The head gaskets were leaking on my ls1 so I pulled them off to replace them. I took them to the machine shop to have them cleaned and resurfaced and they told me they took off .006 to get them flat again. The issue I have now is my stock pushrods appear to be way too long and when I used a length checker they showed 7.225 at 0 lash. I am getting them cc checked today to make sure they didn't screw up at the shop but wanted to know if I could possibly be doing anything that would make my reading off by .100 or if there are any other possible explanations. Thanks

 

stupid question here maybe, but did you make sure the lifter was pushed all the way to the base circle?

 

I think so. I spun the engine by hand until I saw the exhaust rod lift go down, then the intake lift and go down, and then kept going until the piston was at the top of it's stroke. I think that should be TDC.

 

The EOIC method is when you measure the intake rod length when the exhaust valve begins to open (in other words the exhaust push rods begins to come up). Then you measure the exhaust rod length when the intake valve begins closing (intake rod begins it's downward travel from max height).

Is that what you did? I just know that sometimes my lifters would get stuck in the trays and I would have to press them down with the rod to make sure they were in contact with the cam.

 

^ Like said, make sure and give the lifters a little push to make sure they are not still hung up in the trays

 

Hard to see how lowering the head toward the block by .006" would have made the stock 7.400" push rods .175" too long. There's .169" unaccounted for.

Something isn't being measured properly.

Frankly, IMO you've crossed over into BOTH "measure with micrometer, mark with chalk, cut with axe" AND "paralysis by analysis". If it was mine, I'd put it back together, and in the unlikely event I had any problems, I'd buy a set of 7.375" and swap em out.

 

I will try taking the measurement when the exhaust vale starts to open and vice versa and see what I get. I measured multiple cylinders both intake and exhaust and came up with 7.225 every time. I also installed 1 of my old rods and snugged the rocker down to the pedestal (it pushed the valve open) and then rotated the engine with air applied to the cylinder and the valve never closed all the way.

 

Once the exhaust valve starts to open the intake valve will be on the base of the cam and once the intake valve starts to close the exhaust valve will be on the base of the cam.

If you can get the piston to TDC on the compression stroke both valves should be on the base of the cam. The EO/IC method is the way to go IMO.

 

I double checked my measurements with the EO/IC method with the same results. I cc'd the heads at 64.6cc which is down about 2 ccs from what it's supposed to be stock which would be more the .006 of material removed but not .100 either. I am pretty much at a loss. I'm about ready to just throw it back together and see if it will even start...

 

Just make sure you can rotate the engine over by hand a few times before trying to crank it lol