The Saga Continues...

[vandor]

> I didn't think they were interchangeable but what do I know?

Late 1800 and 2000 crank pulleys are physically interchangeable.

> When I time my engine to the 5btdc mark, the engine runs very well but with some put-putting throught the exhaust;

The higher idle indicates that the timing is advance. When you try to start it, does it turn and then suddenly stop, and the seems like the starter has to force it's way past a point? That is an indication of over-advanced timing. The engine will idle seemingly OK even with 30+ degree of timing advance, but will usually miss a little, like your putt-putt through the exhaust.

>However, if I swing the distributor so the crank pulley mark moves toward the 1:30-2:00 position, the engine starts readily >enough and runs smoothly enough but slower - so that I have to add a little idle screw.

That is not unusual for normal timing, if the timing was too advanced before. Idle drop as timing is retarded.

Please let us know what you find when you check TDC.

[digitech]

Ok, here is what is happening.

I re-verified correct pulley alignments and that when #1 is at the top of its travel, the crank pulley mark is perfectly aligned with the TDC pointer. So, I have a 2L crank pulley. At the same time, both the exhaust and intake pulleys are perfectly aligned with the marks on their respective cam housings - best job I've done yet of installing a timing belt. So that checks out as it should.

Went back through my emails and found the Alquati 40/80 is actually installed on the intake and the stock cam is in the exhaust.

The best compromise between a normal crank/start and decent running is occuring when the ignition timing has the crank pulley mark at the 12:00 position - notice I said best compromise.

So, this is xx degrees ATDC, I don't know how many it would equate to but too far retarded in any case. It would appear to me, in order to have the ignition timing correct AND to have decent running with no back firing through the carb that the intake cam needs to be set to some other position and NOT the factory mark. It would appear the intake valves are open (somewhat) when they should be closed. But, what direction would you rotate the cam to achieve this? And what, a tooth or two?

[digitech]

Just heard back from Jon Logan, on of those aha moments - seems he had already degree'd the cams in and made marks. I must have forgot because I set them to the factory marks. I should be able to get the belt off, cams moved and back together in the morning. At this time, I'm not seeing any other issues so I might finally be "home free"!!! Of course I'll keep you posted.

[majicwrench]

The cams are " degreed" in releationship to the crank. In other words, the engine needs to be assembled, TDC needs to be established accurately, THEN you can degree the cams.
Keith

[vandor]

The cams are " degreed" in releationship to the crank. In other words, the engine needs to be assembled, TDC needs to be established accurately, THEN you can degree the cams.
Keith

True, but you can still mark where the cams need to be once true TDC has been found. That's probably as good as you can do with a mail order head.

[digitech]

And that is what was done. The issue has been resolved, the spider runs!! Jon asked me to re-verify the crank mark and when I did, I found the blob of paint to be obscuring the true "notch", a small but as it turns out, a significant error. I also moved the intake slightly more in order to perfectly match the cast in mark on the cam housing. I reset the distributor for #4, put it back together and she started right up; set the timing for 10btdc, reset idle for 1000rpm and she's running pretty good. As soon as I can get the air out of the cooling system, I'll be taking her around the block.

So far, no oil leaks other than one about the size of a 50cent piece after sitting overnight. I believe it's coming from the tranny and if it doesn't get any worse than that, I can live with it!! As you might recall, I was fighting some wicked cam housing leaks which Jon solved with some machine work and some of Guy Crofts special gaskets.

Another bummer - the starter is giving me some problems, the bendix wants to stick after starting. Of course, I had the starter checked while it was out at an independant starter/alternator repair shop - all good. Soon as I put it in and build the engine back up around it, then I get this !

Thanks everyone for the advice and help.

[tima01864]

Sorry to hash tthis back up, Not sure that I understand the #1 cylinder setting the timing. #4 to time the engine?

[18Fiatsandcounting]

Hope this makes sense: The #1 and #4 cylinders move in tandem, that is, when #1 is all the way at the top (TDC), so is #4. At this point, #2 and #3 are all the way at the bottom (BDC). With a timing light, you can time the engine using the #1 or #4 sparkplug, it's totally your choice. However, and this is the tricky part: With cylinders #1 and #4 at TDC and the marks on both camshafts lined up with their pointers, the engine is actually set to fire cylinder #4 at that point. So, when people reassemble an engine at TDC with the camshafts lined up, they rotate the distributor rotor so that it is next to the cylinder #4 plug wire. It's just how Fiat chose to set things up on these engines.

-Bryan

[tima01864]

Thanks Bryan