32 replies to this topic

[dklawson]

Just poked my head in on MM and saw both Larry and Steve had added comments.  Larry's observation was the same as mine, that the pushrod should not have bent from rubbing.  To me (and Larry) it is an indication of the springs going solid.  Carl commented that he thought the springs have plenty of room for compression.   You cannot glance at them and know.  I don't think he is taking into consideration your engine's 1.5 ratio arms, this is an alloy head, and I thought you said this was not a stock cam.

 

As I mentioned in a previous post, you really need pull the head to see what other damage has happened as a result of that apparent binding indicated by the bent pushrod.  With the head off, use a magnet to pull the lifters out and check their faces.  Turn the engine over by hand as you look down the tappet bores checking for damage to the cam lobes.   

 

Trust Steve.  If he says to shim the rockers, shim the rockers.  Plan on new pushrods and for at least a short time, go back to stock ratio arms.  

[Air2air]

Gotcha Doug.  Then I'll look for bent valves, see how they move through the guides.  I'll order pushrods from Jemal and a head gasket of course, fish out the lifters, and check the cam faces with a flashlight - I don't have a dial gauge as Steve suggests.

[dklawson]

Dial gauges and bases are not expensive compared to the parts you are about to buy.  Even inexpensive gauges with mag bases from Harbor Freight will be fine for this purpose.  However, I think visual inspection of the cam lobes and lifter faces after you remove the head will be much more revealing than measurements with an indicator.  BEFORE, removing the head, turn the engine over by hand (spark plugs out, gearbox in neutral) and look carefully at the valve springs to see if they are "going solid" on you at full lift.

 

Take a look at the thread linked below which shows a method of making a bench type valve spring compressor.

http://www.theminifo...g-the-easy-way/

You can probably find suitable materials at Home Depot or Lowes.  With the compressor you can take the valves out and inspect them.  As with the pushrods and lifters, paint mark the valves so they go back in exactly the same position.

 

I doubt you will find bent valves.  To bend a valve, its head has to hit something and that is not suggested by what you have reported and shown pictures of so far.  However, depending on how well this engine was setup by the builder, the clearance on the valve stems may be too tight.  This will be easy to check with the valves removed.  If something doesn't seem right to you, it probably is wrong.  When in doubt, ask here or on MM.