Motor Swap: 1150 into an 1100EZ

[Guest]

I bought an 1150 motor to put into my 1982 1100EZ. My reasoning was that it would be cheaper to start with a $700 1150 (and sell my 1100) than spend the money to build an 1100 up to what the 1150 is to begin with. So I'm getting this 1150 motor this week and I'm trying to understand all the differences from the 1100. This is what I have:

1. 61cc more displacement.
2. Welded crank.
3. Larger Rotor end.
4. 1mm larger intake valves.
5. Better flowing head.
6. Rubber Valve cover Gasket.
7. Painted Black ('82 1100 is silver)
8. About 20 more ponies.

I've seen the stock HP reported as:
1100 HP: 92, 98, 100, 108, and 111.
1150 HP: 119, 124
I'm sure these vary by year, crank vs. wheel, dyno, and who did the test.

When I get it, I'm going to take it directly to a local drag race builder, Larry Cook. He is a good friend of my extended family and has a good reputation for building good motors. I've been talking to him at several family events over the last year. He's going to drop the pan and check it out for me to make sure there's nothing horribly wrong, and he's most likely going to do all the machine work and anything that I can't do myself.

Oh, and this is a street bike. 85% street with the occasional trip to the drags.

Stage 1: My plan is to start with just Carbs. A set of Mikuni RS36, and just feel out the motor stock for a while. Hopefully hit the "PIR Late Night Drags" that start March 1, and see if I can beat my best 11.5 on the stock 1100.
Stage 2 would be to drop in a set of mild cams, tune, and repeat the visit to the drag strip.
Stage 3 would be a slightly larger displacement kit. Tune and test.
Finally Stage 4 would be to have some head work done. Tune and test.

Larry wants me to do Stage 2, 3, and 4 all at once. He says they all need to work together, and it will be easier and cheaper to tune it once instead of 4 times. And I want to spread out the steps over the next couple years and enjoy every phase. Since I'm a tightwad, and I love to tinker, my thinking is that I can do everything in stage 1-3 myself. I'd have to get the block bored by a machinist, but the rest is pretty much "bolt together" work. I'm no engine builder, but I've rebuilt 5+ motors with some success in my life. I've also made some pretty dumb mistakes along the way. I call them lessons and experience. Some might call them "dude, let a professional do it".

So:
1. What are the differences between an 1100 and an 1150?
2. Should I build the motor myself?
3. Should I do it all at once, or spread it out?

Thanks,
Kevin
Here's the bike as it sits:

[posplayr]

This might help you understand some of the discrepancies/range of values for quoted hp

http://www.thegsresources.com/_forum/showthread.php?t=169468&highlight=dyno

IIRC then for comparison
The 1150 stock is 124 hp v.s. the 109 hp for the EZ which is 124-109=15 hp diff or 15*(1-.15)= 12.8 hp at the rear wheel

The 1229 is a whole different animal to the 1133 and I agree with the tuning unless you are truly a glutton for punishment.

You should stay on Phase 1 until you can do 2,3, and 4 all together.

If you had to break it up do

3 and 4 then 2 last.


doing some conservative estimates just in terms of hp per cc

the diff between the stock 1150 and 1100 gives you .259 hp/cc

so a 1229 should get to 140.3 hp not including head work,cams, or the RS36. That is 31 hp gain . You should be easily be able to get your 40 hp with headwork,cams and carbs.

[CivilRock]

Excellent info. This isn't the first time I've gotten great stuff from you Posplayr.

Interesting suggestion on the stages. You say big bore and head work together and cams last. Why?

And I know these cc/hp ratios are theoretical, but you're implying a 1229 piston kit would yield approximately +16.3HP? over the stock 1150, right?

If you were going to give each stage a stand alone HP value, what would it be (at the crank)?
1229 pistons = +16.3
RS36 carbs = 5hp?
348 cams = 5hp?
Head work = 5hp?

BTW, that adds up to +31.3
Add that to the +15 I got just for going to the 1150 and I'm at +46.3 over the stock 1100.

There's no replacement for displacement, right? Seems so. Unless those independent values are way off. Seems to me like I should do a big bore first, then cams and head work down the road together. No? I was thinking of the cam based on Blowerbike's experience getting great results with just a cam and carbs. I do listen to everyone's advice and take it seriously. I also know that there's not one single right answer, and I like hearing everyone's opinion on the subject. From yesteryear to today.

Thanks for entertaining my project. I might be trying to assign values to these mods like they do in video games. You know, when you earn points so you can buy engine upgrades and each one has a specific HP gain? I know the real world doesn't work that way, but there has to be some guys that do a big bore on a stock 1150 head and know the result.

Thanks again,
Kevin

[chef1366]

Swap out the shifter shafts or the 1150 shaft will be too short for the linkage.

[posplayr]

Excellent info. This isn't the first time I've gotten great stuff from you Posplayr.

Interesting suggestion on the stages. You say big bore and head work together and cams last. Why?

because there is not much point in working your way down from the top; anytime you break the seal on the head gasket it is probably necessary to replace the base gasket. Not always but you are taking risk. So options 3 and 4 require base gasket while 2 does not. Also if you do 2 and degree the cams you will need to do it all over again if you later do 3 or 4.

Also the main jets basically have to increase with the bore but a ported head can make a big change. Also cams affect jetting. So As I said before unless you are a glutton for punishment; this is all well trodden ground with many here having personal (and repeated experience) on hopping up the GS.

If you do it all at once you will have a bunch of variables to deal with. Getting the RS36's dialed first will give you a good base to move up to a 1229. 1229 the the largest you can go without re-sleaving the 1150.

And I know these cc/hp ratios are theoretical, but you're implying a 1229 piston kit would yield approximately +16.3HP? over the stock 1150, right?

I would not say theoretical but more empirical. If you extrapolate the rated power gain between an 82 GS1100 to a GS1150 beyond to the new CC displacement you should have a qualified nominal hp gain. Remember the 1150 v.s. 1100 has 36mm v.s. 34 mm CV's , higher lift and a 1mm larger intake valve. So you will have to do something in terms of head and cam to get the same 0.25 hp/cc but nothing too radical; 348's and a ported head should get you well beyond. Other more experienced guys will know better but I would guess that with the RS36 , 348's, head work and 4:1/pods you would gain 10 more hp.

If you were going to give each stage a stand alone HP value, what would it be (at the crank)?
1229 pistons = +16.3
RS36 carbs = 5hp?
348 cams = 5hp?
Head work = 5hp?

Using the Suzuki numbers which are at the output shaft the 1229 would be at 140 hp (+31.3 hp over 1075) and the carbs,cams and headwork should get you to 150 hp (+41.3 hp over the 1075 and 127.5 hp at the rear wheel)


BTW, that adds up to +31.3
Add that to the +15 I got just for going to the 1150 and I'm at +46.3 over the stock 1100.

There's no replacement for displacement, right? Seems so. Unless those independent values are way off. Seems to me like I should do a big bore first, then cams and head work down the road together. No? I was thinking of the cam based on Blowerbike's experience getting great results with just a cam and carbs. I do listen to everyone's advice and take it seriously. I also know that there's not one single right answer, and I like hearing everyone's opinion on the subject. From yesteryear to today.

I think Blower is just recommending (like I think I did) to get it running well with the RS36's and make the most of the motor as it is. Maybe even degree the stock cams for more peak power. It will be strong that way and considerably stronger than your stock bike. Once you dive into the motor your are looking at $1500-$2000+ (depending)

Thanks for entertaining my project. I might be trying to assign values to these mods like they do in video games. You know, when you earn points so you can buy engine upgrades and each one has a specific HP gain? I know the real world doesn't work that way, but there has to be some guys that do a big bore on a stock 1150 head and know the result.

Thanks again,
Kevin

see comment above prior history.

[blowerbike]

1150's made around 101 hp (bone stock) at the rear wheel.
i gave my opinion in your other thread....i have nothing to sell you..
do what i said and when you can run 10.50's-10.70's then upgrade at that point if you choose.
think about that


FYI
RS36's are ****3 tenths and a couple MPH over jet kitted 1150 carbs****
FACTS FACTS FACTS

[Rob S.]

Revs, clutch

CivilRock - I too have an 1100EZ. I've never been to the strip (once as a spectator), but I have been known to act immature on the street.

That 11.5 quarter mile you ran with your stock 1100EZ - remember how high you were revving before you dropped the clutch at the start? Much wear and tear on that clutch?

That's almost what the Cycle World guys got in '82 (11.21), and they don't give a frig what happens to the machine. Plus they're nuts.

[CivilRock]

That 11.5 quarter mile you ran with your stock 1100EZ - remember how high you were revving before you dropped the clutch at the start? Much wear and tear on that clutch?

That's almost what the Cycle World guys got in '82 (11.21), and they don't give a frig what happens to the machine. Plus they're nuts.

I was holding it at about 4500 rpm on the line. I didn't open the case and look at the clutch, but there wasn't any change in the lever position during the night. Honestly, the clutch pack was pretty far down on the list of things to worry about.

Some background notes:
- I replaced the clutch plates less than 5,000 miles ago when I discovered one of them was broken. At that time I upgraded the clutch springs to heavier ones. Later I put back in half of the OEM springs to lighten the clutch pull.
- That night was 10 passes. And that's the only 10 passes this clutch has seen.
- That was my first real drag experience, but I probably have over 1,000 starts between Road Racing, Motocross, Supermoto, Flat Track, and Enduro/XC racing.
- I do have a GSXR1100 swingarm on the bike that's 4" longer than stock. Even then, I had to let off twice because the front wheel got too high.
- The starting area grip was unlike anything I've ever experienced. Your boots stick to the ground.
- 4 of those passes were against my RR buddy on a 2012 GSXR1000 Road Race bike. He's got 10+ years of racing as well, but I was putting 5 bike-lengths on him off the start. Although he would pass me at the 1/8th like I was standing still, and did a best of 10.4 at like 145MPH.

I think a big fat 190 DOT road race tire with 4 more inches of swingarm makes up for a lot of HP losses over the last 32 years.

To give you the short answer to your question: I don't think it hurt the clutch at all.

-Kevin

[storm 64]

I think a slick, wheelie bar, air shifter would lower your ET about a second.. Plus you'll be more consistent and might win races. Oh clutch hub too. All the horsepower in the world is useless if you can't hook it up.

[CivilRock]

I think a slick, wheelie bar, air shifter would lower your ET about a second.. Plus you'll be more consistent and might win races. Oh clutch hub too. All the horsepower in the world is useless if you can't hook it up.

That wheelie bar would make parking at my office difficult. Plus I think I'd high-center in the driveway curb cut. I literally use this bike to get groceries on occasion.

I know all that stuff is fun, but I really enjoy balancing the power with grip and the little lever on the left. Those skills really translate well to the other forms of racing that I like to do.

-Kevin

[storm 64]

Thats cool Rock, I was thinking you were building a drag bike. A hot street/strip bike is fun too

[rapidray]

Swap out the shifter shafts or the 1150 shaft will be too short for the linkage.

No it won't. That was how my maroon bike was set up when I put it together. I used the 1100 countershaft cover & had to shorten the spud coming out of the cover but then the linkage hooked up just fine. If he uses the 1150 countershaft cover it should all bolt right together. Ray.

[gs11ezrydr]

I have not worked on an 1150 in a while, But do they have the same weak backing plates on the clutch baskets like the 1100's I believe the center hub has a metal instead of aluminum sleeve inserted where the splines are. I just remember shimming them to try and stop them from creeping when staging. But was not sure if the basket backing plate was going to have to be modified since there is track use in the future. I work at a Suzuki dealership but not many of these bike in my area here in KY so hard for me to remember all the models and there quirks. We have always raced the 1100's just due to the fact that it seemed like it was a quicker and higher revving engine with the 18mm wrist pins compared to the 20mm in the 1150's New technologies have made the pins so much stronger now no need for the big ones any more. Pro Stock still runs the 18mm pins last time I checked.I'm sure I'll get flack about that lol. Just one mans thoughts

[trippivot]

Good Looking Bike you got there, I like it . solid muscle bike stance!
If you want to keep the ground clearance the term semi/competition will have you weighing compromises. I got to ask, Civil Rock have you thought of what stage level of performance are you are going to be satisfied with?

Here is my STAGE I list - If I wanted to spend my money wisely for a 85%/15% semi/competition 80's era bike.

#1 Get the rs36' mikuni and nice filters - extra jets will help too
#2 set of drop in .348 cams and manual adjuster
#3 put money into the clutch - better basket, modified inner hub, snowflake lock up.
#4 bunch of sprockets 15/ 47~42
#5 tune it , ride it , know it

The head work and bigger displacement higher compression can wait, I just spent $1500~$2000 of your money.
Best news is if you go this route these parts will work great all the way up to 1428cc -- you can make impressive power with the basics.

.................. after the basics come exotics -- with similar costs.

[blowerbike]

No it won't. That was how my maroon bike was set up when I put it together. I used the 1100 countershaft cover & had to shorten the spud coming out of the cover but then the linkage hooked up just fine. If he uses the 1150 countershaft cover it should all bolt right together. Ray.

actually the 1150 is to short as you said.
he has both engines...
the correct way is to install the 1100 shaft in the 1150 and use the 1100 cover.
he has to remove the 1150 basket anyways to get a kit put in it so why not swap shafts?
oh,
with the shorter 1150 shaft on the 1100 chassis that makes the linkage lean inwards..yes it will work but why not do as bill(chef) said?