Has anyone used AE/Covmo pistons 16190 in a Series II or III? Are they four ring, flat top pistons? I've been buying all of my parts from Rick at SS, but it looks like he only has the dished pistons. Does anyone have a source for the flat top style?
Has anyone used the dished in a 1592 and decked the block to increase the compression? How much should it be decked? Any complications with push rod lengths, valve adjustments etc.?
thanks!
Kim
Series III
If you deck the block to up the compression, you will drastically alter the valve geometry. The same applies to skimming the head to up the compression, though the effect is greater on the head side. Decking/skimming also complicates the side cover plate, which has holes in both the head and the block.
You could use hunter 1496 pistons (AE 17747) pistons, which are flat tops, and open the combustion chambers in the head to compensate for the loss in dish volume. The combustion mods to do are either the Holbay config, or the Vizard config.
In either case you will need to remove just a bit more than the usual person does in order to achieve an as stock compression ratio. That is unless you are shooting for the target 9.6/ratio that each one gets you to for performance applications.
Most 1592 folks just use 1725 pistons, which drops the compression about 3 or 4 points. This is good for the average driver/car as the gas thats available today is not quite up tot he stock 9.1/1 ratio.
Also you can install 1496 hunter rods and take a stock set of pistons and have them turned to "near" flat tops. You cant cut a dish in them though as the crowns are too thin at that depth of cut.
The last option is to go with an aftermarket piston mfgr (J&E, DB, Ross, Venolia), and give them a piston to replicate, OR give them the dimensions to which to build an appropriate dished piston. This would cost less than paying someone to make the chamber mods to you head.
HTH
