More measurements

Yesterday I was at the shop and took some more measurements. Please note that these measurements were done with a vernier caliper, and are only for general reference, they are not very precisely done.

Intake valve: 25 mm
Exhaust valve: 22 mm (21,85 to be exact)

Main crankshaft bearing: 32 mm
Big end bearing: 30 mm

Piston diameter at the skirt: 65,4 mm
Top compression ring: 0,62 mm
Piston ring diameter: 15,85 mm

Crankshaft gear: 44 teeth
Clutch boss: 86 teeth

Gearbox gears (standard OEM numbers in parentheses):

Gear:	Input shaft:	Output shaft:	Gearing:
1	15 (13)	31 (37)	2,067 (2,846)
2	21 (19)	35 (37)	1,667 (1,947)
3	21 (18)	29 (28)	1,381 (1,555)
4	25 (24)	31 (32)	1,240 (1,333)
5	26 (21)	30 (25)	1,154 (1,190)
6	22 (24)	24 (26)	1,091 (1,083)

Bridgestone Slick 180/64 R17 circumference (sligthly used): 2,02 m

Using these numbers and putting them in my little nifty calculator (use RRlog if you don't want to do it by hand) gives a top speed of 261 km/h at the end of the Anderstorp main straight, using a 15/49 secondary gearing and running the engine at 15000 RPM.

Visiting Jansberg

Saturday I woke up early, early in the afternoon. After a quick shower, I drove to the shop and set about loading the engine in the back up my car. Some towels to protect the parts, and some plastic to protect the seats secured the engine parts on the backseat. After a nice drive to Helsinge I ended up in the countryside at a small house, if it hadn't been for the workshop sheds next to the house, I would have been sure my GPS had failed me.

I parked the car and knocked on the door, Michael Jansberg came to the door and let me inside. I waited a bit in while Michael finished a new control computer for a 2200 Dynamometer for a Swedish customer. After putting the finishing touch on the computer and interface cards, Michael turned to me. He gave me the grand tour of his workshop, which is divided into several smaller areas. One area for port work, one for mill work, one with a dynamo meter and another for storage of various parts. While going thru the workshop he found various R6 engine parts, some used and some new that he put in a little pile.

After the tour, I fetched the head, crankcase, valves and pistons. Michael looked it all over and gave me a few tips and hints. His overall assessment of engine is that is in a good state. The pistons and bores are fine, and the valves and valve seats are fine. The pitting in the squish area is of no concern, and can be flattened slightly with some light sandpaper. The valves are "RSC" valves, so a replacement valve for the one stuck exhaust valve will be different (OEM). The piston rings are quite worn, which can be seen by the fully polished second compression ring. Michael wasn't impressed with the head work, which amount to a simple porting and decking. He hinted that I'll get some good result with some epoxy.

While we looked over the engine, we talked about high velocity tuning and other topics. Michael recommended the SpeedTalk message board, and I'm quite impressed with that place. It is full of insightful post regarding engine tuning.

I also need to change the main bearing on the input shaft of the gearbox, it has a rough spot. After looking over the engine, Michael gave me the R6 parts he had collected and sent me on my way home. I was most pleased with the visit, Michael is a very knowledgeable man, and he don't mind sharing his wisdom. He took an hour of his weekend and gave me free advice, I'm grateful and will send him a bottle of red grape juice.

Dish washing 2

Today I did some more dish washing. This time it was the crank, the crankcase and the valves. I washed it all in hot water and regular Ajax. The goo from the chain around the output axle was removed with lamp oil.

Tomorrow I have an appointment with Michael Jansberg, I'm looking forward to get his assessment on the state of the engine, and maybe get a few tuning tricks.

Background

A reader suggested that I post a little background info. Like what kind of engine I'm rebuilding, and why.

The engine is from my racing motorcycle, a Yamaha YZF-R6 from 2000. I purchased the bike from another danish road racer at the end of the 2006 season. I used the bike for the 2007 season, racing in the danish rookie championship and running at various trackdays. The engine is supposed to have a V&M SuperSport tuning and in the spring of 2006 a Sigma slipper clutch was installed.

I'm rebuilding the engine for two reasons. First of all it had a high oil consumption, ½-1 liter for a race weekend. Second, I had it on a dynometer and the result was quite disappointing. It had 103 rwhp, on a dyno that measures a stock 2006 R6 at 101 rwhp. My goal is to have 110 horse at the fat rubber, at least.

Dish washing

Today I talked a bit with Michael Jansberg (of WSS tuning fame). He gave me a few hints, and I can probably get him to take a look at the engine head, cylinders and pistons.

So as preparation for that, I went to the shop to take out the gearbox, and clean some parts up.

The gearbox came out nicely. It is, strangely, the only place in the engine where you need a torx key (size T30). The main bearing on the drive shaft seems to have a rough spot, so I might need to change it.

I used some regular detergent to clean the valve cover, camshaft cap and head. It worked nice. To get rid of the remaining liquid gasket, I used Loctite 7200. Loctite really makes it a breeze (a stinking breeze thou) to remove gaskets, and it even took a lot of the soot/carbon deposits with it. Take a look at the difference:



When I had cleaned the head, I noticed some pitting in the squish areas. I guess it's from running with no air filter, and I hope Mr. Jansberg have a few tricks to mend them.

I also took the pistons apart and cleaned them. The cross pin came right out, with out using a driver/puller or anything fancy.

Measurements

Today I went to the shop to take a few quick measurements and remove the stuck valve from the head.

The valve stems measured at slightly below 4 mm for both a random intake and random exhaust valve.

The valve lift was measured at (33,2 - 25,2) 8 mm for intake, and (32,7 - 25,2) 7,5 mm for exhaust.

Removing the stuck valve from the head was quite easy. I have bought some small grinding tips from Proxxon for my mini grinder, and they cleared the head just fine. So two minutes of grinding, and the valve was out.

I also removed the bearing shells from con rod nr. 3, there is some slight discolouration on the back of the bearing shells. I'll try to get a photo of it. The bearings are marked F-112 (the bearing type) and 050D (for size I guess).

Engine rebuild

This winter I'll be rebuilding my engine on the R6.

So far I have managed to dismount it from the frame, and dismantled most of the engine.

(Click on the pictures to get a full-res version)

1. 
   The camshafts looks quite good, only minor wear on them, and no pitting at all.



2. 
   The camshaft journals are fine, slight wear on the camchain side, but that is to be expected.



3. 
   The intake ports are fine, and have been worked over once.



4. The exhaust ports are filled with carbon deposits.



5. 
   The combustion chamber is filled with carbon deposits. The enigne used quite a lot of oil, and it shows on the head and on the pistons.



6. The valves seems fine, but I need to take few messurments to get the valve stem to valve guide clearence. One of the exhaust valves in cylinder 3 won't come out. I guess the head has been hammerd flat because of a faulty hardning. The valves also need a good cleaning, lots of carbon deposits.



7. The camchain was quite used, so a new one will do wonders.



8. 
   The cylinders are good.



9. 
   The pistons looks good, only minor scuffing on the skirts. But a lot of carbondeposits on the crown.
   



10. 
    The crank is fine, and all the bearings looks good. One thing that puzzled me is that the crank bearings are the widest size (green) where they should have been two sizes tighter (black). I guess the reasoning is reduced friction from the bearings.



11. The connecting rod big end bearings are fine, a little blank here and there, but not much wear.



12. The oil pump had to have the chain cut to be removed, so a new chain will get installed. Besides from that, the oil punp seems fine.



13. The oil pickup strainer had quite a few metallic particles in it.



14. The water pump is corroded, from either cavitaion or running plain water (ups).



15. 
    The clutch basket and boss has some indentions from the cluthplates. I might smooth them out.



16. 
    The gears looks good, but I still need to remove the lower shaft, and disassmeble both the shafts.

I have not spotted the reason for the high oil consumtion. As you can see from the images, there has been very little blowby on the pistons, so my current suspect is the valve seals. But I'm going to change them anyway.

If you want to see more pictures (some of them in very high resolution) then have a look at this album.