Pinging Problem.....help
Le Mans Master
Joined: Jan 2005
Posts: 8,226
Likes: 2
From: Lake Wylie SC
An L72 motor factory rated compression is 11.25 but real world figures are about 10.25 as built at the factory. That # can be tuned to run on 93 with no problem
BUT!!!!!...... if it has ever been been rebuilt with factory parts but to blueprinted specs then it will be a true 11.25 static compression motor that with iron heads will not last on the street on 93 octane!!!
Iron head BB motors must be down to at least 10.5 real static compression to run on pump gas on the street.
Doug
BUT!!!!!...... if it has ever been been rebuilt with factory parts but to blueprinted specs then it will be a true 11.25 static compression motor that with iron heads will not last on the street on 93 octane!!!
Iron head BB motors must be down to at least 10.5 real static compression to run on pump gas on the street.
Doug
Team Owner
Joined: Aug 2007
Posts: 58,061
Likes: 7,147
Army
Frank
Thread Starter
Racer
Joined: Jan 2009
Posts: 353
Likes: 2
From: Cuyahoga Falls Ohio
Problem solved !!!!
Well after paying $6.50 a gallon for Sunoco Racing Fuel at 110 octane
and mixing it with 93 octane at a 50/50 ratio the pinging is totally gone!
Draining out the old gas that was a mixture of small toppings off over
the 6 years of the previous owner that never drove the car... and
pouring the new mixture in.... it worked.
Upon my return from the test drive, I added more 93 octane to adjust
the mixture to 25% racing fuel and 75% premium... and will see if this
still works. I will continue mixing more and more premium in and see if
just fresh premium 93 fuel will work out fine.
and mixing it with 93 octane at a 50/50 ratio the pinging is totally gone!
Draining out the old gas that was a mixture of small toppings off over
the 6 years of the previous owner that never drove the car... and
pouring the new mixture in.... it worked.
Upon my return from the test drive, I added more 93 octane to adjust
the mixture to 25% racing fuel and 75% premium... and will see if this
still works. I will continue mixing more and more premium in and see if
just fresh premium 93 fuel will work out fine.
