J&E HC Piston and Web Cam

For 96-2009 DR650SE's

In a word... Nice! :thumbsup: Expectations: If you were hoping these mods would turn your DR650 into a high RPM peak HP beast you should stop reading right now and instead go try to shoehorn a GSXR engine in your DR's frame. :bonk:

My insperation for doing this was generated by a leaky base gasket. Just like most of my other endevours it all starts by something pissing me off about my bike..... BST huck-a-buck, Stock Buick Muffler tonnage, etc. But I could not bring myself to only replace the base gasket. :lol:

My goal was not to destroy the best part of the big DR's power... the awesome low to mid range torque. I decided to go ahead and do some head work while I had it apart but only matching and cleaning work... no port hogging. The head certainly needed some TLC in it's stock form. The valve seat to cylinder head transitions are pretty bleak and there are the typical casting goobers in both the intake and exhaust ports. I matched the intake manifold to the head but, other than clean up and polishing, I did not open the exhaust port any more. I had a nice multi-angle valve grind job done at FastBikes where I did my dyno testing with the FCR carbs. Fresh valve seals were the only new parts required.

The std bore J&E HC piston and Web cam were bought from Procycle (I have a cam core if anyone needs one) and I went to my local Suzy shop for the gasket set (I just went ahead and bought a complete set so I'll have a clutch cover gasket, etc), valve seals, valve cover bolt seals, cam end seal, cam locking tab and oil cooler orings. I used Permatex copper coat on the base gasket, head gasket and head bolt washers. It sure is nice to have a totally leak free dry engine again. :worthy:

I know... shut up and get to the good part! :ride: I put 65 miles on it yesterday after getting it all back together. Torque! Like others have posted the stock powerband doesn't seem changed... it just moved up the food chain a ways. From thump-thumping out from a stop to roll-on torque there is just more on tap everywhere. Obviously more power is available up top as well but, just like the stock engine, its not the strong part of the powerband. The roll-on torque is a riot out of turns and my nearly new Kings rear tire was no match breaking away easily. I can see this being a huge asset for the SM guys shaming all of those superbikes in the tight twisties. Some of you probably know I run 14/42 gearing on my bike because I like to hit the dirt trails. All I can say is this gearing is almost annoying with these engine mods on the street. It quickly runs through the gears leaving you wanting another one. You 15 and 16 toother folks will really like this mod. :banana:

Some other notes: I'm breaking it in with straight 30wt Valvoline dino oil. The first 50 miles I upped the idle to 2k as Web says to do. (they don't specify for how long but I figured 50 miles was a nice round number) The idle is nice and consistant.... maybe even better than stock? (or it's all in my head) I have made no jetting changes or adjustments on my FCR from how it was before the engine mods but after reducing the idle back to 1500 RPM I noticed even less decel popping than with the stock engine internals. Not that it did much of that before but it seems even better. I'll keep an ear on this but I'm wondering if the increased vacuum generated by the smaller total combustion chamber volume is holding the Air Cut Valve open wider... or at least for a longer duration before the spring closes it. Heck, maybe its a cam duration thing....... Interesting. :ride:

I'll post some follow-up reports once I get some more miles logged. It's going to be interesting to get this thing back on the dyno again. I plan on testing the 01/02 GSXR pipe in both flavors (Hindle and TwoBrothers) just for giggles and, of course, the big FCR. :foul:

Oh yeah, If your were thinking of doing these mods anyway don't wait for the dyno report... just do it. My recently calibrated seat-o-the-pants dyno says you won't regret it.

Excellent news Rob!!! I can't wait to get my DR back from the shop and see how the mods feel. My cam should be arriving at Web today or tomorrow so hopefully I will have it back by the end of the week. Also, ordered the JE HC piston from Procycle so that should be here shortly as well. Thanks for the info on setting the idle at 2000 rpm for the break in period too.

Hey Rob! Glad to see you finally got the new parts into the motor. Yeah, the cam behaves better around idle than the stocker. You'll probably notice it pulls a little bit better and smoother right off the bottom in addition to making more power through the rest of the range.

For anyone replacing their piston I recommend a visit to the Mototune web site for a good explanation on break in.

Nice top hear about this. Are you running 87 octane?

/\ Thanks for the link Jeff. Just got the JE piston today too, thanks for the super quick service!

Hey Rob! Glad to see you finally got the new parts into the motor. Yeah, the cam behaves better around idle than the stocker. You'll probably notice it pulls a little bit better and smoother right off the bottom in addition to making more power through the rest of the range.

For anyone replacing their piston I recommend a visit to the Mototune web site for a good explanation on break in.

Oh yeah, I'm a firm follower of the Mototune philosophy...and so is the dyno-shop I use. They like straight weight dino oil for street bike break-in for the first 1k miles and after that run any fancy stuff you want. I'm going to put 300 or so miles on it and then schedule some dyno time. :thumbsup:

Nice top hear about this. Are you running 87 octane?

I have mid-grade in the tank right now. (paranoid) I'm gonna fill it with 87 after I burn through this one. Stay tuned....

I wonder how this motor compares to BSR-1's? I plan on the upgrade over the winter pending the inspection after pulling the clutch.

I'm betting there is some mph on top to be gained with the improvements? With requisite gearing, of course.

For anyone replacing their piston I recommend a visit to the Mototune web site for a good explanation on break in.

And an excellent example of what happens when a mechanic designs a website :thumbsup:

I wonder how this motor compares to BSR-1's? I plan on the upgrade over the winter pending the inspection after pulling the clutch.

I'm betting there is some mph on top to be gained with the improvements? With requisite gearing, of course.

He went with a big bore kit.... so I guess you have to determine if the extra $$ are justified in the end results of the 56cc gain. Now that Procycle has the 725cc kit sorted I'd go for that if I was thinking big bore. May as well get the biggest bang available. :thumbsup:

How about milage (mayby too early too tell atm :thumbsup:), but that something i'v been thinking about..

How is the motor handling the extra horsies? Is there a change in operating temps?

How about milage (mayby too early too tell atm :D), but that something i'v been thinking about..

LOL! Well, I'm not giving the throttle a chance to rest so far. :worthy: Gotta get those rings seated right? :) I'l probably do a little mileage test once I get a few tanks through it. My next test will be 87 octane fuel. :thumbsup:

How is the motor handling the extra horsies? Is there a change in operating temps?

I haven't thrown the infared gun on it yet but it doesn't show any signs of temperature issues.

i run 87 in mine, runs just fine. MXrob i even put a 16/42 gear set on and you wouldn't believe how it pulls geared that high. for you street riders this is the way to go. add procycle's 725 and a little bigger webcam--???? (had a yam TT600 with a little bigger cam than the dr's and different springs) had great mid and top with good low end. this is the power I'm still looking for---close but not quite there yet.

Good deal, I'll be throwing 87 in it next fill up... maybe tonight. Yeah, I can tell the bike will really pull bigger gearing now. I don't have a 16 but I do have a brand new 15 to slap on there. As good as it's running down low I may be able to get away with the taller gearing..... we shall see.

/\ I think I am gonna go 520 15/42 when I get mine back. I will try it with the 525 16/42 it has now, but I think the 15 front and 520 would be a LOT more fun. Would also make it a little more manageable if I decide to do any fire roads or light trails. Will have to see how mileage is affected going back to 15.

/\ I think I am gonna go 520 15/42 when I get mine back. I will try it with the 525 16/42 it has now, but I think the 15 front and 520 would be a LOT more fun. Would also make it a little more manageable if I decide to do any fire roads or light trails. Will have to see how mileage is affected going back to 15.

Are you foreseeing a need to change gearing beyond what is available for the 525 chain? :thumbsup: In most cases 525 chain has a higher tensile strength than 520 does. As an example DID's Pro-Oring chain 520V has a TS of 6,630 and wear resistance index of 2,350. The same model 525V chain has a TS of 8,010 and WRI of 3,140. Now there are 520 and 525 chains that have nearly identical numbers but why go with a narrower sprocket that will wear out faster regardless of chain strength? The 520 sprockets have to transfer the same loads through less surface area. If ya gotta do "observed trials" on your DR650 then I guess you have no choice but to order a large pizza for the back end... but Jesse has a 45 tooth 525 rear and with a 14 tooth front sprocket you should be able to climb any Redwood you run across. :worthy: If you are riding mostly street 520 is not the way to go IMO.

Are you foreseeing a need to change gearing beyond what is available for the 525 chain? :thumbsup: In most cases 525 chain has a higher tensile strength than 520 does. As an example DID's Pro-Oring chain 520V has a TS of 6,630 and wear resistance index of 2,350. The same model 525V chain has a TS of 8,010 and WRI of 3,140. Now there are 520 and 525 chains that have nearly identical numbers but why go with a narrower sprocket that will wear out faster regardless of chain strength? The 520 sprockets have to transfer the same loads through less surface area. If ya gotta do "observed trials" on your DR650 then I guess you have no choice but to order a large pizza for the back end... but Jesse has a 45 tooth 525 rear and with a 14 tooth front sprocket you should be able to climb any Redwood you run across. :worthy: If you are riding mostly street 520 is not the way to go IMO.

Hmm, very good points. I was just thinking about the weight / rotating mass reduction. I guess with a torque monster like the DR though, that's probably a non-issue. Maybe I'll just stick with 525 15/42. That should be fine for my uses.

if you stick to street gearing (riding mostly street) stay with the 525 chain--set up, let us dum-a$$'s do the 520 setup--

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