First Post, First GS-Build 78' 1000 -> 1100, advice needed

[Guest]

Hey all! Let me introduce myself! Im Andrew, from Detroit!

I have a 1978 GS1000 that is rather custom, NOW im tearing into the engine. Having never built up a motorcycle engine like this, I am going to have some questions. More and more as the project goes on I feel.

Anywho, here is a run down on my bike first...

Notched and stretched swing-arm to fit a 2002 GSXR rear wheel, 2002 GSXR front end, hooped/upswept rear frame section with custom seat and integrated tail light, stripped, cleared and striped tank, VH 4-1 Exhaust with racing baffle. Dynatek 2000 kit, all digital gauge cluster, the brand eludes me at the moment...

Anyhow, I have had the bike for almost a couple years now, done alot of the work on it myself, however when I had the bike tuned up last spring the mechanic at the dealer did not torque down one of the upper cam retainers causing the exhaust cam to rattle loose and destroy the cam, and the other upper surfaces in the cylinder head, also he tuned it very poorly.

Needless to say the bike was immobile for a while, and will be for a bit longer.

Current plans are as follows

-1100 Piston kit
-ported cylinder head with larger valves and beefier everything
-carb upgrade
-agressive cam setup
-make a new wiring harness for the bike, eliminating the unused parts of the factory harness that are just hanging around.

Where I am at now:

Motor has been pulled, and torn almost all the way down, the last thing I have to do is blow the case apart and remove the crank to inspect the bearings ect.

Cylinder head was toasted, also had a few burnt up valves from poor tuning.

Cylinder bores were clean and smooth as were the pistons, aside from the 1/8in coating of crap on the top of the pistons.

My next thing is like I said, pulling the case apart to inspect the bottom end for wear before it goes back together.

Is the stock rod/crank setup good for a 1100 kit with a mild head build? Or does that need to be upgraded too?

I am not made of money and the head parts and piston set and machine work is going to be pricey so I was wondering if there are any tricks or tips out here on doing this conversion.

Also, I am curious as to what the best carb setup is going to be to run on this bike. I was looking at Dynoman's site and it looks like they have some custom built carb sets for this motor, but im not sure how much of an upgrade it will be. The stock carbs on the bike were a night mere to get tuned with pods and the exhaust before, so I am wondering what the best setup would be for this motor that might be slightly easier to get dialed in.


So with all of this in mind I will take any advice, tips, ect that is out there, even point me in the direction of previous threads pertaining to this topic so i can do some reading before I get to reassembly. Like I said, I haven't done this before, I am mechanically savvy having worked on VWS for a long time and I have just completed building a traditional 60's lowrider.

Thanks for the help guys! Looking forward to getting to know you all and getting this beast back to tearing up the streets. I'll get some pictures up soon!

Cheers!

A

IMG_2085.jpg

[chuck hahn]

You do realise that a 1 year only bike!!! Whats unique is the indented tank and the wide stripe down the indent ..Yours to do as you wish but it was worth more restored to original.

Heres my E model.







And one of my C model.

[GSX1000E]

Sell the fuel tank. You could get anywhere from $300-750 for it on Ebay if it is all as good as it appears in that bad picture.
Buy an '81 1100E (4-valve) tank with the factory knee indents as it will look much better on that project and the petcock is mounted to the rear.
Find any '80 (or is it '81?) up 1100 (2-valve) stock cylinder to bore over to the 74mm bore as they will still be thick enough after the boring.
And either repair the early head, port those carbs, acquire a set of 29mm smooth-bores or acquire any '80-up 1000 or 1100 2-valve head and carbs.
After market camshafts should also be planned for along with better valve springs.

This is just one of my toys that has pretty much all of what I am recommending and then some.

http://i1294.photobucket.com/albums/b604/GSMagician/GSR%20Projects/DSC03292_zpsc9e1b6f0.jpg

http://i1294.photobucket.com/albums/b604/GSMagician/2014%20Fathers%20Day%20Ride/DSC03552_zps8d4e7a34.jpg

That one happens to be a very big/nasty G model now.

[chuck hahn]

Cutting up a 78 1000 is akin to cutting a 63 split window so you can " make it look cool". But like i said its his and its obviously too late.

By the way, I am from Hazel Park originally..8 1/2 and John R.

[rapidray]

Your crank NEEDS to be welded, along with several other things to make the engine live. I am an engine builder & can answer questions if you want to call me. I can be reached at 714--356-784 five. Merry Christmas, Ray.

[ShadowFocus603]

I like it. Looking forward to seeing more progress.

[DetroitDrag]

Cutting up a 78 1000 is akin to cutting a 63 split window so you can " make it look cool". But like i said its his and its obviously too late.

By the way, I am from Hazel Park originally..8 1/2 and John R.

I had no idea that it was a one year only bike, trust me when I say that I "saved" it from the previous owner who had a bunch of hack body work and wiring stuff done to it, not to mention a bunch of makeshift mod crap.

I just nabbed a ported cylinder-head to take over to the machine shop to have cleaned up and re-seated for the larger valves....

So instead of using the stock cylinder jug, you would recommend using an 1100 jug to start and bore that?

I read something a while back about using a set of carbs from an early gsxr like 89-92 i believe...

looking forward to getting more into this. Hopefully soon, just need to start getting some of the parts.

Curious about the welding of the crank and other bottom end stuff to make sure it doesn't blow to pieces...

[chuck hahn]

Check in on the racing forum for engine and mod advice..I dont do racing or mods. I do stock configuration restos.

[rapidray]

You are fine here in the PERFORMANCE/TUNING/MODS thread, as that is what you are referring to, not racing. Call me if you would like to ask questions. Have a Merry Christmas!!
Ray.

[GS1150Pilot]

That is a badass shop, and a very cool bike.

[trippivot]

you are just posted a 10K investment into a $1K bike. I love it! top end and bottom end are 2 different tasks -- ( parts / machine work) so start with one or the other.

get a different head don't try to fix the one you have- cam cap integrity are pretty important- you can make the small ports of a gs1000 shaft or chain engine flow excellent numbers but most think bigger is better--- late 82-83 1100 shafties have the HUGE "D" ports and if you are not careful you will tune your engine into the 14,000 rev range to get port velocity. stick with a sm port head. -- the 38mm / 35mm valves can be jumped to 40 / 38- the seats have a tendency to fallout when you go big valve and lots of porting - be careful and stay conservative -you may have to weld or epoxy the top of the runner where a porting guy breaks thru - (no biggie) -- WEB makes excellent .425 lift cams -- shim under bucket mandatory - large lift springs and shimming them for lots of seat pressure-- 33 smoothbores are great with the limitations of the 1000 engine -- over carbing can be a huge problem - 1105 pistons -- if you mill the head you'll have headaches everytime you re-build.. it may leak oil but at least you wont rust.

get that done and you are half way there. it is all available at APE - when it comes to porting mid 80 CFM at 10" test is a good place to be satisfied -- you may creep to 90 but then you are pretty thin on reliability.

33 smoothbores flow 97 Wide open.

[GregT]

you are just posted a 10K investment into a $1K bike. I love it! top end and bottom end are 2 different tasks -- ( parts / machine work) so start with one or the other.

get a different head don't try to fix the one you have- cam cap integrity are pretty important- you can make the small ports of a gs1000 shaft or chain engine flow excellent numbers but most think bigger is better--- late 82-83 1100 shafties have the HUGE "D" ports and if you are not careful you will tune your engine into the 14,000 rev range to get port velocity. stick with a sm port head. -- the 38mm / 35mm valves can be jumped to 40 / 38- the seats have a tendency to fallout when you go big valve and lots of porting - be careful and stay conservative -you may have to weld or epoxy the top of the runner where a porting guy breaks thru - (no biggie) -- WEB makes excellent .425 lift cams -- shim under bucket mandatory - large lift springs and shimming them for lots of seat pressure-- 33 smoothbores are great with the limitations of the 1000 engine -- over carbing can be a huge problem - 1105 pistons -- if you mill the head you'll have headaches everytime you re-build.. it may leak oil but at least you wont rust.

get that done and you are half way there. it is all available at APE - when it comes to porting mid 80 CFM at 10" test is a good place to be satisfied -- you may creep to 90 but then you are pretty thin on reliability.

33 smoothbores flow 97 Wide open.

I've just taken 33 smoothbores off a customer GS1000 - 1075, Yosh cams, mildly ported head....And replaced with Keihin CR31's. Night and day difference. The 31's are much more responsive,better midrange and easier to set up. For a street ridden bike, I wouldn't go bigger.

[rapidray]

Actually, the 34RSs work pretty well on a modified, 1000-1100, 8 valve street motor. The 33 roundslides flow a LOT of air on a smaller motor & as Greg said the 31 round slides work better for head airflow port velocity. The flatslides just seem to be a different animal & the 8 valve motors seem to work better with smaller roundslides where they are ok with a little bit bigger flatslides. I need to get a head with some carbs back on the flowbench & look at them for awhile as I haven't done that in more than 20 years now.
Ray.

[GregT]

Actually, the 34RSs work pretty well on a modified, 1000-1100, 8 valve street motor. The 33 roundslides flow a LOT of air on a smaller motor & as Greg said the 31 round slides work better for head airflow port velocity. The flatslides just seem to be a different animal & the 8 valve motors seem to work better with smaller roundslides where they are ok with a little bit bigger flatslides. I need to get a head with some carbs back on the flowbench & look at them for awhile as I haven't done that in more than 20 years now.
Ray.

Agree re the RS series. Never known whether it's a better developed emulsion system or just the accelerator pumps but yes, you can go bigger with no driveability penalty. For some reason though, on these motors the Keihin FCR's just don't seem to match as well.
In my experience anyway...
I'd have loved to try Dellorto roundslide sets which came with accelerator pumps. Unfortunately, I've only ever seen them written up - never seen a set in the metal. From what i can find out the sets are pretty rare. I've used individual Dellortos of course and like them.