This artistic shot was taking by Ariana while at Portland International Raceway on April 23rd while racing with OMRRA.
I ended up making a video on measuring squish. In the video not only do you get to learn a vital measurement when building an engine you also get to see the shop of Burgi Racing and its current motor under construction.
Squish. No it isn't just the sound that fruit makes when someone smashes it or steps on it with their foot. In the engine world it is the distance between the top of the piston and the bottom of the cylinder head. It usually is the smallest on the edge of the piston. This is because the head's combustion chamber has a little bit of over hang into the cylinder. Setting your squish is very important. The first obvious reason is to keep the piston from smacking into the head. That would be bad. But squish is also what causes the sweet spot of the compressed air and fuel to center around the spark plug. This makes it so the fuel can ignite better thus causing higher combusion chamber temperatures which means more pressure and thus...more power.
Well with the new pistons in my bike using heads milled for SuperSport I have to be very careful with my squish. This is because I can't run the smallest squish which keeps the piston from hitting the head. If I did that I'd be over 15.5:1 compression ratio...not good...broken cranks come to mind. :) So I have to play with my squish to set the compression ratio....specifically I have to get it to 1.2mm from its previous setting of .8mm (with the OEM pistons).
So how did it do? Well...using 1 oem base gasket with the oem head gasket my squish was .65mm. I think that puts me up into 16:1 CR terriority. *yikes* So adding another OEM base gasket and it gives me .93mm. So now I have to wait for my order of more base gaskets as it looks like I'll need 3 base gaskets. But that should be ok. Zlock said 3 should be fine...just don't go any more. Of course I could always go and get an aftermarket copper base gasket from Spears Enterprises but I'm gonna trust Dan here. Worst case I leak a little bit of water and I have to tear it apart again and replace the base gasket with a copper one. I think that'd just cost me a day of work....hopefully it'll be warmer when I do that. :)
Edit: It was pointed out to me that I really didn't get the message across about squish. Check out this link for more information. Although its 2-stroke focused...the principle is the same. http://www.kreidler.nl/artikelen/performance-tuning-graham-bell/performance-tuning-graham-bell.pdf
Anyhow I like pictures...here are some.
Well my motor is now ready to be put back together. I got my parts back from Zlock Racing and I'm so freaking excited. As this is my first actual motor build (I've assembled motors before) Dan spent some time with me to go over a couple key things to measure.
First up is squish. Squish is the measurement from the top of the piston to the head at its smallest point. This generally happens at the edges of the pistons and that is the case here. Well it turns out that due to the motor being a supersport motor before and the switch to flat top pistons I have to be very careful with how much squish I have. If I leave the squish set to what it was in supersport form the math says the motor will be up around 15.5:1. That's WAY too high. :) It'd be fast...for maybe a weekend or so before the crank goes pop! Well I don't have the kind of money needed to be replacing parts that often so I need to lower the CR. The goal is 14.2:1 which will be accomplished by adding some base gaskets to the motor.
After the squish is setup its time to do a piston to valve clearance check. Dan is pretty sure I won't have an issue but as with anything...you gotta verify. If you are too close you might not find out until you are sitting at high RPM and do your down shift...then BOOM! Sounds expensive. :)
Other than these two things just some basic general motor rebuild steps are to be taken followed by multiple heat cycles before doing any sustained 100% throttle runs.
For those who are curious as to what I had done or what parts I purchased from Dan...well...I've got nothing to hide and everything to boost about. :)
Crank Lightened and Balanced. ~1.6lbs gone
Zlock Chrome-moly race connecting rods. Similiar to the Carrillo Rods but the mass is moved towards the right end some.
Zlock Designed Wiseco 81mm 2 ring forged flat top piston. These things are 1.2 oz's lighter (with wrist pin and rings) than the stock pistons. That's almost double as light as the Busa pistons.
Cylinder Honed to accept the new pistons (need a little bit more clearance than cast pistons)
Rotor balanced after being lightened. It was way off...glad I got this done.
Valves and seats freshened up. A little bit of clean up done around the non combustion side of the valves for cleaner flow.
Left case main bearing retainer.
And for those who like to see bling...here is some. You can see it all here
Well today I got back some parts and got two new parts from Twin Works Factory Racing (http://www.twfracing.com). Thanks to the man, Zoran I now have some key pieces for my 2011 season and one piece of bling.
Here is a picture of everything that came in the box...it was like Christmas!
First up I got a new battery. This battery weights 1lb 3.2oz and provides longer capacity than the stock >6lb battery. I didn't need to get a lighter battery but it was time for a new battery and now I can have that cheeseburger!
Up next I got my GSX-R rear wheel kit. The kit includes some machining on the sprocket carrier, brake hanger and spacers to make a 2006-2008 GSX-R600 rear wheel fit on an SV650 swing arm. Currently I am using a Bandit1200 rear wheel which gives me a 5.5" wheel. The problem with it is its heavy. So with this kit I can run the much ligher GSX-R wheel which will with making the motor spin up faster giving me a better drive out of the turn.
Finally I got something which should give me another 3-5hp. 42mm throttle bodies. Zoran took my 39mm SV650 throttle bodies and bored them out to 42mm. With this bore the removal of the secondary throttle plates which are used by the computer for a choke. Since this is a race bike and I have a very specific warm up procedure...so I don't need the choke. To remove the FI light that will come on with this stuff disconnected I also purchased the the by-pass box. If I had a 2007 or newer the by-pass box would be a requirement as the ECU goes into a limp home mode ruining any hope for good fueling and power.
This is the stuff that was removed. You can see I'm also saving 1lb of weight. Meaning I can have fries with that cheeseburger!
Well I received the new cases from eBay. Upon inspection they look like they are in good shape.
So I took a trip down to Zlock Racing (http://www.zlockracing.com) with my various parts to get them worked on and to also discuss what to do with the motor this time.
So far the following is getting done:
1. Bearing retainer on the left case. This is to prevent the bearing from walking in on the side of the crank that has the heavy rotor. This was done in my previous cases and it sucks to have to get it done again.
2. Heads getting seats cleaned up and removing some of the casting imperfections. Also looking at what is wrong with those two exhaust valves to see if something more needs to be done.
3. Crankshaft is getting lightened.
4. Cylinders honed
5. Rod bearings and other case bearing getting replaced.
The one thing I need to decide on is to upgrade to Zlock's Racing rods and upgrade to 81mm flat top 2-ring pistons of their design. I'm really leaning towards doing this as these upgrades will give me more safety with stronger rods but they also have their mass more focused towards the big end. The pistons are also lighter and stronger than stock (they are forged vs the cast stock ones). Also with the 2-ring design they have less friction. This with the crankshaft lighten, the motor should be really happy to rev. This will help provide me with faster acceleration. Also with the flat top pistons the compression will be increased even more. It might even increase it just beyond where one would want it to be....but that is something which Dan Zlock will verify.
I promise to provide some photos of the work when I get it back. So the rebuild process continues. This is what happens when you build something on a budget. With an unlimited budget the statement would be..."Make me the fastest motor you can". :) *sigh* I wish I had a billion dollars. :)
Well upon further inspection I found that my cases are cracked from the left side main bearing to a vent hold drilld in the cases. 
So I have some used cases from eBay on their way. I hope they are in good shape cause this really sucks.
Well its come time to rebuild the old SV650 motor. I've decided to do as much of the work as I can mostly for the a learning experience. I mean I've already disassembled and reassembled this motor before due to it popping a freeze plug.
You can see all of the photos I'll be taking up at SV650 Motor Rebuild Photos
But boy...check out what I have to deal with. Those valves shouldn't be sitting there.
Three weeks after I ordered my new suit from ACME Motorwear I got it. WOW that feels factory fast! :)
Here are a couple of photos of my non-factory body in this top of the line suit. Can't wait for racing season to start!
Well today I'm heading down to ACME Motowear to get measured for a new suit. I currently have a GiMoto suit but its finally wearing out after 5 years. ACME also sells GiMoto suits and since they rock and the suit rocks, there is no reason to change anything. Attached is the color scheme I'm planning to go with. What do you think?
