Firing Order?

[18Fiatsandcounting]

It revs fine once it gets going past 2,000rpm, but makes no power. Hitting 60mph is like 18 seconds. Seems like it should be 10-12.

Yes, 10 to 12 seconds is about normal for these cars, and 18 seconds means you've got a tired (or mistuned) engine. If it were me, I'd start with pulling the cylinder head off and doing a valve job, but if you want to proceed directly to a full rebuild with performance parts, that's a good winter project as you note.

-Bryan

[Nut124]

Interesting discusssion and nice explanation Bryan.

I do believe the correct firing order is indeed 4-2-1-3. This means that when the engine is at the TDC mark, the rotor under the cap must be pointing to the #4 pickup inside the cap.

When testing compression, watch the gauge and crank until the pressure stops going up but no longer than 5sec.

Is your throttle propped 100% open? Needs to be or the engine will just pull vacuum.

Your compression should be in the 140-180 range. Check cam timing. Retarded intake cam lowers cranking compression quite a bit.

[18Fiatsandcounting]

Check cam timing. Retarded intake cam lowers cranking compression quite a bit.

Good thought, Nut. A mistimed intake cam would definitely hurt performance and the static compression numbers.

-Bryan

[RRoller123]

And definitely make sure that the throttle plate is held completely wide open, I usually put a small piece of wood in there, or put a clamp on the throttle cable with the plate wide open. It makes a HUGE difference in the compression test results.

140-180 seems a bit optimistic to my experience though, on a std engine.

[18Fiatsandcounting]

140-180 seems a bit optimistic to my experience though, on a std engine.

I agree that 180 on a stock engine would be high. My general experience on the standard 8, 8.5, or 8.9 compression ratios:
Below 120: Meh, not so good.
120-140: OK
Above 140: Happiness, unless it's due to excessive carbon buildup. I'm not usually a purveyor of snake oil, but you can run a can of SeaFoam though the engine and do another compression check. That stuff does seem to remove deposits.

-Bryan

[Nut124]

When all cylinders read low like your numbers indicate, then it is either perfectly uniform (unlikely) but massive wear, or an unrelated common cause.

The common causes could be the compression gauge, the throttle plate or retarder intake cam.

There is another Hail Mary possibility: The piston rings could be gunked up and not floating freely in the ring groove as hey are supposed to. There are suggested fixes for this on Youtube. They involve pulling all plugs and pouring a cup or so of Seafoam or similar engine cleaning solvent in the chamber and letting it sit overnite or a few days.

Care must be taken not to damage the engine by cranking it over with a chamber full of fluid. Calls for an oil change afterwards.

I would suggest that adjustable cam pulleys and cam degreeing is necessary to optimize output from these engines when rebuilding. That certainly was the case with my engine. After my previous performance build, I found the intake cam retarded by 10deg using factory pulleys with the timing marks aligned as good as possible.

Finding good pulleys is another topic.

[RRoller123]

I have always gotten between 140 and 150 on my stock engine prior to the 4mm domed pistons. Haven't checked it now, but it should be higher. If I forgot to open the throttle plate fully, I would get like 100-110 at best.

[jon8christine]

Bit the bullet and pulled the engine for a winter project. I've been talking myself into it all year. First question before I disassemble. Since I'm tearing everything apart, new pistons, cams etc, do I need to worry about setting #1 at TDC, marking cam locations etc? Never built a full engine ground up.

[18Fiatsandcounting]

First question before I disassemble. Since I'm tearing everything apart, new pistons, cams etc, do I need to worry about setting #1 at TDC, marking cam locations etc?

No, you don't need to worry about TDC when disassembling, but that being said, I would check that the timing marks for the cam pulleys are all there, before you pull everything apart. There should be a little through-hole (1/8" diameter or so) in the face of each of the two cam pulleys and the auxiliary shaft pulley, about halfway out from the center of the pulley. Or the equivalent on an aftermarket (non-stock) pulley.

You will need those "timing marks" when you get to the final assembly stage, and so it would be a real bummer to find out that they aren't there for some weird reason.

-Bryan

[jon8christine]

Yeah the holes are all there, but I was planning on buying the adjustable aluminum gears and it looks like they have the holes too

[Nut124]

Good luck with your project. Taking pictures is always a good idea.

If you are planning on adjustable cam pulleys, then you might as well start by checking the timing on your current cams. Do you have the indicators, accessories for that?

I have worked on cam timing a lot lately if you were to have questions.