1st Spider - trying to make sure the engine is what I was told it is

[Modessitt]

Bought a 77 Spider project. A lot of it was disassembled by the previous owner and came to me in pieces. The previous owner bought a "working" engine (I've seen video of it running) from someone else and dropped it in, but the person kept the distributor cap and carburetor. Considering everything I have to put back together, I'm trying to verify everything is what it says it is before I get too far.

One of those is the engine itself. Based on the year (and what the seller told me), it should be the 1800 engine but looking at the block I see a stamp of 131AB.40/7 and 4281917 which isn't on the engine lists I can find online. A search finds a couple threads here mentioning it but no confirmations. One listing online showed someone selling a block with the same stamp and advertising it as a 2000 block.

To confuse things further, the head on it is stamped with 4371507 which I've found online sellers listing as a 2.0 head. But I don't know enough to know if a 2.0 head can be used with a 1.8 block.

So what am I dealing with? I can post some pics if necessary. This is my first Spider. All of my Fiat experience has been with the X1/9.

Thanks for any help.

[18Fiatsandcounting]

but looking at the block I see a stamp of 131AB.40/7 and 4281917

Are these the numbers stamped onto the flat surface next to the oil filter, or the numbers stamped on the side of the block? The latter are usually not much help, and the definitive number is the one next to the oil filter.

Without taking the engine apart, one way to tell an 1800 from a 2L is that the 1800 has a 146 tooth timing belt, and the 2L has 148 teeth on its belt. Requires taking off the timing belt and counting teeth, but you're going to want to replace that belt anyway.

To confuse things further, the head on it is stamped with 4371507.

I've seen this listed as being for both 1800 and 2L. And yes, my understanding is that an 1800 and 2L head are interchangeable, although any emissions stuff might be different. (EGR ports, air injection, etc.)

The easiest way to tell whether you have an 1800 or 2L engine might be to pull a sparkplug, stick a long wooden dowel in the hole so that it contacts the piston, and then rotate the engine by hand and measure the stroke. Both have an 84mm bore, but the 1800 has a 79.2mm stroke while the 2L has a 90mm stroke. You should be able to measure that 10mm difference and thus tell the two apart.

-Bryan

[Modessitt]

Thanks for the response.

That was the number stamped on the block directly under the intake manifold.

I'll look again and see if I can find the spot you're talking about.

[18Fiatsandcounting]

That was the number stamped on the block directly under the intake manifold.

I'll look again and see if I can find the spot you're talking about.

In that case, the number you listed is the casting number, not the part number. This is a continuous source of confusion as two parts with the same casting number can end up very differently depending on how they are machined, additional passageways drilled, more metal machined off in certain areas, etc. In theory, a new block with a particular casting number could be machined by the factory into either an 1800 or 2L block.

What you need to find is the 1" square flat machined surface with two sets of numbers stamped (not cast) into it. That's the block part number and serial number. On early blocks, this is part of the flange where the oil filter housing attaches to the block, and on later blocks it's a separate flat surface just in front of the driver's side engine mount.

-Bryan

[18Fiatsandcounting]

In theory, a new block with a particular casting number could be machined by the factory into either an 1800 or 2L block.

Ooops, a brain-dead goof above on my part: The 2L block is about 10mm taller than the 1800 and extra machining isn't going to turn one into the other. So they would be different casting numbers. The point is simply that casting numbers can occasionally be a good indicator of the final part, but very often that's not the case. Especially with blocks and heads.

-Bryan

[Modessitt]

Thanks. When I was looking for the smooth part previously, the one I THOUGHT was the right spot was blank. I've since found the proper spot and it says 132A1 040.6 which my searching tells me is the 1800 engine from the later (77-78) 1.8 models, so it appears I have the proper engine for my car.

Now comes the fun stuff of trying to figure out what all is missing (not installed vs not present) considering I don't have a complete engine to start from and I've never dealt with the 124 before. Happen to know of a parts manual listing for these things? I have a box of assorted bolts and it would be better to not guess when trying to figure out which go to a brake caliper vs an engine mount etc. Might be better to just order a bunch of new bolts and not worry about it.

I'm also on the lookout for very good pics of a teardown and rebuild of the 1.8 so I can visually verify where things are supposed to be (vacuum lines, essential parts, etc). The service manual I have has pics but some are too zoomed in to verify everything.

[18Fiatsandcounting]

I think the first question is, "Do you have a California car or not?" In 1977, this would make a difference. The tag in the driver's side door jamb should say something to the effect of, "This car conforms to the California emission requirements" or maybe it doesn't say that. Either way, useful info.

If you can, post some pictures of your engine from all angles, and there are people here who could tell you, "Hey that doesn't look right for 1977" or "Looks totally normal for 1977 to me."

-Bryan

[Modessitt]

Thanks. Yeah, I'll get pics up soon in a new thread detailing the entire car. The tag might no be relevant since the engine isn't original to the car but perhaps there are some other things like exhaust etc which may be there for a CA model.

I'm going to have to pull the engine or transmission (or both) since the guy I got it from just dropped them in so he could get a title (they supposedly wouldn't offer a title replacement for a car with no engine). I'm not sure if there is a flywheel in there and he can't remember. I've got a lot of stuff to research and verify. I've got a Weber carb (not installed) but not sure which one yet. Missing the distributor cap and wires. All the brakes, calipers, brackets etc were removed and in a box. The dash gauges are all out but I've got two sets. Just a major project but I'm up for it.