Second radiator behind a flap

Issues pertaining to the TGB/C30X series engine and driveline issues
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cavetroll
Great Britain
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Second radiator behind a flap

Post by cavetroll » Mon Mar 07, 2016 4:02 am

Hi
I cannot find any mention of this anywhere in the manuals for the C303. My truck a 1975 C303 has a second radiator to the side of the main rad, this second rad can be blocked off with a flap I guess in cold climates, does this mean it will cope in hot climates?. The reason I am asking about this is that I intend to take the truck to Morocco in October this year and I want to make sure that the cooling system will be able to cope with 35-40deg heat, I did intend to recore the radiator and put a large electric fan on, the core looks brand new as does the second radiator. can anyone shed some light on this for me.
thank you
Tom

one2many
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Re: Second radiator behind a flap

Post by one2many » Mon Mar 07, 2016 7:14 am

I'm pretty sure your referring to your heater core...in cold whether you use the flap to block airflow over it resulting in warmer air in the cabin and the idea is in warmer weather if you let airflow through the core/small radiator then the air in the cab shouldn't be too unbearably hot. The first part works well but in really hot climates it would be much more comfortable/effective if you were to stop the flow of coolant through the heater core using two ball valves and two T-pieces.

Having air flowing over the heater core will provide a little extra cooling ability, but IMO the Volvo's cooling system is not really up to the task in hotter climates...not really surprising when you think of Swedish temps. I have often wondered whether the Malaysian spec'd Volvo's used the same cooling systems as the Swedish versions.

For your needs I would seriously consider a more modern big core aluminium type radiator, it can be built into the same space only a bit deeper so it supports more cores. A good radiator fabrication shop will be able to build you something with a far greater cooling ability than the original unit, I think this is a wise investment for these vehicles even in moderate climates. Like most things radiators have come a long way in recent years, according to some manufactures they can be 30% to 40% more efficient than the units they are replacing.

Oh! And be sure to use a quality electric fan as a replacement, they aren't all created equal. Belt driven fans move a lot of air and are hard to match but they are noisey especially when running constantly like the Volvo's do.
1985 pinzgauer 712K factory 2.7lt civilian (RHD, 4 door K)
1979 Volvo tgb 1314a (under construction to om606 diesel/722.6 trans. Dual cab/tray)

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VinceAtReal4x4s
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Re: Second radiator behind a flap

Post by VinceAtReal4x4s » Mon Mar 07, 2016 8:00 am

Yes, like he said, that's the heater core. And you need two fans to do it properly. (Push and pull)
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cavetroll
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Re: Second radiator behind a flap

Post by cavetroll » Wed Mar 09, 2016 5:08 am

Thank you, this has been very useful, I have only had the truck a few days and there are so many things that are different to any other 4X4 that I have owned.

dokatd
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Re: Second radiator behind a flap

Post by dokatd » Thu Apr 07, 2016 8:16 am

You don't need to change your rad or use two fans. You need a proper shroud to go electric only and a decent fan. See my post on electric fans in the modification section. Use the Volvo fan as it is available world wide and can be had for just about free in most places.

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Re: Second radiator behind a flap

Post by VinceAtReal4x4s » Thu Apr 07, 2016 12:36 pm

An engineer who tested the needed air flow would argue that one. I also wouldn't trust just one fan, and especially when I'm 100 miles from the nearest paved road in 95degree weather.

If it fails you are 100% screwed no matter where you are. I had one fail on my old Land Rover that was converted.
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dokatd
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Re: Second radiator behind a flap

Post by dokatd » Thu Apr 07, 2016 2:49 pm

He can argue all he wants but he would be wrong. Mine is holding up well in temps exceeding 95*, in fact it cools far better than the mech fan. A mech fan can fail just as easily in the desert and you are just as screwed. You can easily hide a $20 Volvo fan in the back of the truck for an emergency. The Volvo fan is bullet proof, I have one I pulled from an old burnt out wreck in the NM desert that has been cooling my turbo charged Unimog U1300L for 5+ years. Rovers for one reason or another always had trouble with e-fans and cooling. I never really tried on my D90, discos or Rangies. However the cooling issues on rovers was more related to fan technology than failure like you are talking about.

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Re: Second radiator behind a flap

Post by VinceAtReal4x4s » Thu Apr 07, 2016 3:25 pm

That's fine but it's your opinion and lets be blunt here, it is not based on extensive testing and math like an engineered solution is. And you would lose any argument with this person I'm referring to, trust me on that one.

I don't know anyone who is going to carry a big fan around when you could just install another one to begin with, which is the proper way to do it. Who has room for that?

Also, in general, a mechanical fan failing is pretty rare, to say the least, especially compared to the rate of failure of an electronic fan that has wiring, a motor, non-factory mounting solutions and electronic means of triggering. In fact I have never seen a mechanical fan fail 100%.

The old Land Rovers with the 2.25ptr/dsl and 2.5 diesel motor had no special issues with cooling. My failure report was due to an electronic fan simply failing. (This is over 10 years of experience with those motors talking)

Good luck with your set-up and I hope it doesn't fail but it would be better for everyone if you don't put down someone's extensive education and background, and the time they invested into testing this issue in a way that very few people could accomplish. I wish I could share his results but he isn't interested in publishing them for this exact reason and I respect his wishes. It's really too bad since he also built other massive improvements for the 303 that will never be seen or presented online.
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dokatd
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Re: Second radiator behind a flap

Post by dokatd » Thu Apr 07, 2016 4:44 pm

You clearly have little idea of my experience. I have over 18years of rover specific alone experience with some of the most heavily modified rovers in the USA. Close to that on Unimogs and a fair amount of time rebuilding airplanes.

My application of the electric fan is not opinion, it is functioning fact on a daily driven C303, How can anyone disprove what is currently functioning in practice.

And considering a spare fan if desired could fit behind a seat or be secured into numerous places on the truck I cannot see why it would be an issue. But personally I would not carry a spare as the Volvo fan has proven to be dead reliable since the early 90's.

I'm not putting anyone down, just simply stating the fact that two fans are not required in any way shape or form. If anyone has put someone down it is you.

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Re: Second radiator behind a flap

Post by roobar_and_custard » Thu Apr 07, 2016 6:50 pm

Sorry to wade in... we're all friends here. :roll:

All these ideas are valid engineering solutions and you are both right. The automotive industry uses all these proposals in production vehicles, and fan shroud sealing on all concepts is critical to maximising airflow performance.

The real question here is around trade-offs and which ones you are "personally" more comfortable with. It's a choice we all make ourselves when we start modifying these great trucks.

Personally, I would like an electric pusher fan, but will settle for a electric pull fan. I accept the reliability and general airflow performance reduction vs a mechanical fan but I gain a quieter cabin, better fuel economy, and the ability to switch it off when wading. Doesn't make anyone else wrong though...

Keep it nice :D

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Re: Second radiator behind a flap

Post by VinceAtReal4x4s » Thu Apr 07, 2016 8:55 pm

dokatd wrote:You clearly have little idea of my experience. I have over 18years of rover specific alone experience with some of the most heavily modified rovers in the USA. Close to that on Unimogs and a fair amount of time rebuilding airplanes.

My application of the electric fan is not opinion, it is functioning fact on a daily driven C303, How can anyone disprove what is currently functioning in practice.

And considering a spare fan if desired could fit behind a seat or be secured into numerous places on the truck I cannot see why it would be an issue. But personally I would not carry a spare as the Volvo fan has proven to be dead reliable since the early 90's.

I'm not putting anyone down, just simply stating the fact that two fans are not required in any way shape or form. If anyone has put someone down it is you.
You aren't an engineer in these matters, right? Ok so this is, in fact, your opinion. You haven't tested this homemade set-up in all conditions and haven't calculated this out like someone would when building a car. Sure it may work under your conditions, and in your world, in your particular rig, for now, but it's naive to assume that means it's good for everyone else or that it will serve in conditions yet to come. Grandstanding isn't going to make me or anyone else believe anything more.

And yes actually, you are putting down vastly superior knowledge to yours, time and effort of someone that you have no idea about. I wish he bothered to post on forums for the education, or at least for the entertainment in this case. You'd be like a dog with his tail between his legs after it was done. Again, comments like yours are the reason he doesn't bother. Too bad for us all.

Sounds like your Rover background isn't with the 2.25 and 2.5 engines which had no cooling issues at all, so at least that's solved.

And you daily drive a 4x4 that gets around 11mpg and has a few almost (or maybe fully) unobtainable parts that you have to beg and plead to someone in Sweden for, if you are lucky to find them? Hard to believe. That's impressive (and expensive) so hats off to you for that.

We are done with this. Good luck out there.
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