check your igitionn timing uber accuratly.
Turbo Mini Forums

Ok,

it stands to reason that the larger the diameter of the pulley with the timing marks on the easier/more accurate you can measure the ignition timing.

assuming this, when building my engine I drilled a large hole in the transfer case in an easy to get to position so i could see the tip of about 5 ring gear teeth (you can probably tell where i'm going with this...)

I painted one of the tooth tips white at TDC and using a dead stop worked out exactly where the appropriate mark on the transfer housing needed to be.

as the top of the gear does not get touched by the starter the paint stays in position pretty well, but i would advise puting a mark in with a hacksaw as the paint will eventually disapear.

Sooo, how accurate is this?

by my rough calculations, the whole "width" of the tooth is 1.6 deg, and the "width" of a hacksaw blade sized slit is around 1/4 deg.8-)

I dont think ultimate accuracy really matters, YOU only need to know the numbers, so you can compare to what other people are using etc.

Each engine can react differently, and the timing will end up, at whatever it ends up whilst tuning. The number itself really isnt that important.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

Interesting thought, but a bigger wheel is travelling much faster!

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

If memory serves correct some of the early A series had timing marks on the flywheel already

West

Got A GTM With A Honda In the Back, and huge Nitrous bottle where the passenger seat should be when racing!

very true stevie,

as my front pulley is hidden behind an intercooler i caant use it with a strobe hence this system. much easier to get to. i assume a few other people will be in the same situation hence the thread:)


i wnated to check that what i'm seeing in megatune is reprisentative of acutal timing (or at least not a million miles away). i was able to establish in about 2 minuits that the engine is 1.5 deg more advanced than what megatune is saying.

Wil, is a bigger wheel traveling faster an issue?

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

Doesn't matter how big the wheel is, it can still only have 365 degrees in it's circumfarance...

If something is worth doing, it's worth doing half of.

Check out any early haines manual and you will see that Austin Morris used to put graduated marks on the flywheel on the early cars.

That's why there is a blanked inspection port in the wok casting.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

I always set my timing off the flywheel, if you have no marks on the flywheel then you can use the centre of the bolt holding on the diaphragm

Team www.sheepspeed.com Racing

Even if it is no more accurate, it's a lot easier then getting the strobe onto the bottom pulley with all our pipework in the way.

I can imagine that some of the 16 valvers are even more awkward than Joe's.

In the 13's at last!.. Just

I can just about get a strobe on mine, but it takes a while to do!

I like the idea of using the flywheel, much easier to get at with the strobe.

https://www.facebook.com/pages/Fusion-Fabri..._homepage_panel

www.fusionfabs.co.uk



1/4mile in 13.2sec @ 111 terminal on 15psi

I'll get a pic later, i'tll make sense then.

also i can see my primary gear oil seal so check for leakyness.

Doh!
Not enough coffee in me at that point...

On 18th May, 2009 minimadmotorman said:

On 18th May, 2009 apbellamy said:
Doesn't matter how big the wheel is, it can still only have 365 degrees in it's circumfarance...

360 degrees there are however 365 days in a year. Or 366 in a leap year.

i thought all non verto minis had the marks on the flywheel and had the viewing window? i use the marks on the fan belt pully end, seems much easier than trying to use a mirror to look in the hole