Improving Radiator performance

[asra]

I'm having some cooling issues and noticed this post in another thread."Made up a shroud to "suck" more air through the radiater and it's made a fair difference.Bout 10/15 degrees cooler."Any pictures of successful radiator shrouds?Dave

[birdy]

That was on my 914 Dave,wot have you go on your machine??Different engines will have different solutions to different heat problems.[but if your running a 914,I could post a pic of the cowl].

[asra]

Ok, a 582 with oil injection. I'm thinking that the oil reservoir which is right behind the left radiator is blocking the airflow and part of the problem. I've leaned off the coolant from the recommended 50% then tried 30% and now 23% which has helped considerably. Cowls are the next thing to try.DaveImage Insert: 35.11

[NiqueNaque]

Dave,Are you sure your oil injection is working as it should do, ie, it isn't running too lean is it?Cheers,Nick Tomlin.

[asra]

Well.. the magic marks line up where the cable goes in like the manual says, and the oil goes down slowly about as you'd expect it to for the hours flown...How else do you tell? (I really don't know [])Dave

[asra]

Question???? If you mix the fuel to oil at 50 to 1, what would be the mixture be richer or leaner compared to if you mixed it at 25 to 1?Aussie Paul. []www.firebirdgyros.com

[asra]

Dave it sounds like youve got everything where it should be, the only thing i can suggest is bigger rads, or hotter thermostats, now before you go your crazy, listen to this and think about it, just going to use easy figures here, if 65' thermos keep the water in the engine for say 2 minutes, that means the water in the rads only has two minutes to cool, if 75' thermos keep the water in for say 3 minutes, that is more cooling time and so on, it depends on the job that your doing as to how hot you should go, this all sounds backwards i know to keep the engine running at a higher constant temp to allow the rads to do their job more effiently, but it does work, it means alot of stuffin around to get it right however try everything else first.Mark

[asra]

Paul ,I dont understand the question, the oil content will be richer obviously, however the octane level of the fuel will be leaner because of the oil, is that what you were askin or should i just go do something outside.Mark

[asra]

Mark I would have thought that having the water in the engine for longer it will come out hotter, so the radiator has more work to do to bring the temp down enough. The thermo keeps the water in the engine long enough to reach the thermos set temp. That time will depend on what the temp of the water is when it enters the engine. Full on racing engines don't use thermostats, they have a flat plate in place of the thermostat and keep drilling holes in it until the heating and cooling balance at the temp that they want the engine to be at while racing.I can see where you are coming from though. Mark why don't you post it on the US forum, and see what the intellectuals have to say.Aussie Paul. []www.firebirdgyros.com

[asra]

Mark, I posted this question to help people understand what the terms "richer mixture" and "leaner mixture" actually mean when refering to an engine.Aussie Paul.[]www.firebirdgyros.com

[asra]

Paul the part about the race engines you wrote about is the same as i was talking about, just that if you dont have a thermo in at all it takes a long time to get the engine to a safe take off temp,[V] and as you said they drill holes until they get what they want, the same as changing thermos to get what you need, as i said it takes alot of stuffin around. []Mark I would have thought that having the water in the engine for longer it will come out hotter, so the radiator has more work to do to bring the temp down enough,I agree however as you would know not all the water changes at once, so it sort of equals itself out, hmm dont know if that reads right but bugger it all i just know it works. []Mark

[birdy]

Hav'n the water in the block longer also has the water in the rad longer.The water in the block has more time to absorb heat,and the water in the water in the rad also has more time to loose heat,entering the block at a lower temp,it all balances out.Some motors will over heat if theres no thermo/restriction to slow the water.If theres not enough restriction to the flow of the water just after the pump it'll affect a "vacuum"on the suction side of the impeller,causing cavitation.[bubbles]It's not the temp that causes the boiling but the air bubbles caused by the cavitating pump impeller.A lean fuel/air mix will make a petrol donk over heat Dave.Check your plugs for colour or better still, drop the carb needle one groove and see wot happens.It wont harm anything and if it is the problem,the heat will go and the power will increase.[]Hope I'm maken some sence here.[xx(]

[asra]

Birdy, Do you mean drop the needle clip and lift the needle?Aussie Paul.[]www.firebirdgyros.com

[asra]

Birdy, the pics in the photo Gallery does not show the "cowl".Aussie Paul. []www.firebirdgyros.com

[birdy]

Yes Paul,I ment lift the needle/drop the clip one slot.The cowl was only "commisioned" yesterday.