magneto advance curve advice needed please!

[jick]

hi there,

i'm just about to get my Vertex Scintilla OAC mag sent out to be checked over, recharged, and have the advance curve alterered to suit my 2276cc IDA'd fk89 cnc Comp elim. headed,  street and strip weekend car.....

the question i've been asked is do i want it locked out or have advance in it? (6-or12degrees or locked out?)

i'm presuming i need advance in it.... 12degrees?.....am i correct.....i've got no experience with magneto's at all.

can someone explain the deal with the differing advance curve options so i can pretend that i know what i'm taking about. 

cheers...jick.

[Jon]

The advance curve you need out of your magneto is exactly the same as the want out of your 009 or any other distributor. The "right" curve for you depend on how you will use the car and the resistance to knock in your fuel and a whole lot of other small details.
But your not alone in your quest for the right curve for the magneto, I seem to have a similar engine going and I went with the "boring" 009 curve... as it will get the job done. 

[Shubee2 (DSK)]

I had Joe Hunt go threw my Magneto and I have my advance locked out I am Running the Motor on the Street I have High Compression so I Need To Run High Octane Gas Anyway  Runs Great

[jick]

thanks for your help men, much appreciated!

now i'm really confused.

but seriously.... i think you've put me on the right track.

[Lee.C]

Maybe you can help me then dude - I am really confused 

[jick]

Maybe you can help me then dude - I am really confused 

he he.....check out this article i found......helps explain a few things.

http://www.fuelinjectionenterprises.com/magfaq.htm

[Bill Schwimmer]

What is the compression & What type of fuel ?

[jick]

hi there Bill,

the CR is gonna be set at about 11:1, i'll be using the shell optimax unleaded here in the UK which is about 98ron.

thanks dude....jick.

[Bill Schwimmer]

If it was on race gas I would say lock it out. I have run my MSD locked out with my low compression motor & it ran great. However it was hard to start.  With 11:1 & 98 octane gas you might be @ the threshold of detonation @ lower RPM. Try it locked out 1st.  If it pings send it back & get an advance curve put in it. hope this helps    Bill

[axam48ida]

I would not run it locked out on a street car. It will be hard to
start and if you drive it in stop and go traffic-----stop light to stop light with out race gas
in a high compression motor, it will ping!!

[Bill Schwimmer]

Normally I would say that 11:1 w/ pump gas would be a no go . However I think the gas in Europe is a bit better than here in Ca.  11:1  is not that much comp. for an FK89. It will bleed off some of the cylinder pressure @ low RPM. That is the only reason I would try it. As for starting ,you can crank the motor & then hit the mag switch & it might be a bit easier to start rather than cranking it against the ignition like I was doing with my MSD. This is going to be one of those try it & see  situations.

[jick]

thanks guys,

do you think it might be a better idea for me to swap the FK89 for an FK87?  would that take a bit of the guesswork out of it? and have the mag advanced?

[Bill Schwimmer]

Do you have any idea what the car will weigh  & what gear ratios are you going to use ?