11:1 piston and deck the head or just 12:1 and leave the head alone? i wanna stay pump gas
Quote from: ThisGuyAlex on June 13, 2008, 10:02:57 AM
11:1 piston and deck the head or just 12:1 and leave the head alone? i wanna stay pump gas
At your altitude, I'd run 11:1 for pump gas. Your deck height will determine your final compression.
Aaron
i know this....but i was wantin to push it as close to 12:1 as i could get away with on pump gas there's a whole formula for calculating using combustion chamber volume, head gasket thickness, deck height, and piston dome size
Whats your elevation?
i dunno illinois flatlands
Haha where I used to live!! Oh wait....IL is just a flatland lol nah not really but central IL is!
I would say you could probably run a 12:1 with 93 and be just fine. I ride at 5k or above and run 87 with an 11:1
I guess ask guys where you live what compression they are running and what octane. I was just told a lot of us run a higher octane than we really need and we are actually loosing power because of it.
Quote from: Sandeater on June 14, 2008, 10:19:37 AM
Haha where I used to live!! Oh wait....IL is just a flatland lol nah not really but central IL is!
I would say you could probably run a 12:1 with 93 and be just fine. I ride at 5k or above and run 87 with an 11:1
I guess ask guys where you live what compression they are running and what octane. I was just told a lot of us run a higher octane than we really need and we are actually loosing power because of it.
I have a friend that rides a banshee that won't shutup about 100 avgas. He mixes his 50/50 with 100 and 91 before oil mixing. I always turn him down. I did finally get to explain the whole compression thing to him, that raptors are built lower for longevity. The extra octane is a waste of money unless you are 12:1 piston or better.
Octane requirement is a direct reflection of compression, altitude, and cam profile. The higher you are in elevation, the bigger the cam profile, the higher you can go on compression and still run a lower octane fuel.
Quote from: Peels660 on June 14, 2008, 03:28:04 PM
Quote from: Sandeater on June 14, 2008, 10:19:37 AM
Haha where I used to live!! Oh wait....IL is just a flatland lol nah not really but central IL is!
I would say you could probably run a 12:1 with 93 and be just fine. I ride at 5k or above and run 87 with an 11:1
I guess ask guys where you live what compression they are running and what octane. I was just told a lot of us run a higher octane than we really need and we are actually loosing power because of it.
I have a friend that rides a banshee that won't shutup about 100 avgas. He mixes his 50/50 with 100 and 91 before oil mixing. I always turn him down. I did finally get to explain the whole compression thing to him, that raptors are built lower for longevity. The extra octane is a waste of money unless you are 12:1 piston or better.
did he have some warriors before hand?
what does the warrior thing have to do with it?
Quote from: ThisGuyAlex on June 17, 2008, 03:27:30 PM
what does the warrior thing have to do with it?
umm, yeah, warriors? ???
the higher octane than you need does in fact cause power loss.....higher octane fuel is harder to burn.....so you don't get a complete burn = loss of power....
Quote from: ThisGuyAlex on June 18, 2008, 08:45:15 AM
the higher octane than you need does in fact cause power loss.....higher octane fuel is harder to burn.....so you don't get a complete burn = loss of power....
unless you have more compression, ie more pressurized air to help with the burn. :clap: That is the easiest to understand explanation for that I've seen so far, Alex.
i know...it's pretty simple if you take out the 14 syllable big words huh.....
So since I live at 1000ASL I can get away with running 11:1 with Stage 2 hotcam and still use 87?
I was thinking I would have to run 91..... But with the good cooling of the rappy and alum head I guess it can get rid of heat pretty easy....
I am the same way I wanna go to the point where I can still run 87. For now.
throw me a bone....
11:1 on 87 octane at 1000ASL?? ???
guys doing 87 @ 5000ASL so does that mean with me at 1000 that I need more octane? Think I am a bit confused I have now been told both ways.
Quote from: racinjason68 on August 17, 2008, 09:56:55 PM
throw me a bone....
11:1 on 87 octane at 1000ASL?? ???
guys doing 87 @ 5000ASL so does that mean with me at 1000 that I need more octane? Think I am a bit confused I have now been told both ways.
Yes, lower altitude will require higher octane. I'd run 91 with 11:1 at 1000ASL.
awesome... well damn didnt really want to run 91 but.... P&P and HC stage 2 cam with 11:1 guess I will have to do 91.
was told to go with stage 3 as there is not much bottom difference but alot on top.