GS1000 streetfighter idea w/ picture

[80GS1000]

Your best bang for the buck is the 1100cc kit and cams. I would skip the porting if money is tight. The ignition stuff is a sound investment as well. I would try to find a production pipe that works unless you can get the custom one for reasonable $$$.



No it won't. You are fighting too many years of development and too much weight. My 06 GSXR1K weighs 430lb FULL of fuel and makes 160rwhp, with a super flat torque curve. It handles like a 160hp dirt bike, it feels so light. You will never approach those kinds of numbers no matter what you spend... But you WILL have one cool, unique ride that is a superb street bike. Still worth it in the end, IMO.

One thing to remember with the engine work, don't go so radical that it becomes a nasty, tempermental beast that is always breaking and has a razor sharp, top-end only powerband. One of the best features of our GS's is the great, torquey, user-friendly engines and it would be a shame to lose that basic character.

Just my $0.02

Mark

Mark -

Completely agree. What's the fine line between a hot street motor and something which will break constantly? I'd like as much power as possible but not at the expense of reliability. Also don't want a top end screamer either like my 06 Gixxer 750 - gotta love that broad GS torque band.

[Mark M]

Mark -

Completely agree. What's the fine line between a hot street motor and something which will break constantly? I'd like as much power as possible but not at the expense of reliability. Also don't want a top end screamer either like my 06 Gixxer 750 - gotta love that broad GS torque band.

If it was me, I would do the 1100 kit, the cams and maybe carbs and a pipe. If the valves need work to restore compression or replace worn guides, then that needs doing as well. Any bottom end or tranny/clutch work would be to simply repair/replace any worn stuff and ensure longevity.

For cams I would go with a fairly mild grind, say a "hot" street cam. Avoid any racing cams, as they will gut the bottom end and move all the power up high.

My plans for my 82 1100E are an 1166cc kit, stage 1 cams, 34mm flatslides and custom 4-1 pipe (which I will build myself). I may try to find an 1150 head and small port it myself (as per Mototune USA site), but that would be pretty extravagant IMO. I am after around 130rwhp, with 80+ft-lb of torque and a dead flat torque curve. It currently dyno'd at 102rwhp and 69ft-lb of torque, uncorrected for conditions or altitude (I live at 3500+ft).

Mark

[tone]

Just my opinion but the most bangs for your buck you will get is from decent flow work on the head & some reasonable cams :-D

[KiwiGS]

Just my opinion but the most bangs for your buck you will get is from decent flow work on the head & some reasonable cams :-D

I have to agree with Tone here.
I had a stock GPZ900 which put out 99hp at the crank.
After new cams, headwork, flatslides and a new pipe it went to 130hp at the back wheel. And stayed reliable. (raced it for 5 years with no other work except tune ups)
Just my experience and 2 cents
Cheers

[Bad Kaw]

Finally got a chance to go thru this post from start to finish. Gotta say this bike is fantastic. Great job!

On the "head down" approach to your motor build. If I may be so bold: the danger to adding power to the GS motor is that the crank and clutch aren't going to like that. In your list of mods you appropriately address this by welding the crank and reinforcing the clutch. I have seen stock GS1000 clutch baskets damage themselves via hard riding and missed shifts (no mods to the motor). I was riding beside a (sleeper) GS1000 when a 40 bHp shot of nos blew the clutch basket out the side of the engine case. So, my thoughts are - as previously noted by Tone - a well done head is going to see some significant results in power delivery...perhaps take it easy on the accelleration aggression as the bottom end components might not be up to the task after 35K faithful miles. And a 1000cc bike that won't clear 100 mph is communicating that it has a problem, anyhow. I would not know if porting and polishing the head and adding big cams would be enough more power to grenade the bottom end with hard riding, or not; I have never seen a motor done from the top down, but it does make 'build-as-you-go' common sense. This is just a thought to consider; I am sure that others here would have clearer insight to this...I'd just hate to see any of your money wasted b/c you're doing so dang good with it so far!!! What a fantastic bike! Lastly, I would recommend against a dyno run until the bottom end is addressed; I'm sure you thought of that, but they are very handy for tuning and I didn't know if you would be tempted to dyno-tune it after the head work was done or not.

Side bar: KZs suffer from the same problem. Stockers need their cranks welded before true power is added...and when the motors start to get real healthy they need clutch basket reinforcement, also.

Oh, I'm a 'white on top' guy, also...and go with as close to a Cooley fairing as possible...I think it'd look great.

Quick question: why paint the forks?...don't like the gold? Remember, "go fast" parts from back-in-the-day were often gold...just a thought, I like your gold forks!

Good luck on your outstanding project (I'm lovin' watching it come together!),
-KR

[80GS1000]

Compression testing...

I did a compression test on the motor. All tests were done dry and with a cold motor.

Cylinder 1: 90 PSI
Cylinder 2: 95 PSI
Cylinder 3: 100 PSI
Cylinder 4: 110 PSI

According the GS1000 factory service manual, the standard compression reading is 128-184 PSI. The service limit is 100 PSI.

To try to isolate the source of the low compression, I put about a teaspoon of oil into cylinders 1 and 4. Cylinder 1 shot up to 105 PSI and cylinder 4 went up to 130 PSI. I'm thinking worn rings/cylinder walls.....at least the exhaust valves appear to be sealing correctly.

Curious to see what compression will be with the 1100 cc rebore and the Wiseco 10.25:1 pistons....

[UncleMike]

Better bore her.

[catbed]

if you didnt paint the engine yet, you should only paint the head and crank case black, and leave the cylinders silver. in the original picture in your first post, thats how the yoshimura is and i dont know if it is intentional, but it looks unique.

[justin caise]

i liked the classic... Alot of us would give up our wifes for a bike like that. !:-D S.N.

Really? Oooh hey, where's the wifes and gfs photo section? time to go shoppin \\/. (Not that I'd give up my current wife 8-[.)

Just gettin caught up.

Inspirational - I say.

[renobruce]

OK, PJ..... you gonna have that beast ready for July? Time to give us all an update! If not, I guess it would be OK if you brought out the 750.....as long as we get to trade rides again! :-D

[80GS1000]

OK, PJ..... you gonna have that beast ready for July? Time to give us all an update! If not, I guess it would be OK if you brought out the 750.....as long as we get to trade rides again! :-D

Hey Bruce, thanks for the interest. Looking forward to seeing everyone again in July. \\/

Um, heh, the GS1000 in pieces right now scattered across my garage. Needs a motor rebuild due to low compression and a paint job, more frame bracing etc. It's possibly doable in time for July but I need to get my @$$ in gear on the GS project. I've been spending way too much time riding the GSXR and not working on the GS. Got a track school scheduled next weekend at Miller
on the Gixxer and then I think it's time to dedicate some resources to the GS again.

[YoshiJohnny]

if you didnt paint the engine yet, you should only paint the head and crank case black, and leave the cylinders silver. in the original picture in your first post, thats how the yoshimura is and i dont know if it is intentional, but it looks unique.

Yoshimura used GunKote as it disspates heat, if you just paint crankcases and heads they hold heat in which saps power.
Anyone know where I can get a litre of dark gey GunKote???
PJ make sure you get someone who knows what they are doing with regards to rebore..if they get it wrong it gets very expensive.

YJ

[Agitator]

That thing's lookin' pretty sexy. I've gotta' say though... those welds on the bike you quoted were nasty. Solid core mig isn't that hard to run, lmao. Those guys musta' been flaky. OTOH, your welds on your GS project look pretty nice

I think your engine rebuild plan is a good idea. I hope it turns out really well with the motor work. The work you've done on the frame, etc... is very nice.

~Tator

[YoshiJohnny]

Ditch the seat...... :-D

Before you go buying pistons see what Buzz at Dynoman.net can get you he sourced me some 12.5:1 Wisecos which were a bit expensive but should give me a good amount of oomph. SSR and Craig Smith reckon over 135 easy and that's before the wet 50hp NOS I just bought..

c'mon chap the heat is on...

:-D:-D:-D


my frame is going to be done like yours next winter as I am so impressed.

YJ

[80GS1000]

Ditch the seat...... :-D
YJ

Oh yeah I forgot to mention I got a nice cutdown seat for the bike now. Looks like this (not my bike obviously):