Timing lose

[slydog 7,873]

Is your MSD programable? If you have to buy 1 there $450ish new but TBH its really not a $450 issue IMO.

 

Id just bush the dizzy tighter and set base higher

 

Its not really a big issue just something some haven't seen heard of is all bro.

[judgetread 757]

yeh im going to go find some shims and try again

[Crazy2287 1,886]

Interested in the outcome to this.

[Outback Jack 6,352]

When I set up an msd 6al2 ando76 helped me understand the curve.

If you have the timing locked at motor at just an example... 30 degrees.

The timing curve is actually supposed to pull timing (retard) as the engine raises in rpm.

 

So if you set the motor at 30 degree advance.... and set the start up at 15 degree on ignition that is subtracted from the original 30 and any curve put in is subtracting from that point up to full rpm.

 

If it's a standard dizzy with vac advance the diaphragm should do the same and mechanical does it with weights.

 

You guys probably know this shit but just in case something was overlooked.

 

Sent from my GT-S7583T using Tapatalk

[gerg 10,871]

A light bulb went on for me as soon as I read "ignition box". Having internal electronics, there's a very good chance that there's a delay between input and output.

 

A set delay will mean less at lower rpm but will increase in effect in proportion to rise in rpm.

 

Say you have an engine spinning at 1000 rpm. That's 16.67 times a second, or 6000 deg/s. If your ignition box was delayed by say 0.5 milliseconds, that would mean your timing would retard by 3 degrees. No probs, just bump up the timing to compensate, you're back to where you started. Trouble is, as rpm rises, the angular distance covered during this fixed delay goes up so the timing becomes increasingly retarded.

 

Now at 6000 rpm, your crank is spinning at 100 times a second and 36000 deg/sec. That 0.5 millisecond delay now has your spark firing 18 deg later than when triggered, but because you compensated for your initial timing by 3 deg, it's 15 deg late.

 

Yours is nowhere near as severe of course but it's just an example to demonstrate. Yours dropping 5 deg would have a delay equivalent to 1/3 of my example, or 0.167 ms. Sounds like nothing but makes a big difference to actual timing.

 

I really doubt that it's anything mechanical, as trying to flex any engine component by 5 crank degrees will simply break it (just picture what 5 degrees looks like).

[slydog 7,873]

Happen's on engine's with or with out MSD or computer controlled ignitions to due to wear or gear mesh causing again end float on the dizzy

[ando76 4,354]

And after doing 2 Windsor oil pumps in the last 2 weeks I can tell you that what smithy and sly are saying is 100% correct.

 

Windsor use a 1/4(6mm) hex drive, whereas clevo and crossflow use 8mm hex drive. From what I learnt doing these pumps Smithy is all over it with pump loading up the shaft, ESPECIALLY IF the standard pump is not set up properly and is continually passing oil over the relief. Don't even get me started on what a high volume pump would do on a Windsor.

 

If you want to eliminate the issue 100% you will need a crank trigger. Pure and simple. Or as everyone has said - with the known data you have you could very easily draw up a curve on an MSD programmable ignition that would (redneck) over come the issue. Nothing wrong with a bit of redneck tho.

 

I'd do what Smithy has suggested as a starting point.

[judgetread 757]

yep, ill take the endplay out of it tomorrow and try again crank trigger would be great ...

[gerg 10,871]

Very interesting, never heard of that much variation in timing just in the drive but would like to learn more. Crank trigger for the win!

[ando76 4,354]

That's the problem with the dizzy being connected to the oil pump drive. Load transfer is huge and when you start turning them there is a lot of fluid being pumped. Get way with it in stock but as soon as you turn them timing variance is a given. Hence the crank trigger on THOR.

[judgetread 757]

still fucked took all the endplay out of dizzy still retarding

 

Going tp swap pickups now and try other wise ...............................................

 

Edit : Actually its only like 2 degrees now :S maybe cam gear is funky?

Edit 2: Miss read it, still 5 degree's

[NZXD 2,328]

What sort of cam gear is it?

[judgetread 757]

the dizzy gear is the bronze gear to suit cam, but now im at a complete dead end ...

[slydog 7,873]

PFT 2 degree's...move on bro your crying over spilt milk here. Yes its a shock but it is not doing anything bad to the motor just a shock to the system and I have to say I'm very surprised the dyno operators had not seen this before. I set timing on any engine @ 3000rpm for this very thing.

[judgetread 757]

na its 5 still man made a error reading it

[judgetread 757]

main concern is initial would be 39 and box can only take 10 out at cranking speed and it was kicking back on starter at willowbank when it was warm at 34

[NZXD 2,328]

I'm no expert by any means on cams and cam gears, but I have a billet steel roller in my Windsor and it is recommended that the dizzy have a steel gear due to standard or bronze wearing very quickly causing timing issues.

[slydog 7,873]

Oh no...a bronze gear should be used with a steel roller camshaft. Mine's been in for like 2 years now and has basically zero wear so I'd question who told you that bro. Old wives tale Id suggest...

[NZXD 2,328]

Oh no...a bronze gear should be used with a steel roller camshaft. Mine's been in for like 2 years now and has basically zero wear so I'd question who told you that bro. Old wives tale Id suggest...

 

I was just going off what the after market hyd roller 5.0 efi cam manufacturers state when they recommend bits n pieces that should accompany the cam etc.

[ando76 4,354]

How good of a fit was the cam gear on the crank? Was it nice and tight going on? Was the key way tight?

 

Sounds like it is time for a programmable ignition if all that checks out, or perhaps swap out all the ignition components and see if the problem still exists? Process of elimination.

[judgetread 757]

How good of a fit was the cam gear on the crank? Was it nice and tight going on? Was the key way tight?

 

Sounds like it is time for a programmable ignition if all that checks out, or perhaps swap out all the ignition components and see if the problem still exists? Process of elimination.

 

Yeh it all went together nicely, got hold of another distributor to swap tomorrow and try( Ive done alot to the current one basically replaced every part, take endplay out completely, swap gears to a melonized distributor gear, reset pickup, checked all bearing etc etc) still no go.

 

Ive swapped out ignition box with a msd 6al, though maybe the 2 step was doing some funky shit but didnt make a difference.

 

Ive spoken and seen alot of tuners over the past few days and 1/3 say its the ignition box, 1/3 say dizzy and 1/3 go fucks me maybe cam walk lol

 

I know a new dizzy with mechanical advance will combat the problem, it should advance as it retards but regardless of out come timing covers coming off weekend or early next week for a peace of mind check, maybe wrong thrust plate and cam gear  chewed it out a bit or plate retaining bolts have come loose? either way im going to check it out, doesnt cost much for a timing cover gasket ...

[slydog 7,873]

If the cam is walking you should be able to tell via a wider than normal roller path on the lobes if that is so. May only be small amount so may be hard to tell also.

 

It's deff not the ignition,TBH it can't be.Dizzy if it's set up with very little end float/play it should be fine too as it's still working.I know a guy thats trying to sell his programmable MSD for $380 that you would prob get a touch cheaper that is tuneable via a alp top. Would require a bit of dyno time with a open minded operator to get the curve just right for it.You could load up a couple of curves and pick which you want for each occasion to use.IE-street or race tunes.

 

I don't know if these things suffer from cam walk though and I'd guess it would be something you would check on assembly.I did and found 2 lifter bores are not perfect but still good enough to use so 2 years later I'm not having any issues.I know Holden V8's and Hemi 6's need cam buttons sometimes and so maybe your Windsor needs something like that too ? 

 

On a Hemi 6cyl they can walk so far they wreck the gear which cause pump failure then stuff go bang in a bad way. 

[judgetread 757]

hook me up on the programmable mate Id like to replace the 685 anyways

 

They usually dont have cam walk but  its possible if wrong thrust plates are used, for the price of a gasket the peace of mind in checking it will be worth it

[ando76 4,354]

^^^^^^^^^^ I really like that attitude.

[judgetread 757]

Got this sorted!

 

Turned out to be a electrically issue somewhere, removed all the wiring and ignition setup and replaced it all with a 6al-2 programmable, rewired everything.

 

Timing is rock solid again.

 

Thanks again all for the input!