Compression Ratio with pump gas??
04-27-2009, 09:32 PM
#11
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how efficient the heads also play role,so does cam specs.rod to stroke has a bit in it too.inlet temperature,boy ya know there are other things too....good luck,
the bigger the cubic inches the more cylinder pressure more cylinder pressure means more possible detonation.example a 350 chev vs a 632 big chev......11:1 could be more tunable to run without detonation vs a big motor with comparable builds
the bigger the cubic inches the more cylinder pressure more cylinder pressure means more possible detonation.example a 350 chev vs a 632 big chev......11:1 could be more tunable to run without detonation vs a big motor with comparable builds
05-01-2009, 07:29 AM
#12
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Join Date: Dec 2008
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Originally Posted by Tod74
Originally Posted by whitey70ss
is there any way to measure comp. ratio with the engine in the car???
Very accurate... Dave
05-01-2009, 07:50 AM
#13
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Join Date: Oct 2007
Location: Staunton,VA.
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compression ratio on pump gas
Old and Tired, feathers, be my luck that if I told him to do that he would and watch him pull a golden egg out of the collector, but thats how my luck goes. Kris
05-01-2009, 10:15 AM
#14
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Join Date: Feb 2009
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Re: compression ratio-pump gas
Originally Posted by mep
I have a 355 sbc with 10.5 flat tops. It previously detonated when I ran some old steel 64cc turbo Chevy heads, #340292. We replaced them with a set of 68cc AFR alum heads with 180 runners and the detonation went away. I don't know if it was more from the larger chambers or the alum head material, but I suspect it was more from the aluminum since it dissipates heat better. It's may be easier and cheaper to swap heads than pistons. JMO Mep
05-01-2009, 11:05 AM
#15
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Well, I have seen many talks about this subject in the past...
I have a BBC w/ 12.5 pistons. Cast heads that have alot of port & polish, which I was told by the builder it comes out to 10.2 in the end. I run pump gas occasionally w/ zero problems as long as timing is accomidated too. Sometimes I do 50/50 mix also.
One day, I wanted REALLY find out if my builder was right/accurate. So I did the "Balloon Compression test" using a basic auotomotive balloon that fits over the intake w/ carb removed. Using a remote starter, I turned the motor 1.76 revolutions & the balloon inflated to the erect position... something did not look right.... where it should have had the compression mark for 10.2, it said "Trojan"?? I am still confused...
I have a BBC w/ 12.5 pistons. Cast heads that have alot of port & polish, which I was told by the builder it comes out to 10.2 in the end. I run pump gas occasionally w/ zero problems as long as timing is accomidated too. Sometimes I do 50/50 mix also.
One day, I wanted REALLY find out if my builder was right/accurate. So I did the "Balloon Compression test" using a basic auotomotive balloon that fits over the intake w/ carb removed. Using a remote starter, I turned the motor 1.76 revolutions & the balloon inflated to the erect position... something did not look right.... where it should have had the compression mark for 10.2, it said "Trojan"?? I am still confused...
05-17-2009, 11:57 AM
#17
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Re: Time will tell
Originally Posted by heshtesh
I'll be running 12.1 to 1 in my street engine on 93 this summer, think we can pull this off with cam profile and tuning ability with fuel injection let you know how it turns out.
05-17-2009, 01:01 PM
#18
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MASTER JOURNEYMAN
Join Date: Feb 2008
Posts: 45
Might have had a brain fart
This post has made me realize a point i overlooked when deciding to go with the Mass- Flow system. With the Edel Pro- flow system i currently own i have the ability to set parameters such as fuel and timing how i like at any RPM with the hand held programer an important aspect for what i'm trying to do. I'm getting rid of the Pro Flow because the electronics do not allow it to run properly at under 10" of vacum, i won't be able to make it idle. In order to update my Pro- Flow it would require new electronics $ 1800.00,new intake Vortec to standard 23 degree $350.00 and larger injectors $440.00. Fortunately i won't get hurt by this as i still have the ability to choose between the new Edel Pro-Flow & Mass-Flow if the Mass-Flow does'nt have the tuning options of the Pro-Flow.
