Some modification for High Comp. Billet Head
- Thread starter Big Boy
- Start date
stuartracing
New Member
It buys and it installs one manic Mechanic High Comp. Billet Head from Pirate Cycle in my PK80 and my bike loss 10mi/hr. Some recommendation to improve its performance or used as ash tray on the table.
Well ya gotta give us a few more details, like whats the motor doing,whats the plug look like, how old is this motor, is it broke in yet,what carb. is on it, all stock PK80?????
If you decide you don`t want it let me know....I`ll pay ya for it, no problems at all....I need another one big time....
Paul....
This is a relative new engine with less than 40hrs of used. This have a ported inlet and outlet with Walbro carb and Tuned Pipe. With the original slant head with double gasket (from fabric) using a BPR6IX spark plug run about 40 to 42 mi/h. When installing the Billed Head lost 10 mi/h.
Creative Engineering
New Member
I knew this was going to turn into a fiasco...I doubt we will be offering any more on a blind purchase basis.
If you call in and I feel like you know what you're doing...then O.K., otherwise I don't need the hassle.
Jim
If you call in and I feel like you know what you're doing...then O.K., otherwise I don't need the hassle.
Jim
Creative Engineering
New Member
Big Boy,
That is a 3/4" reach plug. Undoubtedly the piston is hitting the plug. It's a wonder it runs at all!
The cylinder head was designed for 3/8" reach plugs and premium fuel.
http://www.ngksparkplugs.com/docs/tech/design_symbols_plugs.pdf
If you look at the chart on this page you will see that the BPR prefix designates a 3/4" reach plug.
Fabric gaskets? What happened to the Aluminum gaskets that normally come on that engine?
You need (1) Aluminum gasket at .025"-.030" thick and a 3/8" reach plug.
Make sure that you snap the gasket onto the machined protrusion...otherwise it will get caught/ruined when you torque the head.
Jim
Creative Engineering
New Member
Furament, K.i.p.
You're killin' me!!!
Saturday morning, 1 a.m., I had emergency surgery for a double hernia...I thought I was sore until I started laughing at your posts.
Jim
Pablo
Master Bike Builder & Forum Sponsor
Actually that is incorrect. "BPR" does not refer to the reach at all. Read the charts carefully. Reach is designated by the suffix.
The OP wrote: "BPR6IX". No such animal that I know of. I think he left the H out. BPR6HIX is the iridium plug. 1/2" reach.
Suffix S = 3/8" reach.
1/2" may still contact though. I imagine he would hear it. Head gasket leak sounds likely. Buy a nice billet head and use a "fabric" gasket? Yikes.
stuartracing
New Member
I`m sure you just need to tune your bike for the billet head....
Whenever you put a new/different part on your bike it will change the tune, sometimes....
EVERY part I`ve installed on my motor has changed it in one way or the other.... But I`ve been able to tune it back to a better running motor....Is it just not revving out to top speed, 4stroking at all, hestitation, or it`s just shutting down 10 mph before top speed.....
I`ll buy your billet head from you if you don`t like it anymore..ok....
Whenever you put a new/different part on your bike it will change the tune, sometimes....
EVERY part I`ve installed on my motor has changed it in one way or the other.... But I`ve been able to tune it back to a better running motor....Is it just not revving out to top speed, 4stroking at all, hestitation, or it`s just shutting down 10 mph before top speed.....
I`ll buy your billet head from you if you don`t like it anymore..ok....
motorhead419
Member
Like Jim says you have to make sure your head gasket fits over the lip on the nice billet head. I had to carefully grind out the head gasket hole. Remove the burrs carefully after you get it to fit . Bolt on--run it--let it cool--re-torque..While you're at it at least get a straight intake manifold..
Masterm222
New Member
I'm with everyone else. If he can't make it work on his bike then I will buy it! I NEED two more! At least two, I really want four because I already have homes waiting for two. I love the one I have. We went riding today and now that the "Grape Ape" ,my new chopper, is running I let my friend ride my Stiletto. 45 down the south frontage road side by side but he could pull away from me at will. He out weighs my by 100lbs.! One difference, the billet head. Jim please get some more made!
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Creative Engineering
New Member
I've got 93 of them on the bench that are getting the final touches.
90 will go to Pirate cycles, the other three I'm keeping here for customer builds.
I made a custom tool this time to profile the squish band and chamber...it took a few more weeks to perfect the tool than I had anticipated, but in the long run it will save a ton of time... (4-days saved everytime I make 100).
The choice was to up the price, and do it the old way...or figure out a better way and keep the price the same.
Jim
90 will go to Pirate cycles, the other three I'm keeping here for customer builds.
I made a custom tool this time to profile the squish band and chamber...it took a few more weeks to perfect the tool than I had anticipated, but in the long run it will save a ton of time... (4-days saved everytime I make 100).
The choice was to up the price, and do it the old way...or figure out a better way and keep the price the same.
Jim
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stuartracing
New Member
These cyl. are the best IMO.....
I almost want another one just to keep OFF the bike so people can see how bad ass they are before you even put it on the motor.......
Creative Engineering
New Member
