What is considered a "reasonable" redline for a 1500?

[dllubin]

Better to fix the drains properly if that location is used for EI. That is a proven rust spot in the exxe due to clogged drains.
Best location for any EI unit is in the spare tire well.

Bernice

In a 74, I'd have to go out of my way to use that ridiculous location - not sure what Fiat was thinking. I helped a neighbor get his 87 X running a couple of weeks ago. The drain was clogged and the box was submerged. Fortunately, it still worked.

I would be careful about putting power electronics in the spare tire compartment unless you provide some ventilation. I normally have the cover closed so about the only airflow in there would be from what is leaking in from the fuel tank side through the partition. I put a CD unit there in the 70s and it got fried. I tried another one (Delta Mark 10B) there and it would occasionally overheat and stop working. I moved it to where the carb fan was originally mounted and it seemed to stay plenty cool there.

 

[Rupunzell]

Delta Mark _ is very old automotive electronics technology. None of that after market and some OEM electronics from that era were reliable or as durable-heat tolerant as current automotive electronics of today. There are automotive grade electronic components made today that are specific to under the hood operating temperatures used by every OEM manufacture today .... and these e-bits MUST be reliable as they are produced in the millions to be subjected to under the hood conditions and often directly mounted to the engine.

As for installing the EI unit in the spare tire well, been doing that with MSDs since the early 1980's when they first appeared on the market, none have failed.. ever. The MSD-SCI has been in the 74's spare tire well about a month after it arrived. It has been absolutely problem free.

Essentially, modern-current automotive electronics are heat tolerant and are FAR more reliable than what was offered decades ago.

BTW, the GM electronic ignition unit used in the marelli EI unit was made by Fairchild Semiconductor introduced in the mid-late 1970's. It is essentially a points replacement system, it does not produce significantly more spark energy compared to more modern electronic ignition systems.

Bernice

 

[Steve Hoelscher]

I have built quite a few of each engine. Yes, 1300s love to rev and even a stock bottom end is only limited by the ability to breath and the valve train components. I regularly turned stock bottom end 1300s I had built to 8000+ rpm. No real knowledge of how far because it was off the tach. As long as the engine pulled I stayed in it.

1500s are a little different. Their less oversquare architecture means the natural power peak is at lower rpm (a higher ratio of valve area to stroke). The bottom end will turn about the same rpm without trouble but there is less need to turn it that far because its likely well past its peak.

Most of the 1500s I built for street/track use (OE type crank/rods/pistons) would pull very happily to 7500 and beyond but there wasn't much use going much past 7500. They will make good power to well past 8000 but it requires more extensive head work and the associated intake/exhaust/compression mods to support it.

 

[dllubin]

Delta Mark _ is very old automotive electronics technology. None of that after market and some OEM electronics from that era were reliable or as durable-heat tolerant as current automotive electronics of today. There are automotive grade electronic components made today that are specific to under the hood operating temperatures used by every OEM manufacture today .... and these e-bits MUST be reliable as they are produced in the millions to be subjected to under the hood conditions and often directly mounted to the engine.

As for installing the EI unit in the spare tire well, been doing that with MSDs since the early 1980's when they first appeared on the market, none have failed.. ever. The MSD-SCI has been in the 74's spare tire well about a month after it arrived. It has been absolutely problem free.

Essentially, modern-current automotive electronics are heat tolerant and are FAR more reliable than what was offered decades ago.

BTW, the GM electronic ignition unit used in the marelli EI unit was made by Fairchild Semiconductor introduced in the mid-late 1970's. It is essentially a points replacement system, it does not produce significantly more spark energy compared to more modern electronic ignition systems.

Bernice

The MSD units are certainly better constructed and better heat sinked than the Delta units were, and the components used are much more reliable today. However, the laws of physics have not changed so keeping electronics cool is still important. Many of the common failure modes have activation energies that result in roughly a doubling of failure rate for every 10C increase in temperature. That being said, the result still may be perfectly acceptable for the application. I checked the specs on a couple of MSD units as far as power consumption. They are roughly an amp per 1,000 rpm for what I assume is a V8. So for an X with an average engine speed of 4K, and a voltage of 14 volts, that would be 28 watts. That is a fair amount of heat in that small an area if there is no air flow. The MSD installation instructions also recommend against installing in an enclosed area.

As far as the GM module goes, I would not expect significantly better performance than the stock points ignition. It is still a Kettering system and a transistor is basically just replacing the points. I suppose at high rpm, it may be better due to the magnetic reluctor setup having a higher bandwidth than the mechanical points. My reason for the change is more driven by maintenance requirements and reliability, and since I need to recurve a distributor, I may as well do the Bosch rather than the Ducelier.

 

[Eastep]

Interesting replies and driving styles being posted. I don't have much to add other then I'm running a 1500 5pd and I shift my car when it's goes waaaaaaaa!!!! The rpm which this occurs is unknown, since my car Ides at 0 rpm indicated on the tach. I do run between 5500 and 6200 rpm indicated, while on the PA Turnpike..... and 222.. and 81... .. and on 30.. basically any road that doesn't have traffic lights, I tend to wind out the car

 

[Rupunzell]

OK fine, "laws of physics" does not dictate a failure rate of doubling every 10 degrees C, it is FAR more complex than that. This is from the voice of one who did failure analysis of parts decades ago.. That is a very gross generalization of electronic components as a whole.

That said, 28 watts is just not that much power in the spare tire well.

At this point, I'm not going to comment any further on this based in this reply as any further comments will not be productive in any way.


Bernice

The MSD units are certainly better constructed and better heat sinked than the Delta units were, and the components used are much more reliable today. However, the laws of physics have not changed so keeping electronics cool is still important. Many of the common failure modes have activation energies that result in roughly a doubling of failure rate for every 10C increase in temperature. That being said, the result still may be perfectly acceptable for the application. I checked the specs on a couple of MSD units as far as power consumption. They are roughly an amp per 1,000 rpm for what I assume is a V8. So for an X with an average engine speed of 4K, and a voltage of 14 volts, that would be 28 watts. That is a fair amount of heat in that small an area if there is no air flow. The MSD installation instructions also recommend against installing in an enclosed area.

As far as the GM module goes, I would not expect significantly better performance than the stock points ignition. It is still a Kettering system and a transistor is basically just replacing the points. I suppose at high rpm, it may be better due to the magnetic reluctor setup having a higher bandwidth than the mechanical points. My reason for the change is more driven by maintenance requirements and reliability, and since I need to recurve a distributor, I may as well do the Bosch rather than the Ducelier.

 

[carl]

Fresh air needs for these things are beyond me but wouldn't you be comparing the stagnant but cooler air of the spare tire well to the very hot environment of the engine bay? I guess that's why Fiat stuck the black box in the leaf plugged compartment but there are louvers that bring in hot air from the engine side. Sounds like six of one and half dozen of another. I have converted several Xs to the 124 style "black box" and mounted them on the engine side of that little louvered wall with no problem...but then Fiat had them mounted very close to the exhaust manifold on some spiders.

 

[dllubin]

Fresh air needs for these things are beyond me but wouldn't you be comparing the stagnant but cooler air of the spare tire well to the very hot environment of the engine bay? I guess that's why Fiat stuck the black box in the leaf plugged compartment but there are louvers that bring in hot air from the engine side. Sounds like six of one and half dozen of another. I have converted several Xs to the 124 style "black box" and mounted them on the engine side of that little louvered wall with no problem...but then Fiat had them mounted very close to the exhaust manifold on some spiders.

I don't see a problem with the engine side of the louvered wall. My concern was putting it on the outside where water can fill up the cavity if the drain tube is clogged. I would probably put mine on the carb fan bracket on the driver side firewall. There is also a big hole from the carb fan intake so there should be good air flow.

The issue with the spare tire well, or at least my spare tire well, is that it is very well insulated so that any heat generated in there has trouble getting out. The rear and sides have thick padding, and the front has the plastic covered door. It reminds me a bit of this toy oven my daughter had when she was young. It was heated by only a 25 watt light bulb but it got hot enough in there to bake. I suppose if the factory padding was removed as well as the gas tank partition, you could probably improve the situation quite a bit.

 

[Black-Tooth]

Don...

I see you are relatively new here... I'm relatively OLD here in so many respects... and admit I've been negligent lately in keeping up on this forum.

What I see written here seems to be all good advice and I don't have too much more to offer, but here goes.

1. How 'bout a G'Meter? I think that might be the most accurate way of determining a shift point when (or before) acceleration starts to drop off. Usually gear-heads are born with them in their bum... but the meter up front is easier to read and possibly more accurate.

2. Of all the advice given, which is good... I recall Ulix for the past decade and a half has been racing his car on European road circuits, and Bernice has raced the 24 Hours of Lemon's several times and has held them together as well. I'd pay special attention to what these two have to say.

Lastly, where the hell is Woodside CA? Oh... I see its in South San Francisco! Have you met the folks at FiatAmerica? They just celebrated 50 years as a club and I u/s there are about 100 members with large groups of them showing up at several events. They also make a pilgrimage to SoCal each November for the Best of France and Italy show. Take a peek here: http://fiatamerica.com/

Tell'um I sent ya and BTW, Dan Yee owes me $20 bucks... if you get it off him, I'll split it with ya.

 

[Cratecruncher]

Don...

I see you are relatively new here...

2. Of all the advice given, which is good... I recall Ulix for the past decade and a half has been racing his car on European road circuits, and Bernice has raced the 24 Hours of Lemon's several times and has held them together as well. I'd pay special attention to what these two have to say.

Welcome to the forum Black-Tooth... I see you also are "relatively" new here.

When I have a problem I like to read and consider ALL responses. When ANYONE posts their suggestions they are contributing valuable content. By it's very nature internet diagnostics are a crap shoot. I think many responses are better than one and nobody is an expert at everything. Those who contribute are not physically present and the original poster may have misinterpreted or failed to mention something important. You never know what someone might say that triggers a new approach. Believe it or not even "young people" can help us solve problems. That's why I think it's important to encourage as much posting as possible and not pick favorites or ENDORSE certain individuals responses based on how highly we think of them.

I hope to see more of your posts in the future.

CRATECRUNCHER

 

[dllubin]

Don...

I see you are relatively new here... I'm relatively OLD here in so many respects... and admit I've been negligent lately in keeping up on this forum.

What I see written here seems to be all good advice and I don't have too much more to offer, but here goes.

1. How 'bout a G'Meter? I think that might be the most accurate way of determining a shift point when (or before) acceleration starts to drop off. Usually gear-heads are born with them in their bum... but the meter up front is easier to read and possibly more accurate.

2. Of all the advice given, which is good... I recall Ulix for the past decade and a half has been racing his car on European road circuits, and Bernice has raced the 24 Hours of Lemon's several times and has held them together as well. I'd pay special attention to what these two have to say.

Lastly, where the hell is Woodside CA? Oh... I see its in South San Francisco! Have you met the folks at FiatAmerica? They just celebrated 50 years as a club and I u/s there are about 100 members with large groups of them showing up at several events. They also make a pilgrimage to SoCal each November for the Best of France and Italy show. Take a peek here: http://fiatamerica.com/

Tell'um I sent ya and BTW, Dan Yee owes me $20 bucks... if you get it off him, I'll split it with ya.

Hi Tony:

Yes, I think it is my body's G meter that normally determines my shift points. However, with a new motor, I was trying to pay attention to the tach as I've got many times more miles on 1300s than 1500s. There is lots of good information and advise on this site. I started checking in a little over two years ago when I got tired of seeing my X collecting dust since 1995 when the timing belt tensioner disintegrated taking most of the valve train with it.

Woodside is about 20 miles south of SSF. The last time I went to Fiat club meetings was in the 70s with a couple of guys I worked with that also had Fiats. They used to meet at Harry's Hofbrau in Mountain View. Not sure if that is the same group you referred to in SSF. If I ever run into Dan, I'll tell him you sent me to collect!