Radiator efficiency?

A good power flush and fresh coolant will likely cool things off a bit. If not, you may need to have the radiator re-cored by a local radiator shop. If so, have them install a heavy duty core to enhance cooling.

 

I have not found this to be a problem with my 77. The only time it has run hot is when the WP blew. I have a suspicion that my car has a stuck open thermostat but because it runs cool I am not willing to open it up to check. The temp is usually at the 1st bar on the gage and very rarely heads for the 195 mark. Once in a while in traffic with the ac on and 90*+ days it will creep up to trigger the fans but you can watch the gage move down again and the fans turn back off. As a check when I look at my oil temp it pretty much tracks with the water temp gage. I think the cooling system is pretty efficient and if these cars run hot I suspect there is some other problem causing the problem. As I mentioned before my Corvette's and V12 Jags held 19-20 qts. in the system and they stayed cool.

 

You must testing this sitting still, correct? Are the fans running? I'm not sure how much cooling it would provide at idle when new with or without the fans running, but keep these factors in mind. It wouldn't hurt to go get the radiator cleaned if you're concerned.

 

Also, what temperatures are you folks seeing at the radiator? I am typically measuring with a precision IR gun 197 dF input, with a 174 dF output, with the temp gage at just shy of 100dC at idle.

David[/QUOTE]



i concur.
last winter when i changed the hoses, fan switch,etc. i measured almost identical temps,
with my el cheapo sears ir gun which i purchased from the guy wearing a trenchcoat.

actually, you guided me thru my first coolant change/air purge and told me what to expect.

gabriella may be getting on in years, but she seems as contented as elsie.

 

I don't know about the 308 QVs, but I just had the 328 radiator recored, and the shop that did it told me that the original core was a "high efficiency" core to begin with. They replaced it with a similar efficiency core, which he says is the highest efficiency you can get in that size core.

It is possible, if you are still running the original core, that the inside has become coated with deposits or crud and the efficiency is lowered. Flushing it may or may not remove that coating. Some shops can "scope" the core through the fittings and tell you how bad the tubes look.

In the meantime, not a bad idea to flush it and the whole system for that matter, make sure all the "crud" is out of the lines, engine block, etc., and refill with 50/50 mix of standard (green) anti-freeze and water, plus a bottle of Red Line Water Wetter. The Water Wetter helps the fluids make better contact with the engine and radiator surfaces and increases cooling efficiency. Also, not a bad idea to change the thermostat and possibly pull the water pump and check the impeller. If you have an original bronze impeller, it could be eaten away fairly badly if the coolant wasn't changed regularly.

 

David 84 and 85 QV had a reputation since new for inadequate cooling. I live and work where 100+ is the norm in summer and we spent a great deal of time and warranty money trying to solve it at FNA's direction. Ferrari finally redefined overheating as boiling over.


That is the reason the 328 got a complete cooling system redesign. With the additional heat generation of the QV the old cooling system could no longer keep up.

 

FWIW, several years back I had the radiator on my '81 308 re-cored by an "older Ferrari radiator guru" in Denver who was recommended to me by Dave Helms. The new core was a high efficiency "4-core" (or something like that --- don't remember) configuration. He also made changes to the baffle locations inside the top tank to affect the flow pattern. Prior to this change, my car was not running overly hot ---- but, the changes made a huge difference!

These days, nothing I can do while driving the car gets the temp above the normal range --- it's been 6 years and about 20K miles on the new core, with only 2 coolant changes (no flushes) over that time period.

 

I just recently had my 1980 recored at an industrial shop. They preserved all the original tanks and mountings and the new core material/size is rated about 1000 BTUs over the original. I'm not sure how that's calculated but he showed the the figures on the old material and the new. Well worth the $$

Rick

 

80 and 81 was never a problem.

 

I was talking recently with our engine builder on the racecars and he was telling me they are sending out the radiators at least once a year and that they were seeing a fairly large percentage jump in flow. Hard to imagine since the water gets change many times during a season but I trust what the guy is saying. This is on new radiators with clean coolant. I can only imagine the difference it makes on one thats been in the car for twenty years.

 

Yeah, that's what Dave and the radiator builder said, too. But, my old core was getting to be in bad shape --- after 65,000 miles (yes, I said "65,000"), so it needed to be re-cored anyway. The upgraded core and baffle work still cost less than an OEM core, so I figured what the heck

 

60,000 miles is not a lot on a rad. I would suspect that the build up of crud was due to lack of fluid changes through the years. A few years back I started to get a "weeping" seem and even though I didn't have a over heating problem I decided to pull the rad and get the tanks re-soldered. When the rad shop pulled off the tanks they ran brushes through the cores and found them in pretty good condition with very little crud in the tubes. They soldered up the tanks and pressure tested and painted it. I reinstalled it and it still runs cool. Cost me $75 at the time and they even knew it was for a Fcar.

 

Dave,
why did the '84 and '85's generate more heat?

George

 

HP=HEAT

More HP and leaner mixtures.

 

Brian,
but since the original car (and I am assuming they did not decrease the size of the radiator since the first cars) was ok, and had somewhere near the same power, I would assume it would all be down to the leaner mixtures. I would also assume that this could be corrected, ie richened up a little, but not so much as to make the cats defective. Thoughts? And thanks for taking the time.

George

 

The cooling system to start with was just big enough to do the job. With the QVs extra power they added the hood louvers. That was all they could do without a big redesign which they just did not have time for. For the 83's that was enough. 84 came along and the power went up and with lambda the mixtures got leaner. They also got rid of the EGR. All those things added up. Many solutions were tried. Simply richening the mixture was just not going to do it. The end result was that Ferrari knew they had to redesign the front end of the car to put in a bigger radiator and increase the air flow. The also moved the A/C condensor. In hotter climates there were a lot of very unhappy 308QV customers and Ferrari tried a lot of things. I remember being given different cam timing specs, different radiators etc. Nothing worked. In the end many owners traded for 328s when they cam out. A 308QV was just not going to be driving around town on a hot day. Like I said, Ferrari at that point redifined what overheating was a considered the case closed.

This is not my speculation. I remember the entire chapter in the cars development very well.

 

This is not my speculation. I remember the entire chapter in the cars development very well.

Brian,
I have no reason to doubt your experiences of the time. I know you have been living it. I just needed more information to understand. Plus, it is interesting to hear a more detailed account of the issues you and others lived with at the time in servicing these cars. I am just glad I live in a cooler climate so I can enjoy mine without a fear of overheating.

Regards,

George

 

This whole discussion is very interesting. It is similar to the problems that Jaguar had when it sent the early E-types to the United States. The car, including its cooling system, had basically been designed for the environment of the UK, where summer temps rarely get much beyond the mid to upper 70s F. When they shipped the cars to places like Miami and Phoenix and LA and even New York, owners found the cars overheating regularly. Jaguar played around with variations on the fans, thermostats, etc. Finally, around 1968, when they redesigned the cars to start meeting US safety standards, they enlarged the opening in the front of the car, increased the size of the radiator, and with lower HP due to "smog" changes like going to dual Stromberg carbs from the triple SUs, the heat load and cooling capacity finally balance out. And then they introduced the V-12 engine in 1971 -- and a whole new set of cooling problems arose that persisted through the end of the XKE in 1974 and through the V-12 XJS right up to the mid-90s when they finally switched back to a 6 cylinder engine.

Apparently, none of the manufacturers were learning from one another's mistakes. Seems like the whole process of development of cooling systems was more of a trial and error system driven by the body designers (see what you guys can fit into THIS space), rather than a bottom-up engineering of what it would take to cool these engine properly.

 

Steve,
I think you summed it up nicely. I wonder what year they all started to get it right? It did seem that all of a sudden you didn't need to worry about your car overheating unless it was "well used" or something was broken. Maybe the late eighties?

George

 

In dealing with my QV's overheating problems, I switched to an Aluminum Racing radiator from Nick's Forza, which was actually made by Evans Cooling. The radiator 'helped', but the problems really lied in the Engine Block/heads, so what we're doing now is a full-rebuild.

Has anyone else switched to an aluminum Radiator, especially the units offered by Evans? I am torn between sending my Evans unit back to Evans for a full clean-out (if that is even possible with a welded aluminum radiator) or to work with the OEM unit I still have, and go with better internals during a rod-out.

 

i've got a aluminum chevy racing rad from summit racing parts. fit and works fine even here at the beach.

 

Most old time real radiator shops can flow test a radiator. This is a machine designed to pump water thru the radiator and measure the gallons per minute. Most radiators over time will build up a crust at the ends of the tubes and slow down the water flow, thus overheating.

You can have them boiled out(old time radiatorshop) or in some cases have them cleaned ultrasonicly. This type of cleaning works well as long as you are not dealing with an aluminum radiator as the ultrasonic activity will casue some fractures of welds. All of this is a make shift solution.

Do it right, spend the money and have a new heavy duty core installed. I had one made for my 308 and the total cost was $400.00. My 308 with the hi output water pump stays at 85-90 degrees in or out of traffic. I also installed new fan sensors from Volkswagen, that are rated at 85 degrees. The cooling system on a 308 is marginal at best so why take a chance on distroying your motor with a old plugged radiator??????

Howard Musolf
1981 308gtsi
1982 400i Cabriolet
Maserati Spider
2 many brass era cars

 

Did you have to weld any brackets, etc. on it ?

 

not sure. dave at smith motorworks put it in. the only thing i know they modified was where the filler cap was. they removed the cap and welded a plate over that corner.