I've recently purchased a used 4-bolt splayed block from a member. The block was for a blower application and has been O-ringed. The car apparently caught fire shortly after the rebuild thus why the engine came up for sale. The block has the three inner billet/splayed main caps and all caps are on ARP studs. The block apparently has very low miles ~150, and after inspecting the block I believe it. My plan was to send the block to the machine shop and have it hot tanked, replace cam bearings, freeze plugs, torque plate honed and all tolerances checked and then pop in a new rotating assembly providing that the tolerances are in line. I wasn't planning on have the block decked but I would base my decision on what the machine shop finds as far as deck height. Using DCR calculators and a Felpro 1074 gasket I come up with this:

Zero Deck .039 Quench 8.36 DCR
.005 Deck .044 Quench 8.26 DCR

Is the zero deck quench above cutting it too close? And if I do have to deck the block, I assume that the O rings have to be removed. What do I do with the block if this is the case. It's been suggested to me that the ring recesses could be filled with liquid nails and then just deck the block. Do I need to even worry about the recesses since they would be covered by the gasket anyways?

If I keep the O-rings can I still use a standard gasket without problem or do I need to find a specialty gasket, and what does this mean as far as compressed height of the gasket?

BTW this is a 383 stoker I'm building here with a 3.75 4340 forged bottom end, 6.00 rods and -5cc dished pistons.

Thanks.

 

I would suggest a two-step process based upon the used "built" blocks I have seen:

1. Have the block cleaned, etc. and checked for align bore, deck height and squareness and side-to-side evenness, bore size.
Correct as necessary.

2. From the (corrected) deck height order pistons to achieve the quench height you want. When they arrive, hone the bore to the clearance recommended by the piston manufacturer and surface finish recommended by the ring manufacturer. Trial assembly will determine what clearancing you'll need. As for the o-ring grooves, it depends on where they are and how big.

There are a number of other steps you might go thru like selection of pistons/rods/crank for compatibility with your power goals and the heads, how they clear things with the 3.75 stroke, and their weights to predetermine how you will balance it.

Airflow is still Job #1, so head choice is critical, of course.

A good engine designer/builder is probably not a bad idea.

My $.02

 

You can't figure out quench until you know the deck height of the block. In turn, you can't select a piston/rod combo. So, get the meaurement before you decide what to do based on the desired quench distance. If the deck is square, and the deck height is one you can work with using available pistons to achieve the desired piston deck, then you are fine. Or, you could always get a custom piston if needed to achieve the desired quench. A quench of 0.039" is fine provided you have good rods and rod bolts and proper piston to bore clearance to avoid excessive "rocking" of the piston in the bore.

How deep are the grooves in the deck?

Rich Krause