Lobe separation
02-06-2005, 03:34 PM
#1
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Lobe separation
Is there a magic number for lobe separation to prevent reversion?
110 degrees has been thrown out ther before.
Does overall lift, flow or cubic inches influence this number?
110 degrees has been thrown out ther before.
Does overall lift, flow or cubic inches influence this number?
02-06-2005, 04:20 PM
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Re: Lobe separation
Lobe sepration plays an effect on it however the major player is duration the amount of time the valve is off seat the intake centerline is at 104-108 it is best in smaller cams to drop the lobe cente to 114 and the intake center line to the before mentiond 110 but size of exhaust and type play a large effect the duration at @50should be under 224 for stock manafolds 234-240 for stuff like powerflow and under 254 for tube type headers, also restrickting the amount of water in the exh helps , like late introduction in the exh when possiable.the cause is the overlap the time both valves are open keeping this time shortist will help prevent most of this
02-07-2005, 11:04 PM
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Re: Lobe separation
Specifically;
605 inches, 9.2:1 compression, 450cfm/345cfm flow at .7". Stellings headers with small .125" hole at the very end of tailpipe to make it "wet"
I can see the water getting sucked up the tailpipe at idle but not at 1500 rpm on up. It does get into the oil.
solid tappet roller Cam specs:
Duration at .050 270 intake 280 exhaust
gross vlavle lift .722 intake and exhaust
lobe separation 110 degrees
seat duration at .020 304 intake 314 exhaust
What changes can keep power up as high as possible but cut the reversion to zero?
605 inches, 9.2:1 compression, 450cfm/345cfm flow at .7". Stellings headers with small .125" hole at the very end of tailpipe to make it "wet"
I can see the water getting sucked up the tailpipe at idle but not at 1500 rpm on up. It does get into the oil.
solid tappet roller Cam specs:
Duration at .050 270 intake 280 exhaust
gross vlavle lift .722 intake and exhaust
lobe separation 110 degrees
seat duration at .020 304 intake 314 exhaust
What changes can keep power up as high as possible but cut the reversion to zero?
02-08-2005, 10:02 AM
#6
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Re: Lobe separation
Originally Posted by JCPERF
If its a Ford it will suck. 
Any input on changing the cam specs?
02-08-2005, 04:36 PM
#7
Re: Lobe separation
Originally Posted by 2112
They are all just air pumps
Any input on changing the cam specs?
Any input on changing the cam specs?
02-08-2005, 05:06 PM
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Re: Lobe separation
Originally Posted by 2112
Specifically;
605 inches, 9.2:1 compression, 450cfm/345cfm flow at .7". Stellings headers with small .125" hole at the very end of tailpipe to make it "wet"
I can see the water getting sucked up the tailpipe at idle but not at 1500 rpm on up. It does get into the oil.
solid tappet roller Cam specs:
Duration at .050 270 intake 280 exhaust
gross vlavle lift .722 intake and exhaust
lobe separation 110 degrees
seat duration at .020 304 intake 314 exhaust
What changes can keep power up as high as possible but cut the reversion to zero?
605 inches, 9.2:1 compression, 450cfm/345cfm flow at .7". Stellings headers with small .125" hole at the very end of tailpipe to make it "wet"
I can see the water getting sucked up the tailpipe at idle but not at 1500 rpm on up. It does get into the oil.
solid tappet roller Cam specs:
Duration at .050 270 intake 280 exhaust
gross vlavle lift .722 intake and exhaust
lobe separation 110 degrees
seat duration at .020 304 intake 314 exhaust
What changes can keep power up as high as possible but cut the reversion to zero?
What do the heads flow at .300" lift? Specifically the exhaust? What is the inside diameter of the primary tubes on the headers? What is the max rpm? Carb or EFI?
02-08-2005, 09:24 PM
#10
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Re: Lobe separation
Are you actually seeing water residue or signs of water on your plugs? If you are looking at the outlet of your tailpipes and seeing variable pulses, which may include some minor reversion I doubt you have a problem. Your description on your headers would leave me to believe you should be OK with just about any cam you choose. Only my .02!
Craig
Craig
