Very hot and bothered

Very hot and bothered

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blitzracing

Original Poster:

6,387 posts

219 months

Sunday 1st July 2018
quotequote all
A friends 5ltr runs at 100'c all the time- the rad' is brand new, as the thermostat (large bore), and both fans are on full speed all the time. The engine bay is like a warp core heat wise, and it simply looks like hot air cant get out of the engine bay. Im going to have a play with the fueling to see if I can cool the catalyst as this cant help but Is the 5lt cooling system really that marginal?

Quick update- ripping off the number plate has made a significant difference- so time for a splitter to force more air in in the air intake and cut the number plate down is size...

Edited by blitzracing on Sunday 1st July 19:51

carsy

3,018 posts

164 months

Sunday 1st July 2018
quotequote all
Fitting a splitter will make a very noticeable difference especially in this heat.

chris52

1,560 posts

182 months

Sunday 1st July 2018
quotequote all


I use a smaller number plate. The under bonnet temps on a Griff are ridiculous. Mine runs at 90deg constant with odd time climbing to 95 but never seen it at 100. Make sure there is a gap at the top of the bonnet between it and the landing panel (black mesh that the wipers bolt through) just a small gap to let the air escape will make a big difference. Removing pre cats will also help.

ChimpOnGas

9,637 posts

178 months

Sunday 1st July 2018
quotequote all
The biggest reduction in heat will come from advancing the ignition timing, the standard setup of 12 degrees only exists to improve emissions.

Ditch the cats and run 18 degrees of timing at idle and you'll see a massive drop in engine bay temps yes

citizen smith

743 posts

180 months

Sunday 1st July 2018
quotequote all
blitzracing said:
A friends 5ltr runs at 100'c all the time- the rad' is brand new, as the thermostat (large bore), and both fans are on full speed all the time. The engine bay is like a warp core heat wise, and it simply looks like hot air cant get out of the engine bay. Im going to have a play with the fueling to see if I can cool the catalyst as this cant help but Is the 5lt cooling system really that marginal?

Quick update- ripping off the number plate has made a significant difference- so time for a splitter to force more air in in the air intake and cut the number plate down is size...

Edited by blitzracing on Sunday 1st July 19:51
Have you carried out an independent water temperature test, simply because the gauges can be inaccurate.


anonymous-user

53 months

Monday 2nd July 2018
quotequote all
For reference, my stock 500 with an "early on" (85) stat sits at 90 all the time. Fans are on most of the time in slow driving. This is during the current weather.

I believe the rv8 optimal running temp is around 90.

BJWoods

5,015 posts

283 months

Monday 2nd July 2018
quotequote all
blitzracing said:
A friends 5ltr runs at 100'c all the time- the rad' is brand new, as the thermostat (large bore), and both fans are on full speed all the time. The engine bay is like a warp core heat wise, and it simply looks like hot air cant get out of the engine bay. Im going to have a play with the fueling to see if I can cool the catalyst as this cant help but Is the 5lt cooling system really that marginal?

Quick update- ripping off the number plate has made a significant difference- so time for a splitter to force more air in in the air intake and cut the number plate down is size...

Edited by blitzracing on Sunday 1st July 19:51
no

something is wrong with that car..

mine sits between 80-90 -

90 even on the hottest days.

(mine has standard number plate, and had no problems without the splitter, and has it's catalysts, totally standard engine wise)
rather than modify around the problem. best to solve the problem? it should not run this hot


Edited by BJWoods on Monday 2nd July 08:51

Loubaruch

1,164 posts

197 months

Monday 2nd July 2018
quotequote all
You definitely have a problem.

My 1996 Griffith 500 did 500+ miles yesterday to Shelsley Walsh and the temperature on the guage never exceeded 80 while on the move.

Even when stuck in traffic ( quite a few times) the temperature with the fans on never exceeded 90. It was a sweltering day so a decent test.

Loubaruch

1,164 posts

197 months

Monday 2nd July 2018
quotequote all
You definitely have a problem.

My 1996 Griffith 500 did 500+ miles yesterday to Shelsley Walsh and the temperature on the guage never exceeded 80 while on the move.

Even when stuck in traffic ( quite a few times) the temperature with the fans on never exceeded 90. It was a sweltering day so a decent test.

steve-V8s

2,899 posts

247 months

Monday 2nd July 2018
quotequote all
I looked at a Griff once that struggled in warm weather but was otherwise OK.

The Fans had been off and were reconnected the wrong way round. Worth checking if they came off to fit the new rad.

debaron

866 posts

196 months

Monday 2nd July 2018
quotequote all
steve-V8s said:
I looked at a Griff once that struggled in warm weather but was otherwise OK.

The Fans had been off and were reconnected the wrong way round. Worth checking if they came off to fit the new rad.
This. bought a Chim that was blowing only one fan the right way. Changed wiring polarity and all was well!

andyy

235 posts

257 months

Monday 2nd July 2018
quotequote all
My 500 ran hot a few times.
2 things worth checking

Make sure that the heat setting for the cabin is hot - this will allow water to circulate through the heater matrix giving you a couple more pints of water to play with.

Second thing which is not so easy - check that the oil pick up strainer isn't blocked. Mine was with old sump gasket and silicone sealant. Oil pressure will be fine but you don't get enough flow and hence cooling

Good luck

Hedgehopper

1,537 posts

243 months

Monday 2nd July 2018
quotequote all
Have you tried bleeding the radiator? You can also bleed the system at the blocked off pipe on the n/s of the engine near the oil filler cap. Make sure you bleed with the heater on maximum.

These engines only overheat if something needs attention.

blitzracing

Original Poster:

6,387 posts

219 months

Tuesday 3rd July 2018
quotequote all
Thanks for the thoughts so far- basically there has been a massive drop in temp with the number plate removed, plus we spent more time bleeding the system- so plan of action is to fit a splitter to force more air in, and make the number plate as small as legally possible to start with. Also worth moving the bonnet clamps up a bit at the rear to increase the air gap. Im still going to have a play with the fueling to see if I can reduce the cat' temp, as it should also improve the MPG. Id recommend COGs recommendation of removing the ported vacuum as well, as I cant find a downside on this mod what so ever.

Edited by blitzracing on Tuesday 3rd July 11:48

Rob_the_Sparky

1,000 posts

237 months

Tuesday 3rd July 2018
quotequote all
Number plates are oversized to what they need to be, You can take about 30mm off the width of a standard 7 figure number plate and still be legal. If you plate has fewer characters or a "1" then you can make it smaller (a "1" is the only narrower character).

See page 10 of this: https://assets.publishing.service.gov.uk/governmen...

"Margins" is what you want to look for, I.e. the minimum amount of material you must have around the characters.

BIG DUNC

1,918 posts

222 months

Tuesday 3rd July 2018
quotequote all
This seems to be curing the symptom, but not the problem.

The Griff cooling system is not that marginal.

When it left the factory it would have had a full sized number plate and the bonnit in the proper position and the fans would not have been running all the time.

It sounds to me like something else is wrong.

Sardonicus

18,928 posts

220 months

Wednesday 4th July 2018
quotequote all
Your 1st big mistake is trusting what the fitted gauge is telling you and the fact you think the under-bonnet heat is excessive scratchchin well even a properly running car will have sweltering heat this time of year under the bonnet if the cat/cats are still fitted even when at correct coolant temps frown get an accurate gauge of the actual engine temperature (thermal gun etc) around coolant stubbs radiator etc keeping away from shiny parts nerd before you go into melt down over this possible issue

blitzracing

Original Poster:

6,387 posts

219 months

Wednesday 4th July 2018
quotequote all
Ill pop Rovergauge on there to check- but my spider senses tell me this is really hot, and the engine starts to stall badly as it reaches an indicated 100'c. Im not loosening the cap to find out it boils ! furious Mind you maybe I'm just used to a nice Ginetta cooling system that never goes above 85'c whatever the ambient temp.

Edited by blitzracing on Wednesday 4th July 12:36


Edited by blitzracing on Wednesday 4th July 12:36

Loubaruch

1,164 posts

197 months

Thursday 5th July 2018
quotequote all
Sardonicus said:
Your 1st big mistake is trusting what the fitted gauge is telling you and the fact you think the under-bonnet heat is excessive scratchchin well even a properly running car will have sweltering heat this time of year under the bonnet if the cat/cats are still fitted even when at correct coolant temps frown get an accurate gauge of the actual engine temperature (thermal gun etc) around coolant stubbs radiator etc keeping away from shiny parts nerd before you go into melt down over this possible issue
As the fans are running continually you can surely rule out guage errors, they are only a guide at the best of times.

Have you checked that all the coolant hoses/circuit are clear?

I found this many years ago:

http://www.bertram-hill.com/griffith-cooling-syste...

Loubaruch

1,164 posts

197 months

Thursday 5th July 2018
quotequote all
Sardonicus said:
Your 1st big mistake is trusting what the fitted gauge is telling you and the fact you think the under-bonnet heat is excessive scratchchin well even a properly running car will have sweltering heat this time of year under the bonnet if the cat/cats are still fitted even when at correct coolant temps frown get an accurate gauge of the actual engine temperature (thermal gun etc) around coolant stubbs radiator etc keeping away from shiny parts nerd before you go into melt down over this possible issue
As the fans are running continually you can surely rule out guage errors, they are only a guide at the best of times.

Have you checked that all the coolant hoses/circuit are clear?

I found this many years ago:

http://www.bertram-hill.com/griffith-cooling-syste...