Yes on some Fiats when TDC is and the cam timing marks are aligned/set No.4 will be on the compression stroke so the rotor has to point to No.4. This has confused quite a few people in the past when they have had to do the timing from scratch.
Technical Crank timing mark
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Technical Crank timing mark
Yes on some Fiats when TDC is and the cam timing marks are aligned/set No.4 will be on the compression stroke so the rotor has to point to No.4. This has confused quite a few people in the past when they have had to do the timing from scratch.
Hi 124BC!Whenever I'm trying to see something clearly, I find it helpful to clean what I'm trying to seee.g.
View attachment 443256
I can see an angled alignment mark (which I've highlighted in red) on the aluminum cover behind the crank cog that seems to me to align with both the crank cog and possibly the auxiliary drive cog? (I'm aware that on the older Fiat T/C engines this auxiliary drive cog had to be set at 34* (approx 4 teeth) clockwise from the vertical position, but I'm not very familiar with the 2 litre engine).
Now as regards ignition timing marks, I reckon that if the bent pointer bracket were to be straightened (preferably in a vise, not on the engine), the 3 points might align with the notch (highlighted in red) on the inner ring of your crank pulley (reverse side shown in your 2nd pic). Maybe try it and see?
I wonder how this pointer bracket became bent - maybe someone bent it out of the way to change a drive belt?
View attachment 443257
If this notch does align with the pointer bracket then the 3 points likely indicate 10*btdc, 5*btdc and TDC (going from left to right), so can be used for ignition timing checks as well as valve timing checks. Be aware that rotating the auxiliary drive cog/belt pulley also rotates the distributor drive shaft thereby changing the ignition timing, so this will have to be checked/reset before trying to start the engine. (might not have been correct originally)
P.S. I also have vague memories that when all the valve timing marks are aligned, the distributor rotor should actually point at no 4 cyl. on the distributor cap, not at no.1 cyl. as is usual. But I could be wrong (wouldn't be the first time).
I heeded all of your advice and am deep cleaning all the parts. I have started an electrolysis bucket and have taken all the gears and pulley off (keeping them organized of course
) I also made sure all the marks lined up with each other and turned. It was not fun having to put the belt on just to undo the whole front end again but I needed to... I turned it one full rotation but head what sounded like a suction cup being pulled off intermittently, which is worrying. Initially I thought it could be some sort of vacuum break in any of the many hoses but I am not confident. I have a a boroscope coming shortly and I am hoping to look at the cylinders. Thats a whole other slew of potential problems that could culminate in rebuilding the heads. Anyways, I ended up stripping down the front so I could access the seals, as I have a leak in one of them. I think I was making a larger deal than it was about the timing marks as I think someone in this thread already said, you can just take a plastic protractor to it and mark those degrees. At this point im just praying the head isn't in need of a rebuild, even though from what I read it is pretty simple. Here is the stripped engine just in the interest of keeping catalogs. Thanks all!
Michael
P.S. the link broken is busted on my end so I am attaching an drive link.
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That's me about the kids plastic protractor . The simple ideas often work.
The other thing I mentioned is I believed it is an "interference " engine , as in valves hit pistons if valve timing wrong, looking at your photo of the front engine I see the valves are inclined in the cylinder head, so I would say almost certainly they would make contact , so be very careful with cambelt timing and gentle turn by hand several revolutions with the spark plugs out to prevent damage.
. The simple ideas often work.The other thing I mentioned is I believed it is an "interference " engine , as in valves hit pistons if valve timing wrong, looking at your photo of the front engine I see the valves are inclined in the cylinder head, so I would say almost certainly they would make contact , so be very careful with cambelt timing and gentle turn by hand several revolutions with the spark plugs out to prevent damage.
For the sake of my understanding, why remove the plugs? Is it vacuum reasons or what?That's me about the kids plastic protractor
The other thing I mentioned is I believed it is an "interference " engine , as in valves hit pistons if valve timing wrong, looking at your photo of the front engine I see the valves are inclined in the cylinder head, so I would say almost certainly they would make contact , so be very careful with cambelt timing and gentle turn by hand several revolutions with the spark plugs out to prevent damage.
It's so you can turn the engine over gently without coming up on compression, so as you turn the engine over assuming valve timing correct there should be no resistance and if valve timing wrong you feel the contact immediately and stop thus preventing damage.
As an example over thirty years ago I went to a foreman of a Rover Dealership that I was a trade customer with to ask for some timing details on a certain engine and he emphasised something I have always done which is the turning by hand, his reason was one of his mechanics had just done a similar engine job and turned the ignition key causing over £2000 worth of damage and that was back then, so they had to put it right!!!
If you get the chance to look at pistons for your engine I suspect they are slightly domed and have "cut outs" to match were the valves open so tolerances will be very small.
From gazing through the spark wells I did not see anything…. Of course this is also my first ever project car so I don’t think I could be any less experienced. I’m replacing seals today so I’ll be sure to take a look for fun lol.It's so you can turn the engine over gently without coming up on compression, so as you turn the engine over assuming valve timing correct there should be no resistance and if valve timing wrong you feel the contact immediately and stop thus preventing damage.
As an example over thirty years ago I went to a foreman of a Rover Dealership that I was a trade customer with to ask for some timing details on a certain engine and he emphasised something I have always done which is the turning by hand, his reason was one of his mechanics had just done a similar engine job and turned the ignition key causing over £2000 worth of damage and that was back then, so they had to put it right!!!
If you get the chance to look at pistons for your engine I suspect they are slightly domed and have "cut outs" to match were the valves open so tolerances will be very small.
Just take lots of photos and don't rush, when it all goes well it can be very rewarding, however when it goes wrong it can be very expensive.
