I want to zero deck my small block 383 from the standard 9.025" to 9.000". I've read in posts that's it's more preferable to shim the head rather than the manifold so that the intake mating surface is flush. About how much should I ask the shop to remove from the head or will they know this already? These are Dart Iron Eagle 200cc/72cc heads with the Performer RPM Air Gap manifold.

I like to come to you guys first...because, honestly, a lot of those guys at shops (but not all of them) dish out a lot of B.S. Plus, I haven't found a shop that I'd keep coming back to yet.

Shim? THats a new one on me, but i'm amatuer. fwiw, the shop that did mine only came to .006 in the hole, they didnt want to go "allt he way"!

shim = shave...typo.

Actually, I'll have my pistons .005 out of the hole. With a .041" gasket, I'll have a nice quench.

I wouldn't ask them to remove anything from the head until you have done a trial assembly. Even though you are aiming for .000" deck, you will want to run a .035" to .045" compressed-thickness head gasket to get proper quench. THEN you can check the fit of your intake manifold and determine whether or not material needs to be removed. The machine shop will be able to determine how much material needs to be removed from the port surfaces of the head OR the manifold and it is possible that the bottom rails on the manifold will need to be milled as well. This is all dependent upon how much the block needs to be milled to get at the desired deck clearance of .000".

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Bill
64 Chevelle Malibu Sport Coupe (original owner) car now has 427" BB, Chrysler HEMI 4-spd. trans., 12 bolt 5.57 w/spool & axles.
"HOT RODDER is NOT a dirty word"
"Too much horsepower is just enough"

I can't figure out why people and shops whack on the intake and make that intake fit only the motor it sets on, worthless once removed. There is a formula to correct the intake side of the head as well as cutting the end rails of the block. Been a puzzle to me for some time.

Maybe they don't know how to do it http://www.chevelles.com/forum/confused.gif http://www.chevelles.com/forum/confused.gif http://www.chevelles.com/forum/confused.gif http://www.chevelles.com/forum/confused.gif http://www.chevelles.com/forum/confused.gif http://www.chevelles.com/forum/confused.gif http://www.chevelles.com/forum/confused.gif http://www.chevelles.com/forum/confused.gif http://www.chevelles.com/forum/confused.gif http://www.chevelles.com/forum/confused.gif http://www.chevelles.com/forum/confused.gif http://www.chevelles.com/forum/confused.gif http://www.chevelles.com/forum/confused.gif http://www.chevelles.com/forum/confused.gif http://www.chevelles.com/forum/confused.gif http://www.chevelles.com/forum/confused.gif http://www.chevelles.com/forum/confused.gif http://www.chevelles.com/forum/confused.gif http://www.chevelles.com/forum/confused.gif http://www.chevelles.com/forum/confused.gif http://www.chevelles.com/forum/confused.gif http://www.chevelles.com/forum/confused.gif http://www.chevelles.com/forum/confused.gif

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www.muncie4speed.com (http://www.muncie4speed.com)
Gold 67
1967 Malibu, 2nd owner.
1971 Malibu, new rat motor going in.
There is nothing like rowing through the gears at 7500. Stick cars are so much fun they should be a controlled substance!



[This message has been edited by Wally (edited 10-29-2002).]

Wally,

Manifolds are cheaper than heads. If I'm going to carve up something so it fits only one engine it's going to be the manifold, not the heads. I might want to use the heads on another un-decked engine later. Decent heads are expensive.

Tom

Yep that's not a bad idea. But, an even better idea it to think about the combo and select the right heads etc. that work better together so you don't need to cut the heads .100 then slice up the manifold.

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www.muncie4speed.com (http://www.muncie4speed.com)
Gold 67
1967 Malibu, 2nd owner.
1971 Malibu, new rat motor going in.
There is nothing like rowing through the gears at 7500. Stick cars are so much fun they should be a controlled substance!

The whole purpose of this is because the pistons I will be getting .02" in the hole and I want a ~.035" quench.

If I use a .015" shim gasket I'll achieve the same thing, but I worry about it. I know I'll have to prep the block to make sure it's a flat mating surface for the head, and that takes some material away from the block and could make my quench too tight for the street, right? Plus, I don't know how reliable shims are for a street/strip car. I've heard good things about the felpro .015" gaskets, but not from any street driven cars.

GM put shim gaskets on production motors. Most of the Z/28 motors had steel shim gaskets if not all. If the surface of the block and heads are prepared right and you use the correct coating for the install, there is no reason why they won't work.

------------------
www.muncie4speed.com (http://www.muncie4speed.com)
Gold 67
1967 Malibu, 2nd owner.
1971 Malibu, new rat motor going in.
There is nothing like rowing through the gears at 7500. Stick cars are so much fun they should be a controlled substance!

The shim type gasket is very acceptable, as long as it is used for iron block and iron heads. The steel shim was used in just about all Chevrolet V-8's in the '50's, 60's and '70's (both standard and high performance engines). Like Wally says, the surface preparation and coating of the gasket before installation are critical. Just don't use them for aluminum heads.

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Bill
64 Chevelle Malibu Sport Coupe (original owner) car now has 427" BB, Chrysler HEMI 4-spd. trans., 12 bolt 5.57 w/spool & axles.
"HOT RODDER is NOT a dirty word"
"Too much horsepower is just enough"

What's the best way to prep the surface?

Is quench really that important or is it an overblown statistic? Look at my mutated big block engine. I didn't buy the parts, it came this way 18 years ago, and I have been beating on it ever since:
454 block, bored .125" over.
396/427 crank.
Here is the good part: wrong piston/rod combination that yields a .080" deck height. That's right, the pistons are .080" down the hole!!! With the head gasket, the quench is well over .100". So, with any sort of decent compression, it should detonate like a bomb (according to everything I have read). It has huge domed Arias pistons (like .400", 43cc's) Cranking compression is 235 psi. Runs fine on 93 octane pump gas, never overheats, never detonates or pings, so go figure. Sure, it isn't the fastest thing on the planet, but mid 12's @110 MPH ain't to shabby either for such a quenchless mutation.

Jim

Jim - I don't think it's an overblown statistic at all. I don't think the factory factored it in stock mills. and I have talked to many engine builders that don't play the quench or squish numbers unless requested by the customer. It's just a way to get a little edge. Some day the rest of the US will be where CA is and the highest octane you can get at the pump will be 91. You'll be a bit more concerned then. I also wonder about your combo with the domes sticking up 5 times as high as the quench distance. That means that the dome sticks up more than 3/10's" above the machined surface of the block. I'm no engine builder but I think that dome has to have an effect in some way...

Fried Guy,
I'd suggest asking your machine shop to "deck to clean" rather than "Zero Deck"; meaning only take as much as they need to make both sides flat. My shop did this, and reported to me 0.007" deck height. (My own measurements agreed after assembly.)

So THEN I went shopping for head gaskets, and found a gasket (GM part!) with a 0.028" compressed thickness. VOILA! 0.035" quench. Right on the low end of optimum range (0.035-0.045") for the street. Could also have used a 0.031", 0.035", or 0.038" gasket; with the corresponding larger quench distance.

Of course, "Deck to Clean" will vary depending on the condition of your block; but it minimizes the intake butchering (I needed none), and leaves a little more material in case I ever need to have the block squared again. And there are LOTS of different head gasket thicknesses available -- I'm sure you'll find one to give you good quench, even if the block isn't "Zeroed".

Cheers,
mark.
'71 Fodor
383

Wally,

you said:
"Yep that's not a bad idea. But, an even better idea it to think about the combo and select the right heads etc. that work better together so you don't need to cut the heads .100 then slice up the manifold."

Exactly. As my old teacher said. "Proper planning prevents **** -poor performance"

I don't understand why guys start off building an engine that's going to require some massive milling deal, but I see it all the time. "I'm gonna buy this, that and some other thing, whack 080 off this, 100 off that amd weld up the the other, ...."

I don't get it. Buy the right stuff to begin with and you don't get stuck paying a bunch of money to get stuff whacked up so it won't fit anything else.

Tom

<BLOCKQUOTE>quote:</font><HR>Originally posted by Fried_Guy:
What's the best way to prep the surface?<HR></BLOCKQUOTE>

The surface prep is same regardless of gasket used and is simple:
Make sure the gasket surface is absolutely CLEAN. I use some rubbing alcohol on a clean, lint-free cloth to clean the surface just prior to installing the heads. Don't allow any of the alcohol to run down into the cylinders, and wipe the surface dry with another clean cloth.
Before the short block assembly has begun the block should be washed completely with hot soapy water, then rinsed and dried. Put some oil on the cylinder walls to resist rust. Also all the bolt holes and bolts (especially the head bolts) should be cleaned with a thread CHASER. Don't use taps and dies to clean the threads, as they will actually displace some material.

For steel shim gaskets, I use heat proof aluminum paint and BRUSH it on fairly thick (after cleaning the gasket with rubbing alcohol). This is the aluminum (silver) paint sold at hardware stores for BBQ grilles. Install the gaskets/heads while the paint is still tacky.

For composition gaskets, I clean them with (you guessed it - rubbing alcohol), then install them dry, with NO sealer.