Why do we have 4 valve reliefs in our stock lopo pistons?
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- 1990 Ford LTD Crown Victoria P72 - the street boat - 5.0 liter EFI - Ported HO intake/TB, 90 TC shroud/overflow, Aero airbox/zip tube, Cobra camshaft, 19lb injectors, dual exhaust w/ Magnaflows, Cat/Smog & AC delete, 3G alternator, MOOG chassis parts & KYB cop shocks, 215/70r/15s on 95-97 Merc rims
- 2007 Ford Escape XLT - soccer mom lifted station wagon - 3.0 Duratec, auto, rear converter delete w/ Magnaflow dual exhaust
- 2008 Mercury Grand Marquis Ultimate Edition - Daily driver - 4.6 2 valve Mod motor, 4R75E, 2.73s. Bone stock -
For the optional 4 valve heads or so they can be used in the right or left bank. Take your pick.Scars are tatoos of the fearless -
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What years got valve-relieved pistons? My points of reference are the '79 351 and '87 302, which (in my cases, anyway) got dished pistons without individual valve reliefs.2012 Mazda5 Touring | Finally working on the LTD again!
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The pistons are directional, but they will mount on either bank. So there's a valve relief for the valves it would avoid on the other side.Comment
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- 1990 Ford LTD Crown Victoria P72 - the street boat - 5.0 liter EFI - Ported HO intake/TB, 90 TC shroud/overflow, Aero airbox/zip tube, Cobra camshaft, 19lb injectors, dual exhaust w/ Magnaflows, Cat/Smog & AC delete, 3G alternator, MOOG chassis parts & KYB cop shocks, 215/70r/15s on 95-97 Merc rims
- 2007 Ford Escape XLT - soccer mom lifted station wagon - 3.0 Duratec, auto, rear converter delete w/ Magnaflow dual exhaust
- 2008 Mercury Grand Marquis Ultimate Edition - Daily driver - 4.6 2 valve Mod motor, 4R75E, 2.73s. Bone stockComment
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Back in the late 80's early 90's there was a co named Arayo that sold 4 valve heads for the 5.0, needed a specific intake & distributor also.Originally posted by turbo2256b View Post
87 Ford LTD Crown Victoria Country Squire Station Wagon. 4.10's, Repacked Trac Loc, Boxed LCA's, Explorer Intake, 65mm T-body, 'Stang Cam, 'Stang Air tube, K&N, GT-40X Heads, 1" Spacer, 1 5/8 BBK's, 2.5" Pypes X-pipe w/high flow cats, Single Chamber Thunderbolts, B&M 'vertor, Po-lice Swaybars.
91 Mercury Grand Marquis Colony Park Station Wagon. K-Code, 4.10's, Repacked Trac Loc, MK VII LSC Engine, 'Stang Upper Intake, Stang Air Tube, K&N, 65 mm T-Body, 'Stang Headers, 'Stang Cat Pipe,'Stang Torque Convertor, 2 Chamber Thunderbolts.
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Ford motorsport also sold some I worked withthe engineer that designed them. They were not so hot for high RPM.Originally posted by mitymerc View PostScars are tatoos of the fearlessComment
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87+ HO engines, and Explorer motors got them. Not sure what else might have reliefs. Lopos have the shallow dish in the middle, and I think the 351's have that big rectangular dish in the piston.Originally posted by 1987cp View Post86 Lincoln Town Car (Galactica).
5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley
91 Lincoln Mark VII LSC grandpa spec white and cranberry
1984 Lincoln Continental TurboDiesel - rolls coal
Originally posted by phayzer5
I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousersComment
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I know HOs got four-eyebrow pistons starting in '87, but the OP explicitly stated that lowpo pistons have valve reliefs.2012 Mazda5 Touring | Finally working on the LTD again!
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Originally posted by 1987cp View Post
It was explained to me that lopo motors had 4 valve reliefs. Sorry.
sigpic
- 1990 Ford LTD Crown Victoria P72 - the street boat - 5.0 liter EFI - Ported HO intake/TB, 90 TC shroud/overflow, Aero airbox/zip tube, Cobra camshaft, 19lb injectors, dual exhaust w/ Magnaflows, Cat/Smog & AC delete, 3G alternator, MOOG chassis parts & KYB cop shocks, 215/70r/15s on 95-97 Merc rims
- 2007 Ford Escape XLT - soccer mom lifted station wagon - 3.0 Duratec, auto, rear converter delete w/ Magnaflow dual exhaust
- 2008 Mercury Grand Marquis Ultimate Edition - Daily driver - 4.6 2 valve Mod motor, 4R75E, 2.73s. Bone stockComment
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my apologies to the misread post police.Originally posted by 1987cp View Post86 Lincoln Town Car (Galactica).
5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley
91 Lincoln Mark VII LSC grandpa spec white and cranberry
1984 Lincoln Continental TurboDiesel - rolls coal
Originally posted by phayzer5
I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousersComment
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No! There can be no apology! I must have satisfaction, or death!2012 Mazda5 Touring | Finally working on the LTD again!
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excuse me i just reliefed myselfScars are tatoos of the fearlessComment
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Originally posted by 1987cp View Post
Cake or Death?86 Lincoln Town Car (Galactica).
5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley
91 Lincoln Mark VII LSC grandpa spec white and cranberry
1984 Lincoln Continental TurboDiesel - rolls coal
Originally posted by phayzer5
I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousersComment
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the cake is a lie!
Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. -- Albert Einstein
rides: 93 Crown Vic LX (The Red Velvet Cake), 2000 Crown Vic base model (Sandy), 2003 Expedition (the vacation beast)
Originally posted by gadget73
... and it should all work like magic and unicorns and stuff.
Originally posted by dmccaig
Overhead, some poor bastards are flying in airplanes.Comment
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