Ignition Timing Advanve make Big difference? Upgraded Camshaft.

[xBrent92]

Question #1
If one bought an upgraded camshaft that gives good power at 24degrees ignition timing would they get even MORE power by advancing the timing 6degrees to the cam recommendation of 32degrees ?
It gives real good power is it stands. But more torque/power is always appreciated if the clutch or torque converter can support it.

Related Question #2: What if a person leaves the timing at 24degrees and runs 30% nitro / 62%methanol mix ? 8% oil Or should the timing be advanced there as well?

 

[FirePowerMinis]

A1: Lazy low compression chamber, added to even lower dynamic compression via excessive overlap, should really like more advance.

A2: Learn basic internal combustion engine theory before attempting exotic fuels, etc

 

[A.J.]

A1: Lazy low compression chamber, added to even lower dynamic compression via excessive overlap, should really like more advance.

A2: Learn basic internal combustion engine theory before attempting exotic fuels, etc

I agree. You can get more performance from running regular fuel with proper timing than you can by just running a fuel mixture. In fact, without proper compression, a "race" fuel can actually reduce performance.

 

[massacre]

+1

Jetting and tuning for methanol is completely different than gasoline

 

[xBrent92]

+1 Jetting and tuning for methanol is completely different than gasoline

I've already got that taken care of. Four ounces in the gas tank made a difference even though its only 30% nitro. Maybe the 62% methanol made the main difference.
I was just wondering about timing in case there is a risk of pre-detonation from the lack of timing and detonation. It runs fine so far with no pinging I just wanted to add a few more ounces to the mix.
I guess if i always keep the carb clean for the fuel flow so i don't run lean i will be alright.
Maybe i should remind that my camshaft has 104LSA 246 duration. .290 lift if that matters in this situation.

A1: Lazy low compression chamber, added to even lower dynamic compression via excessive overlap, should really like more advance.

I already knew the benefits of LSA but i had to study overlap.
So less LSA=more overlap. That being said, with a timing advance, i should see a power increase.
"...the 107 LSA cam was better at low rpm and the 113 LSA cam was worse at low rpm. This motor liked the overlap."

 

[minibikin']

I agree. You can get more performance from running regular fuel with proper timing than you can by just running a fuel mixture. In fact, without proper compression, a "race" fuel can actually reduce performance.

I've said this soooo many times here. Efficient combustion is key. Adding higher octane to an 8:1 motor is like pouring Don Perrignon down the drain.


Sent from my Texas Instruments Speak and Spell...[emoji2]

 

[xBrent92]

I've said this soooo many times here. Efficient combustion is key. Adding higher octane to an 8:1 motor is like pouring Don Perrignon down the drain.


Sent from my Texas Instruments Speak and Spell...[emoji2]

Sorry to make you repeat yourself. Now you have a specific thread for it

(i did spell "advance" correctly in the thread tag...i think)

 

[Bumblebee2]

It would seem to me..(oh god) that an old flathead Briggs, Tecumseh or Clinton would not respond too well to trying to increase output. What do these things run anyways, 6.5:1 compression ratio, side valves, and awful geometry, Mmm, no. The contemporary OHV engines would be a much better bet, and an engine like the Hemi Predator, I'll bet I could get that thing to really put out the power if it didn't vibrate it self to pieces trying. (Running screamingly fast!)

There is an entire science to optimizing the engine design to optimize performance, so doing a little reading on internal combustion design, camshaft profiles and combustion chamber design would be a prerequisite to fun enhancement.

Gotta get me one of those Hemi predator engines to experiment with.

- Bee

 

[FirePowerMinis]

"made a difference", based on what comparison method?

It's possible that you were running rich, and the alcohol leaned it out enough to feel stronger.
You're messing with tuning variables well beyond your understanding.

Looking closer at the LSA quote you referenced, a couple things stand out.
You don't have a high compression 406 SBC
The percentage difference between "best" and "worst" was WAY under what an uncalibrated SOTP dyno would pick up with the decimal moved 2 places to the left.
http://image.superchevy.com/f/18049..._z+dual_plane+torque_and_power_dyno_sheet.jpg

 

[xBrent92]

"made a difference", based on what comparison method?

It's possible that you were running rich, and the alcohol leaned it out enough to feel stronger.
You're messing with tuning variables well beyond your understanding.

That is exactly what i intended. i drilled the main jet to 1/16 ( .0625 ) just so i could mess with racing fuel. I haven't played too much with it yet to find the balance. Should be able to mix more than 5 or 10 ounces with the gas to even things out. Will just need to have the fuel valve open only half way if i just want to cruise around. All the way open would be if i'm planning to stay at least half throttle.

And the way i could tell how it made a difference was listening for how quick the motor reached max RPM.

 

[xBrent92]

Okay..over the past few days i've been experimenting with race gas fuel. i can say it is very difficult to tune the fuel mixture (gas and race fuel mix) especially if you only have a stock jet and oversized jet .

So i just said "forget it" Its too much of a hassle" and advanced the timing by 6degrees, put in fresh gas, and tested it. I would say it gave the same result as the race gas when it worked.

Conclusion: Race gas is only meant for very high compression engines that NEED the extra ignitability. Either that or a couple splashes in the gas will be fine IF your jet is already a bit on the rich side.

Efficient combustion is key. Adding higher octane to an 8:1 motor is like pouring Don Perrignon down the drain.

 

[Bumblebee2]

Race gas in a minibike engine is like putting lipstick on a pig.

If you advance the timing a few degrees may get a little more power, you also run the risk of pre-ignition, engine damage and less power. Retarding the spark will help prevent pre-ignition but will provide less power. In all my dealings with motorcycles I've learned that putting the spark spot on is the best way to go, also check the advance to make certain the spark properly advances when it should.

 

[pomfish]

You guys are forgetting the Number 1 thing in performance...................Stickers.
That's right, Stickers make an engine perform better. And Chrome and my favorite Neon Tube lights.
All these items can add 40-50 or more Horsepower just by adding them and then bragging about them.
10 Million punk kids can't be wrong.

If you aren't using NOS, Nike, Red Bull, Corona, ESPN X-Games stickers well then.........................you just SUCK!

Sarcasm is full on in this post.

 

[xBrent92]

You guys are forgetting the Number 1 thing in performance...................Stickers.


Sarcasm is full on in this post.

an Isky sticker gave me, what.. about 6 horsepower plus some torque? i'll take that one.
a Comet sticker would give me at least 10ft lbs of torque.

There's a difference between a tuner and a ricer. A person should be able to tell the difference.

 

[massacre]

I use straight methanol and it makes great power. Guess my pig needs a makeover lol

 

[Twid]

I use straight methanol and it makes great power. Guess my pig needs a makeover lol

Mmmmm Methanol. I think my pig needs a makeover as well.