For those that are thinking 'deck wha?', deck clearance is the gap between the piston top and the block deck when a piston is @ top dead center (TDC).

I can't seem to find specs for the 5.2 and 3.9 Magnum engines. I've heard guesses of .025-.050 in the hole, but no one I know has actually measured it. OEM head gasket specs are also unknown. For compressed thickness, .047 comes to mind, but I'm not certain. I've heard that gasket bore is 4.060, but again, uncertain. I'd like to get either chrysler's book specs, or some independant measurements. If anyone has them, or knows where they can be found, please, enlighten me. I'd certainly appreciate it.

 

I don't know but... here's a link to where you can get the manual... have a look.

dodge manual

 

It took me about 4hrs to download it with 56k, and it's pulling up as a 'damaged file'. I can't open the thing. Have you downloaded it yourself? In any case, thanks for the heads-up on that. If it worked, it'd be pretty useful, for sure.

 

I've now read a couple stating the pistons were .050" in the hole. With a .047" gasket, that's a .097" quench height (which would explain why these engines have terrible economy and knock so blasted much). But, I have some contradicting info.
With block deck height: 9.058-9.060, stroke: 3.31, rod length: 6.123, and piston compression height: 1.81, I come up with -.006-.008 deck clearance. The piston tops would be .006-.008" out of the hole @ TDC. With a .047 gasket, that would leave .041-.039" deck clearance, which is about where it should be. What am I missing here?

 

I have it at home, took about 40 minutes to download. I'll check when I get there and let you know (probably around 9:00pm PST)

 

Thanks. If you get to this before spending the time to look it up though, it's now not quite as important. They supposedly vary so much, whatever the book says would be of no use.

I acquired some more independant measurements today. Dan 'The Fastman' said his couple have been .060-.062 in the hole, and the engine builder at KRCPerformance said theirs have averaged low-mid 70's. I guess Chrysler just didn't care much for keeping tolerances. It's almost hard to believe they very THAT much. At over .060 QH, I imagine it probably wouldn't make much difference what it was. You'd have no 'squish' with such a gap.

I guess I'll be ordering some .005" tin foil and hope for the best lol...

 

cool, glad you found what your looking for...