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#1
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Switching from stud mount to shaft rockers?
What's involved when switching from stud mount rockers to shaft rockers on an already assembled engine?
The engine currently has Harland Sharp 1.65 rockers with .250 offset and Isky lifters with .180 offset. The heads are 380 cfm High Ports. |
#2
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You will just have to re-measure pushrod length once you get the stand height set. Probably won’t be able to use the same pushrods. That’s about it.
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Come take a ride http://www.youtube.com/watch?v=P7Y8Awfk2I0 2008, 2013, 2015, 2016, 2019 Central Il Dragway Mod track champion and 2015 IHRA Div 5 Mod champion |
#3
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For my Crower shaft they had a tool to get the stand height correct. Then you go to measure for pushrod length, but no direction where the adjusters should be in the rocker for that. I set mine with them halfway through their adjustment to give plenty of room either way to play with lash.
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Skip Fix 1978 Trans Am original owner 10.99 @ 124 pump gas 455 E heads, NO Bird ever! 1981 Black SE Trans Am stockish 6X 400ci, turbo 301 on a stand 1965 GTO 4 barrel 3 speed project 2004 GTO Pulse Red stock motor computer tune 13.43@103.4 1964 Impala SS 409/470ci 600 HP stroker project 1979 Camaro IAII Edelbrock head 500" 695 HP 10.33@132 3595lbs |
#4
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t and d rockers are no where near half out by the directions. I was just looking at this the other day. I think its a turn and a half from all in?
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1969 carousel red firebird 455, richmond 5 speed 1964 540 gto 1971 lemans sport convertible 1972 Maverick under slow construction |
#5
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I already need new pushrods, so that works out good.
I plan on getting T&D rockers. What about the offset? Does that come into play? |
#6
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Quote:
From a long time ago and I am talking 426 Hemi. You wanted the min out of the rocker. This shorted the push rod a small amount which reduced total valve train weight a small amount. Stan
__________________
Stan Weiss/World Wide Enterprises Offering Performance Software Since 1987 http://www.magneticlynx.com/carfor/carfor.htm David Vizard & Stan Weiss' IOP / Flow / Induction Optimization - Cam Selection Software http://www.magneticlynx.com/DV Download FREE 14 Trial IOP / Flow Software http://www.magneticlynx.com/DV/Flow_..._Day_Trial.php Pontiac Pump Gas List http://www.magneticlynx.com/carfor/pont_gas.htm Using PMD Block and Heads List http://www.magneticlynx.com/carfor/pont_pmd.htm |
#7
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Be very careful when measuring geometry. I had to shave +/- .090 off my rocker pads to get that where it needed to be for my HP heads.
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Dave Polichena |
#8
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My directions for T&D are to back the adjuster counterclockwise till the bottom of the screw is up against the rocker arm. Turn clockwise one full turn. That’s the initial setting. Don’t go more than one full turn in either direction from this setting. Otherwise it will cut off the oil supply to the rocker.
__________________
Come take a ride http://www.youtube.com/watch?v=P7Y8Awfk2I0 2008, 2013, 2015, 2016, 2019 Central Il Dragway Mod track champion and 2015 IHRA Div 5 Mod champion |
The Following User Says Thank You to Probird For This Useful Post: | ||
#9
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Yes. You need the correct offset for your heads.
__________________
Come take a ride http://www.youtube.com/watch?v=P7Y8Awfk2I0 2008, 2013, 2015, 2016, 2019 Central Il Dragway Mod track champion and 2015 IHRA Div 5 Mod champion |
#10
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According to the T&D website you measure the center of the #1 and #3 intake valves and the center of the #1 and #3 intake pushrods, subtract, and then divide by 2. and then add .050 for pushrod clearance.
My pushrod centerline width is 3.750 inches. My intake valve centerline width is 2.850 inches. 3.750 - 2.850 = .900. .900 divided by 2 = .450 .450 + .050 = .500 So .500 is my rocker offset? Does that sound right? |
#11
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Pics
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#12
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This^^^^
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#13
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My hp heads needed spacers made to run t&d shafts. Goes to show you that things need checked carefully to determine what's needed.
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#14
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Do you have offset lifters?
GTO George |
#15
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[QUOTE=GTOGEORGE;6125536]Do you have offset lifters?GTO George[/QUOTE
Yes, .180 offset. |
#16
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[QUOTE=Mean Green;6125538]
Quote:
GTO George |
#17
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Not something I would do on an already assembled engine. But that is just me.
__________________
1978 Pontiac Grand LeMans.......out next year Previous - 2001 Jerry Haas-built P/S Grand Am - former WJ car, Hoffman Racing 535" IA2, Tiger Heads/Intake, Single Dominator, PG Best ET: 7.776 @ 175.94, 1.096 60', 2375 lbs. |
#18
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Quote:
Quote:
Stan
__________________
Stan Weiss/World Wide Enterprises Offering Performance Software Since 1987 http://www.magneticlynx.com/carfor/carfor.htm David Vizard & Stan Weiss' IOP / Flow / Induction Optimization - Cam Selection Software http://www.magneticlynx.com/DV Download FREE 14 Trial IOP / Flow Software http://www.magneticlynx.com/DV/Flow_..._Day_Trial.php Pontiac Pump Gas List http://www.magneticlynx.com/carfor/pont_gas.htm Using PMD Block and Heads List http://www.magneticlynx.com/carfor/pont_pmd.htm |
#19
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I never thought it was worth it anything up to 1200 hp I don't see the advantage of using shaft rockers conventional rockers will work fine unless you have some really large lift camshafts but besides that waste of money just my opinion my current combo is close to 1100hp on nitrous no problems don't get me wrong they have their place
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#20
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Mean Green, Dave and Brian,
What do you have for over the nose valve spring pressure? Stan
__________________
Stan Weiss/World Wide Enterprises Offering Performance Software Since 1987 http://www.magneticlynx.com/carfor/carfor.htm David Vizard & Stan Weiss' IOP / Flow / Induction Optimization - Cam Selection Software http://www.magneticlynx.com/DV Download FREE 14 Trial IOP / Flow Software http://www.magneticlynx.com/DV/Flow_..._Day_Trial.php Pontiac Pump Gas List http://www.magneticlynx.com/carfor/pont_gas.htm Using PMD Block and Heads List http://www.magneticlynx.com/carfor/pont_pmd.htm |
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