questions about TDC piston position and deck block height

[Nacho-RT74]

on a 400 the TDC pistons arrives around 3 milimeters below the block deck surface. I Know they are on that way because emission controls, but dunno if difference is on pistons height or crank mains sit lower on block. Wherever is the difference I would wish to know how much the pistons TDC point arrives on earlier HP engines ( 440 and 383 ) without emission controls below the block deck.

[John_Kunkel]

All B blocks have the same 9.98" dimension from the crankshaft centerline to the deck of the block, and all RB engines share the same 10.725" dimension.

Since all B engines have the same rod length and stroke, the piston compression height accounts for the piston deck height. The same is true of the RB engine.

[Nacho-RT74]

ok so the shorter piston is the difference.

Now my main question is, how much is the top of piston below the block deck on TDC on earlier engines ( 383 and 440 HPs or not ). I know on 400 is around 3 mm. I never measured, just optical mesurement, but more less is 3 mm...

Or does the piston arrives just right at same block deck height ?

[firefighter3931]

ok so the shorter piston is the difference.

Now my main question is, how much is the top of piston below the block deck on TDC on earlier engines ( 383 and 440 HPs or not ). I know on 400 is around 3 mm. I never measured, just optical mesurement, but more less is 3 mm...

Or does the piston arrives just right at same block deck height ?

Natcho, the 400's were low compression motors which typically had the pistons .140-.170 below deck. The HP 440's were closer to Zero deck.....usually around .020-.030 below. The problem is that Mopar deckheights are not consistent from block to block and most were over spec by several thousandths of an inch.


Ron

[Nacho-RT74]

I'm just trying to imagine how much to mill down the heads getting more less same power than  post 69 383 engines with open chambers using metallic gaskets

[John_Kunkel]

The '68-'69 440 pistons are .045"-.050" down in the hole, the '68-'69 383 actually stuck above the deck about .005". (positive deck height)