36 mikuni to 38 mikuni and ran 9.68 @134.

This year even in the *@%^$*@%^$*@%^$*@%^$ty air 4200 DA the bike ran upper 9.90's with the 1150 head, small cam, and small carb. Last year in the summer air I thought it was running in the 10.30 range.

There is a guy at the track that had alot of work done to his 1100 head. He was running in the 8.90's. He switched to an 1150 head with about the same amount of work done to it and he started running in the 8.60's.

The cost of it isn't that bad. 1100 head on the cheap end $100./ 1150 head on the cheap end $275. You need to run 1150 studs and intake boots. The stock 1150 valves are +1 over the 1100 head. The runners are way bigger. Get an 1150 head. Clean it up. Do a valve job. Put some ape springs in it and just run it like that.

The gs1150 cam is the drop in upgrade for a gs1100. an inexpensive HP increase.
gs 1100 cams intake 283" 241 exhaust 265" 230
I thought the 1150 had .030" more lift, but I cant find the specs. I had them around here somewhere.

Heads can be expensive. Sometimes I think it's better to do pistons or a good set of mikuni carbs.

[Richie]

i meant like if you did a 31-27 head for an 1100 with the 44 spigots and the same for an 1150 head it wont make a differnace both heads are the same, even if you went to a 33-28 combo if you did the same work to both heads it makes them on a level playing feild, richie

[pano]

Without doing any head work is the swap from the stock 1100 w/stock 1100 cams to the stock 1150 w/stock 1150 cams increase performance in a noticable way. What percentage of increased performance would you attribute to the head and what amount to the cams?

[rosco15]

Jake, How much faster did you go when you switched. And how comparable were the 2 heads.

Using some of the et calculators on the net I'm guessing I picked up 10 - 15 HP. Ony difference was the head. Everything else was the same.

[lecroy]

my opinion is either one will work, in my experiance for the kind of power i need to make by the time you do all the work to it, like i use it cost $3500 or so, or around 5 g's for one like we use now, but at this point there is no advantage to have an 1150 head over an 1100 head, except its faster to take the valve cover off (less bolts)..richie

Yep, this is about what it costs my friends to have their T/G heads setup. They have had FBG build both types. I have seen them put valves threw the head and have FBG rebuild them. Very impressive work. I should take some pictures of the prostock one. They milled the entire intake down and then made a part that bolts to the head to give them more meat to port it. Not sure of the valve sizes in that one.

To me, the valve cover removal is going to be a BIG plus! I bet I bought ten 1100 gaskets last time.

After talking with Bob about his mid 7's turbo bike and the number of 1100 heads he broke, I plan to switch to the 1150 head for the strength alone. He runs around 30 and said the heads start to crack a bit over 20. What
was was interesting is Bob also said the 1150 head he used was stock, no porting and stock valves and the engine was smaller than 1400 cc, electric start. He ran high 7s the whole time I watched him with no NOS. Of course he had a very nice chassis. Maybe $10K in frame I am guessing.

You want it to breath, put a turbo on....

[RacingJake]

With the same G4 cams tried in both heads I picked up 5 mph and drop 2 tenths in the 1/8 mile using the 1150 head. The only thing that was done to both heads was the castings inside the runners were smoothed out.

The runs was done within a week of each other, at night and the weather was the same. They must be better than stock 1100 or why did Suzuki come out with them :?

I like them

[melray]

valves for street-strip rebuild

Howdy- any sources suggested for replacement valves, 1150 head?

Not a serious race engine, looking for increasing size if cost is within reason, especially on the exhaust side.

thanks all

[rosco15]

http://fastbygast.com/

I got mine from FBG. They had the best prices at the time. You want one with a hardened tip where the adjuster hits. You might just consider running stock valves. some good springs. Maybe titanium retainers from ape to lighten up the valve train.