Guess my dad just said screw it new motor

[Casey78]

The general rule of thumb is around 10.25:1 is the limit for pump gas.

Actually, it depends on the cam profile. You can have a 10:1 engine with a cam that causes pinging with good 93 or have a 11:1 engine with a cam that runs fine with decent advance and no pinging.

First question is, what is the cranking compression? With domed pistons, it may have more of a propensity to detonate at lower cranking pressures, but it would be nice to know what cam is in it...

We have no idea on the compression my dad is just estimating but my dad does not want to take the heads off so he's forcing me to live with premium gas it'd be nice if I cold do what my dad did to his 496 the motor started at 12:1 compression and he added a head gasket thick enough to take it to pump gas 10:1

 

[DoubleV]

A head gasket change dropped the CR by 2 full points? That must be one hell of a gasket.

 

[jacobdavis1979]

A head gasket change dropped the CR by 2 full points? That must be one hell of a gasket.

I was thinking that too but i just ignored it lol

 

[Casey78]

A head gasket change dropped the CR by 2 full points? That must be one hell of a gasket.

I was thinking that too but i just ignored it lol

Exactly what everyone says lol
.125 thick 4.5 inch bore on a 4.310 bore engine just copied the text my dad sent me
Solid copper gaskets

 

[pencero]

Have heard of the copper headgaskets but doubt they impact C/R as much as you guys from down south are guesstimating... Bring those cars up here to Indiana when its -5 and lets hear how they sound on regular w/ e-10 in it... I think you guys are only getting away w/ the regular unleaded b/c of the climate

 

[Casey78]

Have heard of the copper headgaskets but doubt they impact C/R as much as you guys from down south are guesstimating... Bring those cars up here to Indiana when its -5 and lets hear how they sound on regular w/ e-10 in it... I think you guys are only getting away w/ the regular unleaded b/c of the climate

We live in Topeka Kansas not south we run regular pump gas nothing special

 

[Casey78]

4.310 bore 4.25 stroke. 6.535 h-beam rod with floating pins. .125 dome SRP forged pistons. 102 CC open chamber aluminum heads .125 thick solid copper gasket for 4.50 bore dads motor

 

[Casey78]

My app never wanted me to log in so I haven't posted in a while

 

[Casey78]

If it shows up that's what I get when I try to log in

 

[Casey78]

Guys sorry its been soo long my dad has finally gotten parts but i have nooooo clue how to add images anymore so i cant post update photos but i have a new cam and lifters put in, intake, block, and oil pan painted black. I am currently waiting on the push rod which should be at our house by tomorrow and really all i can think of right now is getting the transmission rebuilt (th350) and a carb ordered the motor is almost complete now all of this has been done this week. its all been gone through and polished well to what we could get.