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A Look into Racing!

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Kingsspeedshop

Kingsspeedshop

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Well I have been going to the races for quite a few years as a spectator!. Always loved the sound and smell. Anyways This 2017 season I will be a racer for the first time. Was talking to Matt Braley one day about racing and building a ski to compete. Long story short he was on board and excited like I was! The class we will be running in will be Sport GP on the ProWatercross tour. The ski that we will be building is my Resto HX ski I got from backwoods AL called "Field of Dreams". The ski already has quite a few race inspired parts on it so its a good candidate. Matt will be building a fully ported superstock 787 from the ground up. Yes you heard right a 787. i know this class is running fully modded Kawi Triples but with Matt's knowledge and my riding skills I think we will be quite competitive. Over the holidays I got a head start on stripping the ski of parts we will not be using. All of the stuff on the ground will not be used besides the gas tank and a couple of hoses.




 
I'm glad you got this thread started. I've finally got all the holiday travel behind me.

Things I need help with off the top of my head are:

1)Best deal on a big chain wrench. I need to get the coupler off a 97XP engine to use with that driveshaft.

2) Where is the best place to send cases to have the rotary surface turned? I guess I can contact Full Bore or GroupK or something. I have a set of cases here with major port work done but they ate something and have a groove.
 
Kingsspeedshop said:
Not sure..I got it from a guy from the seadoo parts page on Facebook. It's brand new and was never used.
Click to expand...

I saw that style floating around a few years back on another HX. Can you get the starter out with that? I really like the concept behind it. Subbed in already
 
Matt I'll get you a good chain wrench. And Racerxxx I'm not sure if you can get the starter out yet until I get the motor set in there. Now since I have the cradle in my possession I can make more..it's made of mild steel so it would be quite easy to remake.
 
I know that a Spec 2 chamber has to be dented to clear it but that the dent does not take away performance. I'm not sure what other pipes fit.

I can't see testing and tuning from scratch on a HX. I plan to throw together a X4 and then move the setup over.
 
This is going to be an awesome team up! Zack you are built to hang on to something fast and rip it :cheers: Light weight rider with a tuner that loves it as much as Matt is a recipe for success[emoji106]
 
This is awesome I can't wait to see you race in person defiantly worth the drive. Keep us up to date on the race locations.
 
That's awesome, good luck on the course. I've been going to the Hartwell race for the past few years so hopefully I'll see you out there this year. The guys in the GP class are quick on those 1100 HXs
 
This is an awsome build. Everything I want to do but dang no races around me....could luck if you guys need anything I'll do my best to help
 
These are the cases I'm thinking of building an engine out of for this project. As you can see I need to get the RV surface done. Let's look at the porting though. This is the max amount for max HP! Just enough meat is left to support things(barely).



The water cavity has been filled with epoxy because the porting cuts into that area. You can tell how much has been removed from the sides where my little screw driver points.



Here is how much material is normally under the cylinders



Here you can see the little tear drops where the porting cut through into the epoxy



These intake channels have been opened up also.

 
Do you have matched cylinders for that case porting? Hate to see a bottle neck on that rear transfer port or the sides.
 
"matched"? Sure I guess. What I mean by that is that I have about 4 sets of ported cylinders and I have to find the best match and match it myself from there. I'm hoping to use this set with 1.5 over Wiseco's that I've already had bored. If they don't line up though I'll look at these others.

What would our cc be if the stroke was still 74mm and the bore was 83.5mm?
 
Matt Braley said:
"matched"? Sure I guess. What I mean by that is that I have about 4 sets of ported cylinders and I have to find the best match and match it myself from there. I'm hoping to use this set with 1.5 over Wiseco's that I've already had bored. If they don't line up though I'll look at these others.

What would our cc be if the stroke was still 74mm and the bore was 83.5mm?
Click to expand...

That would be an 810cc
 
You really want the cylinder transfer ports to match the case as close as possible. Sort of a matched set of cases and cylinders.


That is what was really cool about the 785R cases they were totally CNC ported. 100% duplicatable time after time. They truly are a work of art in a machinists eyes.
 
racerxxx said:
You really want the cylinder transfer ports to match the case as close as possible. Sort of a matched set of cases and cylinders.


That is what was really cool about the 785R cases they were totally CNC ported. 100% duplicatable time after time. They truly are a work of art in a machinists eyes.
Click to expand...
How many of them are floating around?
 
glsmohio said:
How many of them are floating around?
Click to expand...

Not many. The guy I ride with has a set that he's using. He also has a few of the R cylinders which are triple port cylinders that are very prone to cracking. Which is amazing because skidoo used them in production sleds. The triple ports were good for an extra 8hp.....supposedly. The ones on the sleds have more wall between the exhaust port and the 2 extra ports, on the ski cylinders the space between the exhaust port and small port is about an 1/8" wide or less and always crack. See the 2 small windows on the sides of the those are the ports.

This is a sled cylinder. They started using these around 92-93 in sleds. Much of our Seadoo tech is directly from YEARS of tech/knowledge from the skidoo side of the business. Skidoo was using rotary valve engines back in the late 70's, and they don't look much different from our ski engines.

27.jpg
 
Port height is raised when the RAVE valve opens.

I'm just going to work with the parts enough to get them to breathe well with each other. Now that I take a closer look I'm noticing that some of my ported cylinders are just cleaned up a little and port matched. I'm gonna have to line them up and see which ones have the most material removed.
 
I was taking bout the transfer port height, like advancing the cam timing except its way better cause it has no cam, cams are for sissys
 
Just a quick FYI on the Chain wrench...the normal size one out there readily available is too small by 2-3 links. Best deal I found was on ebay for around 45 bux.
 
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