Chris
I think you have it, restriction of flow to stop HOT SPOTS ... some how l think.....that is the key.
Well done Bill
I'd love to get more details on the cooling system setup. How'd you do the plumbing, radiator, all that stuff . . . and pics too please if possible. Inquiring minds want to know. Greg? Bill? This is a great thread. Keep it going.
'REX . . . Hmmm I like it . . . I can see the vanity plate now . . . 356 P REX . . . & paint some flying tiger style teeth on the front fenders & a Jurassic park logo. A real meat eater.
'REX . . . Hmmm I like it . . . I can see the vanity plate now . . . 356 P REX . . . & paint some flying tiger style teeth on the front fenders & a Jurassic park logo. A real meat eater.
Hi boys...
a quick update on the cooling, my wife and i went a Hot Rod show in Brisbane last weekend, there were couple of kit rods, an AC cobra... nothing like a speedster .....antway I spoke to a custom radiator specialist there, he said with the Rear Engine Front radiator configuration, I should install an electric boost pump in the system, as when the car accelerates you have the weight of the water pressing back against the flow, this can effect the circulation..resulting in over heating... makes sense to me
Anyone got a Harley for sale.....
I had a friend buy a Harley for me in the USA ( texas) the other day, I'm trying to get a total of 4 of them to bring to Australia for resale, so if some one out there has a harley for sale, must be 1988 or older,( our goverment wont allow us to impport newer models)
let me know .....
Been widing the flares on my speedster the past week, will post a pic in a couple of days plus some more on the radiator config
Regards Bill from the Land Down Under
PS An early word of warning, were starting to plan our next trip to the USA ( east coast )...so looking forward to meeting a few more speedster folk
a quick update on the cooling, my wife and i went a Hot Rod show in Brisbane last weekend, there were couple of kit rods, an AC cobra... nothing like a speedster .....antway I spoke to a custom radiator specialist there, he said with the Rear Engine Front radiator configuration, I should install an electric boost pump in the system, as when the car accelerates you have the weight of the water pressing back against the flow, this can effect the circulation..resulting in over heating... makes sense to me
Anyone got a Harley for sale.....
I had a friend buy a Harley for me in the USA ( texas) the other day, I'm trying to get a total of 4 of them to bring to Australia for resale, so if some one out there has a harley for sale, must be 1988 or older,( our goverment wont allow us to impport newer models)
let me know .....
Been widing the flares on my speedster the past week, will post a pic in a couple of days plus some more on the radiator config
Regards Bill from the Land Down Under
PS An early word of warning, were starting to plan our next trip to the USA ( east coast )...so looking forward to meeting a few more speedster folk
Last year, I totally re-did the cooling system on a Spyder. The original builder mounted the radiator horizontal above the mid engine. It wouldn't cool so, I mounted an efficient aluminum radiator with a fan up front and ran -20 Stainless Steel braided hose to the mid-engine mounted Subaru engine.
Provided you get all the air out of the system, it will work just fine.
When I finished, he drove it home (approximately 80 miles) in over 100 degree weather 38C and it stayed at 180 degree's. He's driven it to Palm Springs in the summer and it still stays cool.
Vintage Spyders has been installing Subaru engines for several years as has Special Edition. Neither use the pump you were told to use.
this is the radiator I used: Note the high cfm fan that is attached.
http://store.summitracing.com/partdetail.asp?autofilter=1&part=GRI%2D2%2D58185%2DXC&N=700+115&autoview=sku
Provided you get all the air out of the system, it will work just fine.
When I finished, he drove it home (approximately 80 miles) in over 100 degree weather 38C and it stayed at 180 degree's. He's driven it to Palm Springs in the summer and it still stays cool.
Vintage Spyders has been installing Subaru engines for several years as has Special Edition. Neither use the pump you were told to use.
this is the radiator I used: Note the high cfm fan that is attached.
http://store.summitracing.com/partdetail.asp?autofilter=1&part=GRI%2D2%2D58185%2DXC&N=700+115&autoview=sku
In my opinion, the thermostat isn't solely there to increase pressure. Pressure is going to be increased by the water getting hot and expanding. Water boils at a lower point when it's under pressure and that's why you have a radiator cap with a pre-designed pressure release to keep the radiator and hoses from exploding.
If the thermostat wasn't there, the water would still get hot and probably faster than it should because it isn't staying in the radiator long enough to have a cooling effect from the air transfer.
The hole in the thermostat plate restricts the water in the radiator and allows it to cool when the air flows past the radiator fins.
If the thermostat wasn't there, the water would still get hot and probably faster than it should because it isn't staying in the radiator long enough to have a cooling effect from the air transfer.
The hole in the thermostat plate restricts the water in the radiator and allows it to cool when the air flows past the radiator fins.
The thermostat is a TEMPERATURE switch, not a PRESSURE switch.
When engine is cold, thermostat is closed, and the radiator is OUT of the coolant circulation system. The coolant is routed to RECYCLE thru the engine block so that it warms up quickly.
Upon reaching the thermostats opening temperature, it lets the coolant circulate thru the radiator. If theres an overheating prob, its in the radiator (size, air circ, or clogged)
The size of the hole in the thermostat acts to constrict, and slow the flow rate of the coolant.
When engine is cold, thermostat is closed, and the radiator is OUT of the coolant circulation system. The coolant is routed to RECYCLE thru the engine block so that it warms up quickly.
Upon reaching the thermostats opening temperature, it lets the coolant circulate thru the radiator. If theres an overheating prob, its in the radiator (size, air circ, or clogged)
The size of the hole in the thermostat acts to constrict, and slow the flow rate of the coolant.
Larry, water actually boils at a HIGHER temperature point when it's under pressure, though. The pressure of the whole cooling system is a big part in how effective it will be! The purpose of the t-stat isn't to increase pressure - it's to regulate it, opening and closing at certain temps.
I've also seen some dramatic temperature drops in coolant from also going to a more efficient (usually aluminum) radiator. But I'm not sure I agree that the t-stat does anything to slow down the coolant going through the system. If anything, it's the opposite. Think about it - air comes out of a balloon pretty quickly when you let up on the small neck, right? Same theory applies here - high pressure flows with velocity to low pressure, and you're going to have a higher velocity after the t-stat (going to the radiator), and not before it (in the head you're trying to cool).
It's a popular myth that time spent in the radiator matters; it doesn't. Next time you're up in Boston I'll buy you a couple of rounds and convince you with a more detailed discussion. To continue here would just derail the WRX motor thread even more than we already have, and I'm intently interested in how this turns out. It may have some direct bearing on my own summer projects.
;-)
Chris
I've also seen some dramatic temperature drops in coolant from also going to a more efficient (usually aluminum) radiator. But I'm not sure I agree that the t-stat does anything to slow down the coolant going through the system. If anything, it's the opposite. Think about it - air comes out of a balloon pretty quickly when you let up on the small neck, right? Same theory applies here - high pressure flows with velocity to low pressure, and you're going to have a higher velocity after the t-stat (going to the radiator), and not before it (in the head you're trying to cool).
It's a popular myth that time spent in the radiator matters; it doesn't. Next time you're up in Boston I'll buy you a couple of rounds and convince you with a more detailed discussion. To continue here would just derail the WRX motor thread even more than we already have, and I'm intently interested in how this turns out. It may have some direct bearing on my own summer projects.
;-)
Chris
Chris, I meant to say that water boils at a higher temp. My typo mistake.
Time spent in the radiator does count. If it didn't, then why have a radiator at all. The heat contained in the water is cooled as air passes through the fins of the radiator. The longer the water is in the radiator, the more transfer of heat or, cooling takes place.
The thermostat is the last cooling component that the water passes through before it reaches the engine. If it wasn't there then the water would rush through the radiator and "probably" wouldn't have time to cool properly. If the thermostat sticks in the closed position then the engine overheats as no cool water is entering the hot engine. If the thermostat is thermostat is stuck in the open position then it takes much longer for the engine to warm up but, since the thermostat is in place and providing the restriction, once the engine is up to operating temperatures, the engine stays cool as the water is allowed to stay in the radiator for a prescribed amount of time to be cooled by the passing air.
Every race car that is water cooled has a restrictor plate instead of a thermostat. The reason is to allow the water to stay in the radiator as long as possible and, to preserve the engine should a thermostat stick in the closed position.
If you remove the heat activated plunger in the thermostat, that is the same as having the restrictor plate. Water passes through the hole at the same rate as it would if the heat activated plunger was in place.
Most high speed race cars have an opening as small as 3/8" in their restirctor plate to keep the water in the radiator for a longer time. One of the reasons why they have pace car laps at the beginning of some races is that those laps help bring the water and oil temp's up to operating conditions. Races where there are no pace laps require the car to have pre-heated oil and water in its respective system.
Time spent in the radiator does count. If it didn't, then why have a radiator at all. The heat contained in the water is cooled as air passes through the fins of the radiator. The longer the water is in the radiator, the more transfer of heat or, cooling takes place.
The thermostat is the last cooling component that the water passes through before it reaches the engine. If it wasn't there then the water would rush through the radiator and "probably" wouldn't have time to cool properly. If the thermostat sticks in the closed position then the engine overheats as no cool water is entering the hot engine. If the thermostat is thermostat is stuck in the open position then it takes much longer for the engine to warm up but, since the thermostat is in place and providing the restriction, once the engine is up to operating temperatures, the engine stays cool as the water is allowed to stay in the radiator for a prescribed amount of time to be cooled by the passing air.
Every race car that is water cooled has a restrictor plate instead of a thermostat. The reason is to allow the water to stay in the radiator as long as possible and, to preserve the engine should a thermostat stick in the closed position.
If you remove the heat activated plunger in the thermostat, that is the same as having the restrictor plate. Water passes through the hole at the same rate as it would if the heat activated plunger was in place.
Most high speed race cars have an opening as small as 3/8" in their restirctor plate to keep the water in the radiator for a longer time. One of the reasons why they have pace car laps at the beginning of some races is that those laps help bring the water and oil temp's up to operating conditions. Races where there are no pace laps require the car to have pre-heated oil and water in its respective system.