When my 350 block(010/020 sb) was in the machine shop, I had it punched .060 over/honed w/plate, align bored, oil system reworked and decked to .005(as recommended by the shop instead of "0" decked. Just purchased new set of 062 vortec heads which go to the shop for some work. Looking at target "quench" of .045-.035 gives me few options now for head gaskets. Either fel-pro .039 or GM vortec gasket .028. Would .033(with the GM gasket) be to tight of a quench for mt set up? Pistons are Probe forged w/ .0025 skirt/bore clearance, rods are scat I-beam cap-screw, new scat crank and all parts checked within spec.

Rob, I think you could do .033 IF 1) you don't plan on reving it to the moon 2) your pistons and bearings fit tight. That's a little tight for comfort though IMO.

I run .036" in my 383 and take it to 6500 from time to time (SRP flat tops, Eagle SIR rods, Eagle cast crank). I did notice that the carbon buildup on the piston had just kissed the carbon buildup on the head in a couple places when I took the heads off last month.

PS. I know a guy who is running .026 in a 302 Ford. cast pistons, stock rods, street engine. It was kind of an experiment with a motor built with "junk" parts. It has been going for a couple years now with no problems. I personally would NEVER go that tight.

Rob,

I have run a 355 SBC with cast crank, stock rods, and Wiesco Ultra-Lite pistons at .020" quench. It was a stock car motor that ran 7200RPM regularly. The pistons were .005" in the hole, and I ran a .015" steel shim gasket.

Now I wouldn't reccomend that combination to others, but I would say that your .033" is a little tight, but certainaly it should work.

And BTW I have seen a 550hp 358 Featherlight Mod motor that was running .015". That kept all of the carbon from building on the top of the pistons. :D

In an unplaned experiment, I ran a .021" to .023" quench in a SB. When the heads came off the pistons were just touching the heads and had about a .002" indentations on them. This was with Wiseco pistons, Eagle SIR rods and fairly tight (~.002") bearing clearances. I'm sure .026" would have not had contact. I currently run .032" on this engine which is taken to 7000 rpm on every pass. I think you'll be fine at .033".

I have run them in the bore about .012 with the 1094 gaskets that are .015 thick to 8000 without problems.
A .032-.033 deck won't be a problem with steel rods. It's a bit close but they shouldn't hit & even if they touch it shouldn't hurt anything. Keeps the rods from stretching :D
I ran a 482 rat years ago that I shifted at 8400 & went through the lights at about 8600 with the pistons .007 out with a .039 & they were just showing signs of hitting on the quench side.
Ran it that way for 2 or 3 years & sold it to a boat guy after that. damn thing had so much time on it it was getting a ridge LOL
I like -005 to zero deck with a .040 gasket, it leaves you a little room for error ;)
For info, on small blocks I have run the deck at .025 to over 7500 but don't really recommend it.

Mike (Wolfplace)

On my last 327 the TRW pistons with modified stock rods were .019 down the hole with an .015 SS gasket..
.002 piston clearence and .0024 rods..... ran it for 10 years and never had any problem...it was only a 6000 RPM engine but there no sign of contact at all in it.

Originally posted by Wolfplace:
It's a bit close but they shouldn't hit & even if they touch it shouldn't hurt anything. Keeps the rods from stretching :D
Mike (Wolfplace) Now thats funny Mike...lol

If a guy was forced to use a .041" gasket (400sbc) and his deck height ranged from .030-.040" would it be a good idea to cut the deck down .030" giving quench distances of .041-.051" or cut .035" off an have a .036-.046" quench with some of the pistons protruding out of the block?

Sorry for highjacking your post Robb71 :D

IMO there's nothing wrong with having pistons out of the hole .005 or so, especially if doing so gets you the right quench height.

My pistons are a couple tousandths above deck. No biggie :D

Thank you all for the input! When I assemble the "short block" I will verify what the deck is in relation to the pistons. If less than .005 I will use the .039 gasket, if a little more that .005, I'll use the .028. smile.gif Thanks again

Originally posted by Eric68:
IMO there's nothing wrong with having pistons out of the hole .005 or so, especially if doing so gets you the right quench height. When I was first talking with my machinist about deck height, he told me about several circle-track engines he'd built with the pistons coming out of the hole a few thousandths.

I still had him give me .005 over the pistons and I still plan to go with .028 gaskets on my 383 build.

I've been running .035 on my 357 with no troubles (pistons are .020 in the hole with .015 shim gaskets). I've been driving a lot of miles with this setup with no problems. 2870 miles so far on my expense report for January. And I do hit 6500 rpm regularly with this engine. Hyper pistons and stock Chevy rods. Summit cast crank. Federal Mogul bearings. Checked bearing clearances with plastigage.

Obviously, I don't mind taking chances. So far, my gambles have paid off.

I'm running .032 in my 496 (0.010 in the hole with a 0.022 shim gasket). All 4340 rotating stuff with SRPs. No probs as of yet. Maybe I'll spin her up to 6500 or so and see how it does... graemlins/thumbsup.gif

---Chris