cylinder head choice and compression ratio?

[trbodrt]

Got my 360 assembled with a few pistons to check piston to deck clearence, i'm just about zero decked, about .0011 in the hole using stock crank, scat i beam rods and kb 107's, clevite bearings and speed pro file to fit rings. I have two sets of open chamber stock heads but kind of want to go with a closed chamber head, trying to work on a budget here, my question is what would be a good head choice to achieve a good streetable compression ratio and quench area without having to worry about detonation. just looking for some input from the pro's as this is my first engine build. all input would be appreciated.

 

[Valvebounce]

Your choice of camshaft will greatly influence the amount of static compression you can run without runing into detonation issues.

 

[Mad Dart]

How about a set of these. Beehive springs ready for .600" lift cam with 62-67cc closed chambers available. Mine here have been upgraded For a Solid Roller.......

Brian at IMM Engines user ou812 immengines.com

A set of these at 67cc and your KB107's will have a Pump Gas Friendly 10.25:1 Compression Ratio using a Felpro 1008 gasket at .039 Compressed thickness.

They will wake up your engine big time complete set up for $1395.00

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[trbodrt]

these definitely look like great heads and flow more than the eddys, didn't know you could get them in a 67cc chamber, sounds like a good plan. now I just need the money.

 

[rumblefish360]

In an example;

I have a zero deck 360 with what you have in parts. With the above Fel-Pro gasket @ .039 thickness, the ratio was 10.8 - 1. This works with the pump hi octane gas and resonable cam sizes.

I have also run a J head, open chamber @ 72cc's with pump gas as well.

As above, cam size has a play in this. The amount of overlap was not to big. Cam size duration @ 050 could be as small as 230. Maybe less. IDK?

 

[trbodrt]

rumblefish, the 10.8 to 1 was with the 72cc heads? did you run it on 91?

 

[Mad Dart]

Kbsilovite website has a calculator you can use.

 

[Mad Dart]

ENTER YOUR DATA CALCULATED DATA
Cylinder Head Volume (cc) 67 Cylinder Head Vol (cubic in.) 4.087
Piston Head Volume (cc) 5 Piston Head Vol (cubic in.) 0.305
Gasket Thickness (in.) .039 Swept Volume (cubic in.) 45.665
Gasket Bore (in.) 4.180 T.D.C. Volume (cubic in.) 4.913
Cylinder Bore Diameter (in.) 4.030 Gasket Volume (cubic in.) 0.535
Deck Clearance (in.)Note: Neg. nubmer above deck,
Pos. number below deck .0011 Deck Volume (cubic in.) .0014
Stroke (in.) 3.58
STATIC COMPRESSION RATIO 10.242:1

Am I missing something here??

 

[trbodrt]

I know kb has a calculator but wasn't sure if it was figured with zero deck and what thickness head gasket.

 

[1wild&crazyguy]

lets see some pics of those rhs ports.

I haven't seen any yet.

 

[Mad Dart]

lets see some pics of those rhs ports.

I haven't seen any yet.

When I am done with the TT Mock up you can have one to inspect. I can bring you a Magnum version that is on the mock engine.

 

[crackedback]

Are the pistons .011 or .0011 in the hole?

The last value is a pretty precise measurement and the extra 1 10 thousandth isn't going to make a marginal difference in you computation.

 

[1wild&crazyguy]

that'd be bad ***!

 

[Mad Dart]

that'd be bad ***!

Consider it Done!

 

[1wild&crazyguy]

Anyone taking a cruise today?

might drive to wades, nice drive I hear.

 

[trbodrt]

okay lets just say 1 thousandth in the hole.