Thread: Another build question

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Jim, the first question is......is the block square? If it isn't, your measurements will be off by how much the block is out of square. I have checked blocks that were off by 0.008" from one end of the deck to the other. This will not only cause your p/v clearance to check screwy, but your squish and static compression ratio will be off from one end of the block to the other.

I applaud you for learning to do these things in the right way and not just throwing a bunch of parts together "willy-nilly".

If you don't know how to check the block for square, just ask.

By the way, when torquing down the heads, just hold back on the torque by 15-20 pounds from what you'd use on final assembly so you don't fully compress the gaskets. You'll be close enough to check p/v and the gaskets will still be good to re-use. I, like Pat, have done this many times and skated through. Follow Pat's advice about marking them.

Assemble the heads with some old, stock, worn-out springs. You'll want to use them to break in the motor anyway and you might as well make it easy on the cam to do your checking.

I always use solid lifters to do the p/v check with because I'm never sure the hydraulics won't leak down some and give me an erroneous reading. Leave nothing to chance. You should have a set on hand and add them to your specialty tools collection along with an old worn out set of springs. After a quick google, I came up with these on ebay....
http://cgi.ebay.com/ebaymotors/CHEVR...QQcmdZViewItem

Tighten the rocker nuts down to allow about 0.001" to 0.002" valve lash at the rocker/tip interface to do the checking. You can also check the ratio of the rockers at the same time if you want by mounting a dial indicator on the retainer and recording the valve lift for each valve. If using stock Chevy stamped rockers, you'll probably see quite a range of ratios among the 16-piece set you're using. Some of the more savvy stock-class racers used to make friends with the counter guys at the Chevy dealership to be allowed to go through the rocker inventory and check for the rockers with the highest lift ratio. They'd take them home and check them just like we're talking about here, then return the duds and keep the jewels.

I would check all 8 cylinders at the same time, not just one. You don't know if all the seats are installed in the heads the same distance from the head surface, so one or more could be close and you wouldn't catch it. Install pistons without rings, clay all the pistons and have at it. You're looking for MINIMUM 0.080" on the intakes and 0.100" on the exhausts.