Getting her juices flowing
Discussion
Hi folks,
Having trashed the cylinder heads in one TVR in my time due to over enthusiasm (I suspect) when the car was cold, I'm currently grappling with the thorny subject of how best to warm my current Chim up. I want to make sure I'm getting her fluids to an optimal temperature and flowing nice and freely, before giving her a damn good seeing too, and hence enjoying the thrilling ride I know she can give me.......sorry, in danger of getting carried away with this female analogy (well the wife's away at the moment, you know how it is).
Seriously, what's the best way to get her warm? I use her everyday for my 20 mile commute around the M25 from South Bucks to North Surrey. I tend to go with a 10 minutes below 3000RPM, and then, if the needles above 70, gradually increase the revs. Once the fans are cutting in and she's settled between 80-90 I tend to regard her as ready to perform for me (Oops, my mind's wandering again!).
Does this seem reasonable or am I in danger of trashing my second engine using this type of regime? I don't really drive her too hard but do want to care for the engine. I'm aware my engine monitoring is only limited to coolant temperature not oil temperature and maybe the realtionship between the too aint as straightforward as I'm assuming.
Comments/advice anyone?
Cheers,
- Andy.
Having trashed the cylinder heads in one TVR in my time due to over enthusiasm (I suspect) when the car was cold, I'm currently grappling with the thorny subject of how best to warm my current Chim up. I want to make sure I'm getting her fluids to an optimal temperature and flowing nice and freely, before giving her a damn good seeing too, and hence enjoying the thrilling ride I know she can give me.......sorry, in danger of getting carried away with this female analogy (well the wife's away at the moment, you know how it is).
Seriously, what's the best way to get her warm? I use her everyday for my 20 mile commute around the M25 from South Bucks to North Surrey. I tend to go with a 10 minutes below 3000RPM, and then, if the needles above 70, gradually increase the revs. Once the fans are cutting in and she's settled between 80-90 I tend to regard her as ready to perform for me (Oops, my mind's wandering again!).
Does this seem reasonable or am I in danger of trashing my second engine using this type of regime? I don't really drive her too hard but do want to care for the engine. I'm aware my engine monitoring is only limited to coolant temperature not oil temperature and maybe the realtionship between the too aint as straightforward as I'm assuming.
Comments/advice anyone?
Cheers,
- Andy.
Andy, sounds OK. I start the car up in the garage and leave for 5 mins mostly to allow the gearbox oil to warm as gear change is rough when cold.
Like you I keep to below 3000 revs until temp is at about 70.
One other thing, when I bought the car the dealer said I should 'blat' the throttle a couple of times on start up as it 'helps clear the cr*p out of the engine/catalyst'.
I'd be interested to hear if other PH'ers do the same, or is this bad advice ?
Regards - Ade
Like you I keep to below 3000 revs until temp is at about 70.
One other thing, when I bought the car the dealer said I should 'blat' the throttle a couple of times on start up as it 'helps clear the cr*p out of the engine/catalyst'.
I'd be interested to hear if other PH'ers do the same, or is this bad advice ?
Regards - Ade
Sounds good to me - I probably dont give it quite as long. I run for around 5-7 miles on less than 3000 then open it up from there. To be honest the drive for the first 5-7 miles is fairly fast so the water temp doesnt get above 70-75 anyway (65MPH ish). However, you can really notice on the oil pressure gauge. From cold it is 50 - 60 lbs, then as it gets warm it drops down to 35 - 40 lbs. I know that this is only a guide, but as the oil warms up then it gets thinner - hence the dropped oil pressure.
Not a perfect guide, but I never let it get over 3000RPM with the oil pressure high. Only when it is lower do I start to open it up a little.
Funny thing is that my Citroen TD is really sluggish on power delivery for up to 30 minutes from cold. However, after a nice long motorway run - nice and smooth... for a diesel.
Cheers,
Paul
Not a perfect guide, but I never let it get over 3000RPM with the oil pressure high. Only when it is lower do I start to open it up a little.
Funny thing is that my Citroen TD is really sluggish on power delivery for up to 30 minutes from cold. However, after a nice long motorway run - nice and smooth... for a diesel.
Cheers,
Paul
quote:
Having trashed the cylinder heads in one TVR in my time due to over enthusiasm (I suspect) when the car was cold
Interesting to read that as I've been hearing more about the serpentine bypass design fault which would cause exactly this sort of failure. How many others here have had problems like this?
>I start the car up in the garage
and leave for 5 mins
I really don't understand the fad for this. Unless you are racing, and there's no time to build up any heat before full-throttle use, then all you're doing is running the engine extremely rich for a long time. That should coke it up nicely!
Any normal car these days tells you to avoid doing this, and just drive it, without too much vigour.
>The dealer said I should 'blat' the throttle a couple of times on start up as it 'helps clear the cr*p out of the engine/catalyst'.
Only once it's had a few seconds for the oil pressure to come up, otherwise you're loading the engine with no lubrication. But yes, it does clear unburned fuel out of the manifold and makes it possible to pull out of my parking space on my car!
Jon
and leave for 5 mins
I really don't understand the fad for this. Unless you are racing, and there's no time to build up any heat before full-throttle use, then all you're doing is running the engine extremely rich for a long time. That should coke it up nicely!
Any normal car these days tells you to avoid doing this, and just drive it, without too much vigour.
>The dealer said I should 'blat' the throttle a couple of times on start up as it 'helps clear the cr*p out of the engine/catalyst'.
Only once it's had a few seconds for the oil pressure to come up, otherwise you're loading the engine with no lubrication. But yes, it does clear unburned fuel out of the manifold and makes it possible to pull out of my parking space on my car!
Jon
quote:
I also believe that the bypass is external and goes through the inlet manifold pipework and off to the heater...
People will try to tell you that, but that isn't the bypass it's the heater feed. Nothing like enough capacity for the serpentine pump, and also has a shut-off valve in it. You really do need a proper bypass otherwise you can get very poor water flow during warm-up, leading to all sorts of nasty thermal shocks.
>> Edited by GreenV8S on Tuesday 23 July 16:29
Based on the several serpentine engines I have had, the bypass does seem to work even if the heater is set to cold. The pipework goes through the inlet manifold and I think there is a return in there. If it was a major problem I would expect to see more problems than necessary.
However, it could be an interesting problem if a standard Rover 88/92 degree stat is fitted that won't allow any flow until the mid 80s. With a lower temp stat, the flow will start at around 10-15 degrees lower and will there will be less thermal shock. Add to this a nice gentle approach to revving the engine when cool and the thermal shock problem (if it exists) would be avoided. To me it is just another reason for not wellying the engine when cold.
Some of the dealers drill several holes through the stat to help the flow as well.
On the 520, we deliberately fitted a 1/2 inch bypass just in case...
Steve
However, it could be an interesting problem if a standard Rover 88/92 degree stat is fitted that won't allow any flow until the mid 80s. With a lower temp stat, the flow will start at around 10-15 degrees lower and will there will be less thermal shock. Add to this a nice gentle approach to revving the engine when cool and the thermal shock problem (if it exists) would be avoided. To me it is just another reason for not wellying the engine when cold.
Some of the dealers drill several holes through the stat to help the flow as well.
On the 520, we deliberately fitted a 1/2 inch bypass just in case...
Steve
quote:I've heard that said; blipping the throttle before switching off is supposed to inject unburnt fuel into the cylinders so its starts dry.quote:Why/how?
Blipping the throttle and then cuttoing the ignition wipes all the oil off the bores so you get more wear next time you start up.
Jarv.
Can't see the logic there, unless you are running inordinately rich. You blip the throttle, revs rise because the fuel is getting burnt. Turn off the ignition, no more fuel - its injection innit? With carbs yes maybe, the engine would continue to suck fuel while it wound down. But not an injection engine, surely?
>> Edited by philshort on Tuesday 23 July 23:42
quote:
From cold it is 50 - 60 lbs, then as it gets warm it drops down to 35 - 40 lbs.
Bloody hell Paul, what you got in there? Chicken soup?! Most people get 30 - 10!
No matter what oil I've had in mine (0w all the way to 15w) I've always had between ~30 (idle/low revs) and 45 or higher (more revs/cracking on).
I wonder if this is the famed gauge inaccuracy coming to light again? Doesn't fill me with confidence, I must say.
The ECu interprets the throttle plip as a good reasons to enrich the mixture to give that va-va-voom. You then turn off the engine in mid va-va-voom or as it it often referred to as a va-va moment and the excess fuel continues and washes bore.
Small Vauxhalls don't do this which is why they are called NoVaVa s....
Runs away before the rotten tomatoes go splat...
Small Vauxhalls don't do this which is why they are called NoVaVa s....
Runs away before the rotten tomatoes go splat...
Gassing Station | Chimaera | Top of Page | What's New | My Stuff