five alarm emergency for Lil B

[Blue-S]

The 1971 Fiat 124 Spider with the 1608cc is most Fiat buffs' favorite early (chrome bumper) US-market spider. Nice car! I haven't worked on a 124 Spider for almost 20 years, but I did engine work on all the Spiders that I owned from 1986-1991. I still have a couple of 1800 cylinder heads and some other stuff in the garage!

The auxiliary shaft drives only the oil pump and the fuel pump on the 1608cc engine, because the distributor is up on the exhaust cam tower and is driven from the exhaust cam. You don't really have to time the aux shaft exactly on the 1592, 1608 and 1756cc twincams; only the 1979-1982 2.0L engine in the 2000 Spiders is capable of having interference issues between the fuel pump lobe on the aux shaft and the crankshaft. This is DEFINITELY an interference engine -- pistons can hit valves if the timing is off badly enough. Intake and exhaust valves can hit each other, too.

You COULD try to install the timing belt and carefully turn the engine over by hand, feeling for interference. If I were in your situation, I would rather set the crank & cams to the timing marks, then install the belt. To do this, first verify that all of the pistons are NOT at top dead center. You can do that by pulling all of the spark plugs and dropping a LONG phillips screwdriver or 1/4" drive socket extension (like 12" long) down the #1 spark plug hole. Verify the height of the screwdriver (by eyeball or measurement) then do the same with the screwdriver in the cylinder #2 spark plug hole. Carefully turn the crankshaft slightly to see if the piston is going up or down. You want to have the "higher" piston going down, and the "lower" piston going up. You don't need to move it a lot -- just ensure that none of the piston pairs (cylinders 1 & 4 or cylinders 2 & 3) is close to its highest point of travel.

With all the pistons significantly below deck, you can turn the cams without worrying about crashing a valve into a piston. Use a wrench (not a ratchet) to very carefully turn one of the cams so that the timing hole in the cam sprocket lines up with the pointer that is built into the timing cover mounting bracket. You need to use a wrench while turning the cam so that you can keep the cam's motion under control - it may try to "snap" ahead at certain points of rotation due to the position of the cam lobes. If you feel a hard resistance point, STOP because you have a valve hitting another valve that is being held open by the other cam. You may have to juggle both cams a bit in order to avoid crashing valves into each other while moving toward lining up the timing holes in both cam sprockets with the pointers that are built into the timing cover's upper mounting bracket.

Now that both cams have been lined up (and no valves were bent in the process), carefully turn the crankshaft so that the crank timing sprocket's timing mark is lined up correctly. I can't remember what that mark looks like, but since you have a factory manual you should have a pretty good idea of what to look for. For bonus points, align the aux shaft sprocket more-or-less where they show it on the timing illustration. Next, install and tension the belt. Turn the crankshaft over TWO revolutions by hand, checking for any abnormalities. Your timing marks should line up after two revolutions of the crank. If not, then one of the components was not timed correctly. If the aux shaft timing mark is off a bit, it doesn't matter on the 1608, so don't worry about it. Once you get it running, you should dig out your timing light and verify the ignition timing. I always liked 10 degrees BTDC at idle. It's simple to set, because the distributor has centrifugal advance so there are no vacuum lines to plug. If it still has the points ignition, you should check (and possibly adjust) dwell BEFORE setting ignition timing.

Enjoy!

BTW -- The green Spider shown above could be a 1968 or 1969 US-market car, since those did have the wonderful little round side markers. The Euro market Spiders seemed to keep the round side markers for the majority of their model run. The green car also shows evidence of mounting holes for the US-market front bumper over-riders...which were not on Euro cars.

- Greg

[eightsandaces]

Man you guys %&*ing ROCK! I couldn't get close to this good of information from the fiat blogs. Tomorrow is the day then, many thanks to blueS. Serendipitously, the intake camshaft is almost spot on it's mark, the exhaust cam is only off about a half inch and the crank mark is 1/2 a turn from spec. We are not talking about huge moves so I'm going to use your method with a long screwdriver verify the pistons are all "below deck" then make the turn on the exhaust valves and the halfy turn on the crank and pray to a loving god that everything misses everything else.


IMPORTANT: Once the cams are on target you say to move the crank, is there any chance of a valve strike during this crucial step?

eights, can you move the crank 1/2inch back (gently) and see where your cam markings are?

Originally Posted by eightsandaces

Man you guys %&*ing ROCK! I couldn't get close to this good of information from the fiat blogs. Tomorrow is the day then, many thanks to blueS. Serendipitously, the intake camshaft is almost spot on it's mark, the exhaust cam is only off about a half inch and the crank mark is 1/2 a turn from spec. ?

[eightsandaces]

Originally Posted by Fred Demara

eights, can you move the crank 1/2inch back (gently) and see where your cam markings are?

The upper cam marks are within sight, the intake at about 1:30 and the exhaust at about 4 o'clock, to their respective aim points with the crank pulley notch at the bottom. Since the car was in perfect timing and the auxiliary pump can just be reset to 1, I am strongly thinking of just putting the components on and carefully turning the crank, the timing should not have changed if nothing else has moved and I am confident it has not.

[Blue-S]

Originally Posted by eightsandaces

The upper cam marks are within sight, the intake at about 1:30 and the exhaust at about 4 o'clock, to their respective aim points with the crank pulley notch at the bottom. Since the car was in perfect timing and the auxiliary pump can just be reset to 1, I am strongly thinking of just putting the components on and carefully turning the crank, the timing should not have changed if nothing else has moved and I am confident it has not.

It sounds like you are saying that the camshaft sprocket marks are 90 degrees clockwise from their respective pointers, and the crankshaft timing mark is 180 degrees from its correctly timed position. This assumes that "straight down" on the crank pulley notch is 180 degrees from the timing position - I don't remember. If the components are positioned the way I think they are, then it does appear to be in time. Pistons #2 & 3 should be at TDC right now; I don't remember which of those two cylinders would be firing. If you want to put the belt on the way it is now, it sounds like you can do so. If you want the aux shaft sprocket to be in "correct" time (not that it really matters), just ensure that its timing mark is 90 degrees clockwise from the normal timing position.

If you choose to install the timing belt the way it is now, be sure to remove the spark plugs and verify that #2 & #3 are at TDC, install/tension the belt, then carefully turn it over (clockwise) by hand to verify that the timing marks all line up correctly. After that, you might want to turn it over by hand two more revolutions of the crank to be totally certain that everything is timed correctly. It's not uncommon to find a cam off by one tooth on your first attempt to install the belt.

[eightsandaces]

Blue S, I still need to know this, if I can verify all cylinders below deck and turn the cams perfect to their marks, how do I know the 180 on the crank afterwords doesn't hit something?

I have no reason to believe the timing is off given the precautions of movement already taken. Unless you can tell me the movement of the crank after positioning the upper cams is safe I am going to go with my initial thesis, that the engine is in time or damn close enough that only the smallest of accommodations need to be made. Hopefully it will turn easily and slowly, that's my goal. I'm very concerned and it sucks that my dad who has done this way more than a thousand times can't remember how...

[Blue-S]

If the #2 & 3 pistons are currently at TDC (and I think they are), then you need to turn the crankshaft FIRST. After verifying that cylinders #2 & 3 are at Top Dead Center, turn the crankshaft carefully CLOCKWISE until the crankshaft is about 3 teeth on the timing sprocket BEFORE the timing mark lines up (#1 & 4 TDC). As you do this, the #2 & 3 pistons will be going DOWN and the #1 & 2 pistons will be coming UP. With the pistons below deck, you can turn both cams without worrying that a piston will whack a valve. Next, turn both camshafts counter-clockwise 90 degrees to line up their timing marks with their pointers. If you want to be really slick, put a wrench on each cam bolt and SIMULTANEOUSLY turn both cams back to line up the marks.

[eightsandaces]

Originally Posted by Blue-S

If the #2 & 3 pistons are currently at TDC (and I think they are), then you need to turn the crankshaft FIRST. After verifying that cylinders #2 & 3 are at Top Dead Center, turn the crankshaft carefully CLOCKWISE until the crankshaft is about 3 teeth on the timing sprocket BEFORE the timing mark lines up (#1 & 4 TDC). As you do this, the #2 & 3 pistons will be going DOWN and the #1 & 2 pistons will be coming UP. With the pistons below deck, you can turn both cams without worrying that a piston will whack a valve. Next, turn both camshafts counter-clockwise 90 degrees to line up their timing marks with their pointers. If you want to be really slick, put a wrench on each cam bolt and SIMULTANEOUSLY turn both cams back to line up the marks.

OK Blue, it's going down 11:30 Eastern, I understand exactly what you're saying now. I plan on going very slowly as B suggested anyhow but I understand the sequence now and have a great engine cross section to follow as well which illustrates the piston relationships spot on.

[eightsandaces]

Thanks to everyone who helped, I did it, it runs perfectly, it aligned on the factory marks. By turning the engine carefully I was able to line up everything on the proper timing marks. I placed the pistons below deck adjusted the cams to their marks carefully yielding to pressure and making corrections with both cams. Then once they were lined I carefully turned the crank to it's mark, installed the belt and manually rotated the crank, anyhow thanks to everyone! The tensioner had broken and was being contained by the bolt and flat washer, I caught a potential disaster.


PS Lil B, doesn't this make me a Ferrari mechanic by proxy?

http://en.wikipedia.org/wiki/Ferrari_Lampredi_engine