Performance build question

[80GS850GBob]

Yes I was reading that, should be a night and day improvement for sure but I'm trying to stay era specific. It's not going to be an 'exact' replica but it'll somewhat 1979 ish. The gauge cluster will probably be the most glaring part that won't be era specific.

Oh yeah, I get the era specific thing...that's why I tossed up the bracing page to lend a helping hand for that look of modded factory racer.
Neat thing about exact replicas...no-one can easily tell unless an exact replica is there!
Depending on what you use for the gauges....I plan on my spare 550 L cluster simply because I like the looks of it....I'm trying to keep it all suzi parts even though it's from different eras or models{chuckle}. I'm not sure what my build type would be called, but it's what I have pictured in my head.
There is a way to add Honda f4 forks to have usable adjustments and still look stock{ish}, but it all depends on what you really want out of the build/look.
Build on....folks will still be able to tell it's an old Suzi GS.

[azr]

What is everyone's opinion on a welded crank? The bike is going to have the Weisco 73.5 pistons, Web 118 cams (mildest cams they have), either 29mm smoothbores or something a little bigger. This isn't going to be a track bike just a street bike with some extra 'umph'.

[TeamDar]

A welded crank wouldn't hurt. I would not bother with the 118 cams unless you have a stock engine. with the 1100 big bore kit and more carbs I would go with the 110 grind cams. Still uses shim on top followers but needs more than stock valve springs. Dar

[azr]

A welded crank wouldn't hurt. I would not bother with the 118 cams unless you have a stock engine. with the 1100 big bore kit and more carbs I would go with the 110 grind cams. Still uses shim on top followers but needs more than stock valve springs. Dar

Ya, I saw the 110's on their website but of course it needs the beefier valve springs and I just felt I was going down the rabbit hole farther and farther, but maybe that's going to happen if I start with the 73.5 pistons. My end goal is to have a street able bike that I can go on a 2 week trip with, maybe I'm approaching this wrong with such big pistons???

[Big T]

TeamDar may be confused about the 1100 pistons. Yours will only slightly raise the compression, unlike a 10:1 big bore kit

[TeamDar]

TeamDar may be confused about the 1100 pistons. Yours will only slightly raise the compression, unlike a 10:1 big bore kit

I thought AZR was using a Wiseco 73.5mm 10.25:1 compression big bore kit? Dar

[azr]

Yup, those are the pistons that are going in.

[salty_monk]

So far the plan is 83' 1100E forks blocked off, with emulators and sonic springs. Twin pot calipers with Dan's conversion and some sort modern reservoir.

That's exactly what I have on mine. My springs aren't Sonic but they are straight weight (I cut down a set to give me about 44lb springs - they are about 14" long springs now as far as you can go without them being able to go "spring bound" at full travel - which is ok for me but probably too soft for anyone bigger - you can run softer springs when you have the emulators). Was lucky to get a full set with new uppers a few years ago. I run boots on them now to keep the stone chips away. I put them in the original triple trees.

[salty_monk]

Oh and with the Works performance rear shocks - they are 13.5". Bike is now more capable than I am probably
Had to put a block under the side stand.

Stock engine (pods & 4:1)
I broke the clutch apart & beefed up the springs & had it re-welded.

[MaurieG]

And...your 29's can be bored to 33 if needed.

[Chuck78]

You're definitely on the right track here. Although the only thing you gain woth the 83 1100 forks is an additional replaceable lower fork slider bushing (and they won't look as good as the stock forks, block off plate and all). I'd stick with stock GS1000 forks + RaceTech cartridge emulators, Sonic Springs, Tarozzi etc fork brace & the popular twinpot brake mod; or else I'd fit a VMAX 1200 triple and Bandit 1200 43mm forks, and some custom bushings to run the GS wheel 15mm axle or else an early GSXR 18" front wheel and 310mm rotors adapted to the bandit forks.

Look for a Giuliari GS1000 seat ( I believe there is one on eBay now, maybe across the ocean, but well worth getting for the good looks, and you can get new upholstery for them still). That would really make it look awesome.

If you got that 18 in early GSXR wheel, they look very similar to the GS 1150 wheel that is 3.5 x 18, and you can fit some substantial rubber on that! You will definitely need some substantial rubber in the rear woth that engine!!!

FYI the 1100 cylinders I believe have a .6 mm taller "as-installed" deck height due to the 1.2 mm longer crankshaft stroke. You will want to use the GS 1000 base gasket trimmed out to fit the 1100 cylinders, as it is much thinner than the 1100 base gasket. I believe this is correct, I am recalling this from memory. The 1100 base gasket was around .039" or 1mm? And the 1000 base gasket is .020" or .5mm? Then have the 1100G block decked up to perhaps .3mm milled off the top, to give you a very fresh clean flat head gasket surface as well as giving you a near zero deck (piston flush with top of block as installed, when piston @ TDC). This will bring your compression ratio up to around what Wiseco advertises, otherwise it will be a good bit lower, and the bigger street camshafts will not be as happy.

Call Rapid Ray and send your cylinder head off to him for resurfacing and a fresh Serdi Machine radiused cut valve job, and if you can justify the expense, have him do some mild street porting to it. Not a whole lot is needed to further compliment a power house of a street engine.

As for the welded crank... You WILL definitely want to send the crank to Pearson Racing near Dayton Ohio and have it checked out, new rod bearings and thrust washers, and indexed/welded/trued. This is far more important than any head work.
I have a welded crank and a 79 GS1000 head on a stock 78 engine, because when running even a stock GS1000 engine hard, if you get good enough traction, you will very much be capable of twisting the crank and bending some valves in the process and trashing the head and pistons!!!

Yoshimura exhaust, 73.5mm pistons with decked 1100 block, 79 small port head with Serdi job and minor porting cleanup as discussed, with a cam in the .354" -.380" lift range (Megacycle) or .365" lift range (Web) with VM29 smoothbores will make a very very fun fast and potent street engine. I personally would go no bigger than the .395" lift Web grind, as even those if revved high enough and ridden aggressively enough could require shim under bucket (which is such a pain to adjust valve clearances on...).

Also, inspect the trans very well when the cases are already split apart for the crank welding. The 3rd and 4th driven gears' shift dogs on EVERY GS1000 TRANNY I HAVE are always worn and rounded off. I think this affects 2nd gear??? Send these to APE to have them hardwelded / repaired/reground. Another member on here BadBillyB I believe said he has found the same issue repeatedly. All of the 1000 Transmissions that were on eBay a while back for several months, I inquired about, every single one, and they all had the same issue as well. A few people said that they shifted fine and never jumped out of gear, however. But if you have the cases apart, it is best to have them hard welded and remachined.

GS1150 rear wheel 3.5x17 (? or 18?) rear wheel and spacer modifications as discussed on here (Ask Salty_Monk or Posplayr?), early GSXR front wheel to match + GSXR 310mm rotors... that would be really sweet.
I'd focus on the engine in the off season, and begin accumulating the rest of the wheel/suspension parts for after the revised powerhouse is installed...
If 17" rear wheel, go 140/80-17 or 130/90-17 tire for more height, and 110/80-18 front. Bridgestone BT45V Battlax for some killer grip. Or AM26 RoadRiders (Avon) for decent grip and better rear treadlife.
oh as for the clutch hub, if you can figure out who sells HD backing plates for the 1000 clutch hubs, please share!!!
Otherwise get an 1100E or 1000/1100G basket and HD backing plate kit for it, and then a clutch cover spacer from Nick at SuzukiPerformanceSpares.com so that you can fit the deeper basket in the 1000 engine. This mod is best if running rearsets, however. It pushes the cover out plenty enough to really notice it in regards to the stock footpeg and brake pedal.

This engine/bike will be amazing!

[Chuck78]

I am collecting parts for a similar build, but in a Rickman chassis. I have a custom built 1100 stroker crank (1.2mm longer stroke than stock) that will yield me 1105cc (1085 pistons @ 73mm), 1120cc (73.5mm), or 1135cc (74mm) in GS1100G cylinders. I have small port VM26 79 GS1000 heads and also D-port GS1100G head. I'm undecided on which to use for the big motor. I have Keihin CR31 smoothbore carbs for it. Yoshimura cams in the .360" lift range. Yoshimura Series-1 4 into 1 exhaust.

Oh, lastly, the GS1100G rods are a much more substantial casting thickness if you are looking at really getting a bulletproof bottom end built up. I assume they are the same length as the 1000 rods. I think this is what I am running on the custom stroker crank Nick built that I have. They are wider if I recall, but this just requires using thinner thrust washers when John Pearson or Stan Gardner presses your crank back together.

I am picking up a 2nd GS1000 engine, and plan to use the welded crank in it and GS1100G pistons bored into 1000 cylinders, small port head decked .040", VM26's, stock or mild MegaCycle cams. Budget street beast.

best of luck, and keep us posted.

[Chuck78]

Oh yes.... highly recommended is a GS1100E aluminum swingarm. I think you save 7 lbs of critical unsprung weight when swapping a 1000 swingarm out in favor of one of these... plus you will probaby really benefit from the additional 28mm or so of wheelbase with that beastly engine you have planned!

Also, eye candy... here is a Giuliari seat that I was referring to. Very good looking period correct add-on..


Another thing - if you end up looking into modern forks and don't want to hassle with adapting the front axle from a GS or early GSXR wheel, the CBR600F2 & F3 Wheels I believe Look fairly appropriate on a vintage bike, almost like a directional version of a a vintage Morris mag or Kawasaki version of the same. Diamond J (GSR member, from NY?) has a gs1000 with 41mm VT1000 Superhawk forks and these CBR wheels that I speak of.
Diamond J's fine machine:




It looks very period appropriate compared to any other modern wheel that would bolt on to a modern fork. Then you get wider wheels in 17 inch diameter so you can run really awesome modern tires, but the wheels still look somewhat period styled (but are 17"). Then you can run the 43mm CBR 600 F4 forks which have externally adjustable compression and rebound, or 43mm Suzuki rf900r Forks which have adjustable rebound on the last year model and have equal damping, top-notch, same as Bandit Fork but shorter. These are on 20mm front axles. Then you would have the task of getting the chain line correct in the rear and the proper spacers and break stay Provisions for underslung brake, but aT least you are still dealing with stock GS rear axle size. FYI run an RF900R etc rear axle and nut, same size as GS but hollow!

And yet another period correct GS1000 racer themed build (Dunstall fairing here) that recently got CBR 600 F3 wheels with corresponding 296mm (our twinpot brake mod rotors) rotors and Honda VT1000 Superhawk 41mm forks swapped:

I believe the F2 wheels run a totally different rotor and bolt pattern, but the F3 runs the GS rotor bolt pattern that is shared with many 296mm & 310mm Honda sport bike rotors. The RF and Bandit forks run 310mm rotors, FYI. Could use stock calipers from those and 310mm Honda CB1100 blackbird rotors potentially.


The RF900R and Bandit forks look nearly identical to GS forks, the CBR forks have a lower caliper mount that sirs back outboard an inch or more which slightly throws off the period look for me but still amazing forks worth consideration. The CBR600F4/F4i forks are a bit taller than the RF forks, so that helps you on ground clearance.
Either of those forks will be a nearly direct bolt on with All Balls conversion bearings into a GS frame using VStrom 1000 triples. They have a good amount of offset (19" front wheel on stroms) to work with the GS'S old school rake/caster angle but a 17" modern wheel - provides excellent trail without jacking the rear sky high. Low 40mm range (43mm?) Offset. VMAX1200 triples can be adapted to fit the GS frame with a lower bearing dpacer, and these have 50mm+ offset for use with 18" wheel or 19" & taller rear shocks.

If I build a 2nd 449cc or 489cc GS400/425, I'm going 17" CBR600F3 wheels in RF900R Forks and VStrom 1000 triples...


Mega information overload here, but I'm full of all kinds of ideas on how to spend one's money building killer GS Superbikes!

[Chuck78]

FYI just ditching the stock exhaust for the ultralight Yoshi, & ditching all 3 stock rotors in favor of Honda floating rotors and a right front 90 gsx1100g katana 275mm on the rear will drop that GS1000S dry weight down from 525lbs to an easy 490lbs. Now we're talkin!
Any of the forks I mentioned paired with the F3 wheels, another slight weight reduction and substantial performance increase. GS1100E alloy swinger, 7 lbs more reduced!

[azr]

Lots of great info, sure appreciate it all. I'll need to read over it to grasp it all. The one main thing I need to keep in mind is not to over build the engine. Priority #1 is that I want a bike that will be able to go on a 5000km trip. I'll have to have a chat with Ray for sure. I already have an aluminum swing arm that will be going on and as for the forks, I wouldn't be against changing triples and forks but I can't do anything that will modify the frame/neck as it's an 'S' frame. I'll probably just do what I had on my last 78 1000, emulators and Sonics, worked a charm and I can changes rims if I fancy.