Squish question

[4stroker]

what is the rest of your setup?

 

stock stroke? stock length rods? stock series pistons?

 

are you sure the base gaskets are standard?

 

what does noss say the squish should be?

[Snopczynski]

Your exhaust port duration will affect compression. What pipes?

[Bansh-eman]

Although it is by no means an exact sience, yo can measure the deck hieght( amount the piston sticks out of the cylinder, and then use a mic and measure the edge of the band to the inside of the dome and this will be right around your squish.

 

so if your deck height is 12 tho and your domes band is 30 tho, your squish will be around 42 tho. plus or minus the human error factor.

 

Or just do it the ez way like you have been and bend the wire over and turn the motor over.

 

I use wire thats only 60 thou thick when i tested mine, and the numbers i got measureing the deck hieght and the band came out the be the exact same as the wire.

[dajogejr]

Greg...

I know that's not an exact science....it's not even close.. That method doesn't take into effect the angle of the dome, etc...

 

It would be like telling a machinist to use a tape measure..

 

I use the solder with a soft core (squishes easier) to measure, and I take 4 to 5 measurements per side to check for squish and band.

 

If you can get them both to 17.5 as the length of what is squished...that'd be fine. Also, check the squish in a few spots. Near the outer edge will be thinner, probably thicker slightly as you come to the center of the cylinder.

[bbcmudtruck]

I will check a few times more today, however I was able to get a squish of .059 everytime, in both cylinders. As far as pipes, I have T5s with an aggressive dune port from HJR. Thanks guys

Ryan

[dajogejr]

Based on .059 squish...run it, UNLESS Kevin Herr specifically tells you otherwise...it's his port design.

[lunatic]

I just checked my compression @205 with my snap on gauge and 125 with my brothers cheap auto parts store gauge. And i tryed another @165 so gauges very alot depending on where the shrader valve is in the adapter. I trust my snap on over the others.

[deckheight]

LOL! Drop a teaspoon of oil or even pre-mix down the spark plug hole and check it again w/your brothers gauge...

 

I just checked my compression @205 with my snap on gauge and 125 with my brothers cheap auto parts store gauge. And i tryed another @165 so gauges very alot depending on where the shrader valve is in the adapter. I trust my snap on over the others.

[Bansh-eman]

Greg...

I know that's not an exact science....it's not even close.. That method doesn't take into effect the angle of the dome, etc...

 

It would be like telling a machinist to use a tape measure..

 

I use the solder with a soft core (squishes easier) to measure, and I take 4 to 5 measurements per side to check for squish and band.

 

If you can get them both to 17.5 as the length of what is squished...that'd be fine. Also, check the squish in a few spots. Near the outer edge will be thinner, probably thicker slightly as you come to the center of the cylinder.

Oh I got that Dave. I was simply pointing out that you can get a good idea more then one way

 

I don

[bbcmudtruck]

Right on the money. Thanks for the piece of mind guys.

Ryan

[Snopczynski]

Right on the money. Thanks for the piece of mind guys.

Ryan

 

 

Heres a thought, talk to Kevin and see what he thinks your compression should be, and ask him what thickness base gasket you were supposed to put in it.