Compression and pump gas
#1
Registered
Thread Starter
Join Date: Jun 2006
Location: Littleton,Co
Posts: 371
Likes: 0
Received 0 Likes
on
0 Posts
Compression and pump gas
Hey guys,
Made a post in the Scarab section but thought this area would be good for a technical question.I'll be picking up my new scarab 22 in a couple days.My question is this 502Ci has 9:6.1 compression.The engine has a procharger running 6lbs of boost.My mathmatical computation put the compression at 13:5.1 at WOT.We only have 91 octane pump gas here in Colorado.The guy I'm buying the boat from is in Missouri which is about 1800 feet in elevation and Denver is 5280.The owner says he does add octane booster to the fuel.Do you feel I will have any problems running 91 octane?
Made a post in the Scarab section but thought this area would be good for a technical question.I'll be picking up my new scarab 22 in a couple days.My question is this 502Ci has 9:6.1 compression.The engine has a procharger running 6lbs of boost.My mathmatical computation put the compression at 13:5.1 at WOT.We only have 91 octane pump gas here in Colorado.The guy I'm buying the boat from is in Missouri which is about 1800 feet in elevation and Denver is 5280.The owner says he does add octane booster to the fuel.Do you feel I will have any problems running 91 octane?
#3
Charter Member # 55
Charter Member
Re: Compression and pump gas
IMO, You will need higher octane than 91 for sure.
9.6 to 1 by it self with iron heads would need 91 octane. I'm guessing you would need more like 100 octane if you want it to live.
9.6 to 1 by it self with iron heads would need 91 octane. I'm guessing you would need more like 100 octane if you want it to live.
#4
Registered
Thread Starter
Join Date: Jun 2006
Location: Littleton,Co
Posts: 371
Likes: 0
Received 0 Likes
on
0 Posts
Re: Compression and pump gas
Thanks for the input....
I finally after many attempts got to talk with the procharger tech support.What a filppin' joke trying to get thru to them.Anyhow,I beleive I spoke with a fairly compentent person and he explained that at our elevation the compression will drop a solid point and a half.So if the theory holds correct,the static compression would be 12:1.1 which would be perfect for this aluminum headed motor.I have also confirmed this with AZspeed@marine.
I'm going to get the boat tommorow and cant wait to drive it.
I finally after many attempts got to talk with the procharger tech support.What a filppin' joke trying to get thru to them.Anyhow,I beleive I spoke with a fairly compentent person and he explained that at our elevation the compression will drop a solid point and a half.So if the theory holds correct,the static compression would be 12:1.1 which would be perfect for this aluminum headed motor.I have also confirmed this with AZspeed@marine.
I'm going to get the boat tommorow and cant wait to drive it.
#5
I hate the winter!!
Platinum Member
Join Date: Jul 2001
Location: long island, new york
Posts: 2,707
Likes: 0
Received 0 Likes
on
0 Posts
Re: Compression and pump gas
I dont know much about superchargers. But, I think you should have one of these.
http://www.livorsi.com/catalog/water...NE_KNOCKMETER_
http://www.livorsi.com/catalog/water...NE_KNOCKMETER_