Cam and ignition timing on warm motor FIXED!

carl

carl

True Classic
The 1500 motor I put in the brownx was one I built with a Euro cam and the fire ring shaved from the head for higher compression. I used the 1300 head locating dowels and 1300 belt tensioner as is normal for the head shaving. I'm having a terrible time getting the motor to fire and when it does it sounds and acts very soft.

So my simple question is, when doing the above mods with the standard 1500 cam pulley, you still use the stock timing marks and still set the ignition timing as you would for a stock motor, correct?

In the process it looks like I killed the old starter motor too so I'm not in the best of moods!
 
If it is a long duration cam, it will prefer more static advance. I was told by the supplier to set mine at 20 degrees static with 30 degrees above 3K rpm. That required a recurve on the distributor which was pretty easy but made a big difference. You might get by with an FI Bosch distributor but all the carbed X distributors have way too much centrifugal advance for a long duration cam. If you have a pretty high compression ratio, that will push things the other direction - less static advance needed.

I've been contemplating a shaved head. How much did you take off and what are you expecting for a CR? That seems to be a popular way to gain compression but I have not seen any info as to how much can be removed before running into trouble. Since I no longer need to make the car stock every two years for smog testing, it would be a much more practical thing to do now.
 
This is the factory Fiat cam for European models so I assume no timing games need to be played. I am using a stock FI dizzy. I can't get it to run well enough to even get a timing light on it.

The starter died so this is on hold till I get a new one or have the old one rebuilt.
 
Carl, your engine is not anywhere close to being extreme. Its more like a stock Euro version. You shouldn't have to do anything different than you would with a stock engine with your tune. Set the ignition timing to 10' advanced and check for a total of about 36' advanced at around 3,500 rpm.
Shaving the head doesn't change cam timing enough to make the engine run bad. It simply shifts the powe a bit lower in the curve. You loose a bit higher up, but not that much.
It sounds to me like your cam timing is off by much more than you should expect from simply shaving the head. Like a tooth or so.
Have you ever gone through the process of degreeing a cam? If not this could be your opportunity to learn. You might find it to be a very satisfying process. Start with verifying TDC.
 
carl said:
The 1500 motor I put in the brownx was one I built with a Euro cam and the fire ring shaved from the head for higher compression. I used the 1300 head locating dowels and 1300 belt tensioner as is normal for the head shaving. I'm having a terrible time getting the motor to fire and when it does it sounds and acts very soft.

So my simple question is, when doing the above mods with the standard 1500 cam pulley, you still use the stock timing marks and still set the ignition timing as you would for a stock motor, correct?

In the process it looks like I killed the old starter motor too so I'm not in the best of moods!
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When shaving the head, it is a good idea to shorten the 5 head bolts and the locating dowels the same amount.
 
I did a quick zero miles compression test and got 150/150/130/125 which is oddly low but maybe because the rings have not bedded in? As to cam timing, that's why I'm asking. I assume the same cam pulley is used for the NA and European cams? Maybe I should put the stock cam in just to get it running, although that seems extreme. Just frustrated as I have never had a new motor I built, both spider and Xs, not fire up and run nicely within a few minutes of initial starting.
 
Carl, could your ignition timing possibly be off 180 degrees?
Your description of it's lousy running kinda sounds like it might be.
 
carl said:
I assume the same cam pulley is used for the NA and European cams?
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The location of the cam timing marks differ between early and late engines (1300 vs. 1500?). Early cars had a timing mark on the front engine mount, and cam pulleys to match. Late cars had the marker on the back-side belt cover (at roughly 12 O'clock). If you have an early style pulley and time to the marker on the back-side belt guard (or late style pulley and time to the engine mount mark) your valve timing would be off. I don't know by how much, or if the engine would even run this way.
 
ng_randolph said:
I don't know by how much, or if the engine would even run this way.
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I’ve made that mistake, and indeed that was the first thing I thought of when I read Carl’s original post: cam sprocket intended for use with the other pointer.

If it were off by exactly 180 degrees there wouldn’t be a problem, we’d just set the dizzy to fire #1 instead of #4 when everything is lined up - but it’s not 180 degrees. It will run if you set the dizzy to fire #1, but it will run like crap.
 
Fair enough on using the wrong sprocket, but how do I ID a 1300 from a 1500 sprocket? Guess I should post a pic.

Ugh, obviously I need to look at the locating dowl hole in comparison to the timing mark. I have a verified 1500 cam sprocket, I'll compare it to what I have on the motor now.....tomorrow.
 
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I had a similar issue recently and it turned out that the static timing mark was not good enough to get the engine running right. I was able to get it started but it ran like trash. I finally put the timing light on it and saw the distributor was about 50 to 60 degrees advanced at around 1400rpm, despite the static timing looking right on. When I reset the time to 15 digress it ran great.
 
I wish I could get mine running to the point I could throw a timing light on it.
Ordered a new starter, verified I have a 1500 cam gear, checked the valve clearances (all OK) and set the timing at 10 degrees. Even checked that the carb has no plugged jets. Soon as the starter shows up I will go at it again.

Nice thing about gasoline is you can use it to have your motor run or set your car on fire out of frustration.
 
Again Carl, my logic was following yours exactly. The starter seemed very weak and would suddenly stall out then turn very slowly. I was sure it was a bad starter or ground wiring. Fortunately before I did this I addressed the starting issue. It now no longer happens. Try advancing the distributer by 30 degrees and see if you can start it. Might be another issues but give it a shot.
 
Hey, I'm not adverse to trying anything. Just waiting for my new starter. The old one wouldn't even pass the bench test.
 
Carl, if you don't trust the marks on the pulley, why not remove the valve cover and look at the valves?
Maybe set the mark on the pointer and see if the valves are both closed on cylinder 1 or 4?
 
It's not that I inherently don't trust any particular aspect, it's just the car either doesn't run or runs terribly so I don't know where to start. I'll pull the valve cover and take a look.

Not sure why the cold, no miles on the motor compression readings were so low with a shaved head. Never had a motor I built fail to start up and run fine. Maybe I should clean off the motor that came in the car and started and idled just fine!
 
OK kids quiz time!

Which of these ignition wire orientations at the dizzy cap is correct? Go by the rotation orientation, not just which spigot they come out of.

IMG_3344.jpg


I have two Xs with 1500 motors and the same ignition system. One has the wires in the top and the other has them in the lower photo. One motor runs like mad and the other....err....hardly runs at all.
 
What pisses me off is I got lazy when I saw the wire locations stamped on the cap spigots and just plugged in the wires as indicated. This cap, which is new, is apparently for motors that turn in the opposite direction! No everyone has a spare X to compare to.

My new starter showed up yesterday afternoon so hopefully once I install it the car should be running by days end.
 
It was the damn dizzy cap. Rerouted the plug wires as per the fatrat and she fired right up. Apparently the plug wire numbers embossed on the cap were backwards (meant for a motor that spins the dizzy in the opposite direction). If I hadn't had my other X to compare I'd still be trying to figure this out.
 
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