One of the projects on one of my projects, an H-Production Fiat 850, is upgrading the cooling system. Part of that will be a new, lighter, more efficient radiator. I know what dimensions I need and I can be flexible to a point. But I will be experimenting on some level so a second radiator (in case of error) has to be a consideration. Also, since this is not going to be a plug and play item I will have to create or modify mountings – not a problem just a consideration.
That said, finding an affordable one from a reliable vendor is not easy. I’ve been quoted over $500 for a custom radiator by a couple known cooling vendors – that is just not in my budget.
I have come across some off the shelf rads (made for other cars / motorcycles) that I could adapt to my car that seem to be affordable – less than $200. The problem there is ‘who are these people?’ One manufacturer is: http://gpiautoparts.com/index.php
I’ve run across them via eBay. The problems are:
- They seem to have several eBay names, but all with decent 99 percentile ratings.
- Their ads are poorly worded; I suspect it is a translation issue as they are made in China but shipped from California. If I do decide to try them I can, hopefully, get clarification about the products.
- I’ve read that some aluminum radiators are “glued” together – is this correct?
Since the various eBay vendors have thousands of positive feedbacks I’m wondering if anyone here has dealt with them.
Other input is welcome too. Thank you
A Chinese rad will last longer than a Fiat engine, so buy whatever size you want.
Joking aside, there are some pretty talented Tig welders in China these days.
I have abused the fiat 850 cooling system more than most so I can share what I have learned if you are interested.
My first question for you is, what is your water pump and fan plan?
the factory setup pulls air from the engine bay and forces it through the radiator with the pusher fan on the water pump and then the hot air has to make an abrupt 180° turn down and back. The metal tray on the bottom of the engine compartment is crucial here. Without it the hot air goes right back into the radiator and the car will overheat.
I wound up with a aftermarket aluminum radiator for a civic which just barely fit after a bit of trimming. I also modified the duct behind the radiator to fit a stock civic fan as a puller since I switched from the stock water pump to an electric unit.
I have a fair bit of experience with the abarth style auxiliary radiators and I dislike them. They are usually plumbed in such a way that there is no thermostat so the little engine never really heats up.
In reply to Streetwiseguy :
I just hope the guy / robot who makes their rads is a very good TIG welder.
In reply to Trent (Generally supportive dude) :
Yeah, I fought with the cooling system since before I owned the car – it belonged to a friend (2nd owner) before I got it. He raced with a mostly stock cooling system back in the 80s. It was (still is) ducted to take air from the headlight – that was done by the original owner. But it had the original down flow rad etc. I added an electric fan for slow running and added ducting from the other headlight.
But as you probably know getting power with the Fiat head takes rpm which creates heat and it gets easy to make heads into aluminum ingots. When I ran Nationals in the 90s I upgraded to a PBS water pump and had a restrictor vs. a thermostat. That helped a bit but the head really is the issue. Then, very long story short, in 1994 SCCA essentially told the 850 guys to fk off. So we all parked them.
Forward to 2005-ish and I find out SCCA eventfully allowed the PBS head. The PBS head can make much more power at a lot lower rpm. And not long after I found a good used one – but there is a problem. The dual 40 DCOE carbs stick out right to where the top tank of the rad goes. So I need a rad sized just so and mounted just so plus an expansion tank to make room for the carbs. Then I will need to address exit ducting.
IMO the Abarth system is too much stuff that can go wrong and I’m not sure if it would be legal in Production. I’m not sure an electric pump is legal either. Which pump do you have?
I came across an aluminum rad from a Civic IIRC (now completely sure on that right now) at a Pick a Part and grabbed it but it would need a lot of work to clear. Do you have pics of your setup?
Thank you
I was running 21psi of boost into my 843cc lump. Laid down an honest to goodness 121hp at the wheels. Heat management was crucial. From my numerous hours on the dyno with the original carburetted and big cam transitioning to fuel injection naturally aspirated to turbo charged I learned that these motors make 10% more power at 190-195F than they do at 170F. Getting it to stay in that range was my goal.
I have built 3 engines with the PBS 8 port. It is a great upgrade. I am actually building an original 67 Abarth OT1000 spider right now with the PBS head.
With the aftermarket aluminum radiator I just had to trim off the bent flanges that stick out from the sides of the radiator. It just barely fit. I think I was able to get it down to a hair under 14" wide
Sadly all those photos are stored on photobucket which is holding them all ransom. I did eventually move to a front mounted radiator which worked a bit too well and kept the coolant too cold and required even more work top make it less efficient.
For racing purposes I think the PBS/Abarth style "shorty" water pump is the best bet. I used a Meziere electric and loved it.
Once I finish up a few dozen house projects the little Fiat will get back into the que and get built again
In reply to Trent (Generally supportive dude) :
Yes, heat management was essentially life or death for me. I could never get mine to run below 210 or so. Having talked with the folks at Ron Davis Radiators I have a better idea of what can be done with what I have to work with (rules and space wise). I would be thrilled to be able to get it down to 200 when running at speed.
Any idea of what your horsepower was with the dual 40 DCOEs?
I’m also looking at Mini Cooper rads size wise they are close but the top tank may need to be changed some. There are a few motorcycle rads that may work too.
What pulley sizes have you run? Slowing water pump RPMs would also help with cavitation. I use the PBS 3” on the crank and biggest Fiat pulley (5.75” IIRC) on the pump. I’ve seen a much bigger one too (see pic) it looks to be about 9 inches.
I just quickly looked at an older rules book. If I interpret the rules correctly sorta I could use an electric pump.