Its so Hottttt !!!!
Discussion
OK here is the deal. My 450 has never over heated and it maintains a steady 90 degrees on the temp gauge. So far so good.
As you know wedges produce a boat load of heat under the bonnet, my interest lies in getting rid of the heat. The 390/400/450 Bonnet has 2 vents one at the nose cone near side front above the air filter one near the windscreen on the offside. When the bonnet is closed, both vents (while looking very stylish) actually offer very little in the way of getting rid of hot air or aiding with the through flow of air. Short of cutting holes or adding extra vents in the bonnet, I am at a loss to see how this heat can be got rid of. I am sure that this heat is one of the reasons that the engine pinks occasionally.
Any thoughts ???
Broadside
As you know wedges produce a boat load of heat under the bonnet, my interest lies in getting rid of the heat. The 390/400/450 Bonnet has 2 vents one at the nose cone near side front above the air filter one near the windscreen on the offside. When the bonnet is closed, both vents (while looking very stylish) actually offer very little in the way of getting rid of hot air or aiding with the through flow of air. Short of cutting holes or adding extra vents in the bonnet, I am at a loss to see how this heat can be got rid of. I am sure that this heat is one of the reasons that the engine pinks occasionally.
Any thoughts ???
Broadside
An awful lot of heat is given off from the exhaust manifold or headers X2, buy yourself some exhaust wrap, kevlar webbing on a roll, you use wire to secure it, and it insulates the manifolds hence removing the heat to further along the exhaust pipe outside of the engine room. Sorry for rambling on, but I guess you get the picture.
>> Edited by simonelite501 on Monday 29th July 18:18
>> Edited by simonelite501 on Monday 29th July 18:18
Hi Nigel.
Having owned both a series 1 & 2 350 my experiences in terms of bonnet designs are that they appear to do the job of displacing the heat whilst on the move. The series 1 had 3 sections chopped out of the bonnet for heat displacement and whilst it had an inferior setup in terms of cooling arrangement, which was always prone to getting airlocks in the system yet it never pinked once especially when it got hot. Another factor was that the car was being run on leaded 4 star before it was phased out.
My present car which is a series 2, has the revised curved bonnet with no cut outs for heat displacement, yet has the revised cooling layout to prevent airlocks. Although it does get hot, it hasn't yet overheated but pinks annoyingly in midrange but not when its cold.
My theory is that the pinking is due mainly to the fuel available, (optimax has made life a bit easier) the ECU not being sorted along with the engine not being setup properly to run on unleaded fuel.
As soon as I get the cash my intention is to get the car setup on a rolling road and sorted accordingly. I can live with the heat but not with the pinking which indicates a timing problem. At least with the heat you have the option of setting up the cooling system to work when it needs it, I rather fancy fitting the 2 stage unit as advertised elsewhere on this site.
I reckon steve h will have something to say about all this when he sees this thread. Angus's idea about the exhaust wrap sounds useful too.
Hope you get it sorted
Take care
Andy
>> Edited by Schazzar on Monday 29th July 18:25
Having owned both a series 1 & 2 350 my experiences in terms of bonnet designs are that they appear to do the job of displacing the heat whilst on the move. The series 1 had 3 sections chopped out of the bonnet for heat displacement and whilst it had an inferior setup in terms of cooling arrangement, which was always prone to getting airlocks in the system yet it never pinked once especially when it got hot. Another factor was that the car was being run on leaded 4 star before it was phased out.
My present car which is a series 2, has the revised curved bonnet with no cut outs for heat displacement, yet has the revised cooling layout to prevent airlocks. Although it does get hot, it hasn't yet overheated but pinks annoyingly in midrange but not when its cold.
My theory is that the pinking is due mainly to the fuel available, (optimax has made life a bit easier) the ECU not being sorted along with the engine not being setup properly to run on unleaded fuel.
As soon as I get the cash my intention is to get the car setup on a rolling road and sorted accordingly. I can live with the heat but not with the pinking which indicates a timing problem. At least with the heat you have the option of setting up the cooling system to work when it needs it, I rather fancy fitting the 2 stage unit as advertised elsewhere on this site.
I reckon steve h will have something to say about all this when he sees this thread. Angus's idea about the exhaust wrap sounds useful too.
Hope you get it sorted
Take care
Andy
>> Edited by Schazzar on Monday 29th July 18:25
Schazzar: define how the cooling system was modified to prevent airlocks? I've never seen any two V8s that seem to have the same plumbing!
Also, nobody has ever been able to tell me why the throttle body is heated. It's not like you'd ever get icing in there, with the heat under a TVR bonnet!
Ian
Also, nobody has ever been able to tell me why the throttle body is heated. It's not like you'd ever get icing in there, with the heat under a TVR bonnet!
Ian
I would like to put the exhaust wrap on mine to cool the engine bay and protect the starter motor but am a bit concerned that the exhaust would become hotter where it exits the wrap and might melt something.
I have a series 2 with the exhaust that goes down the spine so it shouldn't melt the floor? Does anyone have experience of this and recommend any places to heat shield. I am intending to move the fuel line to the outrigger whilst the sills are off.
I am less concerned about cracking the original manifold as it would give me an excuse to get some stainless ones, but do these handle the heat any better?
I have just got a 400 bonnet from TET, I thought this might make it cooler, nevermind it looks nice anyway!
Trevor is a top bloke if you need any pannels and the quality of this work is superb!
GF.
I have a series 2 with the exhaust that goes down the spine so it shouldn't melt the floor? Does anyone have experience of this and recommend any places to heat shield. I am intending to move the fuel line to the outrigger whilst the sills are off.
I am less concerned about cracking the original manifold as it would give me an excuse to get some stainless ones, but do these handle the heat any better?
I have just got a 400 bonnet from TET, I thought this might make it cooler, nevermind it looks nice anyway!
Trevor is a top bloke if you need any pannels and the quality of this work is superb!
GF.
quote:
Schazzar: define how the cooling system was modified to prevent airlocks? I've never seen any two V8s that seem to have the same plumbing!
Also, nobody has ever been able to tell me why the throttle body is heated. It's not like you'd ever get icing in there, with the heat under a TVR bonnet!
Ian
I got a diagram from the factory after I enquired about the mods. From what I could tell it was a lot different from the series 1 setup I had on my car, whether or not they changed it again to confuse the issue on other V8s is another thing.
Dont know about the throttle heater though.
Interesting points.
The exhaust wrap I have heard does reduce heat under the bonnet but causes the rest of the exhaust to heat up accordingly, not too keen on that !!
I was reading an old edition of sprint in which Richard Thorpe of Wedge automotive modified the air intake of his 450 SE by routing ducting from the air flow meter forward through the nose cone and fitting a Griff airfilter to this. The filter then had an Aluminium shield made around it to protect it from water/insects etc and the car never pinked again !!!
Will have this mod done at the next service and will keep you informed.
Regards
Nige'
The exhaust wrap I have heard does reduce heat under the bonnet but causes the rest of the exhaust to heat up accordingly, not too keen on that !!
I was reading an old edition of sprint in which Richard Thorpe of Wedge automotive modified the air intake of his 450 SE by routing ducting from the air flow meter forward through the nose cone and fitting a Griff airfilter to this. The filter then had an Aluminium shield made around it to protect it from water/insects etc and the car never pinked again !!!
Will have this mod done at the next service and will keep you informed.
Regards
Nige'
The biggest problem is actually controlling the air temp. The air intake takes air directly from the engine area and this cause the pinking. Richard did do a scope at the front to get cold air to the engine but be caerful if it rains as it is ideally positioned (by necesiity not deliberate) to take in water in deep puddles.
Itke the air in from the back of the bonnet where the windscreen is. The bonnet is ultra thin and there is a 3 inch gap at the back with two 80 mm diameter hoses that take air direct to the triple throttle body. Works a treat but you have to talk Dave at Tower View into making a lightened bonnet....
The car will be at Duxford if you want to look.
steve
www.tvrbooks.co.uk
Itke the air in from the back of the bonnet where the windscreen is. The bonnet is ultra thin and there is a 3 inch gap at the back with two 80 mm diameter hoses that take air direct to the triple throttle body. Works a treat but you have to talk Dave at Tower View into making a lightened bonnet....
The car will be at Duxford if you want to look.
steve
www.tvrbooks.co.uk
Yep but I doubt many of you would make a 3 foot by 12-15 inch scoop in the bonnet to direct the hot air from the rad out over the bonnet and have a three inch gap at the back of the bonnet to further improve the cooling.
The 520 runs sweetly in terms of temp but a considerable amount of engineering, time and money went into the design. The alloy rad was custome made around £500 and uses two uprated Cerbera fans for cooling. The manifolds were wrapped and I haven't experienced any problems with that. The air intakes were changed and a new bonnet made to further improve the air flow.
If you are tweeking engines, a rough rule of thumb is that about every 50-60 bhp is the equivalent of another 1 KWatt heater under the bonnet.
If the car doesn't overheat but pinks then the problem is with the air intake and getting cold air into the plenum. Lowering the under bonnet temp will help but it is not addressing the fundamental problem of where the car is taking in its air. That is where I would look first. That means a different air supply route.
Steve
The 520 runs sweetly in terms of temp but a considerable amount of engineering, time and money went into the design. The alloy rad was custome made around £500 and uses two uprated Cerbera fans for cooling. The manifolds were wrapped and I haven't experienced any problems with that. The air intakes were changed and a new bonnet made to further improve the air flow.
If you are tweeking engines, a rough rule of thumb is that about every 50-60 bhp is the equivalent of another 1 KWatt heater under the bonnet.
If the car doesn't overheat but pinks then the problem is with the air intake and getting cold air into the plenum. Lowering the under bonnet temp will help but it is not addressing the fundamental problem of where the car is taking in its air. That is where I would look first. That means a different air supply route.
Steve
I've gone the route of wrapping the exhaust and it caused my (addmitedly very k'ned anyway) steel manifolds to crack and corrode in very short order. I've since switched to wrapped Stainless and expect no problems, with the wrapping I saw approx a 15-20° drop in air inlet temps when I did this. As previously mentioned some sort of cold air supply to your air intake also helps. I went to the trouble ok making up a cold airbox to tuck into the corner of hte engine bay whcih has also helped drop air temps a bit, or at least delay the onset of them.
Matt
Matt
quote:
Interesting points.
The exhaust wrap I have heard does reduce heat under the bonnet but causes the rest of the exhaust to heat up accordingly, not too keen on that !!
I was reading an old edition of sprint in which Richard Thorpe of Wedge automotive modified the air intake of his 450 SE by routing ducting from the air flow meter forward through the nose cone and fitting a Griff airfilter to this. The filter then had an Aluminium shield made around it to protect it from water/insects etc and the car never pinked again !!!
I saw a similar thread on the TVRCC site. Someone else did the same thing which was fitted by a TVR mechanic in surrey. Wasn't sure if it was Dave Batty, but the intresting thing was that he also reckons he got an extra 5bhp by moving the filter into the cone. Personally I would love to see these mods and how effective they are.
>> Edited by Schazzar on Tuesday 30th July 16:28
I've got a 72 c thermostat that I havn't got round to fitting yet from
www.rimmerbros.co.uk
Is this a good idea on a std engine.
GF.
www.rimmerbros.co.uk
Is this a good idea on a std engine.
GF.
A 72 degree stat is not going to make much difference. The Wedge engines and this should include any new ones including serp ones, (should) have stat bypasses that allow water to bleed past the stat. As a result, the water temp is mixed better and gives a more uniform heating across the engine. The stat doesn't define what temp the engine runs at as a result but more of get the engine warmer. The downside of not having one is that it can take a long time to get the engine upto temp and as a result engine wear can be an issue.
Most engine builders don't fit them because they get in the way when dynoing and the fear of them jamming shut. The 520 has one but has more warning alarms than the Bank of England.
The power incresae with a modified air intake is not an increase... it recovers the power you have when the air/engine is cooler. Hot air looses power. Cold air restores it.
As for overide switches... been advocating this for years. It can save an engine!
steve
www.tvrbooks.co.uk
Most engine builders don't fit them because they get in the way when dynoing and the fear of them jamming shut. The 520 has one but has more warning alarms than the Bank of England.
The power incresae with a modified air intake is not an increase... it recovers the power you have when the air/engine is cooler. Hot air looses power. Cold air restores it.
As for overide switches... been advocating this for years. It can save an engine!
steve
www.tvrbooks.co.uk
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