no compression
Seasoned HDF Member
Joined: Aug 2007
Posts: 8,195
Likes: 3,085
From: NW AR
When you guys put new pistons in, do you replace the wrist pin bushings? If you're not a shop, do you buy a reamer and a tool to push in the bushing? Inside/outside Micrometers? I'm assuming no one does the _real_ old school method of using a brake cylinder hone on an evo.
Seasoned HDF Member
Joined: Dec 2010
Posts: 7,736
Likes: 1,524
From: Coromandel Peninsula New Zealand
When you guys put new pistons in, do you replace the wrist pin bushings? If you're not a shop, do you buy a reamer and a tool to push in the bushing? Inside/outside Micrometers? I'm assuming no one does the _real_ old school method of using a brake cylinder hone on an evo.
Stellar HDF Member
Joined: Aug 2012
Posts: 2,664
Likes: 184
From: Indiana, USA
Agree with Spanners39, take the cover off and check the valve train. Once you see what the problem is, you may decide it is cheaper to fix. Broken spring can be changed without removing the head by applying air to the cylinder thru the plug hole and using a GM valve spring compressor tool, $10 at NAPA.
Stellar HDF Member
Joined: Aug 2012
Posts: 2,664
Likes: 184
From: Indiana, USA
New pistons come with new wrist pins and clips. Check yor rod end bearing ID and compare to service limits in your manual. I have replaced many sets of pistons with a top end rebuild and never had to change a bushing. The wrist pin will slide easily though a properly sized bushing.
Stellar HDF Member
Joined: Aug 2012
Posts: 2,664
Likes: 184
From: Indiana, USA
Use your imagination and don't be afraid to modify the cheap tool if it can save you time and money. I just did this last month on my '51 Farmall. After putting new pistons and sleeves with a new head set i broke a valve spring. Nocked the center out of an old spark plug, welded in an airline fitting and used the 410 valve spring compressor to safely compress the spring and remove the keepers. Bottom line is if you drop the valve in the process you pull the head like you are already contemplating
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Seasoned HDF Member
Joined: Aug 2007
Posts: 8,195
Likes: 3,085
From: NW AR
Another way to keep the valve up that I've heard people do (but not done myself) is to get some rope. Put the piston on the bottom of the compression stroke, pull the plug, feed the rope into the spark plug hole, turn the motor until the piston is pressing the rope up against the valves (holding them up) then pull the keepers, etc. Pull the rope out when you're done and you got it.
Seasoned HDF Member
Joined: Dec 2010
Posts: 7,736
Likes: 1,524
From: Coromandel Peninsula New Zealand
Another way to keep the valve up that I've heard people do (but not done myself) is to get some rope. Put the piston on the bottom of the compression stroke, pull the plug, feed the rope into the spark plug hole, turn the motor until the piston is pressing the rope up against the valves (holding them up) then pull the keepers, etc. Pull the rope out when you're done and you got it.
I do that to lock motors when undoing the crank nut on the cam side or tranny shaft nuts....works well!
