Compression vs/ Octane???

[BigIQ?]

Thanks Garryese, I do know the difference...yes i have stuck pistons and burned holes too...i was just wanting to know if there was a general rule of thumb to go by to start and continue tweaking from there. And yes this is my first seriously mod'd motor....not my first rodeo.
And Yes i do know how to use an egt...

 

[Deano670]

For anyone reading this thread DETONATION typically DOES NOT occur at the crown of the piston it occurs at the outer edge of the piston above the upper ring land. However INCORRECT ignition timing or incorrect spark plugs will eat a hole through the centre of the piston crown.

My two cents

P.S My rule of thumb is anything over 14-14.5 to 1 I start looking for some fuel other than what they sell at the pump

 

[BigIQ?]

Sorry guys...just seems like i'm being thought of as an idiot here....I have talked with the makers of this mod engine with not to much help...so i'm more or less on my own..
I'll try and give what i know bout the motor...
Billet crank
Custom psi 90.88 mm pistons, dry filmed skirts, ceramic tops, blueprinted for this motor with cooling ports for the cylinders.
psi dial-a-dome heads.
AC900 04 carbs
Custom twin fat Jaws pipes, tuned to 2 psi backpressure.
I'm not a motor genius...so dome volumes, swirl characteristics are out of my league. it is running 130lbs on premium, but is capable of much more.
I just rebuilt this motor last summer and have had one ride on it...i set it fat and premixed heavy for breakin...now i'm past that and looking for some more HP.
I do appreciate the info...but i need alittle more schooling when it comes to what you call the makeup of compression.
Cheers.

 

[Ancient Sledder]

I don't want to start a war here, but I'm sure post #7 says there was a piston holed. That is why i commented on the EGT. Sorry.

 

[tanner]

Sorry guys...just seems like i'm being thought of as an idiot here....I have talked with the makers of this mod engine with not to much help...so i'm more or less on my own..
I'll try and give what i know bout the motor...
Billet crank
Custom psi 90.88 mm pistons, dry filmed skirts, ceramic tops, blueprinted for this motor with cooling ports for the cylinders.
psi dial-a-dome heads.
AC900 04 carbs
Custom twin fat Jaws pipes, tuned to 2 psi backpressure.
I'm not a motor genius...so dome volumes, swirl characteristics are out of my league. it is running 130lbs on premium, but is capable of much more.
I just rebuilt this motor last summer and have had one ride on it...i set it fat and premixed heavy for breakin...now i'm past that and looking for some more HP.
I do appreciate the info...but i need alittle more schooling when it comes to what you call the makeup of compression.
Cheers.

BIG IQ to start your sled looks sick!! I like it. You are far from an idiot we all have questions and it seems like these people like to share their Knowledge. A bit of an a$$ kiss from me I guess ?, it is nice to talk to people with answers. The dealers or builders don't seem to give a sh!t after they sell the product. Thanks for thread is made me think of one for my sled!!

 

[Summitric]

YOU CAN START LEANING OUT AND FINE TUNING BY KEEPING A VERY CLOSE EYE ON SPARK PLUGS.... DO YOU HAVE ACCESS TO A BOROSCOPE??? OR GOOD SMALL FLASHLITE AND MAGNIFYING GLASS?? YOU CAN READ SPARK PLUGS FOR SOME OF THE BEST TUNING....

 

[BigIQ?]

Thanks everyone....i got my start point.
Hope to have her pulling stumps by the end of the season.
Cheers.

 

[tommyneddo2186]

nice sled

 

[PullThePin]

That is a goreous sled. I need an iqR mod.