383 piston choice

[66_Coronet_500]

I know this has been talked about alot, but I wanted to have some opinions on my combination of parts. I want to build a stock 383.
I have a 1971 383 with a forged crank and 346 heads. I dont know what pistons I should use. Kb162 or kb400. I am thinking of using the kb400 with 346 heads and a .020 head gasket. As far as machine work I just want the deck squared up and the cylinders bored. If I choose to go 516 head route I plan on using kb162 pistons. Am I on the right track for around 9-9.5 compression? The cam I want to use is the comp 268ah-10. Also any recommendations out there?

 

[mattsinger]

there isnt a lot of choice out there for 383 pistons...I went with the Diamond pistons #51907. Cant beat the quality

 

[Cranky]

I have a new set of .040 over TRW 383 pistons for 1/3rd of KB's price and they have the same compression distance....I would just like to see someone take and use them because I never will. They've been in the box and on the shelf for many years now.

 

[racedodge]

i went with a set of new KB silvolite cast pistons on ebay for $178, broke the engine in on my mopar cruise with 550miles of issue free driving. I will never see above 5000rpm so I do not need an expensive piston to get me cruising. just saying.

 

[Cranky]

Been years since building an engine using Silvolites but I was impressed with the finish of them.

 

[66_Coronet_500]

So ok. Maybe Im asking for a little guidance. What pistons will work to achieve some kind of decent compression for a stock cruising setup. Part numbers? I have the 346 heads currently.....use them or junk them and why?

 

[racedodge]

So ok. Maybe Im asking for a little guidance. What pistons will work to achieve some kind of decent compression for a stock cruising setup. Part numbers? I have the 346 heads currently.....use them or junk them and why?

my silvolites are 9.5 to 1 with an open chambered head, I have 516's on there so it is a tad close to 10 to 1

 

[66_Coronet_500]

whats pn on the silvolites?

 

[racedodge]

I STAND CORRECTED (SEE BOLD):

UEM1271 Pistons, Flat, 4.250 in. Bore, 5/64 in., 5/64 in., 3/16 in. Ring,Chrysler 383 V8, Set of 8 available in 020 030 040 060 Piston Style Flat top, with no valve reliefs Piston Material Hypereutectic aluminum Compression Distance (in) 1.900 in. Wrist Pin Style Press-fit or floating Pin Diameter (in) 1.000 in. Piston Ring Thickness 5/64 in. x 5/64 in. x 3/16 in. Quantity Sold as a set of 8.

Brand:SIL Manufacturers Part Number:1271

http://www.ebay.com/itm/220979060287#ht_2028wt_1163

looks like that seller has 9 sets left.

 

[Cranky]

Advertised CR is always different than what the actual will be. You need a piston that has around a 1.933 CH to be at 0 deck height. The pistons you listed are 1.908 so they will be around .025 in the hole assuming the deck is where it's supposed to be. Uncut open chamber heads run around 90cc then add the gasket volume and you should be able to figure your CR based on final bore size. I like to shoot for no more than a .040 quench with .030 being much better so I'd look at using a closed chambered head then make adjustments to the piston to keep compression in line...based on cam use. I like no less than 10-1 even with cast iron heads and cast aluminum pistons so long as the cam doesn't throw cylinder pressures over 170 psi or so.

 

[racedodge]

Advertised CR is always different than what the actual will be. You need a piston that has around a 1.933 CH to be at 0 deck height. The pistons you listed are 1.908 so they will be around .025 in the hole assuming the deck is where it's supposed to be. Uncut open chamber heads run around 90cc then add the gasket volume and you should be able to figure your CR based on final bore size. I like to shoot for no more than a .040 quench with .030 being much better so I'd look at using a closed chambered head then make adjustments to the piston to keep compression in line...based on cam use. I like no less than 10-1 even with cast iron heads and cast aluminum pistons so long as the cam doesn't throw cylinder pressures over 170 psi or so.

what cranky said :headbang: