cam help: 502 with AFR 305cc heads
11-03-2004, 07:01 PM
#71
Platinum Member
Platinum MemberThread Starter
Re: cam help: 502 with AFR 305cc heads
I talked with Crane Cams today. They were not interested in the flow numbers and that bothers me. At first they said why not use the original HP 500 cam, then I pointed out that the I/E split is too much for these heads ( 8* ) so they recomended pt # 16hr00065.
in lift .587
ex lift 598
dur @ .050
in 226*
ex 230*
112* sep
in lift .587
ex lift 598
dur @ .050
in 226*
ex 230*
112* sep
11-04-2004, 08:32 AM
#72
Registered
Re: cam help: 502 with AFR 305cc heads
I had the same experience talking to Crane. The tech tried to steer me to a 741 for my 540's with AFR's. I'm sure it's a good cam but after talking to a lot of people, I think I could do better. The tech also didn't care what the flow numbers were. Same guy? 
11-04-2004, 11:40 AM
#73
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Location: Portage,IN
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Re: cam help: 502 with AFR 305cc heads
[QUOTE=PatriYacht]
Have you decided yet which cam you're going to use?
Originally Posted by waterbum
How about the 139651 from Crane.
139651 cam: at .050 lift
Opens Closes Max Lift Duration
Intake 13.0 BTDC 51.0 ABDC 109 244 °
Exhaust 67.0 BBDC 9.0 ATDC 119 256 °
These were put in my Dart tall deck 540s. 9.75 to 1 CR. Ported GM heads, dart tall intake, 1050 Holley carbs. CMI tube headers with dumps at end of pipes.
I'm not even sure what all these numbers mean. Engines run good, plenty of HP and torque. Needs 91 octane.
Max HP is around 5800 RPM.
See my comments above. This is the cam I was running in my 540's with Merlin heads. They ran great. Seems like a perfect cam for 540's with older style heads. When I switched to AFR heads the difference was night and day. The idle went to hell, they started reverting badly and they didn't power up the way I had expected. This winter I'm switching to a smaller cam.
Lift is .630
Ian
139651 cam: at .050 lift
Opens Closes Max Lift Duration
Intake 13.0 BTDC 51.0 ABDC 109 244 °
Exhaust 67.0 BBDC 9.0 ATDC 119 256 °
These were put in my Dart tall deck 540s. 9.75 to 1 CR. Ported GM heads, dart tall intake, 1050 Holley carbs. CMI tube headers with dumps at end of pipes.
I'm not even sure what all these numbers mean. Engines run good, plenty of HP and torque. Needs 91 octane.
Max HP is around 5800 RPM.
See my comments above. This is the cam I was running in my 540's with Merlin heads. They ran great. Seems like a perfect cam for 540's with older style heads. When I switched to AFR heads the difference was night and day. The idle went to hell, they started reverting badly and they didn't power up the way I had expected. This winter I'm switching to a smaller cam.
Lift is .630
Ian
11-04-2004, 02:50 PM
#75
Guest
Posts: n/a
Re: cam help: 502 with AFR 305cc heads
Originally Posted by WAGS382
I talked with Crane Cams today. They were not interested in the flow numbers and that bothers me. At first they said why not use the original HP 500 cam, then I pointed out that the I/E split is too much for these heads ( 8* ) so they recomended pt # 16hr00065.
in lift .587
ex lift 598
dur @ .050
in 226*
ex 230*
112* sep
in lift .587
ex lift 598
dur @ .050
in 226*
ex 230*
112* sep
Now, you going to tell me that it doesn't matter what the flow numbers are? He must have been excited about the $1 raise he got.
I guess Jim V and the rest of you professional head porters need to quit improving heads because airflow doesn't matter.. . . dismounting soap box.
Chris
11-04-2004, 03:00 PM
#76
Platinum Member
Platinum MemberThread Starter
Re: cam help: 502 with AFR 305cc heads
Chris,
From what you and rmbuilder are saying this 16hr00065 is pretty close. I called crane again today and they asked for the flow numbers this time and picked the same cam. What do you think?
From what you and rmbuilder are saying this 16hr00065 is pretty close. I called crane again today and they asked for the flow numbers this time and picked the same cam. What do you think?
11-04-2004, 03:22 PM
#79
MarineKinetics
Platinum Member
Re: cam help: 502 with AFR 305cc heads
Ian,
Consider that a 502 CID carries 38" less displacement than RLW and that he's using a 4.25" stroke compared to the 4.00". He's also using a 6.385" connecting rod compared to the 6.135". The displacement will alter the required duration and the stroke will have an effect on max piston speed and where it occurs, piston acceleration, and mean piston speed. All these factors will alter valve timing.
Bob
Consider that a 502 CID carries 38" less displacement than RLW and that he's using a 4.25" stroke compared to the 4.00". He's also using a 6.385" connecting rod compared to the 6.135". The displacement will alter the required duration and the stroke will have an effect on max piston speed and where it occurs, piston acceleration, and mean piston speed. All these factors will alter valve timing.
Bob
11-04-2004, 04:33 PM
#80
~~~~
Charter Member
Re: cam help: 502 with AFR 305cc heads
Originally Posted by PatriYacht
I think I'm going to try the cam RLW was using. A custom Comp cam with 236 in./240 ex. .630 lift on both.
Just for clarification, it is .630"/635".
Consider having Rmbuilder and Chris work up a cam for you.
We (all of us) are still in the development stages of the AFR/540 arena.
I am extremely close but think that there is room for improvement depending on what the desired end result you are after.
Russ
Last edited by RLW; 11-04-2004 at 04:39 PM.
