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87 Octane!

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Old 08-15-2005, 04:59 PM
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Default 87 Octane!

With gas prices going through the roof as of late, has anyone considered an 87 octane friendly head and cam setup? I'll be doing heads/cam the first of next year and wanted to get anyones take on this idea. Just wondered if there is good power to be had with low compression and say a set of AFR's?

Larry
Old 08-15-2005, 05:01 PM
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Popular Hot Rodding did a good write-up a few issues back about building a motor to run on 87 octane. I'm looking more toward a cheap daily driver route, myself.


-Mike
Old 08-15-2005, 05:11 PM
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My take: I'd just stick with high compression and high octane. If the $0.20 a gallon premium on high octane is going to make that large of a difference then modding a muscle car isn't a good idea at this point in time.
Old 08-15-2005, 05:48 PM
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Originally Posted by blkZ28spt
My take: I'd just stick with high compression and high octane. If the $0.20 a gallon premium on high octane is going to make that large of a difference then modding a muscle car isn't a good idea at this point in time.
From the looks of things, it's not going to get any better. The point in time is now. Just trying to get some educated input on this. Maybe a more economical way to make good power. Ya know, power on the cheap!
Old 08-15-2005, 05:56 PM
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Compare how much heads/cam cost, plus the supporting mods, to the $0.20 a gallon that running 87 would get you. We are talking about a 6.7% premium for 93 octane vs 87, assuming gas is about $3/gallon.
Old 08-15-2005, 06:12 PM
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Originally Posted by blkZ28spt
Compare how much heads/cam cost, plus the supporting mods, to the $0.20 a gallon that running 87 would get you. We are talking about a 6.7% premium for 93 octane vs 87, assuming gas is about $3/gallon.
Are you trying to justify the intial purchase of the heads/cam through the savings of the 87 vs. 93? I'm doing heads/cam regardless. I want more power form the car. I just wanted to know if there was comparable power to be had through low compression.

I'm not trying to justify the purchase in gas savings.

Last edited by S1LV3R; 08-15-2005 at 06:21 PM.
Old 08-15-2005, 06:45 PM
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In the end, the issue is cylinder pressure. A good cam designer can compensate for the loss of CR in certain rpms, although your total power potential is reduced. Another way is to leave the CR high and run less timing and run midgrade gasoline. When you want high performance, put in good gas and reload a normal program.

I agree with the others. You are spending money to raise your car's HP. Cutting your CR will reduce your HP. If you spend $250 to gain 10 HP for another mod (a pretty good ratio for mods beyond a cut-out and a lid) that covers the differential for a lot of gasoline assuming the CR lost is worth just 10 HP.
Old 08-15-2005, 11:33 PM
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If u can afford the toys, you can afford the consequences of the toys. I did run 87 on my stock LS1, now I dont think I will
Old 08-16-2005, 12:37 AM
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Originally Posted by blkZ28spt
My take: I'd just stick with high compression and high octane. If the $0.20 a gallon premium on high octane is going to make that large of a difference then modding a muscle car isn't a good idea at this point in time.
I completely agree with that. I never understood why people care about how many miles a gallon our cars get this much.
Old 08-16-2005, 01:14 AM
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Save the money on heads/cam right now and buy yourself a cheap beater that will run on 87. Putting regular gas in a heads/cam LS1 is about as intelligent as sticking your dick in a pencil sharpener.
Old 08-16-2005, 01:19 AM
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Originally Posted by Damian
Save the money on heads/cam right now and buy yourself a cheap beater that will run on 87. Putting regular gas in a heads/cam LS1 is about as intelligent as sticking your dick in a pencil sharpener.
Are we speaking from your experience? Must have some nerve at some point, hehe.

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Old 08-16-2005, 08:21 PM
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buy a beater thast good on gas and drive the car hear and there . your building the car for more power so why sacrafice power on the table to save a few bucks. if your worried about it , id say just leave it stock. it is possible to build a setup to use 87 but when it comes down to it is it worth the loss in power youll get?
Old 08-16-2005, 08:36 PM
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But if you bought a $3000 beater that got 30 mpg to save .20 per gallon you'd have to go through 15,000 gallons in that car to pay for it (not including tax, title, plates, maintenance, and insurance). 15k gallons at 30 mpg is 450,000 miles!
Old 08-16-2005, 08:43 PM
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but your also talking 10mpg MORE than the camaro would get so dont forget to add that to the math .
fbodys have a little over 15gallon tanks so thats 150 more miles the beater would go with same amount of gas.
Old 08-16-2005, 09:33 PM
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Originally Posted by Lithium
I completely agree with that. I never understood why people care about how many miles a gallon our cars get this much.
Not talking about MPG. We're discussing a possible low octane set up!
Old 08-16-2005, 10:09 PM
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Originally Posted by S1LV3R
Not talking about MPG. We're discussing a possible low octane set up!
But what is the difference between worrying about your gas mileage and wanting to buy regular octane instead of premium?
Old 08-17-2005, 07:09 AM
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Originally Posted by blkZ28spt
But what is the difference between worrying about your gas mileage and wanting to buy regular octane instead of premium?
exactly its all comes down to wanting to save a few bucks
Old 08-17-2005, 07:37 AM
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Some people have little trouble with 87 octane, some do. Common issues are reduced power and odd behavior. Timing is pulled if it starts pinging, resulting in the reduced power. I suppose if you're really pinched it may be worth a try, but proper octane is best in the long run.

The question about buying a beater is one of saving money. If you spend thousands to save (maybe) .20 per gallon it will take you a long, long time to get your money back. Miles saved on your hotrod and increased longevity are positives, but you're still spending lots of dough to save a little.
Old 08-17-2005, 07:53 AM
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Also IIRC running 87 octane will cause you to get considerably worse gas mileage which in turn negates the entire reason for running it in the first place.
Old 08-17-2005, 08:06 AM
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Default 87 Octane

Originally Posted by S1LV3R
With gas prices going through the roof as of late, has anyone considered an 87 octane friendly head and cam setup? I'll be doing heads/cam the first of next year and wanted to get anyones take on this idea. Just wondered if there is good power to be had with low compression and say a set of AFR's?

Larry
You do not have to do anything, There is a low octane table that reduces timing for that purpose, You can get away with using 87 as long as you do not get aggressive and just cruise, I know of some vettes that use 87 with no problems, again don't expect to have any performance because the low octane tables have a lot of timing reduced but just for driving to work and back it is ok...



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