COMPRESSION RATIO

« **on:** March 17, 2011, 11:28:38 PM »

IS THERE A WAY TO COMFIRM THE COMPRESSION RATIO WITHOUT TAKING THE HEADS OFF?

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« **Reply #1 on:** March 18, 2011, 12:03:59 AM »

Yes, but pulling a head is easier/cheaper/more accurate.

If you're still coming up this weekend, I've got a boroscope we can use to at least get an idea of what pistons you've got in it and get an idea of where you're at

« **Reply #2 on:** March 18, 2011, 08:32:28 AM »

YEAH MY BOAT IS STILL IN THE SHOP I MAY GET IT BACK NEXT WEEK.THERE REDOIN THE HULL.SO I CAN LOAD THE MOTOR UP IN THE TRUCK AND HEAD UP THIS WEEKEND WHENEVER??
IT CONCERNS ME THAT MAYBE THIS MAY NOT BE WHAT I THINK.SOMEONE SAID TO CHECK IF IT HAS COPPER GASKETS AN NO IT DOESNT THERE BLUE LOOK LIKE FELPRO..SO I JUST WANT TO DOUBLE CHECK.SO IF THE GASKETS ARE ALL THAT NEED TO BE REPLACED THE ID RATHER PULL THE HEADS AND NO FOR SURE..

« **Reply #3 on:** March 18, 2011, 10:11:39 AM »

Give me a call.....we'll set something up. Im a little concerned about the use of felpro "blue" rebuilder gaskets on what was supposed to be a blower motor

« **Reply #4 on:** March 30, 2011, 07:52:38 AM »

If the motor is out, put it on a stand, rotate it so the plug is the highest point of the chamber and fill it, while measuring how many cc of liquid are going in. At the end of every build I do this to check my ratio. There always seems to be an extra 2 or so cc measuring it this way.
My dad once told me that the two cc's were going past the rings. The ring gap is no more than .025 and the top of the piston to cylinder wall has no more than .005 inches. This leaves a gap of .00012 square inches. How long do you think it would take to gravity feed 2 cc's of 30wt oil through a hole that size.

« **Reply #5 on:** March 30, 2011, 01:08:23 PM »

Quote from: HomeBlown57 on March 30, 2011, 07:52:38 AM

If the motor is out, put it on a stand, rotate it so the plug is the highest point of the chamber and fill it, while measuring how many cc of liquid are going in. At the end of every build I do this to check my ratio. There always seems to be an extra 2 or so cc measuring it this way.
My dad once told me that the two cc's were going past the rings. The ring gap is no more than .025 and the top of the piston to cylinder wall has no more than .005 inches. This leaves a gap of .00012 square inches. How long do you think it would take to gravity feed 2 cc's of 30wt oil through a hole that size.

MAYBE if you knew the quench on the motor....but if you knew that you would more than likely know what cc's the heads are.

« **Reply #6 on:** March 30, 2011, 01:27:43 PM »

HEADS ARE 113CC

« **Reply #7 on:** March 31, 2011, 11:10:17 AM »

The quench is irrelevant, you are measuring the total combustion volume. The only variables left would be cubic inch, and a possible air bubble. If it is 496 then all variables are covered.

« **Reply #8 on:** April 03, 2011, 09:56:15 PM »

OKAY IM BACK JUST TOOK A STARTER AND THREW IT ON THE MOTOR HOOKED THE COMPRESION GAGE TO IT AND GOT 120 ALL THE WAY AROUND?

??

IS THAT GOOD

PBWOOD

COMPRESSION RATIO

lbhsbz

COMPRESSION RATIO

PBWOOD

Re: COMPRESSION RATIO

lbhsbz

COMPRESSION RATIO

HomeBlown57

COMPRESSION RATIO

SLCKREG

Re: COMPRESSION RATIO

PBWOOD

Re: COMPRESSION RATIO

HomeBlown57

COMPRESSION RATIO

PBWOOD

Re: COMPRESSION RATIO