1981 GSX1100 Katana Based Project

[Shin-Ken 1074]

Had a phone call today from the engineering shop doing the work on the barrels, there is good news and some bad news. The good news - head and barrels have been ceramic coated and the five plane valve seating has been completed. The bad news - first three cylinders have been bored out however, while boring cylinder #4 the sleeve has spun and done some damage. Number 4 barrel now needs a replacement stock sleeve and then bore it to 76mm so it looks like another week or so to finish the job providing the barrel has not suffered too much damage and can be saved. They are pressing out #4 sleeve now and will inspect the barrel to see what is what.

I hope it can be saved or I'll have a very nice looking, very expensive ceramic coated doorstop.

Running tally = 199.557 kg.

 

[Shin-Ken 1074]

Update on the barrels, the replacement number 4 sleeve has been installed and machined and both the barrel and head are ready to be picked up. While the Kat has been off the road I've been able to modify a few parts to make them lighter, not a lot, but every gram counts and the running tally is now down to 199.211kg. I weighed the OEM fork pre-load units and with the steel core and pin bringing the unit in at 118grams each, I am sure an aftermarket all aluminium pre-load would be lighter so I have ordered a set to test the theory.

Running Tally = 199.211 kg.

Preload Unit OEM by Max Mutarn, on Flickr

 

[Shin-Ken 1074]

Picked up the head and barrel from the engineering shop today. The head is looking pretty good now with its new 5 plane seats, ground valves, new valve guides, new valve stem seals, skimmed head face and the head finished in black gloss ceramic coating.

1197 Head1 by Max Mutarn, on Flickr




1197 Head 2 by Max Mutarn, on Flickr

 

[Shin-Ken 1074]

Number 4 sleeve has been replaced with a new sleeve and machined to suit. I was hoping there would be some weight reduction going from 74 mm bore to 76mm bore and there was, a lot!

The stock barrel with stock 74mm bore weighed 8080 grams, the same barrel with 76 mm bore weighs 7260 grams, another 820 grams lighter! The running tally wont be adjusted until I weigh the stock pistons and pins vs the Wiseco pistons and pins and have the final weights overall.

Had the barrel finished in gloss black ceramic to match the head.

1197 Barrel 1 by Max Mutarn, on Flickr

 

[Shin-Ken 1074]

Weighed the 76mm pistons today and three of them are 216 grams and one is 214 grams. Time to get out the wet/dry oxide paper and the glass plate and get all the weights to match up. Another 6 grams off.

76 mm piston1 by Max Mutarn, on Flickr

76mm Piston2 by Max Mutarn, on Flickr

 

[GS1150Pilot]

How much did the 74mm pistons weigh?

 

[first timer]

Weighed the 76mm pistons today and three of them are 216 grams and one is 214 grams. Time to get out the wet/dry oxide paper and the glass plate and get all the weights to match up. Another 6 grams off.

76 mm piston1 by Max Mutarn, on Flickr

76mm Piston2 by Max Mutarn, on Flickr

Don't forget to do your weight balancing with rings circlips and wrist pins included in the measurement.

You can mix and match the rings and wrist pins (if the rings haven't been sized to the bore yet) to your pistons first to try and balance out all 4 pistons first, then start shaving pistons to get them the same.


Is your crank trued and balanced? If not you will gain some improvement but might not be worth the time spent unless you are bored.

 

[Shin-Ken 1074]

How much did the 74mm pistons weigh?

The stock pistons are still attached to the conrods so no weights for them yet, will try to weigh them over the weekend.

 

[Shin-Ken 1074]

Don't forget to do your weight balancing with rings circlips and wrist pins included in the measurement.

You can mix and match the rings and wrist pins (if the rings haven't been sized to the bore yet) to your pistons first to try and balance out all 4 pistons first, then start shaving pistons to get them the same.


Is your crank trued and balanced? If not you will gain some improvement but might not be worth the time spent unless you are bored.

Yes, I will be weighing each part to ensure matching weights for each complete piston assembly. It will be interesting to compare the weights of the tapered Wiseco pins to OEM pins. The crank is staying in place so there wont be any balancing at this time, the engine has been running smooth so I am confident the crank is true, well hopeful it is true.

 

[Shin-Ken 1074]

The engineering shop have gaped and sized the new rings to the pistons and bore and by luck, each of the ring sets are the same weight. Once the stock pistons and pins have been removed from the engine I'll weigh and compare the stock vs Wiseco parts.


Running Tally: 198.165 kg.


76mm set1 by Max Mutarn, on Flickr


76mm Set2 by Max Mutarn, on Flickr


76mm Set3 by Max Mutarn, on Flickr


76mm Set4 by Max Mutarn, on Flickr

 

[jdub6092]

Bingo!

Ti pipes, aluminium flanges, Ti header bolts, Ti and carbon muffler, all used parts except the bling Ti bolts. Working on the muffler bracket. The muffler was cheap to buy as it had been in a prang and was in a pretty poor state. Needed some work to get it sorted and able to do its job.

Aluminium flange and Ti bolts by Max Mutarn, on Flickr


Ti pipes Ti and carbon muffler by Max Mutarn, on Flickr

Did you fabricate these aluminum split flange clamps?
Any special trick to doing this? I can see where the cuts need to be made, but what kind of fine cutting tool did you use?

 

[Shin-Ken 1074]

Did you fabricate these aluminum split flange clamps?
Any special trick to doing this? I can see where the cuts need to be made, but what kind of fine cutting tool did you use?

Hi jdub6092, I didn't make the ally exhaust flanges, I scored them used from an auction site. I have made a lot of the parts used in this build and if you couldn't find a set of these for sale somewhere, they could be made however, it would be many, many hours of work.

 

[Shin-Ken 1074]

The new Wiseco pins and pin clips are all the same weight, thankfully. Will also weigh them again with all the parts together to confirm weights and how much each piston has to be shaved.


1197 tapered pin by Max Mutarn, on Flickr




1197 pin clip by Max Mutarn, on Flickr

 

[Shin-Ken 1074]

The combined weights are consistent, each complete piston weight equals the combined weight of each part. It confirms number 1 piston being 2 grams lighter than the rest. A double bonus for the build after pistons 2,3 and 4 have been shaved;

1) balanced piston set

2) piston set will be six grams lighter

1197 piston1 by Max Mutarn, on Flickr


1197 piston 2 by Max Mutarn, on Flickr


1197 piston3 by Max Mutarn, on Flickr


1197 piston4 by Max Mutarn, on Flickr

 

[Shin-Ken 1074]

I removed one of the stock 1135cc pistons today and was pleasantly surprised. The Wiseco 1197 cc piston is 26 grams lighter than the stock 1135 cc piston. So with the four 1197cc pistons being 104 grams lighter and the four 76mm bores being 820 grams lighter than the stock bores the total weight reduction is:

924 grams.

When the three pistons are shaved to match number one piston weight there will be another few grams off. Wow, Iam very happy to reduce the weight by that much and have an increase in performance, whats not to like.


1135 OEM piston by Max Mutarn, on Flickr

Running Tally = 198.281 kg.

 

[Shin-Ken 1074]

Number one piston and pin are the lightest of the set at 291.5 grams, number four piston and pin are the heaviest at 292.6 grams so number four is the first one for a haircut. Used a burr to remove the offending 1.1 grams from number four piston and now it is a match with number one piston and pin at 291.5 grams. Used the serious scales for the piston weight, it weighs in 1 tenth of a gram increments.

1197 # 4 piston before by Max Mutarn, on Flickr


1197 #4 piston burr by Max Mutarn, on Flickr


1197 #4 191.5 by Max Mutarn, on Flickr

 

[Shin-Ken 1074]

Piston number three has been shaved and now matches Piston 1 and 4 at 291.5 grams.


1197 #3 291.5 by Max Mutarn, on Flickr

 

[Shin-Ken 1074]

Piston number 2 has been shaved and now all four pistons and pins are the same weight at 291.5 grams.

Running Tally = 198.279


1197#1 piston 291.5 by Max Mutarn, on Flickr


1197 #2 291.5 by Max Mutarn, on Flickr

 

[Shin-Ken 1074]

I have been looking at the muffler and I think there is some metal that could be trimmed from the inlet end-cap, maybe something like 30-40 grams?

 

[Shin-Ken 1074]

Looked over the muffler today and there isn't any wiggle room there to remove any metal from the inlet cap. It's spring mounted and cutting it back may weaken it. Plan B is to hog out the ignition timing cover, should be around 70 grams that can be removed from the cover. I have bought a used road rashed cover to be the Lab-rat so no harm will be done to a wholesome cover. The ignition cover should be here in a week or so.