Im not sure if this belongs in here, or in normal tech, so mods please delete from where you wish...

OK if you had read my post about metal beading getting into the engine, then this may make more sense to you...but anyways....

The machine shop needs to know what new pistons I want to go with before 9am tomorrow morning, so this has to be quick...

I had -16cc inverted dome forged SRP pistons in my car before (.030 over). The machine shop had to bore the grooves out of the cylinder walls, so now I need .040 pistons. So my question is, now that I need new pistons, should I go with the -16cc pistons or go with flat top -5cc pistons?

Heres the rest of my set up...

CC306 Cam
Crane Gold 1.6 SA RR's
Fel-Pro 1074 Head Gaskets
Stock Deck Height
Eagle Forged Crank
Eagle Forged H Beam 6" Rods w/ L19 Bolts
Cloyes Double Roller Timing Set
Milodon 4 Bolt Splayed Mains
Canton Oil Pan / Pickup
M55HV Oil Pump

Ford Motorsports 42lb Injectors
Racetronix Walbro 255 kit
58MM BBK TB
K&N FIPK
1LE Intake Elbow
High Flow MAF
CSI Electric Water Pump
160* Thermostat
Mail Order Tune w/ LT4 Knock Module

What do you think?

 

Not enough info to calculate the CR with the choice of pistons. But in general, I can't see why you would want to use the -16cc pistons unless a blower is going on it. You are going to want in the range of 11.5:1 static CR for your CC306 and I don't see how you would get that with -16cc pistons. But without the specifics, all I can speak to is the general case.

Rich

 

thanks for the reply. Im new at this, what do you need in order to give me a more detailed explanation? what details? Im thinking about zero decking the block as well, good idea?

 

Crank stroke,head combustion chamber CC's, cam spects,valve relief size,block deck height.

 

3.75 stroker crank

Stock head CC, so 58cc

CC306 Cam, so 230/244 .544"I/.576"E w/1.6 112LS

looking at pistons, so either -16 CC D inverted domes, or -5cc flat tops...HELP ME DECIDE BY 9AM TOMORROW!!!

and Im also decking the block, so most likely 0 deck height

and then my Fel-Pro 1070 .039 head gaskets


thanks for the help!!!

 

Have to have the ADVERTISED duration of the cam. If ya have the intake valve closing point that may be at advertised instead of at 50.
Stock heads are 54CC's

 

-5cc flats will be fine.

 

keep quench at .045, and get a good person to take care of the tune.

 

At 5CC's he would have 9.38DCR and 12.66 Static.Even with quench at .045 it's 9.22DCR


That is way too high with his spects for pump gas or ya will have to pull a ton of timing which = NO HP/TQ

 

you would be correct....if you did the math right.

you forgot the headgasket...

 

Nope----- used the one he spected
My program does the MATH CORRECT.

 

get a new program...you've got something wrong.

 

Nope not new--had them for several years and they are the current issue.
I didn't start doing this yesterday or last year.

 

ok...you're right...I'm wrong...

 

-16's it is.