This is a very long post. It carefully documents my interactions with Bisimoto on a camshaft regrind for my F22A cylinder head. I have tried to be completely factual in every detail. I would be interested in any response from the good folks on CB7tuner.com
1) INITIAL CAMSHAFT REGRIND
I ordered a Bisimoto Level 2 F22A camshaft regrind in March 2013. When it came, the specs on the cam card were as follows:
INTAKE
Opens: 1 deg BTDC
Closes: 41 deg ABDC
Intake duration: 258 deg
EXHAUST
Opens: -4 deg BBDC
Closes: 27 deg ATDC
Duration: 246 deg
There are two problems with these cam card specs. First, the calculated duration, from the intake and exhaust opening, is completely different than the duration on the cam card. And neither the reported duration or the calculated duration for the exhaust matched the Level 2 spec.
Intake Exhaust
cam card duration 258 246
calculated duration 222 203
Level 2 duration spec 222 225
I send an email to Bisimoto on 4/12/13 with the above information, asking for help in sorting the information out and understanding what is right and what is wrong. Bisimoto did not respond to my email.
Janet Ruvalcaba from Bisimoto sent me an email on 4/18/13, asking if I had received the camshaft and the other parts I ordered and asking me "if there is anything else that we can assist you with?" In response, I resent her the information from my 4/12/13 email. Bisimoto did not respond to this email either.
2) CAMSHAFT MEASUREMENT
As I did not receive a response from Bisimoto, I decided I needed to better understand what was going on before I took any further action. So, I bought a degree wheel, dial indicator, and mount and installed them on the cylinder head. I set up the dial indicator to measure the valve lift at the top of the valve retainer, set the valve lash to zero, zeroed out the dial indication, took measurements for both the 1st cylinder and the 4th cylinder, and rotated the camshaft twice to double-check my measurements. My measured TDC and BDC might be slightly off, as I did this off of the timing marks on the cylinder head, not the crankshaft, but the duration and lift should be pretty accurate.
I recorded measurements at every 0.050" lift, but for brevity I will only report the duration at 0.050" valve lift and the total lift here (I sent the full list of measurements to Bisimoto with an email on 4/30/13).
INTAKE Duration @0.050" Lift
Measured 201 0.404"
Level 2 spec 222 0.400"
EXHAUST Duration @0.050" Lift
Measured 225 0.378"
Level 2 spec 222 0.372"
So, I sent another email to Bisimoto on 4/30/13, asking (a) why the intake duration was so far off from the Level 2 spec and (b) asking again why the cam card numbers were so far off. Bisimoto did not respond to this email either.
3) BISIMOTO RESPONSE
As Bisimoto had not responded to any of my emails, I called Julio on 5/9/13. He was very friendly on the phone and said he would discuss this with his engineering department and get back to me. Following is the email that Julio sent me on 5/13/13, in its entirety:
Greetings John,
Hope you had a fantastic weekend and thank you again for your interest in Bisimoto technology for your build! After further discussing with the engineering department regarding your camshaft numbers, they had shared that final numbers will be dictated by type and profile of submitted camshaft core. Although every camshaft is ground down utilizing a master with specifications listed on the camshaft card, final number may slightly vary due to differences in models and condition of cores. However, it is still recommend to shoot for a 110 center line for optimal performance. If you have any further questions, please do not hesitate to ask. Thanks.
I sent an email response to Julio the same day. My primary point was that the intake duration was 21 degrees out of spec, which is far outside his statement that the "final number may vary slightly". I also wrote that I had calculated the centerline from my measurements and they were 110 degrees for both intake and exhaust.
Even though Julio said in his email, "If you have any further questions, please do not hesitate to ask", Bisimoto did not respond to my email of 5/13/13, either.
4) WEB CAMSHAFT REGRIND
Over the course of the preceeding month and a half, I had done a lot of research on camshafts. What I learned made me very nervous about putting in a camshaft with 21 degrees longer exhaust duration than intake duration. Few camshafts are ground with significantly longer exhaust duration than intake duration, plus the primary camshaft factor affecting power is the intake valve closing point. Thus, the extended exhaust duration on the camshaft Bisimoto sent me seemed like it would degrade my idle without any significant power gains. In addition, the Bisimoto cam was ground with a 110 degree lobe separation angle and somewhat wider separation angles are supposed to be better for higher rpm power.
So, I went out and bought anther camshaft core and called up Web cams directly. They were happy to do a camshaft regrind for me. I asked for more exhaust valve lift and a 114 degree lobe separation angle. I measured it after I got the regrind back. The intake duration and lift were almost identical to the Bisimoto camshaft, the exhaust duration and lift matched the intake duration and lift (exhaust lift was up from 0.378" to 0.400"), and the lobe separation was exactly 114 degrees (instead of 110 degrees for the Bisimoto cam). The duration is actually fairly conservative, but compared to the F22A6 cam it has about 6 degrees more duration and a lot more lift, 0.400" compare to 0.365". (Yes, while I doing all of this I also measured a F22A1 and a F22A6 camshaft. I'll post those specs in a separate thread.)
5) FINAL LETTER TO BISIMOTO
I had no use for the camshaft, so I boxed it up and sent it, along with a letter or explanation, to Bisimoto on 7/29/13. In the letter I acknowledged that I was not supposed to return the camshaft without a return shipping authorization. I went on to say that the camshaft was severely misground, as documented in my multiple phone calls and my emails dated 4/12/2013, 4/18/2013, 4/30/2013, 5/9/2013, and 5/13/2013, so I had bought a properly reground camshaft from Web and had no use for their camshaft. I also suggested that a reputable company that produced a part so badly out of spec would stand behind their product and issue a refund.
Bisimoto never responded to this letter either.
If anyone wants a camshaft with 24 more degrees of exhaust duration than intake, maybe Bisimoto will sell it to you cheap. It's already been fully paid for.
1) INITIAL CAMSHAFT REGRIND
I ordered a Bisimoto Level 2 F22A camshaft regrind in March 2013. When it came, the specs on the cam card were as follows:
INTAKE
Opens: 1 deg BTDC
Closes: 41 deg ABDC
Intake duration: 258 deg
EXHAUST
Opens: -4 deg BBDC
Closes: 27 deg ATDC
Duration: 246 deg
There are two problems with these cam card specs. First, the calculated duration, from the intake and exhaust opening, is completely different than the duration on the cam card. And neither the reported duration or the calculated duration for the exhaust matched the Level 2 spec.
Intake Exhaust
cam card duration 258 246
calculated duration 222 203
Level 2 duration spec 222 225
I send an email to Bisimoto on 4/12/13 with the above information, asking for help in sorting the information out and understanding what is right and what is wrong. Bisimoto did not respond to my email.
Janet Ruvalcaba from Bisimoto sent me an email on 4/18/13, asking if I had received the camshaft and the other parts I ordered and asking me "if there is anything else that we can assist you with?" In response, I resent her the information from my 4/12/13 email. Bisimoto did not respond to this email either.
2) CAMSHAFT MEASUREMENT
As I did not receive a response from Bisimoto, I decided I needed to better understand what was going on before I took any further action. So, I bought a degree wheel, dial indicator, and mount and installed them on the cylinder head. I set up the dial indicator to measure the valve lift at the top of the valve retainer, set the valve lash to zero, zeroed out the dial indication, took measurements for both the 1st cylinder and the 4th cylinder, and rotated the camshaft twice to double-check my measurements. My measured TDC and BDC might be slightly off, as I did this off of the timing marks on the cylinder head, not the crankshaft, but the duration and lift should be pretty accurate.
I recorded measurements at every 0.050" lift, but for brevity I will only report the duration at 0.050" valve lift and the total lift here (I sent the full list of measurements to Bisimoto with an email on 4/30/13).
INTAKE Duration @0.050" Lift
Measured 201 0.404"
Level 2 spec 222 0.400"
EXHAUST Duration @0.050" Lift
Measured 225 0.378"
Level 2 spec 222 0.372"
So, I sent another email to Bisimoto on 4/30/13, asking (a) why the intake duration was so far off from the Level 2 spec and (b) asking again why the cam card numbers were so far off. Bisimoto did not respond to this email either.
3) BISIMOTO RESPONSE
As Bisimoto had not responded to any of my emails, I called Julio on 5/9/13. He was very friendly on the phone and said he would discuss this with his engineering department and get back to me. Following is the email that Julio sent me on 5/13/13, in its entirety:
Greetings John,
Hope you had a fantastic weekend and thank you again for your interest in Bisimoto technology for your build! After further discussing with the engineering department regarding your camshaft numbers, they had shared that final numbers will be dictated by type and profile of submitted camshaft core. Although every camshaft is ground down utilizing a master with specifications listed on the camshaft card, final number may slightly vary due to differences in models and condition of cores. However, it is still recommend to shoot for a 110 center line for optimal performance. If you have any further questions, please do not hesitate to ask. Thanks.
I sent an email response to Julio the same day. My primary point was that the intake duration was 21 degrees out of spec, which is far outside his statement that the "final number may vary slightly". I also wrote that I had calculated the centerline from my measurements and they were 110 degrees for both intake and exhaust.
Even though Julio said in his email, "If you have any further questions, please do not hesitate to ask", Bisimoto did not respond to my email of 5/13/13, either.
4) WEB CAMSHAFT REGRIND
Over the course of the preceeding month and a half, I had done a lot of research on camshafts. What I learned made me very nervous about putting in a camshaft with 21 degrees longer exhaust duration than intake duration. Few camshafts are ground with significantly longer exhaust duration than intake duration, plus the primary camshaft factor affecting power is the intake valve closing point. Thus, the extended exhaust duration on the camshaft Bisimoto sent me seemed like it would degrade my idle without any significant power gains. In addition, the Bisimoto cam was ground with a 110 degree lobe separation angle and somewhat wider separation angles are supposed to be better for higher rpm power.
So, I went out and bought anther camshaft core and called up Web cams directly. They were happy to do a camshaft regrind for me. I asked for more exhaust valve lift and a 114 degree lobe separation angle. I measured it after I got the regrind back. The intake duration and lift were almost identical to the Bisimoto camshaft, the exhaust duration and lift matched the intake duration and lift (exhaust lift was up from 0.378" to 0.400"), and the lobe separation was exactly 114 degrees (instead of 110 degrees for the Bisimoto cam). The duration is actually fairly conservative, but compared to the F22A6 cam it has about 6 degrees more duration and a lot more lift, 0.400" compare to 0.365". (Yes, while I doing all of this I also measured a F22A1 and a F22A6 camshaft. I'll post those specs in a separate thread.)
5) FINAL LETTER TO BISIMOTO
I had no use for the camshaft, so I boxed it up and sent it, along with a letter or explanation, to Bisimoto on 7/29/13. In the letter I acknowledged that I was not supposed to return the camshaft without a return shipping authorization. I went on to say that the camshaft was severely misground, as documented in my multiple phone calls and my emails dated 4/12/2013, 4/18/2013, 4/30/2013, 5/9/2013, and 5/13/2013, so I had bought a properly reground camshaft from Web and had no use for their camshaft. I also suggested that a reputable company that produced a part so badly out of spec would stand behind their product and issue a refund.
Bisimoto never responded to this letter either.
If anyone wants a camshaft with 24 more degrees of exhaust duration than intake, maybe Bisimoto will sell it to you cheap. It's already been fully paid for.
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