Cooling and heating normal on 4.3 Griff?
Discussion
I have been diving through the old threads on cooling and ventilation and wonder if I have a problem or not. My 4.3 temp goes up to around 80-90 degrees and stays there. At the moment I stop for a moment (traffic lights) the fans immediately kick in (around 90+). Even with the current cold weather. When I drove in the summer on the motorway I also had to use the fans for additional cooling. On the other hand it did not get really warm inside the car during the cold weather recently. The engine was very nice and warm though! I fitted an alloy rad and it improved the cooling a bit. I suspect I have a coolant blockage problem. The heater produces warm air. Both coolant hoses attached to it with open heater valve get (hand) warm. Potential issues that don't help:
1. My heater fan is not working properly, because there is a leak at the perspex covers. (Little to no airflow on max speed).
2. Fan belt needs to be tightened. Can't imagine the water flow could be effected because of it though.
I read about a TVR specific thermostat that needt to be used instead of the LR one. Is it possible that this is fitted leading to a lower coolant flow?
Thanks,
Peter
1. My heater fan is not working properly, because there is a leak at the perspex covers. (Little to no airflow on max speed).
2. Fan belt needs to be tightened. Can't imagine the water flow could be effected because of it though.
I read about a TVR specific thermostat that needt to be used instead of the LR one. Is it possible that this is fitted leading to a lower coolant flow?
Thanks,
Peter
Thanks for the fast response guys.
Indeed the fan belt drives the pump and that was why I suspect it now. I can not imagine that, because it's a bit loose the water pump flows less. The charging is OK (14/15 volt and no warning light) and no slipping noises. It only wobbles a bit.
I do need a small spoiler. Mine is lacking and I was considering to do this after installing the alloy rad. The rad is new and I can not imagine a blockage in there. If there is one it's somewhere else. What surprises me is that the whole design is so air/speed dependent. It does not overheat but it needs the airflow through the bay or the fans to cool it down, even if it's freezing. Is this normal?
Peter
Indeed the fan belt drives the pump and that was why I suspect it now. I can not imagine that, because it's a bit loose the water pump flows less. The charging is OK (14/15 volt and no warning light) and no slipping noises. It only wobbles a bit.
I do need a small spoiler. Mine is lacking and I was considering to do this after installing the alloy rad. The rad is new and I can not imagine a blockage in there. If there is one it's somewhere else. What surprises me is that the whole design is so air/speed dependent. It does not overheat but it needs the airflow through the bay or the fans to cool it down, even if it's freezing. Is this normal?
Peter
jonjo said:
The RV8 produces a lot of heat regardless of the ambient air temperature - if your fans are cutting in and out as required I don't see the problem - that's what they're supposed to do - would you rather have a fan attached to the water pump pulley permanently turning?
You know for a new comer your knowledge is pretty impressive JonJo 
Peter66 said:
It does not overheat but it needs the airflow through the bay or the fans to cool it down, even if it's freezing. Is this normal?
It's not normal, but if you look at the angle of the radiator and the path that the air is following under the front of the car you'll see that the incoming air has a choice of turning up into the radiator opening or down and back under the car. The splitter helps encourage it to turn up, but without the splitter it doesn't take much persuasion to make it go down instead. It might only take a small change in the rake of the car affecting the air pressure under the bonnet, or a slight change in the bonnet clearances etc, to make the difference.
A couple of us have changed the way the air is blown through on precats.
Precat has his fitted right next to the heater matrix in the inner wing, a guy on the TGP has made a duct from the original motor location to direct air up over the inner wing.
My car has a pipe attached to the motor going over the inner wing to a Griff 500 airfilter box which is attached to the heater box.
Nightmare of a job, but the air flow is phenomenal, it actually whistles through the windscreen vents.
However, even though my air flow is good, the dash front vents are still crap!!!
Precat has his fitted right next to the heater matrix in the inner wing, a guy on the TGP has made a duct from the original motor location to direct air up over the inner wing.
My car has a pipe attached to the motor going over the inner wing to a Griff 500 airfilter box which is attached to the heater box.
Nightmare of a job, but the air flow is phenomenal, it actually whistles through the windscreen vents.
However, even though my air flow is good, the dash front vents are still crap!!!
If its similar to the Chim, the flap in the mixer box which diverts the air is not a very good seal. I only 'destroyed' a spare one out of interest and was really disappointed in how cr@p it was. The foam which sealed the edges of the flap was in quite a sorry state, seems like it wasn't a very good selection of material IMHO 
There again, de-misting is not a problem if you have the roof off so maybe blocking the windscreen vents is the answer.
Don't know about the early Griffs, but my Chim only has the heater box connected to the windscreen vents and the footwells, direct out of the mixer box on the passenger side and over to the drivers side via the duct at the rear of the engine (prone to leaking). If that duct is leaking, and it seems to get trapped between the back of the engine & bulkhead, it is quite possible there is a lot of pressure lost.
Dave
There again, de-misting is not a problem if you have the roof off
so maybe blocking the windscreen vents is the answer. Don't know about the early Griffs, but my Chim only has the heater box connected to the windscreen vents and the footwells, direct out of the mixer box on the passenger side and over to the drivers side via the duct at the rear of the engine (prone to leaking). If that duct is leaking, and it seems to get trapped between the back of the engine & bulkhead, it is quite possible there is a lot of pressure lost.
Dave
Basically both of you are right, when the divert flap is moved one way or the other it doesnt seal off the opposite direction properly.
As Dave says, with the footwell vents closed and the dash ones open, even with the flap in the right posistion, the air still escapes to the screen. Basically there is less resistance than the smaller tubes going to the dash.
Looking at the later cars, it seems much better as the flap is smaller and toward the front end.
I have the flow I need to demist the screen if required, the roof should be off as much as possible, so I have decided to forget the rest.
The sun will shine !!!!
As Dave says, with the footwell vents closed and the dash ones open, even with the flap in the right posistion, the air still escapes to the screen. Basically there is less resistance than the smaller tubes going to the dash.
Looking at the later cars, it seems much better as the flap is smaller and toward the front end.
I have the flow I need to demist the screen if required, the roof should be off as much as possible, so I have decided to forget the rest.
The sun will shine !!!!
Hi Peter, I fitted a lip spoiler and it made a good 5-10 deg difference to running temps at speed, but made the car run a bit too cool in winter at m/way speeds.
From memory the TVR-specific stat was a lower opening temp than std LR and *might* have small holes drilled in it to assist water flow (but note I might be completely wrong about this, it's been a while!).
Car did have twin fans rather than the early single type. In hot weather as long as it was moving above crawling speed, fans never came on, only when sat in traffic. Maybe the rad isn't sealed to the nosecone correctly - it may have been fitted without cowling etc.
Cheers, Andy
From memory the TVR-specific stat was a lower opening temp than std LR and *might* have small holes drilled in it to assist water flow (but note I might be completely wrong about this, it's been a while!).
Car did have twin fans rather than the early single type. In hot weather as long as it was moving above crawling speed, fans never came on, only when sat in traffic. Maybe the rad isn't sealed to the nosecone correctly - it may have been fitted without cowling etc.
Cheers, Andy
The TVR specific stat has a larger opening in the middle and so can flow more, you can get them from clevor trevor. When I replaced mine it does help a little bit mainly its quicker to come back down to 86-90 once the fans kick in.
So you can probably achieve the same effect by drilling a pair of 3mm holes in the std LR stat
Matt
So you can probably achieve the same effect by drilling a pair of 3mm holes in the std LR stat
Matt
Hi Andy,
Nice that you reply. I am so happy that I bought the Griff last year. I will defintely fit a lip-spoiler. Amazing that it can make such a difference. I think the repair was done on a tight budget (resulting in an old RR rad and 2 small old fans). I replaced it with an alloy one with cowlings and twin fans. Just what I needed to know. When driving slowly I need to use the over ride switch to operate the fans before it gets too warm and more difficult to cool down. I am not looking forward into improving the heater and its related hoses, but will need to do it one day. Thanks also to the others for your feedback. Will keep you posted on the progress!
Merry Christmas and a Happy New Year to all of you,
Peter
Nice that you reply. I am so happy that I bought the Griff last year. I will defintely fit a lip-spoiler. Amazing that it can make such a difference. I think the repair was done on a tight budget (resulting in an old RR rad and 2 small old fans). I replaced it with an alloy one with cowlings and twin fans. Just what I needed to know. When driving slowly I need to use the over ride switch to operate the fans before it gets too warm and more difficult to cool down. I am not looking forward into improving the heater and its related hoses, but will need to do it one day. Thanks also to the others for your feedback. Will keep you posted on the progress!
Merry Christmas and a Happy New Year to all of you,
Peter
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