most lift a stock 5.0 can take?
02-06-2008, 09:53 PM
#22
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RE: most lift a stock 5.0 can take?
ORIGINAL: silver91gt
you may be able to use it on a stock shortblock, or you may not. there are too many variables and factory tolerances to "guess" if it will hit or not. You will have to put it in, and check how close it is. there is no getting away from it.
and the max recommended lift for stock heads and springs is 0.540"
I misread what cam it was, and edited my previous post
you may be able to use it on a stock shortblock, or you may not. there are too many variables and factory tolerances to "guess" if it will hit or not. You will have to put it in, and check how close it is. there is no getting away from it.
and the max recommended lift for stock heads and springs is 0.540"
I misread what cam it was, and edited my previous post
Stock springs are "acceptable" for a max .450" lift on the exhaust side and .490" lift on the intake side. This allows the minimum .060" clearance between coils from bind.... and this has nothing to do with the required spring pressure rate to control those valves that they lack. Reason why a stock set of valve springs = a stock cam....... anything else requires an upgrade..... if you want to do it correctly that is.
Peak valve lift has nothing to do with possible PTV problems. peak lift occurs at >100 deg. from TDC (or the piston >1.85" away from the block deck or down in the hole)..... a .700" lift will cause the piston to be >~1.150" away from the valve........ so how can they collide?.....
02-06-2008, 11:17 PM
#24
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RE: most lift a stock 5.0 can take?
An f cam with 1.6s straight wont hit the pistons, but if you put 1.7's it will if you install it straight up, only thing changed is lift, so if it has nothing to do with it then why does it hit at all?
02-07-2008, 07:25 AM
#25
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RE: most lift a stock 5.0 can take?
ORIGINAL: Mustangkiler
An f cam with 1.6s straight wont hit the pistons, but if you put 1.7's it will if you install it straight up, only thing changed is lift, so if it has nothing to do with it then why does it hit at all?
An f cam with 1.6s straight wont hit the pistons, but if you put 1.7's it will if you install it straight up, only thing changed is lift, so if it has nothing to do with it then why does it hit at all?
Multiply the .050" tappet lift for the rocker ratio and what is the difference....... .080" with 1.6 rockers and .085" with 1.7 rockers a huge .005" lift difference at the overlap events. At TDC the intake will be opened further and the exhaust closer to its seat, but if a change in rocker ratios would cause them to collide, the PtV clearance using the lower ratio rocker was not the minimum required. My junk has an X-303 with 1.72 rockers (=.583" lift)....... did it have any PtV issues when I checked for it 15 yrs ago?...... nope. Have they collided during that 15 yr. period even when revved @6500 rpms?....... nope. Again..... peak lift â‰* PtV problems
02-07-2008, 10:05 PM
#26
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RE: most lift a stock 5.0 can take?
ORIGINAL: Joel5.0
Is that a specific case you have worked on?....... or a "rule of thumb" derived conclusion? If you install a F-303 following the events @.050 (Int = 4°/42° and Exh = 52°/-6°)..... you have the intake @.050" lift at 4° BTDC and opening + the exhaust @.050" lift at 6° BTDC and closing..... at TDC.
Multiply the .050" tappet lift for the rocker ratio and what is the difference....... .080" with 1.6 rockers and .085" with 1.7 rockers a huge .005" lift difference at the overlap events. At TDC the intake will be opened further and the exhaust closer to its seat, but if a change in rocker ratios would cause them to collide, the PtV clearance using the lower ratio rocker was not the minimum required. My junk has an X-303 with 1.72 rockers (=.583" lift)....... did it have any PtV issues when I checked for it 15 yrs ago?...... nope. Have they collided during that 15 yr. period even when revved @6500 rpms?....... nope. Again..... peak lift â‰* PtV problems
Is that a specific case you have worked on?....... or a "rule of thumb" derived conclusion? If you install a F-303 following the events @.050 (Int = 4°/42° and Exh = 52°/-6°)..... you have the intake @.050" lift at 4° BTDC and opening + the exhaust @.050" lift at 6° BTDC and closing..... at TDC.
Multiply the .050" tappet lift for the rocker ratio and what is the difference....... .080" with 1.6 rockers and .085" with 1.7 rockers a huge .005" lift difference at the overlap events. At TDC the intake will be opened further and the exhaust closer to its seat, but if a change in rocker ratios would cause them to collide, the PtV clearance using the lower ratio rocker was not the minimum required. My junk has an X-303 with 1.72 rockers (=.583" lift)....... did it have any PtV issues when I checked for it 15 yrs ago?...... nope. Have they collided during that 15 yr. period even when revved @6500 rpms?....... nope. Again..... peak lift â‰* PtV problems
Take a TFS1 cam specs:
Intake Opening: 3* BTDC
Intake Closing: 38* ABDC
Exhaust Opening: 49* BBDC
Exhaust Closing: 4* BTDC
Add the intake opening and closing plus 180* = 180 + 41 = 141.
221/2 = 110.5*
110.5*/180 = .614
.614 x 3.0" = 1.842" in the hole when the TFS on the intake side is at peak lift.
Is this what you are you using?
02-08-2008, 12:44 AM
#27
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RE: most lift a stock 5.0 can take?
I am referring to a builda friendroundby medid so all im asking is if lift has absolutely nothing to do with it then why does he have ptv problems as soon as he changed to 1.7 rockers? Also did you install the x cam straight up? and what kind of pistons did you use 87-95 stock style pistons andi f so did you have to get them notched?
02-08-2008, 08:22 AM
#28
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RE: most lift a stock 5.0 can take?
ORIGINAL: 5spd GT
Joel, correct me if I am wrong...
Take a TFS1 cam specs:
Intake Opening: 3* BTDC
Intake Closing: 38* ABDC
Exhaust Opening: 49* BBDC
Exhaust Closing: 4* BTDC
Add the intake opening and closing plus 180* = 180 + 41 = 141.
221/2 = 110.5*
110.5*/180 = .614
.614 x 3.0" = 1.842" in the hole when the TFS on the intake side is at peak lift.
Is this what you are you using?
ORIGINAL: Joel5.0
Is that a specific case you have worked on?....... or a "rule of thumb" derived conclusion? If you install a F-303 following the events @.050 (Int = 4°/42° and Exh = 52°/-6°)..... you have the intake @.050" lift at 4° BTDC and opening + the exhaust @.050" lift at 6° BTDC and closing..... at TDC.
Multiply the .050" tappet lift for the rocker ratio and what is the difference....... .080" with 1.6 rockers and .085" with 1.7 rockers a huge .005" lift difference at the overlap events. At TDC the intake will be opened further and the exhaust closer to its seat, but if a change in rocker ratios would cause them to collide, the PtV clearance using the lower ratio rocker was not the minimum required. My junk has an X-303 with 1.72 rockers (=.583" lift)....... did it have any PtV issues when I checked for it 15 yrs ago?...... nope. Have they collided during that 15 yr. period even when revved @6500 rpms?....... nope. Again..... peak lift â‰* PtV problems
Is that a specific case you have worked on?....... or a "rule of thumb" derived conclusion? If you install a F-303 following the events @.050 (Int = 4°/42° and Exh = 52°/-6°)..... you have the intake @.050" lift at 4° BTDC and opening + the exhaust @.050" lift at 6° BTDC and closing..... at TDC.
Multiply the .050" tappet lift for the rocker ratio and what is the difference....... .080" with 1.6 rockers and .085" with 1.7 rockers a huge .005" lift difference at the overlap events. At TDC the intake will be opened further and the exhaust closer to its seat, but if a change in rocker ratios would cause them to collide, the PtV clearance using the lower ratio rocker was not the minimum required. My junk has an X-303 with 1.72 rockers (=.583" lift)....... did it have any PtV issues when I checked for it 15 yrs ago?...... nope. Have they collided during that 15 yr. period even when revved @6500 rpms?....... nope. Again..... peak lift â‰* PtV problems
Take a TFS1 cam specs:
Intake Opening: 3* BTDC
Intake Closing: 38* ABDC
Exhaust Opening: 49* BBDC
Exhaust Closing: 4* BTDC
Add the intake opening and closing plus 180* = 180 + 41 = 141.
221/2 = 110.5*
110.5*/180 = .614
.614 x 3.0" = 1.842" in the hole when the TFS on the intake side is at peak lift.
Is this what you are you using?
02-08-2008, 09:03 AM
#29
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RE: most lift a stock 5.0 can take?
ORIGINAL: Mustangkiler
I am referring to a builda friendroundby medid so all im asking is if lift has absolutely nothing to do with it then why does he have ptv problems as soon as he changed to 1.7 rockers? Also did you install the x cam straight up? and what kind of pistons did you use 87-95 stock style pistons andi f so did you have to get them notched?
I am referring to a builda friendroundby medid so all im asking is if lift has absolutely nothing to do with it then why does he have ptv problems as soon as he changed to 1.7 rockers? Also did you install the x cam straight up? and what kind of pistons did you use 87-95 stock style pistons andi f so did you have to get them notched?
http://s55.photobucket.com/albums/g1...OVL_Visual.flv
Yep.... straight up as in @5° advanced the X-303 grind comes with. Keep in mind that "straight up" would usually mean LSA = ICL values..... if you have a 112° LSA, the ICL has be 112° for the cam not to have any advance, but since the X-303 grind has a 5° advance (LSA = 112°, but ICL = 107°) in its profile, using the 0° setup would usually mean the ICL is at the cam card specs....... reason why should always degree a cam..... and yes....'87 pistons, no notching done.
02-08-2008, 11:05 AM
#30
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RE: most lift a stock 5.0 can take?
ORIGINAL: Joel5.0
Nope....... engine stroke is not symmetric.
Nope....... engine stroke is not symmetric.
If I so, of course I know this, and it would be at a differen position with a 3.4" stroke, but I used a 3.0" stroke because it is a 302.
Please expound on what you mean
