S Series radiator options.
Discussion
I will start by apologising, this post may go on a bit but thought it worth doing as it may be of use to someone.
This is something I have been thinking about for a couple of years, but since my S has been in pieces longer than that (I know, I know
) it was not urgent.
Well last week it became more urgent, the time had come to fit a rad. I looked at my grotty original item, tested it and unsurprisingly found a couple of leaks.
This left me with 3 options as I saw it.
1) Re-core - quoted approx £140 +vat at the local radiator fix it man. Possibility.
2) Alloy replacement - approx £450
not of my hard earned!
3) Try an alternative rad from something else.
Now I have had a possible alternative in mind, as I said, for a couple of years and after a day or two mulling the options I decided to go for it and placed an order.
It arrived Thursday around lunchtime, after about an hour looking, thinking and measuring, I decided that it would fit and set to work.
The radiator is an after market, all alloy unit designed for a pre 2000 model Subaru Impreza Turbo.
These can be had on Ebay for around £125, I paid a little less due to bidding on an auction. I didn't expect it to be black (usually more expensive) but it suits me as I don't really do “bling”.
Size wise it is pretty close to the original, about 2” wider but that doesn't seem to be a problem.
The rad is not a direct drop in replacement but is not too difficult to fit either. It has two locating pegs on the lower edge just like our cars but unfortunately they are approximately 10mm closer together on this rad. A plate could be fitted to the brackets on the chassis and then drilled to the correct dimensions for the mounting pegs but I opted to cut the brackets out, move them in 5mm at each side and weld them back in.
The top fixing is fairly simple. I cut the old mounting brackets from the rad mounting frame and made some new bolt on ones. These have a peg welded on that fits into a rubber bush in the mounting bosses in the new rad. I will make the nuts on the mounting frame captive when finished.
An added bonus of this rad is that it has a drain tap at the bottom and a small vent pipe at the top which will be joined into the vent from the thermostat housing to the swirl pot. When done this means that the rad will self bleed meaning nomore worries about radiator air locks.
I have run the car up in the garage to test the new installation. I tested it with the car at idle speed and at a constant 2500rpm. Bearing in mind being inside and stationary means no natural air flow, in both tests when the temperature came up the fan had no problem bringing it back down to normal and the fan shutting off again.
Although I have not yet tested on the road I am confident that this setup will work well and don't foresee any issues.
I realise that this change may not be something every owner can do but hope it may be of use to at least some of you and does add another option when faced with a past it's best radiator.
Here are a few pics of the installation, just because, well, we all like piccies don't we?
Please ignore the fact that everything looks a bit rough, nothing has been fettled and finished but will be now that I know everything works.
Cheers,
Carl.
This is something I have been thinking about for a couple of years, but since my S has been in pieces longer than that (I know, I know
) it was not urgent.Well last week it became more urgent, the time had come to fit a rad. I looked at my grotty original item, tested it and unsurprisingly found a couple of leaks.
This left me with 3 options as I saw it.
1) Re-core - quoted approx £140 +vat at the local radiator fix it man. Possibility.
2) Alloy replacement - approx £450
not of my hard earned!3) Try an alternative rad from something else.
Now I have had a possible alternative in mind, as I said, for a couple of years and after a day or two mulling the options I decided to go for it and placed an order.
It arrived Thursday around lunchtime, after about an hour looking, thinking and measuring, I decided that it would fit and set to work.
The radiator is an after market, all alloy unit designed for a pre 2000 model Subaru Impreza Turbo.
These can be had on Ebay for around £125, I paid a little less due to bidding on an auction. I didn't expect it to be black (usually more expensive) but it suits me as I don't really do “bling”.
Size wise it is pretty close to the original, about 2” wider but that doesn't seem to be a problem.
The rad is not a direct drop in replacement but is not too difficult to fit either. It has two locating pegs on the lower edge just like our cars but unfortunately they are approximately 10mm closer together on this rad. A plate could be fitted to the brackets on the chassis and then drilled to the correct dimensions for the mounting pegs but I opted to cut the brackets out, move them in 5mm at each side and weld them back in.
The top fixing is fairly simple. I cut the old mounting brackets from the rad mounting frame and made some new bolt on ones. These have a peg welded on that fits into a rubber bush in the mounting bosses in the new rad. I will make the nuts on the mounting frame captive when finished.
An added bonus of this rad is that it has a drain tap at the bottom and a small vent pipe at the top which will be joined into the vent from the thermostat housing to the swirl pot. When done this means that the rad will self bleed meaning nomore worries about radiator air locks.
I have run the car up in the garage to test the new installation. I tested it with the car at idle speed and at a constant 2500rpm. Bearing in mind being inside and stationary means no natural air flow, in both tests when the temperature came up the fan had no problem bringing it back down to normal and the fan shutting off again.
Although I have not yet tested on the road I am confident that this setup will work well and don't foresee any issues.
I realise that this change may not be something every owner can do but hope it may be of use to at least some of you and does add another option when faced with a past it's best radiator.
Here are a few pics of the installation, just because, well, we all like piccies don't we?
Please ignore the fact that everything looks a bit rough, nothing has been fettled and finished but will be now that I know everything works.
Cheers,
Carl.
mk1fan said:
Already done. Plentiful supply thanks to the popularity of the Subaru in motorsport.
Mine is a Subaru Impreza STi 1999 model. Not sure which model name or time period this covers. I think 2002 was the change over year.
I got some stainless bobbins and some genuine Subaru upper mount brackets to keep it as 'stock' as possible. Such an easy mod that the Reserve will be getting the same.
Even the hoses can be retained.
Mine is a Subaru Impreza STi 1999 model. Not sure which model name or time period this covers. I think 2002 was the change over year.
I got some stainless bobbins and some genuine Subaru upper mount brackets to keep it as 'stock' as possible. Such an easy mod that the Reserve will be getting the same.
Even the hoses can be retained.
Yeah I remember a pic of it resting in place and did ask if it was the Subaru rad at the time as I thought I recognised it. Didn't know you had fitted it as you never mentioned it again.
Does it as work well in real use as it seemed to in my garage tests?
The Big G said:
I decided in the end to get the original recored but with a additional core added. This keeps its originality and helps keep it cool when stuck stationary in heavy traffic when out in a hot summers day. Did have issues with this in the past and almost overheated in central London one day. It also is easily repairable too if it does have problems, can continually be recored if required. Unlike a alloy rad. Hopefully over cooling won't be a issue for me now!!
I fully agree with all of that, recore was one of the options and still is should it ever be required as I still have my crusty original rad.I just decided to try some newer technology which came with the benefits of a self bleeding rad, a functioning drain tap and in this case was £60 cheaper.
When you say you now have an extra core, the rad should have been a 3 row core already, does that mean that yours is now a 4 row core?
O/T a little but maybe if somebody here has more knowledge they could help me out.
On many threads about cooling systems I see people mention/question the possibility of having over cooling problems.
Now I may be being a bit thick but, surely, if the correct thermostat is fitted and is working correctly, then over cooling should not be possible.
As I understand it when the engine is cold, the stat is closed, heavily restricting coolant flow through the rad. As it warms the stat begins to open allowing flow through the rad. At a pre-determined temperature the stat is fully open allowing maximum coolant flow through the rad.
Now if the engine coolant temperature begins to drop then the stat will start to close again, restricting flow and allowing he engine to remain at optimum temperature.
If all of this is happening as it should I fail to see how, even if a huge rad was fitted, that over cooling can be an issue.
If over cooling is an issue, it seems to me that it is the opening temperature of the thermostat that is too low and in fact nothing to do with the size of the cooling radiator.
Happy to be corrected if anyone can explain to me why this would not be the case or I am over simplifying it.
Cheers,
Carl.
On many threads about cooling systems I see people mention/question the possibility of having over cooling problems.
Now I may be being a bit thick but, surely, if the correct thermostat is fitted and is working correctly, then over cooling should not be possible.
As I understand it when the engine is cold, the stat is closed, heavily restricting coolant flow through the rad. As it warms the stat begins to open allowing flow through the rad. At a pre-determined temperature the stat is fully open allowing maximum coolant flow through the rad.
Now if the engine coolant temperature begins to drop then the stat will start to close again, restricting flow and allowing he engine to remain at optimum temperature.
If all of this is happening as it should I fail to see how, even if a huge rad was fitted, that over cooling can be an issue.
If over cooling is an issue, it seems to me that it is the opening temperature of the thermostat that is too low and in fact nothing to do with the size of the cooling radiator.
Happy to be corrected if anyone can explain to me why this would not be the case or I am over simplifying it.
Cheers,
Carl.
Thanks for confirming what I thought chaps.
mk1fan said:
The way TVR configured the cooling system on the S V6 the coolant circulating the system is exposed to the rad even when the thermostat is closed.
Agreed, that is why I also re-routed the bypass hose into the bottom radiator hose rather than the swirl pot as recommended by Griffinr some time ago.mentall said:
What a wonderful forum this is! Thanks to all concerned.
So presumably, for those of a penny-piching persuasion like me, this could easily be made to fit? Adequate for a 218BHP Impreza Turbo.
That appears to be a standard rad with 26mm thick core, presumably single row and may not be man enough.So presumably, for those of a penny-piching persuasion like me, this could easily be made to fit? Adequate for a 218BHP Impreza Turbo.
The one I used is the uprated aftermarket all alloy version for that model car.
Griffinr said:
I was wondering if anybody else had carried out the mod, the improvement on my car was quite dramatic I presume you experienced the same.
Ah! re-reading the start of this thread I see you may not have got as far as running it yet.
Rob.
Not seen the road yet, probably won't do until spring but have run it up in the garage and so far all seems good.Ah! re-reading the start of this thread I see you may not have got as far as running it yet.
Rob.
Edited by Griffinr on Tuesday 17th November 10:38
Carl.
christianyoung said:
i'm in the process of doing this to my car, from what i understand (im not with the car atm) there are two pipes coming from the thermostat to the swirlpot (3&7), which do you join in too, or are they obviously different sizes?
Sorry, I didn't check in here yesterday.Join into line 7, it's the lower one of the two small diameter hoses at the top of your swirl pot.
3&7 are very different, 3 is around 15mm and feeds into the swirl pot around 1/2 way up, this is the one you re-route to the bottom hose if doing Griffinr's mod, capping the spigot on the pot itself.
HTH,
Carl.
Edited by Ceejay73 on Wednesday 7th August 22:53
In brief, as I understand it:
The 15mm hose is a bypass hose allowing some coolant flow when the thermostat is closed.
In the original arrangement this coolant is fed to the swirl pot and then the rad thus preventing the thermostat performing it's purpose correctly as it still allows quite a lot of coolant flow through the rad even when the stat is closed.
This in turn leads to extended warm up times and in extreme conditions could lead to overcooling.
Moving this hose from the swirl pot to the bottom hose means that, when the stat is closed, there is still flow so that the pump is not pressurised but it is not being cooled again when it isn't required. This means faster warm up and no overcooling providing the stat works and is correct (better for the engine).
The now unused spigot on the swirl pot should be capped off.
As Stated, this mod was Griffinr's idea,not mine but I have applied it in my car and it seems to work with no problems encountered.
Cheers,
Carl.
The 15mm hose is a bypass hose allowing some coolant flow when the thermostat is closed.
In the original arrangement this coolant is fed to the swirl pot and then the rad thus preventing the thermostat performing it's purpose correctly as it still allows quite a lot of coolant flow through the rad even when the stat is closed.
This in turn leads to extended warm up times and in extreme conditions could lead to overcooling.
Moving this hose from the swirl pot to the bottom hose means that, when the stat is closed, there is still flow so that the pump is not pressurised but it is not being cooled again when it isn't required. This means faster warm up and no overcooling providing the stat works and is correct (better for the engine).
The now unused spigot on the swirl pot should be capped off.
As Stated, this mod was Griffinr's idea,not mine but I have applied it in my car and it seems to work with no problems encountered.
Cheers,
Carl.
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