Radiused cam raced 3 years on bean oil

Just got these photos of a radiused race cam and lightweight radiused lifters from Lars after 3 years of racing. Looks much better than you would expect from a flat tappet cam that gets beat up after just a year. The curved surface of the lifter gives better geometry and reduced wear. Running on Castor R bean oil could have a lot to do with the longevity.

Castor bean oil in the sump or as a fuel additive?

My radius cam and lifters are so awesome, Jim. It is truly a mid range monster. No real need to push it past 6g rpm although running it up to 7200 in third was not big deal. How can something so responsive be so smooth? And that lumpy cam idle can only be decribed for me as a "turn on". The bike is BAD.

Don't seem like modern distillers have improved on nature's bean oil but for having to drain before congealed to varnish. A dash in gas tank smells like the old model airplane days. Caster oil is famous as best lube on extra tight interference fit pressing.

I've tried a lot of solvents to remove the varnish formed from Castrol R - nothing seems to remove it. Using it is a good way to turn your bike into an instant shit-heap. The only good thing about it is that when it hasn't dried on a surface, it is soluble in methanol. So it is probably better in the bottom end when you have blow-by, if you are using dope.

CASTOR is the ONLY Oil that runs TOWARD heat , rather than away .

Its got a higher ' flash point ' than synthetic ' two smoke ' oils , thus stays on the job - & gets ' to work ' .

theres Anti Varnish stuff around . At leasts when it ' glues up ' a engine , its a preserveative . Though it takes forever to lock it .
Boiling it usually frees it off . Boiling in ANTI FREEZE is the best ' de varnisher' and injun cleaner. Not neat glycol though ,
or poofe .

as its inflamable .
Mum , the pots boiling over . What are you doing in my oven . etc .

Always loved the smell of bean oil at the GNC flat track races. Especially when it was wafting from the exhausts of machines with Torco, Shell, Royal Purple and other oil company sponsor stickers.

If you're tearing down regularly, it's the best lubricant there is. If not, it becomes a gummy mess on the pistons and ring lands.

pete.v said:

Castor bean oil in the sump or as a fuel additive?

My radius cam and lifters are so awesome, Jim. It is truly a mid range monster. No real need to push it past 6g rpm although running it up to 7200 in third was not big deal. How can something so responsive be so smooth? And that lumpy cam idle can only be decribed for me as a "turn on". The bike is BAD.

Click to expand...

Which one you got Pete (I've forgot if its a JS1 or 2 you have)?
I have a JS1 and it really does make for a nice motor. Something inside me though just keeps nagging away saying "yeah but what would a JS2 be like"?!

Fast Eddie said:

pete.v said:

Castor bean oil in the sump or as a fuel additive?

My radius cam and lifters are so awesome, Jim. It is truly a mid range monster. No real need to push it past 6g rpm although running it up to 7200 in third was not big deal. How can something so responsive be so smooth? And that lumpy cam idle can only be decribed for me as a "turn on". The bike is BAD.

Click to expand...

Which one you got Pete (I've forgot if its a JS1 or 2 you have)?
I have a JS1 and it really does make for a nice motor. Something inside me though just keeps nagging away saying "yeah but what would a JS2 be like"?!

Click to expand...

Yes, I have the JS2. I do not know why, but I needed to advance the cam 10 degrees, which is the perfect timing setting for the cam in hand. I cannot say if they vary from cam to cam due to Jim's mood while grinding or if it just my particular bike. It really doesn't matter to me

Having a hotter cam and requiring some cam timing adjustment just may part of the game. When riding, I have no problem accecpting that thinking, if you get my jist.

Although not officially a race bike, I sure would like to take it to a track day sometime.

Pete,

When you degreed the cam and advanced it 10 degrees where did the new IN and EX lobe centers come out?

Some early JS cams (labled JS1A or JS2A etc came with instructions to advance the cam 5 or 10 degrees (depending on the cam), because the cam grinder took a while (and some extra $) to get the keyway location dialed in right.

Now the later JSB cams are correct.

I use instructions as laid out by CR Axtel (JS1 cam is an Axtell profile). This goes by the relation of the lobe centers to each other and to TDC and makes more sense that the older technique of closing and opening locations. The cam lobe centerline are more reverent than the location at opening/closing because the ramps can be gentile or steeper from grind to grind etc. For example - a cam with long opening ramps can show more duration but actually be milder than a cam with shorter opening ramps but with more duration at low and medium valve lifts. Its also easier and more accurate to use lobe centers and shows the relationships better from cam to cam.

Instructionn for radiused JS stage 1 and stage 2 below,

STAGE 1 CAM TIMING

You must have at least .185” gap between the valves when they are on the seats for adequate valve clash clearance with a JS stage 1 cam. Use the butt end of a drill bit to measure. Trim the OD of the valves or sink them into the head to get adequate clearance.

WITH .005” TAPPET CHECKING CLEARANCE AT TDC THE INTAKE VALVE LIFT SHOULD BE APPROX .165" AND THE EXHAUST VALVE LIFT SHOULD BE APPROX .145" ADJUST YOUR CAM TIMING ACCORDINGLY. (Your specs may vary but In lift should be approx .020” greater than ex). This will give the correct intake lobe center of 102 degrees.

ALWAYS VISUALLY CHECK THE VALVES AT TDC. Looking in through the port; with a tiny flashlight (magnification helps) – you should see that the intake has a little more lift than the exhaust. THIS IS ASSUMING THAT THE VALVE SEATS ARE LEVEL AS WITH NEW STOCK HEADS.




STAGE 2 CAM TIMING

You must have at least .185” gap between the valves when they are on the seats for adequate valve clash clearance with a JS stage 2 cam. Use the butt end of a drill bit to measure. Trim the OD of the valves or sink them into the head to get adequate clearance.

WITH .005” TAPPET CHECKING CLEARANCE AT TDC THE INTAKE VALVE LIFT SHOULD BE APPROX .170" AND THE EXHAUST VALVE LIFT SHOULD BE APPROX .150" ADJUST YOUR CAM TIMING ACCORDINGLY. (Your specs may vary but In lift should be approx .020” greater than ex). This will give the correct intake lobe center of 103 degrees.

ALWAYS VISUALLY CHECK THE VALVES AT TDC. Looking in through the ports with a tiny flashlight (magnification helps) – you should see that the intake has a little lift than the exhaust. THIS IS ASSUMING THAT THE VALVE SEATS ARE LEVEL AS WITH NEW STOCK HEADS.

WZ507 said:

Pete,

When you degreed the cam and advanced it 10 degrees where did the new IN and EX lobe centers come out?

Click to expand...

I don't know if Jim just answered your question or not but I used an old school method prescribed by
Jim.

With the cam at TDC and peering through the exhaust port, the intake valve will be slightly more open than the exhaust when going into the intake stroke if set correctly

This may seem totally simplistic and beyond the scope of technical thinking, but it seems to me to be impossible to get wrong. I certainly looked at the valve position while at 5 degree retarded, at stock settings, 5 advanced, 10 advanced, and 15 advance. The difference is night and day. There is no mistaking the difference between 5, 10 and 15 degrees advance when looking into the exhaust with 10 degrees being right on the money and of course the actual running of the machine.

The only exception and to fine tune even further, which to feel is not needed, would be to have a vernier cam gear or to start filing the key. But I think that is splitting hairs for a hot street cam. Either way, my determination would be by visually inspecting the valve position through the exhaust port at TDC, again having the intake slight more open as the exhaust is closing.

pete.v said:

WZ507 said:

Pete,

When you degreed the cam and advanced it 10 degrees where did the new IN and EX lobe centers come out?

Click to expand...

I don't know if Jim just answered your question or not but I used an old school method prescribed by
Jim.

With the crank at TDC and peering through the exhaust port, the intake valve will be slightly more open than the exhaust when going into the intake stroke if set correctly

Click to expand...

Thanks to you and Jim for the info.

My question was not answered directly, but with the information provided was answered indirectly. Jim's set-up methodology is unambiguous since there is only one specific cam installation position that conveys a 0.020" offset in lift between IN and EX with the crank at TDC. Jim states that this occurs when the IN lobe has a centerline of 103 deg. Since the JS2 cam has a LSA of 105 deg, the EX centerline has to occur at 107 deg, and this specified cam installation position is therefore 2 degrees advanced.

When you advanced your cam 10 deg, to achieve the result specified by Jim (IN open 0.020" more than EX), the actual result was that it was advanced 2 degrees to move the IN CL from 105 deg to 103 deg. Evidently you had one of the early cams before the keyway was correctly located.

WZ507 said:

pete.v said:

WZ507 said:

Pete,

When you degreed the cam and advanced it 10 degrees where did the new IN and EX lobe centers come out?

Click to expand...

I don't know if Jim just answered your question or not but I used an old school method prescribed by
Jim.

With the crank at TDC and peering through the exhaust port, the intake valve will be slightly more open than the exhaust when going into the intake stroke if set correctly

Click to expand...

Thanks to you and Jim for the info.

My question was not answered directly, but with the information provided was answered indirectly. Jim's set-up methodology is unambiguous since there is only one specific cam installation position that conveys a 0.020" offset in lift between IN and EX with the crank at TDC. Jim states that this occurs when the IN lobe has a centerline of 103 deg. Since the JS2 cam has a LSA of 105 deg, the EX centerline has to occur at 107 deg, and this specified cam installation position is therefore 2 degrees advanced.

When you advanced your cam 10 deg, to achieve the result specified by Jim (IN open 0.020" more than EX), the actual result was that it was advanced 2 degrees to move the IN CL from 105 deg to 103 deg. Evidently you had one of the early cams before the keyway was correctly located.

Click to expand...

Yes - right on.

But no one should be confused between advancing a cam 5 degrees more than when it came out imperfect when installed with the stock sprockets and cam keyway location as provided. This is what Pete did.

OR

Advancing a cam 2 degrees so the intake lobe center is advanced 2 degrees more than it would be compared to both lobe centers being the same distance away from TDC (straight up cam timing).