Long duration cam ????

[Bill Hilly]

My bike's engine ,and head are internally stock, but I have the exhaust, carb, and pod filter on it. I intend to port and polish the head, and install a 4° advance key, but I have been thinking that while doing these mods, it may be the time to change cams. I like the power curve of the motor now, and really don't want or need to run the motor above the rpm that it current pulls to. Would the motor with just port work, and advance key run well with the stock cam ?, Or would a long duration cam offer a notable performance increase throughout the entire rpm range? I have watched a video on the cams, and it was stated that a press was necessary. I don't have a press, but I do have a big old Rock Island vise. Could I use that to press a cam gear. If I should get a cam, what is recommended? I intend to get a thinner head gasket, but won't I also need a gasket for the stator, housing?
Thanks

[DSAdventures]

Could you share which flavor of bike you have? That will most likely help the engine discussion.

[Bill Hilly]

Originally Posted by DSAdventures

Could you share which flavor of bike you have? That will most likely help the engine discussion.

I have a 2021 TBR7D. Showing a little over 2,000 on the odometer. 17/46 sprockets, and it actually runs good enough now, to meet my needs. I had thought that I would just leave it alone internally, until it needed work, but I caved. It would be nice to have another HP, or two, but as it is, it now is OK, and like I said, I actually like the power curve of the bike . I just was wondering,if I will still gain enough performance from the porting, and advance key to make it worthwhile, if I use the stock cam.

[Megadan]

The increased duration cams don't increase the effective operating power curve very much and just give a good boost through the power curve. They are a great match to a ported head with the other mods.

The video you watched was likely mine (oddBallperformance on youtube). The press was necessary with my install because the cam I ordered from Brazil did not come with a new cam gear and had to be swapped out. Many of the performance cams now sold on ebay with increased duration come with the gear already installed and a new pin as well (like this one) https://www.ebay.com/itm/174384771774

It also comes with a new crank gear but you don't need it so it can be set aside in the spare parts box.

I would recommend that if you use the old cam followers to use a bit of light sand paper to re-surface the pads that come in contact with the cam. Or you can order a new set. Some of the performance cams on ebay come with the roller cam followers like the ones I installed on my bike during the whole process.

Be aware that the cam will increase the valvetrain noise a bit on your bike. Even with the valves set to a tighter spec they will be just a tad bit more clattery than before.

[Bill Hilly]

Originally Posted by Megadan

The increased duration cams don't increase the effective operating power curve very much and just give a good boost through the power curve. They are a great match to a ported head with the other mods.

The video you watched was likely mine (oddBallperformance on youtube). The press was necessary with my install because the cam I ordered from Brazil did not come with a new cam gear and had to be swapped out. Many of the performance cams now sold on ebay with increased duration come with the gear already installed and a new pin as well (like this one) https://www.ebay.com/itm/174384771774

It also comes with a new crank gear but you don't need it so it can be set aside in the spare parts box.

I would recommend that if you use the old cam followers to use a bit of light sand paper to re-surface the pads that come in contact with the cam. Or you can order a new set. Some of the performance cams on ebay come with the roller cam followers like the ones I installed on my bike during the whole process.

Be aware that the cam will increase the valvetrain noise a bit on your bike. Even with the valves set to a tighter spec they will be just a tad bit more clattery than before.

Thanks again Dan, I saw your video after I posted, and it was very detailed, and I appreciate it. The first one I saw was a guy that goes by X Moto, and it wasn't as detailed. I was surprised at how high the guy had to go on his main jet, and his carb still wasn't in great tune. I will probably go ahead, and cam it too.. The XMoto guy had a video posted after changing cams, and he stalled the motor a few times on a trail leading from his fishing spot, and I thought that he may have lost low rpm power in his cam change. I seen a bunch of those cams on eBay, and some did look like the lobe was thick, like on the one you installed on your video, and some looked like they had the thin pointed lobe. The one in the link you posted looks thick, so I will probably get that one. Thanks again.

[Megadan]

Originally Posted by Bill Hilly

Thanks again Dan, I saw your video after I posted, and it was very detailed, and I appreciate it. The first one I saw was a guy that goes by X Moto, and it wasn't as detailed. I was surprised at how high the guy had to go on his main jet, and his carb still wasn't in great tune. I will probably go ahead, and cam it too.. The XMoto guy had a video posted after changing cams, and he stalled the motor a few times on a trail leading from his fishing spot, and I thought that he may have lost low rpm power in his cam change. I seen a bunch of those cams on eBay, and some did look like the lobe was thick, like on the one you installed on your video, and some looked like they had the thin pointed lobe. The one in the link you posted looks thick, so I will probably get that one. Thanks again.

I walked Xmoto through some of the details when he did his upgrades. His huge jet was due to the pe30 carb he was using. He ended up at a 172 iirc. For comparison, I am running a 145 on my pe28FL, and I ran a 140 on the pz30b.

There isn't really a loss of low end, but there is a reduced vacuum at idle. The cams require bumping up the idle a couple hundred rpm to really prevent the stalling issue.

[Bill Hilly]

I ended up going ahead, and ordering one with roller rockers. I think I ordered a long duration, too me looking at the pictures it looks like the lobe is thick, the description reads that it's not a standard cam, and can add power. I think I have everything now except the lower jug to block gasket. I will try to add one to my order from CSC, so I don't have to pay more shipping. I ordered this set-up https://www.ebay.com/itm/174384704948

[Megadan]

Yep that looks like the increased duration camshaft. You should be good to go with that.

[Deckard_Cain]

Originally Posted by Bill Hilly

I ended up going ahead, and ordering one with roller rockers. I think I ordered a long duration, too me looking at the pictures it looks like the lobe is thick, the description reads that it's not a standard cam, and can add power. I think I have everything now except the lower jug to block gasket. I will try to add one to my order from CSC, so I don't have to pay more shipping. I ordered this set-up https://www.ebay.com/itm/174384704948

Do note however, that many of the cam retainers (the thing with the o-ring that the cam and cam gear rolls on) do not fit... so you may have to use your old one. Which is fine.