Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: ngrainqey on 23 November 2008, 21:44:44

Title: extra v6 cooling...
Post by: ngrainqey on 23 November 2008, 21:44:44
hiya,
im just wondering- aswell as fitting a secondard aux fan to the passenger side of the front of the rad....
what do people think i should do to get vented air to cyl5 and 6?

i'v been thinking either chavy vents on the bonnet (wehay actually bonnet vents that have purpose :P and i have a spare bonnet to play with luckily)
or have two ducts clipped to the back of the rear rad fan and use the rad for the air supply

thinking about it more indepth i could put mesh on the fog light plastics and put ducts there (needs to be moving though really for that to work hence why i said behind the radiator

let me know
thanks
Title: Re: extra v6 cooling...
Post by: cem_devecioglu on 23 November 2008, 21:57:08
from some miggy modification sites I remember they increased the water flow capacity of the block..(they really dont give much detail) ..
and they used higher capacity water pump..

also air cooling can be done but I think it needs extra cooling surfaces mounted.. :-/

also I see somewhere else they do port polishing on V6 air inlets..
Title: Re: extra v6 cooling...
Post by: iainb on 23 November 2008, 21:59:46
The problem is the air slows down under the bonnet so venting the hot air is a must. Yes a chavy vent in the lower wing or even the bonnet will help  :-/
Title: Re: extra v6 cooling...
Post by: ngrainqey on 23 November 2008, 22:05:44
yeah, if i could then i'd go for more subtle air vents like on the camaro
(http://i101.photobucket.com/albums/m75/grainqey/camaro.jpg)
Title: Re: extra v6 cooling...
Post by: iainb on 23 November 2008, 22:12:45
ER..........yes, ok I think. Getting rid of the hot air rather than trying to push more cold air into the engine bay is the way forward
Title: Re: extra v6 cooling...
Post by: ngrainqey on 23 November 2008, 22:24:19
Quote
ER..........yes, ok I think. Getting rid of the hot air rather than trying to push more cold air into the engine bay is the way forward

how would i be best going about pushing hot air out?
i'd need cold air coming in to replace the hot air.

unless your suggesting i have a complex hoover like arrangement :P
-cold air coming from the top via vents, a hairdryer fan lol! and then it going out by the exhaust manifolds!
Title: Re: extra v6 cooling...
Post by: iainb on 23 November 2008, 22:37:32
If the exhaust vent for the hot air is greater than void for the cold air you have created a vacum, which will drag in more cold air. At the same time you dont want the hot air exhausting under the car as this will cause turbulance and compromise the road holding. ::)
Title: Re: extra v6 cooling...
Post by: ngrainqey on 23 November 2008, 22:44:53
Quote
If the exhaust vent for the hot air is greater than void for the cold air you have created a vacum, which will drag in more cold air. At the same time you dont want the hot air exhausting under the car as this will cause turbulance and compromise the road holding. ::)

point taken ian!
you could just force cold air in and try and disperse the hot air, anyway those camaro vents are at the top, and we all know hot air goes up! lol...
might have to try and get some templates drawn up for surgical bonnet operation! lol - just wondering what shape would look best/which way round to have them :P
Title: Re: extra v6 cooling...
Post by: iainb on 23 November 2008, 22:46:45
IAIN :'(
Title: Re: extra v6 cooling...
Post by: ngrainqey on 23 November 2008, 22:53:14
Quote
IAIN :'(

sorry iain :(
it's a different way of spelling ian
want a hug? no? lol sorry matey!
Title: Re: extra v6 cooling...
Post by: Kevin Wood on 24 November 2008, 09:58:51
The cylinders are cooled by liquid. Getting air to their vicinity will do nothing at all!

Kevin
Title: Re: extra v6 cooling...
Post by: SteveMJ on 24 November 2008, 18:16:39
Quote
The cylinders are cooled by liquid. Getting air to their vicinity will do nothing at all!

Kevin
Spot on - specific heat of air is so much less than that of water.  (http://en.wikipedia.org/wiki/Specific_heat_capacity)  the table about half way down the entry shows the huge differnce.

Steve
Title: Re: extra v6 cooling...
Post by: tmx on 24 November 2008, 18:54:14
i swear my v6 has 2 fans! does the 3.0 have 2 if it does why not just swap the rad?
Title: Re: extra v6 cooling...
Post by: ngrainqey on 24 November 2008, 20:30:21
Quote
i swear my v6 has 2 fans! does the 3.0 have 2 if it does why not just swap the rad?

afaik the 2.5 has a single fan and 3.0 has the twin fans...
i happen to have a set of twin fans ;)
Title: Re: extra v6 cooling...
Post by: ngrainqey on 24 November 2008, 22:10:16
just a question,
how much does the low running temp thermostat lower the temperature?
Title: Re: extra v6 cooling...
Post by: iainb on 24 November 2008, 22:17:43
It dont it just opens earlier
Title: Re: extra v6 cooling...
Post by: ngrainqey on 24 November 2008, 22:22:03
oh right so just cuts in lower down...
might be needing one of them then :P

thanks iain!
spelt it right now ;)
Title: Re: extra v6 cooling...
Post by: iainb on 24 November 2008, 22:23:44
Smug mode averted. ::)
Title: Re: extra v6 cooling...
Post by: ngrainqey on 24 November 2008, 22:43:48
lol!
ok for some...
i'm here trying to avoid block meltage :P - in theoretical terms atleast!
rather a headache...
i think i'v been making progress tonight though.
i'v found a site on the internet or two for silicon pipes!
i just need to make sure i have the right manifold with the turbo :( hope i get the right one or it's chop and weld time.. or splash out on a saab 3.0 turbo manifold!
and cool running thermostats are quite expensive from memory :(

Title: Re: extra v6 cooling...
Post by: markey mark on 24 November 2008, 22:45:34
cool running stats from courtney about £38ish iirc  :y
Title: Re: extra v6 cooling...
Post by: iainb on 24 November 2008, 22:55:48
Years ago you could buy a sleve to replace the thermostat its job was to slow the flow through the head.
 This if still available would do what you want.
 The down side is the heater would be useless except at high engine RPM.
But you would minimise the risk of over heating.
 You should consider increasing the size of the Rad as well, as turbo charging the engine will increase the temp !
Title: Re: extra v6 cooling...
Post by: ngrainqey on 24 November 2008, 22:56:31
Quote
cool running stats from courtney about £38ish iirc  :y

rly markey?
shows my memorys shite lol!
thought they were around 80/90ish quid!
anyways i'm off to bed to dream about a turbo miggy!
Title: Re: extra v6 cooling...
Post by: Kevin Wood on 25 November 2008, 15:27:25
The thermostat does nothing to the effectiveness of the cooling system. It's just there to stop the engine being overcooled. If you have a problem with overheating the thermostat will already be fully open, so the problem is elsewhere. Ditto the fans. They only protect the engine from overheating in traffic and do nothing when the car is moving at speed.

Certainly don't remove the 'stat or replace it with a sleeve. This is never the correct solution. It will result in the engine running too cool 90% of the time and won't increase the overall cooling available.

If you tune the engine to the nth degree you will find one of two things:

The radiator is not big enough to keep it cool any more.

or

The poorer cooling of the back cylinders on the V6 rears its' head.

Kevin
Title: Re: extra v6 cooling...
Post by: ngrainqey on 25 November 2008, 17:56:05
Quote
The thermostat does nothing to the effectiveness of the cooling system. It's just there to stop the engine being overcooled. If you have a problem with overheating the thermostat will already be fully open, so the problem is elsewhere. Ditto the fans. They only protect the engine from overheating in traffic and do nothing when the car is moving at speed.

Certainly don't remove the 'stat or replace it with a sleeve. This is never the correct solution. It will result in the engine running too cool 90% of the time and won't increase the overall cooling available.

If you tune the engine to the nth degree you will find one of two things:

The radiator is not big enough to keep it cool any more.

or

The poorer cooling of the back cylinders on the V6 rears its' head.

Kevin
lol thanks for that kevin, i know about the issue with overheating on cyl 5 and 6 but what would actually work to cool them better besides increasing the cooland channel diametre?
also...
what do you need to bore out the coolant channels?
just take the head off and take the crank case off and stick a long and bigger drill down it?

thanks
Title: Re: extra v6 cooling...
Post by: Kevin Wood on 26 November 2008, 12:20:17
As I understand it, there is a modification to add an extra coolant inlet from where the oil cooler cover plate bolts to the block. Don't know any more than that but I recall it being mentioned before.

I assume the oil cooler is removed and replaced by a plate with a coolant union on it, and a separate oil cooler is fitted. I am not sure if this coolant inlet is used in addition to, or instead of, the coolant transfer pipe at the rear of the block and, not having dismantled one of these engines that far, I'm not really sure exactly how it works.

Maybe a search would dig up more information. :-/

Kevin
Title: Re: extra v6 cooling...
Post by: GmasterT on 26 November 2008, 13:31:06
Just a quick note, In drifty land we sometimes space the hinges so the bonnet is lifted slightly at the back, Dont know how well it it would look on a proper car that isnt a driftyfied datsun (the pointness of the jap machine kinda suits) but may be worth a go.

The theory (it works) is that the air can then escape out of the back of the engine, howver the aerodynamic bods then argue a low pressure point on the bottom of the windscreen, but meh to them!

Possibly a mod with the screen scuttle as a meet halfway point?

I may well end up doing it to mine if she proves difficult in drifty summer season :)  :y
Title: Re: extra v6 cooling...
Post by: nabsim on 26 November 2008, 13:46:33
You can get louvres cut into the bonnet and they look good. One of the guys on vvoc had this done to his 2.5 vec. Can have a look where he had it done if you are interested.

I thought my 2.5vec has two fans on the radiator, (is auto though). I have been knows to get things wrong on a fairly regular basis though. I can check when I am at home though. If there is two is it possible to fit the fans/mounts from the vec to the Omega?

Just to add, the 2.5/2.6 vec's get very hot as there is no room at all under the bonnet. I know some people took the rubber off the top edge of the scuttle panel. This let a lot of hot air out from the engine bay but also increased cab noise.
Title: Re: extra v6 cooling...
Post by: Marks DTM Calib on 26 November 2008, 14:16:05
Cant see it doing much to a good rear wheel drive car.....the air should exit down the tunnel pretty effectively and doing the spacing could worsen teh coolaing as a result.

The plastic under tray helps cooling quite a bit....
Title: Re: extra v6 cooling...
Post by: ngrainqey on 26 November 2008, 18:05:56
Quote
Cant see it doing much to a good rear wheel drive car.....the air should exit down the tunnel pretty effectively and doing the spacing could worsen teh coolaing as a result.

The plastic under tray helps cooling quite a bit....

i dont have a plastic undertray on mine :(
lol
Title: Re: extra v6 cooling...
Post by: Techno on 26 November 2008, 18:25:53
I'm sure my 2.5 V6 has two fans (infront of the rad) and one the the rear left had side, so three in all.
Title: Re: extra v6 cooling...
Post by: ngrainqey on 26 November 2008, 18:35:36
Quote
I'm sure my 2.5 V6 has two fans (infront of the rad) and one the the rear left had side, so three in all.

mine has a single front one :(
Title: Re: extra v6 cooling...
Post by: Techno on 26 November 2008, 18:57:39
What year/model is yours?  Mine is 97 2.5 V6 CD I would have thought all V6's would have been the same or my be it's different for earlier models.

Just out of interest have you raised this because yours has a cooling issue or just that they run hot?  I say that as mine and others I've seen run at between 90* and 95* on the temp gauge and that is hotter than most other cars I've owned others running at a little over 80*.
  
Title: Re: extra v6 cooling...
Post by: ngrainqey on 26 November 2008, 19:04:17
Quote
What year/model is yours?  Mine is 97 2.5 V6 CD I would have thought all V6's would have been the same or my be it's different for earlier models.

Just out of interest have you raised this because yours has a cooling issue or just that they run hot?  I say that as mine and others I've seen run at between 90* and 95* on the temp gauge and that is hotter than most other cars I've owned others running at a little over 80*.
  
im just wanting to reduce the engine temp at normal running really for using a garret turbo :P

btw mines a '94

this is what i had in mind (the bonnet inlets)
(http://i101.photobucket.com/albums/m75/grainqey/camaro.jpg)
Title: Re: extra v6 cooling...
Post by: ngrainqey on 26 November 2008, 19:10:11
this shows the vents better
(http://i101.photobucket.com/albums/m75/grainqey/camaro2.jpg)
Title: Re: extra v6 cooling...
Post by: Techno on 26 November 2008, 19:11:56
I see, well if mine runs at over 90* with 3 fans and your runs the same with 2 does it?  Fitting an extra one should reduce the running temp but by how much can't say.

You could as I think you and other have suggested fit bonnet louvers I had these on my old Cosworth and they really work, mate at the time replaced his bonnet (due to damage) with a standard one while awaiting repair the heat shot up so they do work.  :)

They worked more by sucking the heat out rather than forcing air in the good old vacuum effect, they are other ways but with the Omega we are very limited with under bonnet space.  

How about increasing the size of the oil cooler?
Title: Re: extra v6 cooling...
Post by: ngrainqey on 26 November 2008, 19:20:37
well im adding an external one instead ;)