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Post by geh3333 on Jan 9, 2015 16:06:15 GMT -5
I really wish I knew what size can I used . I know I mentioned before ,I bought a "racing cam " from eBay and it was not listed nor was it marked when I received it ,so i have no clue what size it is . all I know is it made a night and day difference from the stock cam .
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Post by jerseyboy on Jan 9, 2015 16:30:23 GMT -5
With all those miles on yours you might be measuring it before you know it..lol..hopefully not though..
Well Im just waiting for my new rocker assembly and exhaust nuts them Im ready to start slapping this thing together..
Cant wait to push the starter switch man...should be soon...
I learned alot from you guys doing this so wanted to say thanks for all your help..
Soon my signature will say...
60mm BBK
Big Port Head
A10 Cam
Tom
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Post by rcq92130 on Jan 9, 2015 19:30:29 GMT -5
Looking forward to another 60mm rider!
BTW - if GEH was helpful, throw the guy a few boners.
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Post by jerseyboy on Jan 9, 2015 20:35:43 GMT -5
Hopefully the next post you guys see on here will be a video of my scooter running...Ill strap the camera to it some how and take a rip roar around the block  |
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Post by xyshannen on Jan 10, 2015 4:02:34 GMT -5
Not 100% sure bro..I read an A8 was compared to stock so I figured A10 would give me just a little more lift...and it did 1mm across the board. Didn't want to go to big cause then you get alot of slap on the valves to seats...but I guess with a better head that would be fine.Plus i still have a 24mm carb.. I bet the A10 will take alot of air and fuel,,heck the stock cam can handle a 30mm carb. The cam size is something I am going to experiment with in the future though... I wasn't on my computer earlier or I would have linked this.. Just incase you haven't seen it. wildswede.se/Baotian/Cam_horsepower2.jpgIn this graph you can see the cam's # has nothing to do with it's performance. As for how much lift they have I really can't say. I do know the creator of this graph (a fellow member) stated that the lift of the a14 was s much that any larger and it would stress the valves. As for my a11 it's one heck of a performer! It does just about open the valves about as much as the springs would allow but not so much so to cause any problems. I did have to shave a mm or two off of my intake valve well on the piston because it was hitting the piston. I asked my question because according to the chart the a10 has no advantages low end or top end over a good number of cams you could have chosen...Eh it's still better than stock. Geh, from what I understand, most cams sold as "performance" cams are usually a9s. As for the stock being comparable to the a8. Maybe in top end performance, but the a8 should be pretty aggressive on the low end. I don't think I would label anything about the stock cam as aggressive. |
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Post by geh3333 on Jan 10, 2015 4:12:58 GMT -5
Not 100% sure bro..I read an A8 was compared to stock so I figured A10 would give me just a little more lift...and it did 1mm across the board. Didn't want to go to big cause then you get alot of slap on the valves to seats...but I guess with a better head that would be fine.Plus i still have a 24mm carb.. I bet the A10 will take alot of air and fuel,,heck the stock cam can handle a 30mm carb. The cam size is something I am going to experiment with in the future though... I wasn't on my computer earlier or I would have linked this.. Just incase you haven't seen it. wildswede.se/Baotian/Cam_horsepower2.jpgIn this graph you can see the cam's # has nothing to do with it's performance. As for how much lift they have I really can't say. I do know the creator of this graph (a fellow member) stated that the lift of the a14 was s much that any larger and it would stress the valves. As for my a11 it's one heck of a performer! It does just about open the valves about as much as the springs would allow but not so much so to cause any problems. I did have to shave a mm or two off of my intake valve well on the piston because it was hitting the piston. I asked my question because according to the chart the a10 has no advantages low end or top end over a good number of cams you could have chosen...Eh it's still better than stock. Geh, from what I understand, most cams sold as "performance" cams are usually a9s. As for the stock being comparable to the a8. Maybe in top end performance, but the a8 should be pretty aggressive on the low end. I don't think I would label anything about the stock cam as aggressive. One of these days when I have to pull the cam I'll do some measurements. As long as my scoot is running really good I will not pull any major components. All I know is that can makes a huge difference. |
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Post by jerseyboy on Jan 10, 2015 11:06:16 GMT -5
Think I saw that a long time ago,,I would have got the A9 if I saw it sooner,,I thought I read somewhere that the number had to do with lift...oh well..I know its got 1mm more lift than my stock cam so its a gain either way. According to the chart I should have got an A8,,I do  % of my riding around 5-6K RPM and its the highest out of all of them down there,,Im not going to race over 7K much ever at all,,maybe for a few top speed GPS runs but thats it.. Funny how the 13,14,15 fall on their faces..huh....maybe the dewd testin was using a stock head and block or something. Thanks for the chart! |
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Post by xyshannen on Jan 10, 2015 12:01:53 GMT -5
No problem. That thing really should be posted in a sticky at the top of this forum.
See I don't think the a9 is better than the 11. (why I went with the 11) the nine might have more pull past 8k, but the 11 has more top end and better torque up to 8k. As I see it the 9 would only be my choice if I were wanting to drag race. Those extra 500 rpms would give you a little more top end speed. As I see it if you run these motors over 8k for long periods of time, they won't last very long. It's heat and RPMs that kills these motors. They don't last that long to begin with so running it at 8500 (or 8k for that matter) longer than the time it takes to do a speed test run isn't really something you want to do. With the way my motor is built I can cruise at 55 mph at 7k and still have plenty of power left. I'm running 10 gram rollers.
You'r right about that a8, I'm actually planning on getting one so I can see the difference. Like you I would rather have more power at lower RPMs. I didn't build my engine so I could run my scoot at 70+ mph/ I'm more worried about having power to get out of the way on normal surface streets. I'll never take my scoot on the freeway.
Oh and good job on getting the new rocker assembly. Cams make wear patterns in rockers and each cam's wear pattern is different. Not changing the rockers is good way to knock out the lobes on a new cam.
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Post by alleyoop on Jan 10, 2015 12:38:09 GMT -5
Yes, I put those graphs up long time ago when some folks wanted to know a little about the cams. These tests were done overseas so I just copied the graphs the texts where in some other language I think german not sure. I have some more different graphs from their tests as well.
Jerseyman just do NOT Video your speed runs going down hill..LOL
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Post by jerseyboy on Jan 10, 2015 17:45:34 GMT -5
I will try to find a flat area,,but also will do uphill and down hill,,I will edit in writing if I am going up,down,or flat on the video..heck I might not go nowhere if the motor dont start..lol..my first attempt at a BBK.
The A8 looks like it has the most grunt or bottom end torque where I like to run..we will see...
somebody needs to get a hold of all the cams and measure them ALL the way around to see the differences if they are not by order in lift...
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Post by wilds on Jan 11, 2015 2:41:12 GMT -5
Here's an image of the lift of Original, A8 and A14 cams I measured.  The A14 cam compressed the valve springs to the max, couldn't even get a feeler gauge in between the springs. The lobs on the A14-cam is like on a "flat nose cam", and it's really heavy to turn the engine around when the valves are on the top of the lobs. I have an A12 cam also but haven't measured it or I can't find the image of it... The cams I measured had the same lift (or a slight difference) on both intake and outtake. The biggest problem with these chinese cams is that the chain sprocket is only pressed on the cam. If it's slightly off the timing will be totally off also! As I understand the big hole in the sprocket should be aligned with the "red marking" on the image below:  No marking for better visual:  |
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Post by jerseyboy on Jan 11, 2015 11:26:50 GMT -5
Yes,,
Mine center sprocket hole is lined up with that notch on both my cams by eye..the Taiwan cam looks much better quality than my chinese.
My A10 Taiwan also does NOT have a cam stopper on it to worry about,,so now I can spin my motor backwards if I need too.
The A8 and 14 are very similar in the chart above yours..looks like both are close in the bottom then the 8 has a bit better in the mid,,then the 14 has a small advantage in the top after 8k..but like I said it all depends on how the tests for the chart where performed,,not enough info on what setup they used to extrapolate that info...more testing needed.
I really appreciate the info with the chart Wilds!!,,I will put it in my scooter file brother!!
Tom
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Post by xyshannen on Jan 11, 2015 20:39:21 GMT -5
jerseyboy Just a note about if the tests done on the cams outputs were on a stock gy6 or not. According to the HP readings they were getting, their engine(s) had to at least have a free flow exhaust with a good intake and probably a complete performance ignition.
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Post by jerseyboy on Jan 11, 2015 23:36:13 GMT -5
jerseyboy Just a note about if the tests done on the cams outputs were on a stock gy6 or not. According to the HP readings they were getting, their engine(s) had to at least have a free flow exhaust with a good intake and probably a complete performance ignition. Yes you are 100% correct about that,, No way will a stock ignition setup see 10k RPM's..LMAO!!! |
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Post by jerseyboy on Jan 12, 2015 20:13:19 GMT -5
All done!
Its a little louder than Im used too,,might just be cause I'm not used to hearing it with all the covers off...and these stiffer valve springs with the bigger cam making a little slam noise..also needs to be broke in.
Runs good,,idles,takes fuel..I will fine tune it when I get it all back together...
Could not use the performance 30mm intake,,no room,,so might have to mod something up.
The motor was already warm when I made the video,,it was running for 10 minutes or so..
Thanks for all the help and I will post videos of my speed on different terrains soon as it warms up a bit.
Tom
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% of my riding around 5-6K RPM and its the highest out of all of them down there,,Im not going to race over 7K much ever at all,,maybe for a few top speed GPS runs but thats it..
..BAD TO THE BONE..
