FRANKENMOTOR - Clack or smoke?

[regcheeseman]

Well I've just put near 300 miles on my golf this weekend and adjusted the timing fractionally four times in the process.

It either runs awful at idle and billows smoke when cold as below (the family sat having their breakfast just downwind were less than happy.


or with a tiny bit more advance I loose the smoke almost completely but the clacking starts.

Half tempted to fit the GTD head back on......

[theman53]

I think I would live with the clack. I think that is too much smoke for cold starts, but that is just my opinion.

[nathan_b]

Too thick head gasket..

Mine did that with a 3notch, now has a 2 notch and is much better. Piston protrusion is that of a 2 notch, but we are out in custom world here.

[rallydiesel]

Is your cold start timing advance adjustment maxed out?

[Powered by Spearco]

I was going to ask that. I've seen the lever misadjusted so many times that all is needed is to unbolt the lever and reposision it on the shaft.

When I put a gauge to my pump after timing it by ear, it read .86mm  . It puffs and pops white smoke for a few seconds, but once throttled up and some heat is generated, it quits.

Also my first attempt at building this engine, I used a 3notch gasket in the hopes to run more boost, it smoked even worse. Now its got a 1notch gasket.

Yeah, mine clacks but not as much with timing set anywhere spec. 1.0mm or higher.

[regcheeseman]

I have no cold advance. When I built the pump I deleted the cold start advance completely as I've never needed it on previous (non- franken) builds.

I'll build another pump, retain the cold advance and then see.

Then I'll look to 2 or 1 notch gaskets....

At the moment I've compromised and got minimal smoke and some clack, set at 1.1mm. But it feels that power is down on the loads of smoke/no clack position.

[Smokey Eddy]

run the correct thickness head gasket and you will be able to set the timing properly for no smoke, no clack, lots of power.
I managed to on my frankenbuild.

[regcheeseman]

It has the correct thickness head gasket - do you mean the incorrect thickness head gasket?

How incorrect should I go, 2 or 1 notch?


Meanwhile back with the pump..... AAZ pumps do not come with cold advance, I had four in my box - none have cold advance. They have a cold fast-idle setting, that's it.

However I had a GTD pump that I had to scrap - that had a cold advance lever. I'll try that.

[nathan_b]

aaz pumps came in mk3s and mk3 aaz cars definitely have a cold start lever in the dash.....

[nathan_b]

what injectors are you running? 1.6 or dual stage aaz?

[regcheeseman]

aaz pumps came in mk3s and mk3 aaz cars definitely have a cold start lever in the dash.....

Yes they do but it doesn't advance the timing it merely lifts the idle setting - at least it does on the five pumps currently in my possession.

Have a look where the cable goes, if it goes to the lever near the lid of the pump it's fast idle, if it goes to the lever tucked down near the bottom of the pump that's advance (and probably also linked to provide a fast idle)

Early pumps may differ as will other markets.

I'm running AAZ injectors.

[nathan_b]

funny, early pumps ONLY advance timing, mid mk2 advance and bump up the idle, mk3 only bump up idle. Interesting progression..

Could be an issue with running dual stage injectors? Mine does great with 1.6 stuff on it, maybe the "extra" fuel injected to reduce clack is not burning or soemthing roughly along those lines.

[Mark(The Miser)UK]

I'd be careful with a one hole gasket, if pistons say 3 hole.  You might be talking 0.25mm gap, which can easily get lost somewhere.
Clearly you problem is unburnt fuel. Probably compression is on the low side due to the AAZ head, so injection is more finicky when cold. An advance lever would clearly work. On the KATE it seems that certain models came without a cold start timing advance, but it seems that Mk3 Passats did and some Golf types.

Can you do a compression check before removing the head?

The GTD pump sounds like a better option,Was it not fixable?
I take it you have pop tested those  injectors. Most plain nozzles pre inject anyhow. GTD's should be 274's AAZ twin springs are 308's but 261's and 265's also used. Some AAZ's weren't twin spring; is that correct?

[regcheeseman]

It is solely a compression/timing issue.

The smoke is gone within 100 yds of driving, then it idles clean. Not a pump or injector problem

The GTD pump sounds like a better option,Was it not fixable?

I sacrificed the GTD pump because I wanted the advance mech for myself and the LDA top for a mate's pump build

Besides I've a spare known good GTD and AAZ pump sat on the shelf. 

The GTD wont fit in the bracket properly unless I make a concentric spacer.

There's no reason that the GTD would be any better though - aside from having an cold advance. (which I'll fit to the AAZ)

I'm going to whack in the 2 hole gasket and the cold advance.

Now the boost pipes are complete, it's going very nicely and needs more fuel - I'm loath to give it any more until I can lessen the smoke at idle and retard the timing to an optimum position - it's in a compromise setting at the moment.

[regcheeseman]

Few tweaks needed after the shakedown.



swapping to a two notch gasket instead of a three.

add a cold start advance mech from a 1.6 pump to the 1.9 pump body

All this to get rid of the smoke at start-up and be able to run more power friendly timing setting.

Found a couple of problems, whilst pulling the head, water pump bolts were very loose, pump bracket bolts loose and the inlet manifold has 3 bolts fitted instead of 6.