Mods while engine is out?..

ajbuwalda · Post by **ajbuwalda** » Fri May 04, 2012 4:31 pm

Hi i have just done a head gasket and waterpump gasket, as i am pulling the heads off i was wondering if there is anything else i could alter or do to improve the engine? And also i have bought another ea81 engine to tinker with and realised thatit had no thermostat, it ran brilliant and the temperature was alot lower without one, is that a smart thing to do????

Smokey · Post by **Smokey** » Fri May 04, 2012 6:08 pm

Can't help re performance of the EA81. Perhaps iridium plugs, bigger gap. MSD Blaster etc coil. The usual service parts that add up, new leads etc.

Re no thermostat. Cooler is not always better. If the rad needs attention. Running with no thermo could help temps but its not addressing the problem. However the worst part of no thermo is that the water doesn't stay in the rad very long. So say its 40 deg and ur on the highway. Pull off onto back streets and the cooling system may nit be able to keep up. Its moving through the rad and back into the hit engine too fast. The thermostat keeps the right engine temp but also keeps coolant in thevrad for the air too cool until needed.

Sent from my Galaxy Nexus using Tapatalk 2

Brumby Kid · Post by **Brumby Kid** » Fri May 04, 2012 6:27 pm

Send me a PM. Doing exactly that now.
Depends on what you want to spend. Full rebuild or not. I would advise at bare minimum radiator service and head service. Then if you want rings bore hone, crank linish, cam grind, new bearings.

Cheers Cam

ajbuwalda · Post by **ajbuwalda** » Fri May 04, 2012 6:38 pm

Thanks guys, just puzzled as i put new head gaskets in 3000ks ago now gone again, i am maybe thinking of doing an ej22 conversion, maybe just maybe....

Brumby Kid · Post by **Brumby Kid** » Fri May 04, 2012 7:08 pm

What car?
How did you do them last time? Exactly how? Did you get the heads pressure tested? Faced? Do you use coolant? Did you torque the heads right?

ajbuwalda · Post by **ajbuwalda** » Fri May 04, 2012 7:25 pm

Pull the motor straight up and onto a table, take manifol off rocker covers and arms, pushrods ect. Then take the heads off and reface, then put back together with new gaskets.
I personaly dont believe in coolant, just antifreeze.
I have a 91 brumby. Also thinking of getting a webercarby but cant find any cheap!!

akpv · Post by **akpv** » Fri May 04, 2012 7:39 pm

Smokey wrote: Re no thermostat. Cooler is not always better. If the rad needs attention. Running with no thermo could help temps but its not addressing the problem. However the worst part of no thermo is that the water doesn't stay in the rad very long. So say its 40 deg and ur on the highway. Pull off onto back streets and the cooling system may nit be able to keep up. Its moving through the rad and back into the hit engine too fast.

You don't want the engine running cold but this info is incorrect, the faster the water runs through the radiator more cooler the engine will be.

steptoe · Post by **steptoe** » Fri May 04, 2012 9:16 pm

do you believe in retorque HG after initial warm up and cool down ?
I have found to use anything other than genuine HG's the rest all take a few extra pounds after warm up, cool down over night.

What are your blown HG symptoms ? Welch plugs replaced last time or confirmed to be stainles or brass? Many orignals are mild steel and rust through.
Subie engines need anti corrosion stuff for engine water

ajbuwalda · Post by **ajbuwalda** » Fri May 04, 2012 9:39 pm

Welsh plugs! Completely crossed my mind, all the water was draining into the oil and the heads arent warped or cracked, so i assumed hg... I will be checking welsh plugs though, and i always re tighten any bolt, i do it the next day after warm up and the next weekend just to be sure.
I got a new radiator cap and done the waterpump gasket, then the hose and now head gasket, but the cap is the right one, 13lb, tested and checked.
Just didnt like change i guess

steptoe · Post by **steptoe** » Fri May 04, 2012 9:51 pm

thank nncoolg for sinking that one in my head last year !

Still, an engine out to do 'em

YouTube · Post by **El_Freddo** » Sat May 05, 2012 12:50 am

ajbuwalda wrote:I personaly dont believe in coolant, just antifreeze.

Same thing!

akpv wrote:You don't want the engine running cold but this info is incorrect, the faster the water runs through the radiator more cooler the engine will be.

No it won't. If the coolant/water/liquid is moving too quickly through the radiator it's not being cooled effectively in hot weather. Cooler times it'll be fine but get that 45 degree day and you'll have all sorts of issues without a thermostat. Different story if you've got a gutted thermostat so it's just the rig in there..

steptoe wrote:do you believe in retorque HG after initial warm up and cool down ?

Nope, hence why the HG's I use are called monotorque!

One improvement you can do is shove an EA82 inlet manifold on - it's slightly bigger in diametre than the EA81 unit, thus it breathes better. It's common for the american guys to do this when they do the weber conversion

Other than that there's really not much you can do other than head work - and some will say that for a non performance engine it's not worth the coin, unless you're doing all the work yourself and you know what you're doing. Just put it back together and make sure you've got all the old head gasket removed before installing the new one!

Cheers

Bennie

steptoe · Post by **steptoe** » Sat May 05, 2012 8:27 am

Must be a Victorian thing , believing coolant is also antifreeze. That stuff available to shove in the cooling system is sometimes green and is just an anti corrosive stuff has no antifreeze properties - bought a few litres by mistake from repco with their branding on it. If you saw green shtuff in my rad you'd think you saw antifreeze. May have been for the tropics market.

What is coolant anyway ? water first ? something added to be able to lift boiling temp above waters 100 C - thought that was just called pressure ?!

Then there are labels calling stuff antifreeze/antiboil with corrosion inhibitors - sort of covers all bases when it says this !

I understand m o n o torque HG's concept and have discussed with a few machine shop workers and owners who still insist a single torque HG still needs a retension despite name and claims. They don't belive me when I tell of my experience with genuine Sube HGs for EA82 - not taking any more fromt the torque wrench on second tension !

Vic must also have a good supply of ACL's monotorque - further north of the border we are told NLA - they went down with miss subishi
I am sold on genuine HGs

YouTube · Post by **El_Freddo** » Sat May 05, 2012 9:40 am

steptoe wrote:Must be a Victorian thing , believing coolant is also antifreeze. That stuff available to shove in the cooling system is sometimes green and is just an anti corrosive stuff has no antifreeze properties...

What is coolant anyway ? water first ? something added to be able to lift boiling temp above waters 100 C - thought that was just called pressure ?!

There's coolant and there's antifreeze/antiboil. Coolant will last longer in protecting your cooling system from corrosion and it's much cheaper in the long run if you're just daily driving.
Antifreeze/antiboil is a much more concentrated mix that needs replacing a lot earlier than just coolant.

Both are sort of the same in composition - what the antifreeze/antiboil has over the regular coolant is a pot load more glycol - this is the stuff that really changes the properties of the water's boiling and freezing point. It's really only needed if you're putting your cooling system under extreme stress of hot climates or very cold climates. I'm running a 33% mix (or there abouts) of Techalloy antifreeze antiboil, it last 2 years or 40,000km as the bottle says. I've found it to be good, it shouldn't freeze above -19, Hotham doesn't get any where near that, the worse I've seen is -12 and a blistering wind!
And when out in the wyperfeld NP I didn't have temp issues even when she was getting really hot, still no boiling!

steptoe wrote:Vic must also have a good supply of ACL's monotorque - further north of the border we are told NLA - they went down with miss subishi
I am sold on genuine HGs

Dunno about that, my local's distributor still has them available, i thought you'd be able to get them up there too

Cheers

Bennie

akpv · Post by **akpv** » Sat May 05, 2012 10:51 am

El_Freddo wrote: No it won't. If the coolant/water/liquid is moving too quickly through the radiator it's not being cooled effectively in hot weather. Cooler times it'll be fine but get that 45 degree day and you'll have all sorts of issues without a thermostat. Different story if you've got a gutted thermostat so it's just the rig in there..

I can see the logic you are trying to use but it is just incorrect. Yes it spends less time in the radiator cooling down but will also spend less time in the engine heating up.

eg slow rate of flow 1min in engine followed by 2min in radiator, fast rate of flow .5min in engine, 1min in radiator NOT 1min in engine 1min in radiator.

The rate of heat transfer is proportional to the difference in temperature between the coolant / water and the air. In order to maximise the heat taken out of coolant (or coolth put into the coolant) you want to keep the coolant as hot as possible while it is in the radiator (sounds anti intuitive i know). The faster your coolant is flowing the more uniform the temperature of the coolant will be throughout the cooling system and therefore the more heat that can be taken out by the air. I can crack out the heat transfer formulas if you want.

Another way to think about it is how a thermostat works, it is closed when it is cold, open when hot. The more flow the better for cooling the engine.

Edit - This article explains it better than I did: http://tc.wagoneer.net/sblog/static.php ... ling_myths

Double edit - http://www.pirate4x4.com/tech/billavista/Cooling/

For those that cling tenaciously to myths, I am going to take one last crack at forever dispelling the Granddaddy of them all when it comes to cooling systems.

The myth is stated as either:

Coolant can be pumped too fast through the engine for it to absorb enough heat, or
Coolant can be pumped too fast through the radiator for it to cool properly, or
Cooling can be improved by slowing the flow of coolant through the radiator so it cools more completely.

NONE of these is true. The simple truth is that higher coolant flow will ALWAYS result in higher heat transfer and improved cooling system performance.

The reason the myth is so persistent, is that: a) without knowledge of fluid dynamics and laws of thermal conduction it does make a kind of intuitive sense and b) it is based on a tiny kernel of truth, but that kernel of truth does not explain the overall system behaviour and so, interpreted out of context, leads to a completely erroneous conclusion.

So, let's start with the tiny nugget of truth. If you had a sealed rad (no flow) full of hot coolant, and subjected that rad to airflow, yes, the longer you left the coolant in the rad, the more it would cool. However, if you were to plot that cooling over time, you would find that the RATE at which the cooling takes place is an exponential curve that decreases with the temperature difference between the hot coolant and the air. Put another way - when the temperature difference (delta-T) between the hot coolant and the airflow is large, heat transfer (cooling) initially takes place very, very quickly (almost instantaneously). But as that happens, and the coolant cools, the delta-T becomes less, and the RATE at which further cooling happens gets less and less until the point where the coolant and air are almost the same temperature and continued cooling takes a very long time. This is Newton's law of cooling. To illustrate this, recall my "quenching steel in a bucket" analogy.

A good example of this law can be seen when quenching a red-hot piece of steel in a bucket of water. At first, the temperature difference (delta-T) between the red-hot steel and the water is huge - therefore the initial heat transfer occurs at a great rate - the steel initially cools very fast - almost instantaneously. However, after this initial cooling, the delta-T is much smaller, so the remaining cooling occurs much more slowly. If you removed the steel after a second or two - it has cooled a lot - but it will still be warm. To continue cooling the steel to the temp. of the water, you have to leave it in there quite a bit longer - because as it cools - the rate of cooling continually decreases as well. In short - initial cooling is fast, but subsequent cooling occurs more and more slowly until cooling that last little bit takes a long time.

So what does this mean? Basically it means, the longer the coolant stays in the rad, the less efficient the cooling that takes place is - to the point that the rate of cooling is so slow as to be detrimental to overall system cooling. Better to dump the big load of heat right away and go back quickly for another load than hang about waiting for a last little bit of insignificant cooling to happen.

To understand fully, we have to put our rad back into the whole system where coolant is flowing and consider the effects of flow rate on the system as a whole.

Slowing the coolant in the rad may allow that coolant (the coolant in the rad) to dissipate a little more heat (but not much), and at an ever decreasing rate (exponentially decreasing) BUT since the cooling system is a closed-loop system, you also have to consider what’s happening outside the radiator if you slow the flow - especially to the coolant in the engine. If you slow the coolant through the rad, you slow the coolant through the engine too. And this coolant is subject to the same laws - the greater the initial temperature difference between the engine and the coolant, the greater the rate at which the coolant absorbs the heat from the engine. BUT - if we leave the coolant in contact with the engine for longer by slowing the flow through the rad, the delta-T between engine and coolant decreases and with it the rate at which the coolant in the engine absorbs the heat from the engine. Meanwhile the engine is banging away producing heat, but the coolant is absorbing it at a slower and slower rate - that heat has to go somewhere, and since the slow coolant is becoming less efficient at absorbing it - it stays in the metal - and the metal overheats!

Meanwhile, back at the rad, you're wasting time trying to shed the last little bit of heat when the delta is small instead of carrying away the “big chunks” of heat. And the situation just gets worse and worse in a downward spiral.

Imagine emptying a truckload of sand using a small wide-mouth container vs. a larger narrow-mouth container. The job will get done quicker by making more trips with the smaller container that takes less time to fill and empty, rather than taking the time to fill the larger narrow-mouth container and then taking the time to empty it – that extra in the larger narrow-mouth container isn’t worth it – better to dump the load and go back for more.

Or, how about this for those who are fans of elaborate metaphors

Imagine a circular train track with two stations opposite each other and rail cars that fill the whole track. One station has an endless supply of passengers trying to get on and the other is where they get off and disperse. Your job as the train driver is to move as many people as possible to keep them from accumulating at the embarkation station and crushing each other. Now imagine the passenger cars are funnel-shaped on the inside. This means the first big batch of people can get on and off quickly, but completely filling the car takes a lot longer as people have to squeeze into the narrower portion.
So, you could drive the train slowly, only moving along after each car has completely filled and completely emptied… but efficiency will be greatly reduced as it takes so long to get those last few people on or off the car – meanwhile the never ending supply of people at the embarkation station never stops and the system backs up and the people get crushed because, even though more people get on or off each car, the whole system is less efficient.

OR

You could drive the train fast, quickly loading and unloading the big, easy-to-fill, portion of each car, forget about the smaller portion, and keep picking up and dumping off a large group of passengers as fast as you can. In fact – the faster you go, the better…the more efficient at moving large numbers of people the system will be. Screw the last stragglers – they’re insignificant and won’t help you – just move the big chunk and move on, going back for more, more often.

So – you want high flow / high (turbulent) speed so it picks up and dumps off the most heat quickly – it’s inefficient to try and shed the last little bit of heat when the delta is small, and can lead to overheating because you’re wasting time not carrying away the “big chunks” of heat.

Smokey · Post by **Smokey** » Mon May 07, 2012 5:58 pm

Can't believe I read all that. I still disagree. And on two fronts:

1) the article doesn't address the fact that the engine is designed to run at X temp. As its the most fuel efficient at X. The rest of the system is designed around said X temp also. Oil viscosity for example.
2) it states that temp will be lowered faster if the temp diff is greater. Isn't that what happens when thermostat controlled flow. Ie cooler water faster cools engine as it enters engine. And hot water faster cools when it reaches an already cooler water temp in the radiator.

Funny reading though about the train station. If only it could work in real life hahah

Sent from my Galaxy Nexus using Tapatalk 2

akpv · Post by **akpv** » Mon May 07, 2012 11:45 pm

To answer your points

1) I wasn't arguing it was better to run your car without a thermostat, I was arguing that it will not make it overheat / run hotter. You are dead right, the thermostat is there for a reason, the engine isn't designed to run cold.

akpv wrote:You don't want the engine running cold but this info is incorrect, the faster the water runs through the radiator more cooler the engine will be.

(I meant the cooler the engine will be)

2) Yeah nah. First of all you don't want to be cooling down water with the already cool water in the radiator, that will heat that water up! The idea of the radiator is to use air to strip away the heat. Cold water will cool down an engine quicker than hot water but the engine wouldn't be as hot if you hadn't restricted the flow in the first place. Having a slow flow will be unsustainable, if it is too slow it will eventually overheat.

Anyway I'm done, original OP: Taking out your thermostat will not cause your car to over heat.

Smokey · Post by **Smokey** » Tue May 08, 2012 7:43 am

Fair enough mate. Didn't mean to attack u. Was bored on the train

Sent from my Galaxy Nexus using Tapatalk 2

Post by **Alex** » Tue May 08, 2012 8:56 am

I'd be more concerned about the excessive amount of time for the motor to warm up without a thermostat

Sent from my HTC Velocity 4G using Tapatalk 2

Silverbullet · Post by **Silverbullet** » Tue May 08, 2012 9:39 pm

Alex wrote:I'd be more concerned about the excessive amount of time for the motor to warm up without a thermostat

THANK YOU!

Was waiting for someone to say that, was about to say it myself

This is why I wouldn't consider even gutting my T-stat for a road car let alone taking it out; the warm up time is absolutely ludicrous. E.g, my old T-stat wasn't closing properly, but was open so little I didn't even notice it until I compared it to a new one. So about <1mm all round. On a cool morning (I guess about 10-15 deg C ambient) it would take, no joke, 20 minutes or more of normal driving at 60 for the choke to pop in (choke would pop in as I was pulling into the car park of my destination!) and this had a huge impact on my fuel economy and how quickly I fouled plugs because the choke was out constantly.

Engines are designed to run at certain temp for maximum efficiency and power, for a road car you want it up to temp as quickly as possible and stay there.
There's my bit on the subject

Back on topic while it's out why don't you give the engine a top to bottom scrub and clean with degreaser, thinners or whatever it takes to make it shine. Makes it look so much nicer to look at and work on

steptoe · Post by **steptoe** » Tue May 08, 2012 9:49 pm

If only Jonno could remember where he stashed his thermostat for the Vortex - been running without