750cc pushrod bike build

Started by Rchop, February 15, 2009, 04:14:09 PM

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Rchop

Scott Stites (isiahstites) has started a new CNC business and he made my turbo flanges for me. Here are some pics of the machining process...















Each unexpected discovery is first ridiculed, then objected to and finally considered self evident
www.frsengineering.com
#4836 A-PBF 750cc(complete)
#765 A/G 650cc

55chevr

Randy,
Can Scott cut out triple trees with his machine?


isiahstites

Quote from: 55chevr on May 30, 2010, 07:16:28 AM
Randy,
Can Scott cut out triple trees with his machine?



Joe I can make quite a bit. Some things are more complicated than others. I am working on a design for a set of triple trees right now.

Scott

55chevr

Let me know when you are ready ... I want to make a top tree for S1 Buell ... you might even still have one from your donor Buell ...

Rchop

Turbo installation is complete. The biggest problem was the oiling system since the resevoir is higher than the turbo. I think I finally solved the problem with an inline ball check valve that I will install just before the turbo oil connection. The valve has about 2 lbs of seat pressure that should stop oil from draining into the turbo at rest.


http://www.frsengineering.com/pp162.JPG

During test runs on the country road in front of the house, I was able to get it up to about 5300 rpms in 3rd gear with 7lbs of boost before I was going too fast for the street and and my A/F was going over 15. If I can get the fuel mapping right, this should work well.


http://www.frsengineering.com/pp160.JPG


http://www.frsengineering.com/pp161.JPG
Each unexpected discovery is first ridiculed, then objected to and finally considered self evident
www.frsengineering.com
#4836 A-PBF 750cc(complete)
#765 A/G 650cc

Rchop

New turbo installation is well underway. Exhaust pipes have been cut and reassembled with a new transition to a T-25 inlet flange...


http://www.frsengineering.com/pp163.JPG

The shaft was broken on the old turbo and I don't know exactly what caused the failure, so I made changes that could account for multiple reasons. These include a larger turbo and a Blow Off Valve on the plenum. I'm hoping the American made Garrett turbo will solve the Chinese bearing failure if that was the major issue.


http://www.frsengineering.com/pp164.JPG

I just have to mount the pipes and turbo and then weld and wrap the new dump pipe. I'm adding a v-band connector to the end of the dump pipe so I can change ends when running faired or un-faired.
Each unexpected discovery is first ridiculed, then objected to and finally considered self evident
www.frsengineering.com
#4836 A-PBF 750cc(complete)
#765 A/G 650cc

1212FBGS

ummmm..... is that bov mounted in the right direction?
kr

Rchop

#202
yes, the flange that is welded to the plenum has a curved base that was sized to weld onto the turbo inlet pipe, but I didn't have enough room on the pipe.
Each unexpected discovery is first ridiculed, then objected to and finally considered self evident
www.frsengineering.com
#4836 A-PBF 750cc(complete)
#765 A/G 650cc

1212FBGS

isnt the exhaust of a BOV usually on the side and the intake on the bottom?
kr

Jasontmc

The BOV is mounted correctly.

Look at the vacuum port at the top of the BOV ,   when the throttle is chopped the vacuum is applied to the top of the diaphragm and the boost px moves the BOV slide up against the spring and allows the boost  to vent to atmosphere.

Rchop

Quote from: 1212FBGS on July 15, 2010, 01:53:16 PM
isnt the exhaust of a BOV usually on the side and the intake on the bottom?
kr

I saw them in all different configurations Kent. I ordered this one because I wanted a more compact installation.
Each unexpected discovery is first ridiculed, then objected to and finally considered self evident
www.frsengineering.com
#4836 A-PBF 750cc(complete)
#765 A/G 650cc

wobblywalrus

Will you be putting a bigger air filter on that bike?  The restriction from the small filter might not be a problem, the turbo suction can handle that.  It is the possibility of high vacuum pulling dirt through the filter.

Rchop

Quote from: wobblywalrus on July 16, 2010, 09:42:56 PM
Will you be putting a bigger air filter on that bike?  The restriction from the small filter might not be a problem, the turbo suction can handle that.  It is the possibility of high vacuum pulling dirt through the filter.

I want to keep the profile as small as possible since it's sticking right out in the airstream. With the lower HP of the 750cc, every little bit helps. The new filter for this turbo is about the same size and I have always gotten good performance from K&N's.
Each unexpected discovery is first ridiculed, then objected to and finally considered self evident
www.frsengineering.com
#4836 A-PBF 750cc(complete)
#765 A/G 650cc

AHG

I Have really enjoyed seeing your machine come together.
Well thought out, and nicely engineered; from the chassis to the engine.
Best of luck, and God bless when it reaches the salt.  :-)

Drew Gatewood
~ I CAN COUNT MY LIFE ON ONE HAND ~
Faith, Family, Friends, Fun & Fast Motorcycles

Rchop

Thanks Drew, I appreciate the encouragement.
Each unexpected discovery is first ridiculed, then objected to and finally considered self evident
www.frsengineering.com
#4836 A-PBF 750cc(complete)
#765 A/G 650cc