Is this true?

[StaticSag]

I was told today that if you run higher than 30% blend nitro that you have to add another brass washer under the glow plug. I couldn't understand this and was wondering whether or not it is true. I have always ran 20%. If this is true can you explain the reasoning behind it for me. Does it have something to do with the extra compression from the higher content fuel?

-Sag

 

[gutterboy]

On some engines you might have to. I have an OS Maxx 15cv that I changed to 30% but didnt have to add one. My friend had to add a shime to his 2.5 because of the 30%

 

[StaticSag]

So what are the signs that I should look for that would indicate I would need to add the washer? I am gonna try the new Megatech NEO 16 ST.....ODonnel's 30%.

-Sag

 

[olds97_lss]

Unless your racing, I wouldn't bother with anything higher than 20%.

It does have to do with the added explosion factor of the 30% fuel. More nitro=more bang. More bang in a small space could cause engine damage and/or poor running.

Anything higher than 20% just isn't worth the damage it may cause to your engine. It kicks up the temps and hammers your engine harder. Unless your running a racing engine, you probably won't notice much of a performance gain anyway.

 

[StaticSag]

I will in fact be racing but the reason for trying 30% is a new lhs....really local...is selling the O'Donnel and to get the trinity 20% I have to drive 60 miles. I will try the 30 and keep a close eye on things and see what happens. That 60 mile trip gets old....lol

-Sag

 

[olds97_lss]

I know the feeling. My closest LHS is 40 miles away, and it's not that great.

 

[scottm]

Adding shims under the head lowers compression and reduces detonation. You can get some of the same benefits by going to a colder plug. Colder plugs delay the start of combustion, similar to reducing ignition timing on a spark engine.