GS(X)1100E turbo EFI

[lecroy]

Well, I don't know exact details of history of this bike. As far as I know it's imported from US to Finland at late 80's by my friend and he raced it actively till beginning of 90's.

Terry's last note on the bike:
"This bike was assembled by Jack O'Malley @ Orient and shipped to Europe maybe it did go to Finland. But it's not the bike I rode I know where it is."

Quite a piece for sure.

[ArttuH]

Terry's last note on the bike:
"This bike was assembled by Jack O'Malley @ Orient and shipped to Europe maybe it did go to Finland. But it's not the bike I rode I know where it is."

Quite a piece for sure.

Most likely we are talking about the same bike. As far as I know it's assembled by Orient Express. Here is one dyno picture from my hard disk:

[ArttuH]

And then back to the original topic.

Ready and waiting for the spring!




Allright, actually it's not completely ready yet. There is still something little to tinker while waiting. But all major things seem to be ready now.

[ArttuH]

On the road again!



Spring finally arrived here few weeks ago and since that I have been testing and tuning the bike. Now tuning is in pretty good order and I can tell some impressions about results of all this work.

First of all, the bike handles really nice now. It feels stable under hard acceleration, in corners and even at high speed. Previously I was able feel it leaning sideways when giving full throttle for it and above certain speed it felt like it was going to fly off. Now it's much better. Suspension adjustments still need some attention (now there is much more things to adjust) so I suppose to get it even better when I get everything right.

Also the brakes feel much more powerful. But there is something wrong with the front brake, it's soft even though it has new steel lines and I have bleed it in all possible ways. I guess that next I will try to change seals in the master cylinder, it's almost only thing left what I can imagine.

In the engine side there isn't much difference. It feels a bit stronger at top end, maybe, depending on boost level and VNT settings. I have spent plenty of time by investigating EGT and knock sensor readings from the datalogs and trying to determine safe values for the boost and ignition timing. I guess that in the end I just have to crank up the boost and see what comes out But before that I will try to just enjoy about it for a while as long as it stays in one piece.

There are few changes what I would like to try during the summer if I have enough time. The first one is a priority breather. Off-boost throttle response is slightly sluggish no matter how I tune fueling and it would be interesting to see if the breather improves this. Another one is more sophisticated control for the VNT vanes. With current pressure actuator it's impossible to find good balance between low end boost and exhaust back pressure at partial throttle. If I adjust it to build boost early then when cruising at 120 km/h the boost wanders around 3 psi and EGT goes above 800°C. Doesn't sound very healthy in longer term.

But after all I'm now very happy about the result of this extended winter rebuild project!

[TurboChris]

Arrrghhhh.....it's beautiful!!! And I am bitterly jealous......Enjoy!!

[ArttuH]

The summer is turning to fall here. Bike has been working just fine, I have done about 5000 km on it. Though now it seems that the engine will need some attention during next winter. It has started to consume oil and when I did compression test one cylinder gave clearly lower readings than others. So I have to build completely new engine for next summer or if (very likely) I don't have enough time for that make some quick renovation for current engine.

During summer I added some things to the bike. One was oil cooler. I used standard EFE cooler that seems to be efficient enough despite its small size. Unfortunately I wasn't able to use original hoses since the headers were on the way. I solved the problem by using teflon hoses joined to EFE hose ends. Result looks a bit clumsy but at least it holds the oil inside.



Another addition was a lock-up. The clutch was holding just fine without it but since I had all the parts available I just had to try it With stock springs the clutch is now light as a feather to use. And doesn't slip. Only problem is that the clutch doesn't disengage completely at high rpm even if I pull the lever all way down. Is this something normal with the lock-up?



Ceramic coating on the headers wasn't as durable as I was hoping. As you can see on first picture the collector part has got some rust. This is actually quite understandable since temperatures are very high there and the front wheel throws water and dirt straight on the collector. And I think that I applied too thin layer of coating on the headers. Turbine housing has survived much better. It's not black anymore either but it doesn't have any rust.

[lecroy]

Big welcome back! Between Blower's blown bike and yours, I can't decide which was the best performance project I have ever seen on this website. Glad to hear the bike is running great.

Another addition was a lock-up. The clutch was holding just fine without it but since I had all the parts available I just had to try it With stock springs the clutch is now light as a feather to use. And doesn't slip. Only problem is that the clutch doesn't disengage completely at high rpm even if I pull the lever all way down. Is this something normal with the lock-up?

I put an MTC snowflake on my old GS this summer. I would not recommend it on a daily rider.

If your using stock springs and kept the same height, the static pressure should be the same and the force to pull in the lever should be the same. Normally your putting lighter springs in to get the softer pull. So, I'm not sure why yours would have changed.

I don't understnd the second part as well. The clutch is still disengaged the same way it was before the lockup was added. It shouldn't have anything to do with RPM. My guess is that the arm angle changed to keep the cable the same length and there is not enough movement now to fully release it. I had to cut an inch or so off the stock cable's jacket to get mine long enough to work right.

This would go hand in hand with your first comment. If the arm angle has changed it would effect the pull in force.

[ArttuH]

Thanks for compliments!

And one more photo from summer to help your decision. Mine and Blower's bikes in a portrait:



When I installed the lock-up I replaced HD springs with old stock springs. That's why it's lighter to use. But I don't understand either why it doesn't disengage properly at high rpm. The arm angle should be exactly like before and the clutch works perfectly at low rpms, up to around 6000 rpm. But above 7000 rpm it drags a bit even if I pull the lever down, not much but enough to disturb gear change. So if I accelerate on second gear up to red line, lift the throttle and start coasting and then try to shift up I usually can't get the next gear in. Normal up-shift when I release throttle simultaneously with shifting works fine.

Anyway, I will check again cable free play and other possible adjustments. Maybe there is something simple and obvious that I have missed.

[lecroy]

Argh, I can't decide!! On technical merrit alone, they both boggle the mind!!

This makes it much clearer. I thought you just put the same springs back in. Once your in motion there can be a lot of force on the pack at the higher RPM depending on how much weight you have on it. I wonder if your seeing that added force compressing the cable and brackets enough that you just don't have enough travel to fully disengage it.

Don't laught too hard at what I am about to post. It's the truth and maybe will help. On my bike I use a motocross hand clutch assembly. It's billet, uses ball bearings and has a real nice feel to it. I had flipped the interenal spring on it and added an air cylinder to drive it. When I switched to the MTC multi-stage made one more tweek to the design. You have heard of a 1/4 turn throttle I'm sure. I changed the levers angles to make it a very short pull clutch. I can go from fully disengaged to fully engaged in about half the distance with it. This was a very simple mod. I just put a pin through the lever where the cable runs in the grove. If you don't have enough travel, maybe something like this would help.

[ArttuH]

I wonder if your seeing that added force compressing the cable and brackets enough that you just don't have enough travel to fully disengage it.

Very much possible. I have to play with cable adjustment and see if I can make it any better. Thanks for tip.

[ArttuH]

All right, here we go again! The bike has been neglected almost the whole winter since I have been busy with finishing my new garage. Finally got it ready enough to move the bike and tools in. So it's time for late winter overhaul.

So the plan is to make just quick and cheap renovation for the engine since it was burning increasing amounts of oil and compression readings were uneven between the cylinders. I'm also going to build new "stage II" engine during next winter so it doesn't make sense to waste too much money and time to this one.

The first unpleasant surprise revealed when removing the turbo. Joint between the air filter and the turbo had a small leak and the engine has been sucking dust through it whole last summer. And this showed up on the compressor wheel. Fortunately the dents weren't too bad and the turbo seems to be completely fine otherwise.



Opening the top end didn't produce more nasty surprises. The cylinder bores had some light scratches but nothing too bad. The pistons were quite fine, diameters were within the specification and ring grooves were fine too. #2 had some light scrubbing marks on the skirt. Piston tops had quite heavy carbon build-up.



The head was ok too. There was plenty of carbon too and some signs that inner cylinders have been running hotter than outer ones. The exhaust valves were somewhat pitted but still sealed quite well. The exhaust valve guides were quite worn but were still within the specs.



So the plan is to clean everything, hone the cylinders, get new piston rings, lap the valves with grinding paste and put all back together. Should be fine for this summer.

[ArttuH]

While cleaning the carbon deposits I found "interesting" dents on one piston top and combustion chamber. I'm not sure if these are signs of detonation or if there has been some "foreign object" passing through. Opinions?



Ultrasonic cleaner did the trick for the pistons. Even the ring grooves got completely clean without cumbersome scraping. I also got shallow (1mm) dishes machined on the tops. This should drop the compression ratio close to 9:1.

[ArttuH]

I measured the combustion chambers and found out that inner ones were slightly smaller than others. So I opened them up a bit to get the volumes equal.



Cleaned the exhaust ports and at the same time also tried to make them slightly smoother and more flowing. Hope that I didn't ruin the shapes completely.



Now I'm waiting for new wrist pins and circlips and then I can start assembling the engine.

[posplayr]

ArttuH

Beautiful GS1100ED; really bad ass. No way I could do anything like that.

On the pitting, I have seen almost the identical on a my pretty carboned up stock GS1100ED.

Good Luck.

Jim

[49er]

While cleaning the carbon deposits I found "interesting" dents on one piston top and combustion chamber. I'm not sure if these are signs of detonation or if there has been some "foreign object" passing through. Opinions?



Ultrasonic cleaner did the trick for the pistons. Even the ring grooves got completely clean without cumbersome scraping. I also got shallow (1mm) dishes machined on the tops. This should drop the compression ratio close to 9:1.

Hi ArttuH
Not sure it those marks are through detonation or a foreign object passing through that #3 chamber. I'm leaning towards the latter even though your inner cylinders have been running considerably hotter than the outer ones. Your previous pics of the headers show a lot more rusting on the #2&3 pipes compared to the outer ones. Some heat difference is normal to a more minor degree for all air cooled transverse 4's, but yours looks to be significantly hotter.

The top pic showing those marks also appears to show cracks coming from the top exhaust valve seat area. Have a closer look. It certainly looks like 2 fine cracks coming out of the seat ring and going up over the chamber edge out across the deck surface.
Is this a common fault on these heads?