Best power modifications for a 1592cc?

[Cmat20]

Hi all,

I'd like my car to make a little more power for getting up hills and keeping with traffic. My car has the 1592cc, with a new DFEV carb and electric choke. Besides the carb, it has no other performance mods. I'm curious if there are any relatively simple mods which will make a noticeable difference on power. Is it worth getting a performance air filter setup? I'm curious if there are options besides building the motor or changing the camshafts that will make a worthwhile difference. The car is super fun, it just really struggles on climbing hills without running high rpm the whole time. I think an extra 10 hp would make the difference.

Thanks for any help! I'm just hoping to learn what my options are.

[18Fiatsandcounting]

It shouldn't struggle on hills, unless you're trying to climb some pretty steep grades in 5th gear. These engines do need to rev, but it sounds like something might be amiss (or you just have an old/tired engine).

Try this: Mentally time how long it takes to accelerate from 40 to 60 mph in 4th gear on a level road. If it's more than 10 seconds, something is wrong.

My experience is that a free-flow air cleaner makes the engine sound better and easier to work around that side of the engine, but it doesn't do much in terms of performance.

-Bryan

[Nut124]

I'm with Bryan here. These engines, particularly the smaller bore ones, need some rpm to make power.

I would try a good tune up and perhaps some diagnostics, compression test perhaps. No use bolting on expensive parts if the engine is worn out.

Check the breather hose, crank case pressure at idle. If you plug it with your finger, does it build up pressure quick? This would be blow by going past the rings.

Ignition timing can affect power. Check timing at 4000rpm and above. Should be about 35 BTDC. Never more than 38-40.

[Cmat20]

It does sound like I may just be used to engines which don’t need much rpm to make power. The car does fine on normal rises in the road, but I was driving a mountain pass this weekend and was wishing for more power. It accelerates well on level ground, but it just feels like it has no torque. That’s probably normal though, which is why I was looking into upgrades. At say 4000rpm it does fine, I wasn’t sure if that’s normal for the powerband of these motors. The car has fresh plugs, a new gas tank and fuel filter, fresh oil, and runs quite well. It makes normal oil pressure as well. Still, with 95k miles I should probably look into testing the compression. Any idea at what mileage an engine rebuild is usually required?

Assuming that my car is working normally, where would you start to add power?

[Nut124]

Generally, most performance mods, cams, header, carbs, add power by shifting power band up, producing more torque and HP at high rpm. These mods often hurt low/mid rpm power.

The only mod that adds low end torque, power is forced induction.

[18Fiatsandcounting]

At say 4000rpm it does fine, I wasn’t sure if that’s normal for the powerband of these motors.

Yep, that's normal. They loved to be reved, and 4000 and above is where they are the happiest. Flog it like a rented mule! (Bryan's favorite saying) Keep in mind that these engines are only 100 cubic inches or so, with early 1960s engine technology, and they can't be compared to your garden variety modern econobox that will likely outperform your spider. But that's not the point.

That being said, higher compression and cams can help you out here, and I'll leave it to the experts to guide you on that. I am not one of those experts.

-Bryan

[SteinOnkel]

Any idea at what mileage an engine rebuild is usually required?

There is a compression minimum.

[Cmat20]

Generally, most performance mods, cams, header, carbs, add power by shifting power band up, producing more torque and HP at high rpm. These mods often hurt low/mid rpm power.

The only mod that adds low end torque, power is forced induction.

That’s very helpful to know, I always assumed that they would shift the whole curve. Sounds like I should just enjoy my spider and focus on restoring it.

Thanks for all the information everyone!