Quick Question, Do you need to lap valves on new heads??
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From: Costal Alabama
Car: 1989 Iroc-Z
Engine: 350, ZZ4 equivalent
Transmission: Pro-Built Road Race 700R4
Axle/Gears: 3.23 Dana 44
Quick Question, Do you need to lap valves on new heads??
The guy at NAPA today told me i need to lap the valves on my new set of bare heads and new SS valves to ensure a good fit, is this true??
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From: Ontario, Canada
Car: 1988 Firebird S/E
Engine: 406Ci Vortec SBC
Transmission: TH-350/3500stall
Axle/Gears: 7.5" Auburn 4.10 Posi-Traction
really depends. But you want to be real carfull not to get too carried away lapping in the valves. You can quicky grind in a groove in the valve seat and head angle which will shortern the life of the valve job.
if the valve job is finished, install the valves and check them for seal with a fluid in the ports. if they leak consider getting a qualified Cylinder head machinist to go over the valve job.
Get him to check the guide/ valve stem clearance too.
Could be well worth the added expense to have and expert go over them in the long run.
if the valve job is finished, install the valves and check them for seal with a fluid in the ports. if they leak consider getting a qualified Cylinder head machinist to go over the valve job.
Get him to check the guide/ valve stem clearance too.
Could be well worth the added expense to have and expert go over them in the long run.
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Joined: Jan 2004
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From: Texas
Car: 92 RS
Engine: L03
Transmission: T-5
Axle/Gears: 3.23
F-bird is right...have a pro check them...however if you want to do it yourself...
get lap compound, and just do it yourself, but be CAREFUL to only take off the minimum. You will know it when you see it...small ring of polished metal on the head...then you know it will make a complete seal. CLean it off and install.
But I also would recommend having a pro do it...or at least check your work.
get lap compound, and just do it yourself, but be CAREFUL to only take off the minimum. You will know it when you see it...small ring of polished metal on the head...then you know it will make a complete seal. CLean it off and install.
But I also would recommend having a pro do it...or at least check your work.
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