J&E HC Piston and Web Cam

Help I could provide would be along the lines of custom made piston, sleeve, head & base gaskets & sleeve installation at cost.

The 830cc quoted above was referring to a hypothetical stroker motor. Nobody has really looked hard into whether there is room in the motor for a longer stroke. I understand Lukas may be checking into it. With the stock stroke a 108mm bore will make 751cc. Our existing sleeve could take a 108mm piston (if any existed). If a daring individual wanted to bore the cases to fit a larger OD cylinder sleeve we could probably go 110mm (779cc) or maybe 112mm (808cc) on the bore.

It all depends on how big of a bang you are willing to risk when it all lets go. :thumbsup:

I may SERIOUSLY look into this!

I just happen to know 2 places that make a business of stroking motors that I've had some contact with in the past. Most motors have a couple millimeters of clearance between the rod and the case, so you can usually go a few without case mods. But then over that amount, these place will put a couple mm deep "channel" in the case to provide additional clearance for longer strokes. I'll have to check with them to see what it would take with our motor...

I want to referesh my motor and change all the seals, bearings, etc before doing major mods like this, as mine already has over 30K on it...

Maybe I'll take it to them while I have it apart and see what they can do.

Stoke(mm) Bore(mm) Displacement (cc)

Stock 82 100 644

Stock 82 106 723

Stock 82 108 751

Stock 82 110 779

Stock 82 112 807

+1mm 83 106 732

+1mm 83 108 760

+1mm 83 110 788

+1mm 83 112 817

+2mm 84 106 741

+2mm 84 108 769

+2mm 84 110 798

+2mm 84 112 827

+3mm 85 106 750

+3mm 85 108 778

+3mm 85 110 807

+3mm 85 112 837

+4mm 86 106 759

+4mm 86 108 787

+4mm 86 110 817

+4mm 86 112 847

I am still waiting on my crankcase splitting tool so I have not been able to check into the clearance issue yet.

TR,

Do let use know what you find out. There are some other considerations that Jeff pointed out to me as well: There is no shorter rod for the DR (maybe a custom one?), and it won't be possible to locate the pin hole further up on the piston. The solution would be a spacer under the cylinder and increasing cam chain length.

Does anybody know the cam chain size? I think the stock one comes in one piece and doesn't have a master link

so you can usually go a few without case mods. But then over that amount, these place will put a couple mm deep "channel" in the case to provide additional clearance for longer strokes.

As you say, case clearance can be addressed. The really big stroker Banshee quads get additional material welded to the crankcase to allow an even deeper channel for rod clearance. The limiting factor will probably be clearance between the big end of the rod and the transmission. Even that can be fudged a little. I've seen rods with the big end notched for clearance and the offending transmission gear can have the tops of the teeth ground off.

I was a bit of a space cadet last night (late night)... i just realize in my post (stoke calcs) that if you increase the upward motion (stoke) of the piston 2 or 3 mm, you also increase the downward motion by the same amount. Therefore moving the rod postion out by 2mm yeilds a +4mm increase in stoke. So if we have 2-3mm of case clearance, we can stoke by 4-6mm before case mods are required. I know that's very rudimentary, but after thinking about it, I probably could have posted some much larger stroking figures (+10 to 12mm)

Stoke(mm) Bore(mm) Displacement (cc)

+6 88 100 691

+6 88 106 776

+6 88 108 806

+6 88 110 836

+6 88 112 867

+8 90 100 707

+8 90 106 794

+8 90 108 824

+8 90 110 855

+8 90 112 886

+10 92 100 722

+10 92 106 811

+10 92 108 842

+10 92 110 874

+10 92 112 906

+12 94 100 738

+12 94 106 829

+12 94 108 861

+12 94 110 893

+12 94 112 926

I am still waiting on my crankcase splitting tool so I have not been able to check into the clearance issue yet.

TR,

Do let use know what you find out. There are some other considerations that Jeff pointed out to me as well: There is no shorter rod for the DR (maybe a custom one?), and it won't be possible to locate the pin hole further up on the piston. The solution would be a spacer under the cylinder and increasing cam chain length.

Does anybody know the cam chain size? I think the stock one comes in one piece and doesn't have a master link

Yup, I had thought about both of those...

The spacer (depending on how big) will also require some modification to the engine mounting bracket between the frame and the cylinder head. Granted that's WAAYYY easier than building a custom Rod. That would probably be the easiest (and probably the best) way to go though...

Something also to consider is the issue of a shorter crank with longer stroke (proposed) VS. a longer crank with shorter stoke (like stock config). I'm not sure what the power(ft-lb vs HP) tradeoffs would be, but It's very well known that alot of classic muscle car builders, in lieu of stroking ther motor (or in addition to it) want to go with longer rods (more leverage) for increased torque. Shortening the rods in order to stroke it a couple MM would reduce the potential gains you might obtain by sticking with stock length rod. However I realize for every 1mm you stroke the engine, you only have to reduce rod length by .5mm.

Which brings up another idea... keep the same stroke, add a cylinder spacer and longer rod... More torque on the same amount of displacement...

As you say, case clearance can be addressed. The really big stroker Banshee quads get additional material welded to the crankcase to allow an even deeper channel for rod clearance. The limiting factor will probably be clearance between the big end of the rod and the transmission. Even that can be fudged a little. I've seen rods with the big end notched for clearance and the offending transmission gear can have the tops of the teeth ground off.

Don't think I want to go quite THAT far... notching gear teeth is a bit extreme in my opinion. I realize more power mods will eventually reduce it's reliability, but for a regularly driven bike I don't think I want to start cutting into essential internal components. Maybe clearance the case... weld a bit of material, but that's where I think I'd draw the line...

I think the case mods would be fairly straightforward.. That's not untouched territory. Plenty of example & experience there...

The question in my mind, since there are no comercially available stroker cranks available for the 650, is modification of the stock crankshaft, or building a new one altogether... ??

The question in my mind, since there are no comercially available stroker cranks available for the 650, is modification of the stock crankshaft, or building a new one altogether... ??

The only realistic option is to relocate the rod pin on the stock crank - if there is enough material to do so. A custom crank would probably cost the same as your DR.:thumbsup:

The only realistic option is to relocate the rod pin on the stock crank - if there is enough material to do so. A custom crank would probably cost the same as your DR.:thumbsup:

That was kinda my point...

Donno how much material would be neccesary around the rod pin to keep it from letting loose. Obviously the more power, the more you need. Donno how much material there is there now, to see if it's even feasible to move the rod pin...

sorry to get off your current line of thought, has anybody checked into how much a higher comp piston to make use of 93oct would cost to make and how many you'd have to buy? i've seen threads on every different aspect of building this motor but this. i've seen the threads on shaving to get a little more compression but none on a higher comp piston option. who could do it? if anybody knows i'll make the calls.

sorry to get off your current line of thought, has anybody checked into how much a higher comp piston to make use of 93oct would cost to make and how many you'd have to buy? i've seen threads on every different aspect of building this motor but this. i've seen the threads on shaving to get a little more compression but none on a higher comp piston option. who could do it? if anybody knows i'll make the calls.

Do you mean a higher compression piston than the JE 10:1? If you want a little more compression it can be had by milling the head. In general, large bore air cooled motors don't tend to last very well with real high compression ratios. IMHO going much beyond 10.5:1 would not be a very good idea. Big CRs might be appropriate for a race motor (torn down and freshened up every season) but then again the DR650 mill isn't really an appropriate platform for any kind of racer.

Don't think I want to go quite THAT far... notching gear teeth is a bit extreme in my opinion.

I see a lot of motors that only have maybe a couple of millimeters clearance between the rod one of the transmission gears. Dunno if the DR is designed that tight. Lukas will let us know as soon as he gets his case tool.

I've got one apart right now. I'll look into it when I start reassembling.

i've seen threads on every different aspect of building this motor but this. i've seen the threads on shaving to get a little more

compression but none on a higher comp piston option. who could do it?[/Quote]

.

I agree on the compression issue, you would have to run race gas and it would be hard on the crank and rod.

.

I have always wondered if the ignition timing curve is all that good.

Does anyone have a copy of the curve used in the US DR650

.

One thing I have not seen is the possibility of using a Turbo.

You can get huge power increases with a little boost.

It's just like putting bigger valves in(or at least intakes)

.

A blower might be even easier to do, I have seen blowers on Banshee's.

They just build a box around the whole carb and the mixture stays correct.

There are a number of small blowers out there.

.

Then there is another possibility, I did it and it definitely worked. Actually it worked so good that I took it off.

I couldn't run the stock front fender, something was in the way.

I was afraid that I was going to blow the bike up and it had low miles.

I had a bike with just a few thousand miles(2002) and already had a JE piston, a Webcam, a Factory pro jet kit and a supertrapp installed

and yes I cleaned up the pipe inlet(that was pretty obvious).

.

Of course the shop I bought the bike at had already told me my warranty was void.

.

When I was installing the carb kit it required a new spring on the diaphragm.

It turns out that at the factory they got the Diaphragm pinched in the top of the carb at an angle and the shop made me pay $33 for a new one

on a 1500 mile bike:mad:

.

.

.

.

.

.

.

.

Anyway you could try this, it was relatively easy.

I am thinking about reinstalling it, it was FUN:ride:

tn_DR650injectors.jpgtn_DR650portinjector.jpg

The biggest pain in the butt is the fuel pump, it pulls allot of power.

I have been trying to come up with a good way to use Propane.

I could use the little torch size bottles, and invert them.

That way I would get liquid Propane as well as liquid Nitrous.

More cooling, more Volumetric efficiency.

And Propane has a Motor Octane of 120, so no need to run "hot" fuel

to compensate for the Nitrous.

In case you are wondering, I used what was supposed to be a 25 hit.

25 HP more on a 40 HP bike, that is why I took it off.:thumbsup:

i asked about the higher comp piston cause i noticed every other high comp piston ive seen comes in two versions, one for 93oct and one for race gas, but the one for the dr650 still works with 87oct.

i asked about the higher comp piston cause i noticed every other high comp piston ive seen comes in two versions, one for 93oct and one for race gas, but the one for the dr650 still works with 87oct.

Yep, that's because those pistons were likely for race bikes not street oriented bikes? Since the DR650 is no race bike I'm sure J&E took that into consideration when deciding how much bump to install on the piston top. :thumbsup:

Shady Dave, i thought about going the nitrous route and considering that the fuel pump would draw a bunch of current on an already limited charging system, decided to give it a pass. Your propane idea has merit but would require some experimentation to get the right amount metered, and if you hit the button and the propane tank was near empty ... well, it could be a problem. Summit (no affiliation) has a 'sneaky pete' system that is the right size and price ...

The limiting factor will probably be clearance between the big end of the rod and the transmission. Even that can be fudged a little. I've seen rods with the big end notched for clearance and the offending transmission gear can have the tops of the teeth ground off.

The offending transmission gear is.......

3rd!

Can the locating pin transfer from the stock cam to the new one? If it does, what's the best/safest way to remove it from the stock cam? Mine seems to be pretty well seated in the stocker...

Can the locating pin transfer from the stock cam to the new one? If it does, what's the best/safest way to remove it from the stock cam? Mine seems to be pretty well seated in the stocker...

Well, usually it will just fall out of the cam and into the motor when you are removing the sprocket :banana:

If it won't pull out you can tap it out from the back with a small drift.

Well, usually it will just fall out of the cam and into the motor when you are removing the sprocket :banana:

I read that in the manual and figured since I didn't drop mine into the motor it must be broken or defective. :banana:

If it won't pull out you can tap it out from the back with a small drift.

Thanks :lol: NordieBoy was right, I need a bigger hammer. :banana::banana:

Edited by Mfed

Ok, another general question - no shops in San Fran seem to know what moly paste is (you can see why I do all my own work...:banana: ), so obviously no one carries it. I have found a shop that carries Redline synthetic assembly paste though, but I don't know anything about it. Anyone have any experience with this stuff, or thoughts/opinions/etc.?

http://www.redlineoil.com/product.aspx?pid=77&pcid=17

I know I can order the moly paste online, but that's like getting a radio controlled helicopter on xmas morning with no batteries :lol:. The motor is apart, the piston arrived this morning, and the only thing I'm missing is moly paste. If this Redline stuff is as good or better that means I can pick it up today and spend the evening breathing life back into the DR instead of helping the gf clean the kitchen... :banana:

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now