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Ever Drop Your Bike & Scratch Up The Engine Cases?

Started by ~JM~, October 25, 2013, 10:51:04 AM

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Pat Conlon

Let me put it this way...see that Corbin seat?
I really need it...to keep my ass from sliding back on the seat as the bike wants to accelerate out from under me.
I have to remember to fight the inertia and keep my upper body bent forward with my weight over the tank.
She pulls *hard* to about 8.5k when the rejetted CV36's start to run out of air, still a very exciting ride.

Torque is where it's at for street riding.
1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

Flying Scotsman

1984 FJ1100
1985 FJ1100
1990 FJ1200
1999 GP1200 (165 + hp)

~JM~

Quote from: Pat Conlon on October 31, 2013, 10:52:07 AMLet me put it this way...see that Corbin seat?
I really need it...to keep my ass from sliding back on the seat as the bike wants to accelerate out from under me.
I have to remember to fight the inertia and keep my upper body bent forward with my weight over the tank.
She pulls *hard* to about 8.5k when the rejetted CV36's start to run out of air, still a very exciting ride.

Torque is where it's at for street riding.

Indeed! I've preached Torque over Horsepower for years. After all Torque is a direct measurement. HP is a computation.

Do you mind if I ask what kind of expense & downtime one should prepare for if you were to have this type of engine built? Is 1350cc the maximum displacement available, or is that the recommended displacement to retain reliability?

Thank you
~JM~

Pat Conlon

It's kinda hard to estimate cost, like asking, "How much does a bag of groceries cost?"  It depends on what's inside.
Timing depends on the schedule of the engine builder and his sub contractors. Send Randy a e-mail for some specifics.

I have been told that the 82mm pistons are the largest you can fit in a sleeved XJR cylinder block.
The 82mm Hank Scott Pro pistons with the shorter skirt and lighter pin are about the same weight as the oem piston.

Amazing the advances made over the last 25 years in piston design. Here's a visual comparison:


Other manufacturers have made larger displacement cylinder blocks for the FJ, but they are specific for drag racing and do not have the cooling fins needed for heat dissipation on a street bike, like the XJR cylinders have.

Cheers. Pat
1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

airheadPete

HOLY S*%#t! THAT'S the replacement piston size!?!?!  :bomb: :wacko3:

Ahem, so, how long do your tires last? (as they die a screaming, smokey death.)  :lol: :lol: :lol:
:hi:
'92 FJ1200.    '84 R100CS
'78 GS750E.   '81 R100RS
'76 R90/6       '89 R100GS
'65 R60/2

airheadPete

P.S., HP is for kids. Torque is for discerning adults.  :drinks:
'92 FJ1200.    '84 R100CS
'78 GS750E.   '81 R100RS
'76 R90/6       '89 R100GS
'65 R60/2

Dan Filetti

No matter what you do HP = torque @ 5252RPM.  (actually the formula is hp= to *rpm/5252) but effectively this means that they are inextricably equal @ 5252 RPM.  All this talk of torque being 'better' than HP smacks of the kind of silly conversation you may read on a Harley forum.

Dan
Live hardy, or go home. 

~JM~

Quote from: Dan Filetti on November 01, 2013, 07:27:53 AMNo matter what you do HP = torque @ 5252RPM.  (actually the formula is hp= to *rpm/5252) but effectively this means that they are inextricably equal @ 5252 RPM.  All this talk of torque being 'better' than HP smacks of the kind of silly conversation you may read on a Harley forum.

Dan 

For a bit of clarity... What I meant was, for an engine being built for street usage, the general rule is that it's better to build for torque production, than it is to build for horsepower potential. Large amounts of torque that starts low in in the RPM scale is more usuable & more fun to the seat of the pants driving experience, than a high winding, high horsepower engine. Plus parts longevity & reliability is enhanced with the low RPM, high torque engine. Just remember that I said as a general rule.

~JM~

movenon

All I know is that my "ass dyno" tells me the FJ is just about right. Enough TQ to pull through without a lot of shifting If I embarrassingly get caught in a higher gear and plenty of RPM for HP.
George
Life isn't about having the best, but about making the best of what you have...

1990 FJ 1200