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Tech Talk => Engine Mechanical / Electrical => Topic started by: jimpen on September 06, 2014, 03:21:55 PM

Title: What octane ?
Post by: jimpen on September 06, 2014, 03:21:55 PM
I'm running 13-1 CR with vp110 what are you guys running?
Title: What octane ?
Post by: jyeager on September 06, 2014, 03:52:27 PM
I'm running 13-1 CR with vp110 what are you guys running?
Iam running Sunoco 110. Get it for about 8 bucks a gallon at Parker oil. I am only 10.2 to 1 but running a where from 38 to 40 degrees of timing and nitrous on top.


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Title: Re: What octane ?
Post by: Flusher on September 06, 2014, 04:36:11 PM
Iam running Sunoco 110. Get it for about 8 bucks a gallon at Parker oil. I am only 10.2 to 1 but running a where from 38 to 40 degrees of timing and nitrous on top.

Hey Jake, did you go through any power tuning procedure to arrive at your 38-40 degrees of advance?  Did you see a change in RPM with the increased timing?  Lower E.T.?  Both?

Thanks,

Joe
Title: Re: What octane ?
Post by: Flusher on September 06, 2014, 04:41:50 PM
How did you all arrive at your octane level?  Jim, I am assuming that yours is based on a recommendation by Bostick?

Thanks,

Joe
Title: Re: What octane ?
Post by: capogniracing on September 06, 2014, 04:42:15 PM
8.5-1, 8lbs of boost running AV. Is that safe or should I go to 110??


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Title: Re: What octane ?
Post by: jimpen on September 06, 2014, 04:50:37 PM
Flusher your right and I'm sure Jake has a retarder for the NOS and WOT.  I'm about the same with 10 degrees of retard from 8982 MSD.
Title: Re: What octane ?
Post by: Flusher on September 06, 2014, 04:52:00 PM
8.5-1, 8lbs of boost running AV. Is that safe or should I go to 110??

How do your plugs look?  Any signs of detonation (peppering [aluminum] on ceramic)?
Title: What octane ?
Post by: capogniracing on September 06, 2014, 04:53:49 PM
No look good no shavens, Evenn look a lil rich.


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Title: What octane ?
Post by: capogniracing on September 06, 2014, 04:56:10 PM
I've talk to 4 different people and they said your good, but always helps from an outside source.


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Title: Re: What octane ?
Post by: jimpen on September 06, 2014, 04:57:42 PM
You good till it blows up.  It's only ten grand no worries.

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Title: What octane ?
Post by: capogniracing on September 06, 2014, 04:59:23 PM
Haha ill ask the guy with that white cp running 10.5-1 with 6 lbs on e-85. Lol


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Title: Re: What octane ?
Post by: Marcsrollin on September 06, 2014, 05:00:41 PM
14-1   I run VP C-12 In the Youngblood

87 in the pontoon!!!  Haha
Title: Re: What octane ?
Post by: jimpen on September 06, 2014, 05:02:39 PM
I'm pretty sure he doesn't want to talk about it right now

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Title: Re: What octane ?
Post by: capogniracing on September 06, 2014, 05:05:32 PM
Lol ya looking at the picture I wouldn't  either lol


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Title: What octane ?
Post by: capogniracing on September 06, 2014, 05:07:19 PM
But on serious note Danny - wet reckless is running 7.8-1 on 8lbs on 91 for years, am I a ticking time bomb or ok??


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Title: Re: What octane ?
Post by: jyeager on September 06, 2014, 06:13:04 PM

Hey Jake, did you go through any power tuning procedure to arrive at your 38-40 degrees of advance?  Did you see a change in RPM with the increased timing?  Lower E.T.?  Both?

Thanks,

Joe
We did all the tuning on the dyno at auto marine engineering. It pulls 200 more rpm on the good tune up than the pump gas tune up. For the 11.0 tune up we spray 150 shot and retard 4 degrees. Just make passes and read your plugs. It will tell you if it likes it or not. 👍🚤💨💦💦💦


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Title: Re: What octane ?
Post by: jyeager on September 06, 2014, 06:17:40 PM
The boat used to run 12.30's on motor and now it runs 11.80's with good air.


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Title: Re: What octane ?
Post by: Flusher on September 06, 2014, 06:49:20 PM
I've talk to 4 different people and they said your good, but always helps from an outside source.

You didn’t mention what your timing is.  Also, if you are not seeing specks of aluminum on your spark plug ceramic insulators, you are probably not experiencing detonation.

If you decide to go with the race gas, you could probably run less ignition advance as you do with AvGas because AvGas burns slower and therefore takes longer to build cylinder pressure after ignition.

AvGas is cheaper and will keep your operating expenses lower.

Check this out http://speedtalk.com/forum/viewtopic.php?f=1&t=26433 (http://speedtalk.com/forum/viewtopic.php?f=1&t=26433)

You got to sort through the BS though

Cheers,

Joe
Title: Re: What octane ?
Post by: Flusher on September 06, 2014, 06:53:18 PM
The boat used to run 12.30's on motor and now it runs 11.80's with good air.

Is that primarily in your engine tune or did any of those gains come from setup?

You are making great gains, keep it up   :thumbup:
Title: Re: What octane ?
Post by: jimpen on September 06, 2014, 07:10:47 PM
Jake is the 11.80's on the bottle?  What mph?

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Title: What octane ?
Post by: jyeager on September 06, 2014, 08:28:01 PM
Jake is the 11.80's on the bottle?  What mph?

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That was with messing with hardware and the new all motor tune. 11.809 all motor, right about 94. We spray about 5 to 6 seconds to run 11.00's We went 10.557 at 103 in Oregon with about 9 seconds of the 150. That track is quick water grains were never over 20 air never went over 2500 feet.
 
We have got it down to where each second of nitrous is about  1.5 to 2 tenths or so. Depending on the weather. At firebird, throw everything out the window. Hahaha

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Title: Re: What octane ?
Post by: icecreaman on September 06, 2014, 09:04:37 PM
But on serious note Danny - wet reckless is running 7.8-1 on 8lbs on 91 for years, am I a ticking time bomb or ok??


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There's more to the equation than just static compression and boost.  It really is a math equation, but you need to know what your top end can flow.  Carbs, cam, valve size, intake runners all play into how much octane is required and how much timing you can run to keep you out of detonation.  When I built my motor, I was trying to keep it a pump gas motor.  It's 8-1 static compression, 8lbs of boost and 30* timing.  I had John at C&J do my carbs, he ran the numbers and said I'd be very border line on pump gas.  Add in the heat at the river and I could be out of the safe zone for pump gas.  I run 30% VP110 with 91 pump gas to keep me safe.

I've read a fare amount on AV gas vs race gas and still don't understand much.   I've read guy's who swear by Av gas, and I've read some seemingly very smart guy's who say it's no better than 91 octane because it gets its rating differently, it uses different additives to get the 100 rating.  At the end of the day, it's the btu's the fuel produces, and the burn time that count.  I know I'm probably saying it wrong, but this is another very confusing topic.  That's why I choose to stay with race gas.  It takes the question  out of it for me.  And blending 30% race fuel with 91 pump gas gets the cost right on point with Av gas.
Title: Re: What octane ?
Post by: Flusher on September 06, 2014, 10:20:25 PM
There's more to the equation than just static compression and boost.  It really is a math equation, but you need to know what your top end can flow.  Carbs, cam, valve size, intake runners all play into how much octane is required and how much timing you can run to keep you out of detonation.  When I built my motor, I was trying to keep it a pump gas motor.  It's 8-1 static compression, 8lbs of boost and 30* timing.  I had John at C&J do my carbs, he ran the numbers and said I'd be very border line on pump gas.  Add in the heat at the river and I could be out of the safe zone for pump gas.  I run 30% VP110 with 91 pump gas to keep me safe.

I've read a fare amount on AV gas vs race gas and still don't understand much.   I've read guy's who swear by Av gas, and I've read some seemingly very smart guy's who say it's no better than 91 octane because it gets its rating differently, it uses different additives to get the 100 rating.  At the end of the day, it's the btu's the fuel produces, and the burn time that count.  I know I'm probably saying it wrong, but this is another very confusing topic.  That's why I choose to stay with race gas.  It takes the question  out of it for me.  And blending 30% race fuel with 91 pump gas gets the cost right on point with Av gas.

When you are blending, how do you measure?  Do you use a hydrometer?

Thanks,

Joe
Title: Re: What octane ?
Post by: beerjet on September 06, 2014, 10:29:33 PM
14-1   I run VP C-12 In the Youngblood

87 in the pontoon!!!  Haha
Weak sauce....
O0
Hi Marc!

-beerjet-

Title: Re: What octane ?
Post by: jyeager on September 06, 2014, 10:35:04 PM
Man, every body just switch to E-85 that way you can just poor everclear in the tank. Jk though. I think you are good at 110 bud.


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Title: Re: What octane ?
Post by: Flusher on September 06, 2014, 10:40:04 PM
What octane is that apple pie rated at?

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Title: Re: What octane ?
Post by: icecreaman on September 07, 2014, 08:23:34 AM
When you are blending, how do you measure?  Do you use a hydrometer?

Thanks,

Joe

No hydrometer, nothing that technical.  My tanks are 10 gallons so I break it down to 3 gallons  VP to 7 gallons 91.  I know that's not exactly 30%, but it's close enough for me.  If I'm mixing less than 10 gallons then I just do some quick math and and try to measure my blend. 
 
I'm planning on adding methanol injection so I can quit mixing and just run pump gas.  That seems to be a legit answer to "Do I have enough octane?".
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