A uniquely American experience (Harley Content)

[Jalopyshoppe]

I recently rebuilt my FXR's engine. Typical Harley performance thinking these days is to add cubic inches. I went a different route and spent money and time on the cylinder heads, valvetrain, and camshaft. I kept the 80ci (1341cc) displacement, but upped the compression from 8.5:1 to 10.8:1. Additionally I installed a .540 lift 267/270 (@0.050) camshaft. The heads started out as a set of mild port street heads done by Dan Baisley in Portland, OR. I sent them back to Baisley to be opened up farther and have the combustion chamber reshaped to accommodate the new pistons. The flywheels stayed in the cases, this time, but the original build had them lightened and knife edged for quicker acceleration.
The end result is an engine that's barely rideable on the street. Unless it's turning 3000 RPM, the bike spits, lugs, and generally misbehaves. It's a loud, aggressive, and anti-social piece of transportation.

I couldn't be happier. This bike rides like it's powered by a Boss 302 that was warmed over by a top notch engine builder of the day.

I recognize that modern engine design, fuel injection, and revised tuning methods render this kind of powerpland obsolete. Even still, it's deeply satisfying to operate an engine like this. I am more than a little sad to know that enthusiasts are less and less likely to know what it's like to drive a very aggressively cammed small block V8 car on the street. Even the most aggressive cam profiles offered today for LS based stuff are substantially more streetable than the cars of the 60's/70's. I know that modern stuff is BETTER. Like A LOT BETTER. I'm the first person to admit that there are OEM stock bikes that are faster. There's just some intoxicating joy in riding or driving a big valve/big cam/high compression engine.

 

[GPzPop]

Amen, Brother Fish!

 

[buellistic]

I recently rebuilt my FXR's engine. Typical Harley performance thinking these days is to add cubic inches. I went a different route and spent money and time on the cylinder heads, valvetrain, and camshaft. I kept the 80ci (1341cc) displacement, but upped the compression from 8.5:1 to 10.8:1. Additionally I installed a .540 lift 267/270 (@0.050) camshaft. The heads started out as a set of mild port street heads done by Dan Baisley in Portland, OR. I sent them back to Baisley to be opened up farther and have the combustion chamber reshaped to accommodate the new pistons. The flywheels stayed in the cases, this time, but the original build had them lightened and knife edged for quicker acceleration.
The end result is an engine that's barely rideable on the street. Unless it's turning 3000 RPM, the bike spits, lugs, and generally misbehaves. It's a loud, aggressive, and anti-social piece of transportation.

I couldn't be happier. This bike rides like it's powered by a Boss 302 that was warmed over by a top notch engine builder of the day.


I recognize that modern engine design, fuel injection, and revised tuning methods render this kind of powerpland obsolete. Even still, it's deeply satisfying to operate an engine like this. I am more than a little sad to know that enthusiasts are less and less likely to know what it's like to drive a very aggressively cammed small block V8 car on the street. Even the most aggressive cam profiles offered today for LS based stuff are substantially more streetable than the cars of the 60's/70's. I know that modern stuff is BETTER. Like A LOT BETTER. I'm the first person to admit that there are OEM stock bikes that are faster. There's just some intoxicating joy in riding or driving a big valve/big cam/high compression engine.

a 540 lift? How much did you have too grind off the rocker box covers?

 

[Jalopyshoppe]

a 540 lift? How much did you have too grind off the rocker box covers?

No rocker box mod required. Kibblewhite sells a valvetrain kit that fits and clears .600 lift. I do use S&S roller tip rockers, stock ratio.

 

[SFMCjohn]

solid lifters ...? :toothless

bet it sounds awesome ... :ride

 

[FLH03RIDER]

SWEET, although we do need a sound clip at a minimum!

 

[dittoalex]

What about brakes, do you need to supplement with rear brake in corners?

 

[Gary856]

So what kind of riding is this type of engine meant to do? Stop light races? Just straight line stuff?

 

[Jalopyshoppe]

I use Hy-Lift hydraulic roller tappets. I don't know of many solid lifter cam options for Evo based Harley engines.

I'll set up my GoPro at some point on this bike. I don't really have the skills to post it, but I bet someone can help me.

I have upgraded the brakes and suspension on this bike. The front uses a single 15" rotor with a Harley/Brembo 4 piston caliper and sintered pads. The rear is a 12" rotor with a GMA 4 piston unit with sintered pads as well. Braided lines on both ends. The bike is 480 pounds wet (chromoly frame, light wheels, aftermarket billet trans case, etc). It stops very well. Dual rate spring 15" tall (stock is 12") rear shocks with custom valving. The front forks have custom damper rods for extra travel (7"), Race Tech gold valves, and .95mm/kg springs.

I built and geared this bike for canyon carving. I'm running a custom primary sprocket (22t vs 24t stock) and 22/51 final drive. My focus has always been useable power that comes on quick and winds tight. Something like a more brutal Buell. Like a flat track bike for the street. It's not about drag races (it launches like shit), nor about top speed (hits rev limiter in 5th at 135mph). The idea is an engine that spins up quick and delivers brutal corner exits.

 

[flipstyledsm22]

On my old HD I went with the big bore kit and pumped my EVO up to a 93in. Had the Martin Brothers Medustas on it as well (more for looks)... It roared! Congrats on your build!

 

[SFMCjohn]

I use Hy-Lift hydraulic roller tappets. I don't know of many solid lifter cam options for Evo based Harley engines.

:thumbup

“solid-lifters?” was just an old high-school parking-lot greaser joke ... :toothless

The idea is an engine that spins up quick and delivers brutal corner exits.

all in a famously sweet-handling, set-up, FXR frame ... nice.
fully capable of suprising sport-bikers, imo ... enjoy! arty

 

[ratsblast]

Good to hear you are happy with the results, I know about spending an inexplicable amount of time and money on a Harley. At least a FXR is an iconic bike worthy of attention.

I figure Harley uses a few dirty tricks to keep their audience captive. The unmuffled bass thump of the exhaust concusses the inner ear equilibrium making the rider receptive to the Harley message. Next, the uncatalyzed exhaust contains carbon monoxide which blocks oxygen to the brain, "Everytime I ride this bike I get warm and fuzzy all over, my fingers even go numb." Next thing you are pin striping ghost flame skulls and braiding a "get back whip."

 

[CDONA]

Big lift & compression red flagged this for me, first question Shovel or Evo. Your second post cleared this.
How tight will it wind?
What is your life expectancy for the crank?
I miss the top end rush of a cam pulling on top

Old iron head sporties, did sing wound out, solid lifters

 

[Gary856]

It'd be great to see some pics of this cool bike with all the work done to it. Very surprised to read about the low, 480 lb wet weight.

Now and then I thought about picking up a FXR due to its reputation of great handling. The performance mods are bewildering 'cause I don't have the knowledge to judge which bike is a better buy, so I'm heavily influenced by the looks. I like the looks of mag wheels, and I had assumed dual front disc would be desirable.

 

[Gary856]

My focus has always been useable power that comes on quick and winds tight. .

How tight will it wind?

What does "winds tight" mean?

 

[ST Guy]

RPM

 

[Jalopyshoppe]

It'd be great to see some pics of this cool bike with all the work done to it. Very surprised to read about the low, 480 lb wet weight.

Now and then I thought about picking up a FXR due to its reputation of great handling. The performance mods are bewildering 'cause I don't have the knowledge to judge which bike is a better buy, so I'm heavily influenced by the looks. I like the looks of mag wheels, and I had assumed dual front disc would be desirable.

The weight loss required using a custom frame, instead of an OEM Harley piece. Ditching the mag wheels helped considerably, as they weigh 40lbs each before assembly. That kinda kills the look for a lot of people.
I shift this thing around 6500 rpm, but the rev limiter hits at 7200. That's tightly wound for a 4 and 1/8" stroke engine.
Which bike to buy is a real matter of priority and budget. If you're not a Harley mechanic or planning to be one, buying anything pre twin cam era is kind of a bad idea. They're not bad bikes, but they're old and getting older.

My next engine is already being assembled, and it utilizes a 4" stroke to lower the Piston speeds. I'm considering a 4" bore to give me 100ci, but I may run a smaller bore for more heat capacity, depending on what I take away from research.

 

[firstbuell]

I use Hy-Lift hydraulic roller tappets. I don't know of many solid lifter cam options for Evo based Harley engines.

I'll set up my GoPro at some point on this bike. I don't really have the skills to post it, but I bet someone can help me.

I have upgraded the brakes and suspension on this bike. The front uses a single 15" rotor with a Harley/Brembo 4 piston caliper and sintered pads. The rear is a 12" rotor with a GMA 4 piston unit with sintered pads as well. Braided lines on both ends. The bike is 480 pounds wet (chromoly frame, light wheels, aftermarket billet trans case, etc). It stops very well. Dual rate spring 15" tall (stock is 12") rear shocks with custom valving. The front forks have custom damper rods for extra travel (7"), Race Tech gold valves, and .95mm/kg springs.

I built and geared this bike for canyon carving. I'm running a custom primary sprocket (22t vs 24t stock) and 22/51 final drive. My focus has always been useable power that comes on quick and winds tight. Something like a more brutal Buell. Like a flat track bike for the street. It's not about drag races (it launches like shit), nor about top speed (hits rev limiter in 5th at 135mph). The idea is an engine that spins up quick and delivers brutal corner exits.

once I'd read yer OP, I knew the rest of the thread would be worth continuing to read - you 'get' it, deep

even my mild '71 307-turned-350 with mild torque cam & small 4bbl displayed itz modest version of the visceral V8 sensations you described - unmatchable, as no import V8 offers pushrods & carb

that'd be comparing a RC51 to yer Uly