11-19-2022, 10:49 PM | #1 |
Join Date: Feb 2021
Posts: 994
|
Long duration cam ????
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 |
|
11-20-2022, 01:05 AM | #2 |
Join Date: Nov 2022
Location: Seattle
Posts: 32
|
Could you share which flavor of bike you have? That will most likely help the engine discussion.
|
|
11-20-2022, 10:22 AM | #3 |
Join Date: Feb 2021
Posts: 994
|
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.
|
|
11-20-2022, 04:24 PM | #4 |
Join Date: Apr 2017
Location: Omaha, NE
Posts: 8,100
|
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.
__________________
Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 2024 Royal Enfield Shotgun 650 https://chinariders.net/showthread.php?t=34124 |
|
11-20-2022, 05:37 PM | #5 | |
Join Date: Feb 2021
Posts: 994
|
Quote:
|
|
|
11-20-2022, 06:40 PM | #6 | |
Join Date: Apr 2017
Location: Omaha, NE
Posts: 8,100
|
Quote:
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.
__________________
Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 2024 Royal Enfield Shotgun 650 https://chinariders.net/showthread.php?t=34124 |
|
|
11-20-2022, 09:35 PM | #7 |
Join Date: Feb 2021
Posts: 994
|
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
|
|
11-21-2022, 03:24 AM | #8 |
Join Date: Apr 2017
Location: Omaha, NE
Posts: 8,100
|
Yep that looks like the increased duration camshaft. You should be good to go with that.
__________________
Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 2024 Royal Enfield Shotgun 650 https://chinariders.net/showthread.php?t=34124 |
|
11-21-2022, 08:57 AM | #9 | |
Join Date: Aug 2019
Location: Bay City, MI
Posts: 398
|
Quote:
|
|
|
|
|
Thread Tools | Search this Thread |
Display Modes | |
|
|