degree key

[madjimmax]

I picked up a brand new billet pro design on fleabay for $45 + $6 shipping. I think they usually cost about $100.

[TIM LUTZ]

Nope. +4 degrees and 93 pump gas are a perfect match. Even more so with a reshaped head. When you start raising compression you need more advansed timing to copensate for the slower burnning hi octaine fuel you need with the higher compression.

[bigborebanshee]

No drawbacks to degree key IMO.The degree key is only as reliable as the mechanic who installs it.The key itself does not keep the flywheel from turning,it only locates the flywheel.If you shear a key,one of 2 things happened. Either you failed to properly torque the flywheel or used never seize on the tapered shaft.Both installation errors.

[dajogejr]

Nope. +4 degrees and 93 pump gas are a perfect match. Even more so with a reshaped head. When you start raising compression you need more advansed timing to copensate for the slower burnning hi octaine fuel you need with the higher compression.

 

I agree...+4 and pump gas is a great mix on a stocker motor.

If you start raising the compression in conjunction with timing...you may start needing more octane.

Compression has more to do with the need for octane than timing does...in smaller doses (timing).

 

Ultimately...compression ratio will dictate the need for octane and think of timing as icing on the cake.

 

In addition to what TL said...higher compression and more timing create more heat, hence the need for higher octane.

 

That being said...a degree key is not a bad idea.

However, I'd spend a few more bucks and get a timing plate. You'll have the ability to advance the timing as you see fit. What if your motor likes 2 degrees...or 9 degrees...?

[sheeowner31]

Nope. +4 degrees and 93 pump gas are a perfect match. Even more so with a reshaped head. When you start raising compression you need more advansed timing to copensate for the slower burnning hi octaine fuel you need with the higher compression.

thanks bro thats the answer iv been waiting for so now im def gonna have it installed

[TIM LUTZ]

I agree...+4 and pump gas is a great mix on a stocker motor.

If you start raising the compression in conjunction with timing...you may start needing more octane.

Compression has more to do with the need for octane than timing does...in smaller doses (timing).

 

Ultimately...compression ratio will dictate the need for octane and think of timing as icing on the cake.

 

In addition to what TL said...higher compression and more timing create more heat, hence the need for higher octane.

 

That being said...a degree key is not a bad idea.

However, I'd spend a few more bucks and get a timing plate. You'll have the ability to advance the timing as you see fit. What if your motor likes 2 degrees...or 9 degrees...?

Actually timing plays a KEY role in any high compression motor 2 stroke or 4.. As we increase compression we need a more stable, slower burning (high octane) fuel to prevent a sudden burning of the air/fuel mixture (detonation) We need to light this slower burning fuel a lot earlier to get the max power out of the motor. The goal is to ignite the fuel before top dead center and have a well established flame front around 10 to 15 degrees after TDC and maximum combustion pressure at 90 degrees of crank rotation where the connecting rod has the most leverage on the crank shaft. The exception to this would be nitro methane or diesel fuel that has a much faster burn rate but does still require proper ignition (or in a diesel,injector) timing.

Edited August 8, 2010 by TIM LUTZ

[sheeowner31]

I agree...+4 and pump gas is a great mix on a stocker motor.

If you start raising the compression in conjunction with timing...you may start needing more octane.

Compression has more to do with the need for octane than timing does...in smaller doses (timing).

 

Ultimately...compression ratio will dictate the need for octane and think of timing as icing on the cake.

 

In addition to what TL said...higher compression and more timing create more heat, hence the need for higher octane.

 

That being said...a degree key is not a bad idea.

However, I'd spend a few more bucks and get a timing plate. You'll have the ability to advance the timing as you see fit. What if your motor likes 2 degrees...or 9 degrees...?

thanks man so im gonna have it installed on +4 since thats the most common setting and see how it goes should be fine id think just dont wanna have to change to 110 cuz idk if i can even get it out here but id rather stay with 93

[dajogejr]

Actually timing plays a KEY role in any high compression motor 2 stroke or 4.. As we increase compression we need a more stable, slower burning (high octane) fuel to prevent a sudden burning of the air/fuel mixture (detonation) We need to light this slower burning fuel a lot earlier to get the max power out of the motor. The goal is to ignite the fuel before top dead center and have a well established flame front around 10 to 15 degrees after TDC and maximum combustion pressure at 90 degrees of crank rotation where the connecting rod has the most leverage on the crank shaft. The exception to this would be nitro methane or diesel fuel that has a much faster burn rate but does still require proper ignition (or in a diesel,injector) timing.

 

I agree.

I think we're saying the same thing, in different ways.

My point was...take a stock motor, bone stock.

You'll need more octane as a result of compression before you would for timing....

 

That's what I meant by icing on the cake for octane and timing.

 

Detonation OR Preignition is a motor killer...2 stroke or 4!

[sheeowner31]

I agree.

I think we're saying the same thing, in different ways.

My point was...take a stock motor, bone stock.

You'll need more octane as a result of compression before you would for timing....

 

That's what I meant by icing on the cake for octane and timing.

 

Detonation OR Preignition is a motor killer...2 stroke or 4!

what do u mean by detonation or preignition is a motor killer??

[SAVAGE420]

what do u mean by detonation or preignition is a motor killer??

 

Just like it says. Deto and preignition will pop your top in no time at all.

[sheeowner31]

Just like it says. Deto and preignition will pop your top in no time at all.

ok but how would 1 of those happen exactly ??

[TIM LUTZ]

ok but how would 1 of those happen exactly ??

Detonation, Crap fuel, Too much timing, Too much compression for a given octane, lean jetting to name a few.

 

Preignition, Carbon buildup (this can also cause detonation due to increased compression) Running too hot a spark plug of when anything in the combustion chamber gets hot enough to pre ignite the fuel before the spark plug.

Edited August 9, 2010 by TIM LUTZ