what compression hight do i need

hey yall im in need of compression hight info ,im buildin a sbc with a 302 crank 3.00 stroke and a283 block with a ,30 over ive got a line on 6.125 rods 4.25 longer than stock any body have pistons for me that will fit in this screamer mouse

 

Pistons will have to be custom ordered. Not a good combination. Looking at $600.00 pistons and six week wait.

 

Um...so you're building a 283 then...

I'm confused.

 

Well that's a hell of an into, right?

 

I don't know about you, but I didn't get a very good first impression. lol

 

So the rods are 4.25 longer.
Things that make you say Hmmm.

 

Stock 283 rods are only 1.875 inches long?

 

even with a typo your math is off and that is one long rod for a 3" stroke

 

We have a 302" on the dyno now, uses a set of 350" Chev "dome" pistons, 14.5 cc's to be exact. With some 6.250" H-beam connecting rods it went right together.

Don't expect a bunch of power on "pump" with any iron heads, we are actually changing to aluminum heads after the dyno session and upping the C.R. to 10.8!

(Add) Missed the 283 block above, would definitely change that to a 4.000" bore platform. This is a large-journal build, 1969 "DZ" type.

Thanks, Gary in N.Y.

P.S. With this setup you have numerous piston choices! We are using the L2509F/L2510F, TRW's. C.R is at 9.75" with some L/C heads.

 

Id rather go with a shorter rod to decrease dwell time at both ends of the stroke to get that air moving. I run a 6.125 in my 377 but there again I also run a blower

 

Are the 6.125 rods 2" journal?

 

Ditto on this, with that little stroke your better of with factory length of 5.700 to get the piston off TDC sooner.

 

Is it a "Corvette" engine? BTW, what happens if you take a Nova engine and put it in a Corvette?

 

Don't understand your combo, you can't get a 6.125 in a sbc standard deck block as the pin ends up in the middle of the rings. You need a .300 tall deck block.
Good luck

 

Someone didnt do their reading before they started typing.!

 

I use alu buttons to locate the pins and they are notched to support the oil ring.

 

Not exactly accurate, as I stated above we have a set of L2509F/L2510F pistons (these are based on the conventional 350" SB platform) with a 6.250" rod and the pins still aren't "through" the oil rings!

You need to remember he's working with an extremely short stroke, this allows a 1.250" C.H. and no oil rail supports!

Thanks, Gary in N.Y.

P.S. Here's a shot of the setup!

 

A 1.38 pin height will not put the pin in the ring package.

 

I think this thread has made me dumber. I wish now that I had never clicked on it.