3 angle valve job
04-12-2001, 10:17 AM
#2
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a three anle valve job is having work done on the valves to clear the airway in 3 degrees. It works best than those stainless steel valves and should give u an additional 5-10 hp.
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92' camaro
New 305 block TPI conversion, Flat top pistons,Bore over .30 Forged parts all around,Edelbrock intake,ported plennum,ported corvette alluminum heads, accel cam,52mm throttle bodie, SLP runners Home aid cold air induction, Air foil,ford SVO 19lb injectors,fuel regulator,cloys timing chain, comp alluminum roller rocker arms and pushrods MSD 8.5 mm wires, bosch plattinum plugs, hypertech cap & rotor and coil, Edelbrock TES headers, free flowing catalytic converter and a 3 inch force II flowmaster exhaust system, and a 3 inch cutout,Zoom multi friction clutch, T-5 tranny,billenstien shocks&struts.
Soon to come!!!
Procharger system 12lbs o boost.
New paint job(hawaiin orchid purple)Cast alluminum ZR1 rims w/ 275 tires.
Favorite quote: "where ever u go, there u are"
Other car;
1971 plymouth Duster
Mods:340,edelbrock victor jr. intake, 650 4 barrel holley, heddman headers,40 series dual flowmasters, cold air intake,4:10 gears, just got a new paint job and cragar rims with 315 tires in the back.
:Yeah its not a chevy but damn how many 71' dusters have u seen in the streets.
------------------
92' camaro
New 305 block TPI conversion, Flat top pistons,Bore over .30 Forged parts all around,Edelbrock intake,ported plennum,ported corvette alluminum heads, accel cam,52mm throttle bodie, SLP runners Home aid cold air induction, Air foil,ford SVO 19lb injectors,fuel regulator,cloys timing chain, comp alluminum roller rocker arms and pushrods MSD 8.5 mm wires, bosch plattinum plugs, hypertech cap & rotor and coil, Edelbrock TES headers, free flowing catalytic converter and a 3 inch force II flowmaster exhaust system, and a 3 inch cutout,Zoom multi friction clutch, T-5 tranny,billenstien shocks&struts.
Soon to come!!!
Procharger system 12lbs o boost.
New paint job(hawaiin orchid purple)Cast alluminum ZR1 rims w/ 275 tires.
Favorite quote: "where ever u go, there u are"
Other car;
1971 plymouth Duster
Mods:340,edelbrock victor jr. intake, 650 4 barrel holley, heddman headers,40 series dual flowmasters, cold air intake,4:10 gears, just got a new paint job and cragar rims with 315 tires in the back.
:Yeah its not a chevy but damn how many 71' dusters have u seen in the streets.
04-13-2001, 07:48 PM
#5
Scott,
I'mm making some assumptions since you didn't include engine data with your post. Fisrt assumption is that you have an '87 convertible. Second is that you have the original engine, which should have been a 305 in a convert, and third is that the engine is basically using stock heads.
The 3-angle grind on the almost-shrouded 305 valves will not make as much difference as it might in a chamber with more clearances, like a 350. You'll probably see just as much flow improvement if you radius the front side of the valve margin in the small chambers (see diagram).
The left valve is a "standard" grind configuration. The center valve shows the conventional three-angle grind, and teh right valve is a radiused face. Imagine yourself as an air molecule exploding past the edges of the valves, and you might see how a small chamber would restrict flows even around a three-angle grind.
Other than greater cost, another disadvantage of the three-angle grinds is that the valves are more sensitive to sealing, and good compression may be harder to maintain over the long haul with the extra angles. The problem is as the valve faces and seats wear, the angles no longer match well, causing leaks much sooner than with a single 45°/46° grind setup. Radius on the front face has no effect on sealing, but can improve flows around the otherwise sharp corners of the margin/face of the valve. Short trackers around here are getting an extra 5+ HP from this alone. Oddly enough, there is no reported gain from a radius on the exhaust valves, but no loss either. I've done is on one of my own 350s, and have had no problems. I didn't dyno before and after, so I have no empirical data to support the theory - just reported increases from third parties.
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Later,
Vader
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"What a Day..."
Adobe Acrobat Reader
[This message has been edited by Vader (edited April 13, 2001).]
I'mm making some assumptions since you didn't include engine data with your post. Fisrt assumption is that you have an '87 convertible. Second is that you have the original engine, which should have been a 305 in a convert, and third is that the engine is basically using stock heads.
The 3-angle grind on the almost-shrouded 305 valves will not make as much difference as it might in a chamber with more clearances, like a 350. You'll probably see just as much flow improvement if you radius the front side of the valve margin in the small chambers (see diagram).
The left valve is a "standard" grind configuration. The center valve shows the conventional three-angle grind, and teh right valve is a radiused face. Imagine yourself as an air molecule exploding past the edges of the valves, and you might see how a small chamber would restrict flows even around a three-angle grind.
Other than greater cost, another disadvantage of the three-angle grinds is that the valves are more sensitive to sealing, and good compression may be harder to maintain over the long haul with the extra angles. The problem is as the valve faces and seats wear, the angles no longer match well, causing leaks much sooner than with a single 45°/46° grind setup. Radius on the front face has no effect on sealing, but can improve flows around the otherwise sharp corners of the margin/face of the valve. Short trackers around here are getting an extra 5+ HP from this alone. Oddly enough, there is no reported gain from a radius on the exhaust valves, but no loss either. I've done is on one of my own 350s, and have had no problems. I didn't dyno before and after, so I have no empirical data to support the theory - just reported increases from third parties.
------------------
Later,
Vader
------------------
"What a Day..."
Adobe Acrobat Reader
[This message has been edited by Vader (edited April 13, 2001).]
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