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[Ranger Max]

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[Steve P.]

RON, I KNOW YOU WILL ANSWER HERE..... CLEAN OUT YOUR IM BOX....................




SORRY TO EAT UP YOUR QUESTION.........   Carry on........

[8WHEELER]

Yes the compression ratio's were adjusted buy the pistons not the heads starting in 68.
Before 1968 closed chamber heads were used on most all big blocks, raising the compression
with less piston height.



Dan

[firefighter3931]

The 383 2bbl engine has lower compression height pistons than the 383 4bbl engine. Sure it'll work but you need to do a deckheight measurement to dial in the static compression ratio. The 4bbl pistons, from what i remember were positive deck....the 2bbl slugs are "in the hole".

Ron

[DFS68_Charger]

I have a 383 2V & 383 4V motor. The Pistons in the 2V are actually dished to reduce the compression and are not "down in the hole".
The 4V pistons are flat tops. I'm pretty sure the piston to deck height are the same for both motors.

DFS

[firefighter3931]

What would be the best deck height for aluminum heads (street pump gas)>?

The closer to zero deck the better. Ideally, you want .040 piston to head clearance for maximum quench effect. The head gasket effectivel creates the quench didtance with a closed chamber head and flattop piston at zero deck. Compression ratios can be manipulated by increasing/decreasing the chamber volume.

Max, get a dial indictor on the piston and find out how far they are below the deck surface...then we can calculate the static compression ratio with different head combinations.

Ron

[firefighter3931]

I have a 383 2V & 383 4V motor. The Pistons in the 2V are actually dished to reduce the compression and are not "down in the hole".
The 4V pistons are flat tops. I'm pretty sure the piston to deck height are the same for both motors.

DFS

Excellent info   Any idea how far down they are ? What's the volume of the dish ?

Ron

[DFS68_Charger]

I,ll try and get a measurement on the dish volume when I get a chance. I'm on a job up in Toronto through the New Year and don,t get home until next Thursday. Did'nt mention it before, but both motors I have are 68 383's. The 2V is original to my car and is completely disassembled. The 4V is out of a different 68 Charger and currently in mine (Wish I had bought the whole car I got that motor out of).

DFS

[Chryco Psycho]

L2293F Speed Pro pistons & use a .057 thick Cometic head gasket this should be approx 10.8:1 compression
I use a Lot of the Engle cams but it depends what RPM range you want the powerband to be in & piston to valve clearance as the Eddy heads do not have the valves in the stock location   

[Chryco Psycho]

Summit , Mancini any good engine parts supplier should have the pistons
you could easily use a K56 Engle with a stock converter