I bet you're just luv'n all us back-seat mechanics right now.............
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| Uncloaking Mystery camshaft.. Now I have Numbers! https://slantsix.org/forum/viewtopic.php?t=43251 |
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| Author: | wjajr [ Tue Jan 18, 2011 6:09 am ] |
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FOPAR: Quote: How about one of those "push the button to open the fingers" pick-up tools
I have a BOLO out on it…It is around here somewhere.
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| Author: | wjajr [ Tue Jan 18, 2011 6:15 am ] |
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Ed: Quote: I'm trying to decipher your numbers using the calculator in the Dyno2000 program.
Gone Fish'in. Be back with check of numbers once #1 intake lifter is nestled in its hole. Hopefully it will happen in this life time... Bill |
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| Author: | wjajr [ Tue Jan 18, 2011 7:20 am ] |
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Success!!!! All it took was a length of #12 copper wire, and a length of # 6 copper wire, a little itty-bitty LED light, 90 seconds, and Bob’s your uncle. That sucker is back in place. Bill |
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| Author: | wjajr [ Tue Jan 18, 2011 9:43 am ] |
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[quote]I'm trying to decipher your numbers using the calculator in the Dyno2000 program. Numbers aren't making sense. Your intake duration seems too small with too much lift, and the exhaust seems duration seems too long (lift about right). Can't figure out what numbers to put into program. It wants: Intake Valve open as degrees Before TDC Intake valve close as degrees After BDC (bottom dead center) Exhaust valve open Before BDC Exhaust valve close After TDC Can you translate to these figures?[/quote] Ed, I hope these numbers are better. I guess I’m a bit confused as to which numbers to record where the wheel is two 180 degree scales indexed from TDC, and a second ring of smaller numbers indexed from BDC. Previously I was recording TDC indexed degrees. The wheel is zero @ TDC in line with timing marks on pulley and chain cover using piston stop method of finding TDC. There appears to be no slop in timing chain. Dial indicator is aligned in X & Y axis to push rod centered in rod hole of head. No sticking of lifters, so I think my set-up is accurate. _______________________________________ Intake valve open BTDC 76* or start of ramp Intake valve closed ABDC 70* or end of ramp Duration 354* Intake full lift, or center line 96* Total lift at lifter 0.321â€, or at valve 0.481.5†@ 0.050†Opening BTDC 55* Closing ATDC 145* Theoretical Center [55+145] / 2 = 100* _____________________________________ Exhaust valve open BBDC 103* Exhaust Valve close ATDC 75* Duration 352* Exhaust full lift, or Center line 104* Total lift at lifter 0.322â€, or at valve 0.483†@ 0.050†Opening ATDC 157* Closing BTDC 68* Theoretical Center [157+68] / 2 = 112.5* ____________________________________ |
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| Author: | sandy in BC [ Tue Jan 18, 2011 12:35 pm ] |
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Something funky still.....or you have a wayyyyyy big cam with low lift. |
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| Author: | Joshie225 [ Tue Jan 18, 2011 1:25 pm ] |
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Many, but not all, mechanical cams have their advertised duration given at at .006" tappet rise. Please give the opening and closing points at .006" tappet rise and .050" tappet rise. |
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| Author: | emsvitil [ Tue Jan 18, 2011 1:48 pm ] |
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I bet you're just luv'n all us back-seat mechanics right now.............
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| Author: | wjajr [ Tue Jan 18, 2011 5:10 pm ] |
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Hi Josh, When you say "Tappet Rise", would this be measuring off the lifter? If so I have listed 0.050†open & close events for intake & exhaust. These lobes on this cam have long slow starting & ending slopes. _____________________ Intake @ 0.006" lift Opening BTDC = 52* Closing ATDC = 97* Duration 315* _________________________ Exhaust @ 0.006" Opening ATDC = 97* Closing BTDC = 47* Duration 310* _______________________ Hope this is what you were looking for. Bill |
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| Author: | wjajr [ Tue Jan 18, 2011 5:16 pm ] |
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Quote: I bet you're just luv'n all us back-seat mechanics right now.............
Ed, this exercise would be easer if I had a cam card to compare to as measurements were being made. I’ll get through this with your help. Bill |
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| Author: | emsvitil [ Tue Jan 18, 2011 5:34 pm ] |
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| Author: | Joshie225 [ Tue Jan 18, 2011 6:14 pm ] |
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Bill, Sorry, but your numbers don't make sense. If the intake valve opens say 10° BTDC and closes 40° ATDC the valve is open 230°. 10+180+40=230 You give an opening of 52° BTDC and closing of 97° ATDC. 52+180+97=329 not the 315° you listed. If this is an old cam design the recommended lash could be pretty wide and make the .006" tappet (lifter) rise numbers look pretty wild. Your .050" numbers don't look right either. There is no way the intake valve opens 76° BTDC. Closing 70° ATDC is less ridiculous. Even if these valve events were accurate that's 326° intake duration not the 354° you give. Let give an example of a pretty healthy Mopar Performance cam. This cam opens the intake valve 34° BTDC, closes it 62° ATDC. Exhaust opens 66° BBDC and closes it 30° ATDC. The overlap is easy to find. The intake valve opens 34° BTDC and the exhaust closes 30° after so the overlap is 64°. Intake duration is 34+180+62=276°. Exhaust duration is 66+180+30=276°. As you can see your numbers are really far off from our example. Here are some links that may help. http://www.tildentechnologies.com/Techn ... asics.html http://www.rbracing-rsr.com/camshaft.html |
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| Author: | DusterIdiot [ Tue Jan 18, 2011 6:50 pm ] |
| Post subject: | Lol... |
Quote: All it took was a length of #12 copper wire, and a length of # 6 copper wire, a little itty-bitty LED light, 90 seconds, and Bob’s your uncle. That sucker is back in place.
I knew he could finger it out!!!  Kind of reminds me of that old joke about the proctologist that became an auto mechanic...but I digress... -D.Idiot |
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| Author: | wjajr [ Wed Jan 19, 2011 5:56 am ] |
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Josh, I had a misunderstanding of the 0.050†measurement. I took it to be 0.050†down from nose, and not 0.050†of lift along ramp. So that was one discrepancy generated. Thanks for the hand-outs, quite helpful. I hadn’t seen those sheets. I was using two other sets of directions, as the ones the came with my kit were rather brief, and were asking to compare readings to one’s cam card. Bill Intake: @ 0.050†lift Opening BTDC 18* Closing ABDC 142* Tappet lift 0.321†Intake Center line: Measured 0.050†down each side of lobe. [C + O] / 2= Center* [145 + 54] / 2 = 99.5* Exhaust: @ 0.050†lift Opening BBDC 130* Closing ATDC 5* Tappet lift 0.324†Center line [158 + 68] / 2 = 113* |
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| Author: | Joshie225 [ Wed Jan 19, 2011 12:00 pm ] |
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Bill, I think you're adding 90° to the intake closing and exhaust opening events. An intake opening of 18° BTDC is perfectly reasonable, and a closing of 52° would be about right giving a 250° duration at .050" lifter rise. That's a pretty long duration cam. Going down .050" from peak lift is used to find the relative centerlines of the intake and exhaust lobes. Using that information is a good way to calculate the lobe centerline which is sometimes referred to the lobe displacement angle. |
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| Author: | wjajr [ Wed Jan 19, 2011 6:47 pm ] |
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Josh, I’m growing tired of this kicking my six. My degree wheel is split up into several scales running to 180 degrees clock & anti clock ways that seem to confuse the heck out me. So I graphed the events as illustrated in the tutorials you hot linked. Intake: Opening .000†start of ramp 73* ATDC .006†53* ATDC .050†18* ATDC Center line .321†@ 99* Closing .050†213* BTDC .006†262* BTDC .000†281* Valve open @ .006†for 315* Exhaust: Opening .000†291* ATDC .006†266* ATDC .050†.231* ATDC Center line .324†@ 113* Closing .050†5* BTDC .006†48* BTDC .000†69* BTDC Valve open @ .006†for 314* Overlap @ .050†23* Overlap @ .006 101* Center line separation 113* + 98* = 221* Hot Lash Intake = 0.024†Hot Lash Exhaust = 0.026†[img]http://i294.photobucket.com/albums/mm87/wjajr/100_1378.jpg[/img] |
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