GS(X)1100E turbo EFI

[ArttuH]

Then some rant about "HD transmission bearings". I bought a set of these bearings, branded as Schnitz Racing. It includes all four bearings for the transmission, two large and two small ones. The large ones were fine, they even had more balls than original ones so maybe they really are stronger. But then the small ones... On the photo the original one is on the left and "HD" on the right.



As you can see there are two differences. At first the HD bearing doesn't have snap ring groove. This isn't very critical since these bearings shouldn't get any side load. Another thing is missing dust seal that the original one has. At first I thought that it doesn't make any practical difference but then I realized that this is actually pretty important thing. Pressure oil feed to the gears and clutch goes through ends of the shaft and these dust seals are necessary to prevent oil to escape straight through the bearings. So with these HD bearings the gears and clutch wouldn't get any pressure lubrication!

I'm not sure how tragic this would be in practice. I guess that this might be ok in drag use where the transmission doesn't see too many revolutions between engine rebuilds but I wouldn't try my luck with street engine that is supposed to see plenty of road.

Fortunately these were just standard bearings so it was easy to get ones with snap ring groove and dust seal from local engineering shop. I'm just wondering why they didn't put correct bearings in the kit at the first place

[ArttuH]

After getting the correct bearings it was time to start assembly.

The APE head studs and main bearing studs installed.


Transmission got undercut for second and third gears.


Cases vent together nicely, all shafts are still spinning and even the gears seem to work.

Assembling the clutch.


Pressure plate with steel buttons for lock-up. Thanks for Blower1!

[ArttuH]

And then top end.

I adjusted compression ratio by machining dishes on piston tops. The result should be about 9.1:1. Minimum crown thickness with dishes is a bit over 5mm, I hope it's enough. I also got ceramic coating on piston tops. Interesting to see if it lasts or give any noticeable benefit



I checked ring end gaps and adjusted them to slightly larger. I also weighted the pistons and found about 1 gram maximum difference between them. Almost started to remove material from heaviest pistons but then I weighted the wrist pins too and found out that they were varying by 0.5 grams. So proper mix resulted about 0.5 gram maximum variation for piston + pin combinations. Good enough, I think

[ArttuH]

Fitting the cylinder block and pistons caused normal amount of swearing but went fine overall.


The head required less work than I initially thought since the valve guides were all good. Just to be safe I decided to get new exhaust valves so they are now 1 mm oversized (24 mm) stainless ones. Along the seat work the head got light porting too. Meaning that porting was limited to valve seat area. This resulted about 10% increase in flow bench figures.

After installing the head with Cometic steel gasket I timed the cams to 106° in. and 110° ex.

[49er]

And then top end.

I adjusted compression ratio by machining dishes on piston tops. The result should be about 9.1:1. Minimum crown thickness with dishes is a bit over 5mm, I hope it's enough. I also got ceramic coating on piston tops. Interesting to see if it lasts or give any noticeable benefit



I checked ring end gaps and adjusted them to slightly larger. I also weighted the pistons and found about 1 gram maximum difference between them. Almost started to remove material from heaviest pistons but then I weighted the wrist pins too and found out that they were varying by 0.5 grams. So proper mix resulted about 0.5 gram maximum variation for piston + pin combinations. Good enough, I think

Great pics Arttu. You should be OK with 5mm crown thickness. You're not boosting over 1.5 bar are you?
Your piston/pin weight combinations should be good at 0.5 grams variation.

I see your piston weighs around 216 grams. I got my 850's down to 198 grams . The crowns are just 3 mm thick while running 10.5 -1. I reasoned that they would be strong enough because of the high domed shape. I didn't install the JE pins as they were quite heavy (could have run diesel compressions with them), so I bought new stock 850 pins and ground their lengths back 1.5mm to match the JE gudgeon bosses. Saved some weight using the modified stock pins as well.

Did you check all the sealing surfaces on your Cometic Steel head gasket. Some GSR 1100/1150 engine re-builders have had unhappy experiences with oil spewing from their engines, after fitting MLS gaskets.

The different transmission bearing designs could account for early bearing failures as you have pointed out. I'd be sticking with the originals with shields and the snap ring locating grooves too.

[ArttuH]

I wasn't especially interested to minimize piston weight since I'm not going to spin the engine extremely high. Probably I will set the rev limiter to 10k which should be quite safe.

I checked the head gasket briefly and didn't notice anything suspicious. I also added a very thin layer of sealant around the oil holes for extra safety.

Actually I guess that those HD bearings itself would do fine without shields but but the gears and and shift forks may suffer if they lost pressure lubrication.

[49er]

Suprised to see that you are increasing the overlap by advancing the inlet cam like that. Is this the timing that you ran on your earlier turbo motor?

[rapidray]

Pressurized engines usually like a little more spacing. Ray.

[ArttuH]

Hehe. Actually I was going to set the cams to 110/110° but I hadn't slotted the intake sprocket enough for that. When I found that out I was too lazy take the cam off again.

With previous engine I tried several cam settings from 104/106 to 111/113 and didn't notice any huge difference. So I will start with this setting and maybe change it later if it seems beneficial.

[49er]

Hehe. Actually I was going to set the cams to 110/110° but I hadn't slotted the intake sprocket enough for that. When I found that out I was too lazy take the cam off again.

With previous engine I tried several cam settings from 104/106 to 111/113 and didn't notice any huge difference. So I will start with this setting and maybe change it later if it seems beneficial.

I only asked because I believe that most forced induction engines don't benefit from increasing the overlap between the valves. Turbos might be more accepting of increased overlap because of the inherent lag down low, but supercharged engines happily blow raw fuel out the exhaust at lower rpms.

[ArttuH]

I only asked because I believe that most forced induction engines don't benefit from increasing the overlap between the valves. Turbos might be more accepting of increased overlap because of the inherent lag down low, but supercharged engines happily blow raw fuel out the exhaust at lower rpms.

It seems that optimal cam timing with a turbo depends a lot of turbo sizing and other details of the setup. If the turbo is sized so that exhaust back pressure doesn't exceed boost significantly cam timing affects pretty much the same way than on N/A engine. If there is more exhaust pressure than boost then it might be beneficial to reduce overlap. And if the boost is clearly higher than exhaust pressure it might be good idea to reduce overlap too, just like with a supercharger, but this isn't too common situation with turbos.

[WilliamGLX81]

Hey!

Wow, I'm suprised you wanted more boost on an 1100 anyway, but neat setup! I really like the custom manifold.

The beginning of the thread looked like it wasn't under use yet, and my only advice is that you should add a water cooling setup to the turbo.
I have a turbocharged volvo 740. 2.3L makes 195lb-ft of torque and 170~ish hp.

In their discovery of the awesomeness of MOAR BOOST, they found that watercooling the turbo made a huge difference in oil temps in the engines.
I think it will really be worth it to you to protect the engine and turbo's bearings to add a water jacket setup. Turbos add massive heat energy to the system, and the bike is air cooled. That, plus the shared oil for engine, turbo, and transmission makes me think the bike is going to eat oil like it does gas.

I'd either add an oil cooler and reservoir to the setup, or water-cool the turbo.
There is a small-ish (for a 2.3L) turbo that's available on the 85-89 volvos. I think it's a Mitsubishi TD04, the TD03 is a larger one. The only reason I mention it is that it has a built-in waterjacket and cooling setup.

I really like the project though Hope you finish it up.
-William

[49er]

Hey!

Wow, I'm suprised you wanted more boost on an 1100 anyway, but neat setup! I really like the custom manifold.

The beginning of the thread looked like it wasn't under use yet, and my only advice is that you should add a water cooling setup to the turbo.
I have a turbocharged volvo 740. 2.3L makes 195lb-ft of torque and 170~ish hp.

In their discovery of the awesomeness of MOAR BOOST, they found that watercooling the turbo made a huge difference in oil temps in the engines.
I think it will really be worth it to you to protect the engine and turbo's bearings to add a water jacket setup. Turbos add massive heat energy to the system, and the bike is air cooled. That, plus the shared oil for engine, turbo, and transmission makes me think the bike is going to eat oil like it does gas.

I'd either add an oil cooler and reservoir to the setup, or water-cool the turbo.
There is a small-ish (for a 2.3L) turbo that's available on the 85-89 volvos. I think it's a Mitsubishi TD04, the TD03 is a larger one. The only reason I mention it is that it has a built-in waterjacket and cooling setup.

I really like the project though Hope you finish it up.
-William

Good feedback William. I've never bothered with turbos on bikes for the very reasons you have mentioned.

You would need to arrange a decent pressurised holding tank and a small radiator along with a reliable pump. This would add quite a bit of weight and affect the handling of the bike.

I think I would be opting for more oil capacity and better oil cooling as a safeguard.

[ArttuH]

Hi William.

The bike has been turbocharged with the original engine for three active riding seasons. Hopefully I will get this new engine in use within next few weeks.

As far as I know water cooled turbos are developed mainly to prevent heat soak after engine shut down. This is a problem in many car installations. The turbo is really hot after driving since it's crammed in the middle of the engine bay so it gets very little cooling air flow. And when the engine is shut down cooling oil flow to the bearings stops and glowing hot turbine side starts to heat bearings. This makes remaining oil to boil and result is carbon build-up on the bearings. Water cooling helps to keep bearings cool enough in this situation.

On bike installations the turbo usually gets plenty of cooling air and thus it survives fine without water cooling. My current turbo has that water cooling jacket and originally I planned to route the oil cooler line through it. But required plumbing was looking too challenging since there is quite little space between the turbo and engine so I gave up the idea. Separate water cooling system for turbo would be way too complicated.

With my previous set-up I hadn't any special problems with oil temps. Temps were higher with turbo but even adding tiny GS1150 stock cooler was enough to drop temps to original level. So I think that this new 13-row cooler should be enough to keep temps on reasonable level.

And then some project progress. The engine is in the frame

[WilliamGLX81]

BeaU-teeful! I like the paint on the engine.

Just so long as you addressed it. I was worried about oil degrading faster, but you do have a point about the turbos being exposed. And the heat soak was one reason for going water-jacket on the turbos, but I thought the other was just general cooling capacity of oil... No clue which was more important.

Looks like the point is moot though

So how does it ride? Does it fly through the gears? Is it the original transmission, or did you swap it out with one with longer gears?
And is the turbo wastegated, or always on? I would assume it's got a built-in wastegate, but it's off a diesel.

And I didn't realize the engine was water cooled... whups. Guess it'd be a lot more of an issue with a strictly air-cooled bike like my 650.

Ride on!
William