[BottledFedMR2]

Awesome! Can't wait to see your findings. Are you going to run it in series, or replace your existing?

I'm first going to try and run it in series, if that's works then I'll leave it. If it doesn't then my plan is to remove all the OEM coolant components and run 2 electric pumps in series. One before the rad and one after the rad. I'm researching pumps and options right now. The Aerospace one is great because it only runs on 4 amp but I don't like the double house setup. I feel putting that one before the rad will only complicate the hoses. No to mentions there isn't much room for it near the block even if you remove the water housing. I found a EMP Stewart pump for $400 that put's out 55 GPM and runs off 8 amp. Plus it's a complete drop in and has the required fitting's we need in the exact size we need. The cool thing is it's linear with the pipes. Measures 7 inches in length so you can install it by the steering rack and it wouldn't take up any space. Weigh's ~ 5 lbs. To run this I think your best option would be to convert the power steering to manual. Which can be easily done. There is a couple of good write up out there on how to do it. Doing this would free up the ampere's we would need to run at least two pump's on a smaller racing battery.

http://www.summitracing.com/parts/EMP-E389A-BK14/

 

[BottledFedMR2]

Another thing we are going to do is get ride of the MR2 "over flow bottle" the Toyota's coolant setup is different from the Acura as it doesn't have a real overflow . We are purchasing some Ktuned parts in the GB that's allows to get a cylinder head temperature as well as increase the pressure on the system which we are hoping will decrease if not eliminate the cavitation.

 

[dblotii]

I'm first going to try and run it in series, if that's works then I'll leave it. If it doesn't then my plan is to remove all the OEM coolant components and run 2 electric pumps in series. One before the rad and one after the rad. I'm researching pumps and options right now. The Aerospace one is great because it only runs on 4 amp but I don't like the double house setup. I feel putting that one before the rad will only complicate the hoses. No to mentions there isn't much room for it near the block even if you remove the water housing. I found a EMP Stewart pump for $400 that put's out 55 GPM and runs off 8 amp. Plus it's a complete drop in and has the required fitting's we need in the exact size we need. The cool thing is it's linear with the pipes. Measures 7 inches in length so you can install it by the steering rack and it wouldn't take up any space. Weigh's ~ 5 lbs. To run this I think your best option would be to convert the power steering to manual. Which can be easily done. There is a couple of good write up out there on how to do it. Doing this would free up the ampere's we would need to run at least two pump's on a smaller racing battery.

http://www.summitracing.com/parts/EMP-E389A-BK14/

Before you put a pump in-series near the radiator, make sure the minimum area in that pump is at least as big as the radiator hose or you have good chance of not getting a net gain at full engine speed.

My main recommendation is to not fool around with extra pumps until you are sure you have gotten all of the air out of the current system, because until you do, you don't really know if the OEM pump is really sufficient. If there is air in the system, the system will not pressurize, and if it does not pressurize, you will cavitate the pump at high pump speeds.

Dave

 

[BottledFedMR2]

Before you put a pump in-series near the radiator, make sure the minimum area in that pump is at least as big as the radiator hose or you have good chance of not getting a net gain at full engine speed.

My main recommendation is to not fool around with extra pumps until you are sure you have gotten all of the air out of the current system, because until you do, you don't really know if the OEM pump is really sufficient. If there is air in the system, the system will not pressurize, and if it does not pressurize, you will cavitate the pump at high pump speeds.

Dave

We found the pump with a 1.25 inlet and 1.25 outlet which the same size of the factory pipes. I understand what your saying if its smaller than your create a bottleneck. You cannot know for certain if all the air is out. I'm bleeding as it idles and I get no air out anymore. There is heat present but its very low, if I step on the gas the heat goes up almost instantly and it's so hot you don't want to keep your hand in front. I think it is safe to say I have removed all the air but if I take it on the dyno, it will over heat after 2-3 pulls. So I think the cavitation happens at high RPM's, then I get steam from the boiling of the rad fluid and it creates air.

 

[dblotii]

We found the pump with a 1.25 inlet and 1.25 outlet which the same size of the factory pipes. I understand what your saying if its smaller than your create a bottleneck. You cannot know for certain if all the air is out. I'm bleeding as it idles and I get no air out anymore. There is heat present but its very low, if I step on the gas the heat goes up almost instantly and it's so hot you don't want to keep your hand in front. I think it is safe to say I have removed all the air but if I take it on the dyno, it will over heat after 2-3 pulls. So I think the cavitation happens at high RPM's, then I get steam from the boiling of the rad fluid and it creates air.

Boiling of the antifreeze does not create air, it creates steam which re-condenses. You should put a pressure gauge on the coolant reservoir to measure the peak cooling system pressure during a dyno pull, and also inspect the hose that goes into the stat at full-power to make sue it is not collapsing. Also make sure that the cooling flow direction through the hot bottle is in the correct direction. Only one direction works to de-aerate the coolant.

Dave

 

[b16a2delsol]

So after 3 months with the swap done I have decided to put the rear interior back in. But I have a dilemma; the Fuel line cover doesn't fit with the -6an 90* fittings I have tried. The fitting I have now is the smallest one I could find but the cover still doesn't seat correctly. Now before I go have this thing hammerformed, has anyone found a fitting to allow the cover to fit?

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[CSPIDY]

Found this on MR2 Roadster.com (sorry if this has already been posted) couldn't resist.

http://m.autoevolution.com/900-hp-t.../900-hp-toyota-mr2-goes-all-need-for-speed-in-arizona-street-racing-105637.html

 

[gawdzilla]

so i think i finally got my k20a2 swap's coolant bled. i do tend to agree that the belt driven honda pump seems underdriven, given the difference between a typical short run front engine setup vs. our mid engine setup. i notice a significant increase in flow (via visible coolant temp drop) when the engine is brought above 3800 rpm. i vacuum bled the system. one of the mistakes i was making was overfilling the expansion tank and capping it too early, leaving no room for expansion and purging of the air bubbles. i guess it was my fear that the tank would go empty and suck in air. another thing i read from the 2zz swap coolant bleed tips was to restrict the upper return on the expansion tank. i added a small restrictor, and also elevated that hose before it enters the tank. seems to have helped... maybe let air through the top hose instead of a steady flow of coolant? heat seems consistently warm now. btw i am running the k24 water pump, the one without the water outlet for the k20 oil warmer. not sure if that makes a difference.

 

[KseriesPower]

so i think i finally got my k20a2 swap's coolant bled. i do tend to agree that the belt driven honda pump seems underdriven, given the difference between a typical short run front engine setup vs. our mid engine setup. i notice a significant increase in flow (via visible coolant temp drop) when the engine is brought above 3800 rpm. i vacuum bled the system. one of the mistakes i was making was overfilling the expansion tank and capping it too early, leaving no room for expansion and purging of the air bubbles. i guess it was my fear that the tank would go empty and suck in air. another thing i read from the 2zz swap coolant bleed tips was to restrict the upper return on the expansion tank. i added a small restrictor, and also elevated that hose before it enters the tank. seems to have helped... maybe let air through the top hose instead of a steady flow of coolant? heat seems consistently warm now. btw i am running the k24 water pump, the one without the water outlet for the k20 oil warmer. not sure if that makes a difference.

IF you keep ALL oem lines intact and plug the heater core line coming out of the head (just like the 1zz) and fill it properly, you will have zero cooling issues and it will act IDENTICAL to the 1zz setup

When you start adding a bunch of aftermarket shit, deleting lines, etc. you will run into problems.

The 1zz celica water pump is the same part number as the 1zz MRS pump.

 

[BottledFedMR2]

so i think i finally got my k20a2 swap's coolant bled. i do tend to agree that the belt driven honda pump seems underdriven, given the difference between a typical short run front engine setup vs. our mid engine setup. i notice a significant increase in flow (via visible coolant temp drop) when the engine is brought above 3800 rpm. i vacuum bled the system. one of the mistakes i was making was overfilling the expansion tank and capping it too early, leaving no room for expansion and purging of the air bubbles. i guess it was my fear that the tank would go empty and suck in air. another thing i read from the 2zz swap coolant bleed tips was to restrict the upper return on the expansion tank. i added a small restrictor, and also elevated that hose before it enters the tank. seems to have helped... maybe let air through the top hose instead of a steady flow of coolant? heat seems consistently warm now. btw i am running the k24 water pump, the one without the water outlet for the k20 oil warmer. not sure if that makes a difference.

There is no difference between the actual pump's. The only difference is in the casting wheat her it has a provision for the cooler or not.

IF you keep ALL oem lines intact and plug the heater core line coming out of the head (just like the 1zz) and fill it properly, you will have zero cooling issues and it will act IDENTICAL to the 1zz setup

When you start adding a bunch of aftermarket shit, deleting lines, etc. you will run into problems.

The 1zz celica water pump is the same part number as the 1zz MRS pump.

What does 1zz stuff have to do with this? Maybe you meant K series. Correct, your setup is identical to the Toyota system designed to run the Toyota engine's, I to had that setup initially. The Honda engine was designed to work with the Acura/Honda setup, which is different than the Toyota. Honda's system was design to pump the water approximately 4-5 ft, now your putting that design into a car that requires 20-25 ft. Honda may over design the efficiency of the pump, I do not believe to the extent of 20-25 ft and under aftermarket modification which require greater coolant efficiency, though. I agree you'll most likely get by if your stuff is completely stock stuff, but when you start running higher compression ratio's and internal modification which are going to increase HP and engine temp's, then you'll start to have the problem's. When you compare the Toyota pump to the Honda pump you can see the difference. Toyota also made one pump different which had more "fin's" on it and was designed to flow better at higher RPM's. I also read the Midlana thread and he has the exact problems we are having and took the same step's as we did. I am 100% convince that there is cavitation happening at higher RPM's while the stock guy aren't noticing it because you still have some flow, it is happening. Midlana's thread is also 400 whp turbo car.

I guess we will just wait and see we are ordering parts this week and should know by this weekend. We are re-designing the cooling system and making it track legal. We are remove the "puke tank" and putting in a Ktuned plate with filler cap and a high pressure cap. This will allow us to put the aftermarket temp sensor right on the cylinder head as well as ease when filling and bleeding the system.. Currently, we are getting a 40 degree difference reading from the coolant hoses to the ECT sensor. Then we will run a real overflow tank that has a 1/8 tube from the filler neck, that has a peacock on the bottom for empting. This makes it track legal, problem with the Toyota setup is when you blow coolant is just blows it all over your engine bay and on to the track it is suppose to blow into a overflow bottle that catches everything. Then we will put the Steward 45 GPM pump in the front of the car. We are also removing the power steering and converting it to manual so we can decrease the amperage draw, because I do not know the limits of the Honda alternator, yet.

 

[KseriesPower]

There is no difference between the actual pump's. The only difference is in the casting wheat her it has a provision for the cooler or not.



What does 1zz stuff have to do with this? Maybe you meant K series. Correct, your setup is identical to the Toyota system designed to run the Toyota engine's, I to had that setup initially. The Honda engine was designed to work with the Acura/Honda setup, which is different than the Toyota. Honda's system was design to pump the water approximately 4-5 ft, now your putting that design into a car that requires 20-25 ft. Honda may over design the efficiency of the pump, I do not believe to the extent of 20-25 ft and under aftermarket modification which require greater coolant efficiency, though. I agree you'll most likely get by if your stuff is completely stock stuff, but when you start running higher compression ratio's and internal modification which are going to increase HP and engine temp's, then you'll start to have the problem's. When you compare the Toyota pump to the Honda pump you can see the difference. Toyota also made one pump different which had more "fin's" on it and was designed to flow better at higher RPM's. I also read the Midlana thread and he has the exact problems we are having and took the same step's as we did. I am 100% convince that there is cavitation happening at higher RPM's while the stock guy aren't noticing it because you still have some flow, it is happening. Midlana's thread is also 400 whp turbo car.

I guess we will just wait and see we are ordering parts this week and should know by this weekend. We are re-designing the cooling system and making it track legal. We are remove the "puke tank" and putting in a Ktuned plate with filler cap and a high pressure cap. This will allow us to put the aftermarket temp sensor right on the cylinder head as well as ease when filling and bleeding the system.. Currently, we are getting a 40 degree difference reading from the coolant hoses to the ECT sensor. Then we will run a real overflow tank that has a 1/8 tube from the filler neck, that has a peacock on the bottom for empting. This makes it track legal, problem with the Toyota setup is when you blow coolant is just blows it all over your engine bay and on to the track it is suppose to blow into a overflow bottle that catches everything. Then we will put the Steward 45 GPM pump in the front of the car. We are also removing the power steering and converting it to manual so we can decrease the amperage draw, because I do not know the limits of the Honda alternator, yet.

If you are puking water out of the reservoir, you have a blown headgasket OR you are lifting the head. DEAD giveaway. Air is getting into your system causing that drastic temp delta.

The 1zz celica and MR2 spyder water pump share the same part number. So how does one have more fins than the other?

Also, the coolant routing for the 1zz and K20 is DAMN near identical. Hardpipe behind thermostat and coolant port coming out of the head. On a front engne car both of these go to the heater core. On the MrS, the port coming out of the head gets plugged

As far as power steering goes, the EP3 had electric power steering. It probably also shares the same part number as other Honda cars without power steering (id double check though)

 

[gawdzilla]

Not sure I completely agree with the "overflow tank" style vs. "expansion tank" style thoughts, Brandon. Nor the "track legal" points. What track rules are you referring to? Any real racing will require water anyway. Coolant is strictly banned, which makes blowing the expansion tank or dumping from your overflow tank no different.

I always felt expansion tank style was superior and preferred. e36s run the same expansion tank style that the mr2 has. track going e36s "upgrade" to the expansion tank style. it is supposed to be a self bleeding system when implemented correctly with the expansion tank located at the highest point. It's probably why the market for coolant swirl pots also exists.

I believe the problem w the k swap is
a) improperly bled system
b) sub optimal pump flow. too low at low rpms, and cavitation at high rpm. plus the much longer coolant runs. that's where a well regulated electric pump can assist the mech pump, or replace it's function altogether. I don't think changing to an overflow tank with high pressure cap is the solution.

Either way, my plan is to keep pretty stock k20a2 power, but i'm still interested to see the electric pump results.

 

[BottledFedMR2]

If you are puking water out of the reservoir, you have a blown headgasket OR you are lifting the head. DEAD giveaway. Air is getting into your system causing that drastic temp delta.

The 1zz celica and MR2 spyder water pump share the same part number. So how does one have more fins than the other?

Also, the coolant routing for the 1zz and K20 is DAMN near identical. Hardpipe behind thermostat and coolant port coming out of the head. On a front engne car both of these go to the heater core. On the MrS, the port coming out of the head gets plugged

As far as power steering goes, the EP3 had electric power steering. It probably also shares the same part number as other Honda cars without power steering (id double check though)

I'm not currently puking out of the res because we stop before it hits that point. I'm saying if your on the track and it overheats, it will puke out the reservoir and spill all over the engine bay and the track. That is the illegal part, it is suppose to spill over into a container, not on the track. We can bleed the system perfectly and run it on the street or idle for hours and no air comes out. But when we lay on it and start doing WOT stuff the temp sky rocket's and then air appears. Not to mentions there is very little heat at idle, once at 2500-3000 rpms we start to get heat coming out of the vents at the normal operating temp.

Sorry, I was referring to the 2zz as far as the water pump, apologies on the confusion. There is a metal version and a plastic version with more fins on it.

I still need to find out the draw on the Mr2 PSP and then compare that to the Honda system. The MR2 has a 40 AMP fuse on it, so when adding that and the rest of the car to a 10 AMP draw on a electric water pump, it's cutting it close.

 

[BottledFedMR2]

Not sure I completely agree with the "overflow tank" style vs. "expansion tank" style thoughts, Brandon. Nor the "track legal" points. What track rules are you referring to? Any real racing will require water anyway. Coolant is strictly banned, which makes blowing the expansion tank or dumping from your overflow tank no different.

I always felt expansion tank style was superior and preferred. e36s run the same expansion tank style that the mr2 has. track going e36s "upgrade" to the expansion tank style. it is supposed to be a self bleeding system when implemented correctly with the expansion tank located at the highest point. It's probably why the market for coolant swirl pots also exists.

I believe the problem w the k swap is
a) improperly bled system
b) sub optimal pump flow. too low at low rpms, and cavitation at high rpm. plus the much longer coolant runs. that's where a well regulated electric pump can assist the mech pump, or replace it's function altogether. I don't think changing to an overflow tank with high pressure cap is the solution.

Either way, my plan is to keep pretty stock k20a2 power, but i'm still interested to see the electric pump results.

I'm referring to open track days and autocross stuff, where the rule's are more "preserve and limit clean up to the track." If its water based then yes your absolutely correct, most people are going to be running coolant at these event's though. Also, by elimination this bottle I'm hoping to also be able to increase the system pressure. I believe the OEM cap is only rated to 15-16 lbs, where as the Honda has a an aftermarket one which I can increase pressure to 19 lbs. this will possibly help with preventing cavitation. I am hope the nail in the coffin with be the water pump. Again the other benefit is I can monitor cylinder head engine temp's with this plate. Increasing the pressure will decrease the capability f cavitation as Dave previously mentioned.

 

[dblotii]

I'm not currently puking out of the res because we stop before it hits that point. I'm saying if your on the track and it overheats, it will puke out the reservoir and spill all over the engine bay and the track. That is the illegal part, it is suppose to spill over into a container, not on the track. We can bleed the system perfectly and run it on the street or idle for hours and no air comes out. But when we lay on it and start doing WOT stuff the temp sky rocket's and then air appears. Not to mentions there is very little heat at idle, once at 2500-3000 rpms we start to get heat coming out of the vents at the normal operating temp.

Sorry, I was referring to the 2zz as far as the water pump, apologies on the confusion. There is a metal version and a plastic version with more fins on it.

I still need to find out the draw on the Mr2 PSP and then compare that to the Honda system. The MR2 has a 40 AMP fuse on it, so when adding that and the rest of the car to a 10 AMP draw on a electric water pump, it's cutting it close.

Some points:
The number of blades (not fins) in a water pump design do not determine how powerful a pump is. There are many parameters to pump design, but the most important is the difference in diameter between the base and the tip of the blades. You can't really change that in an automotive pump without redesigning the pump housing. The number and shape of the blades is an optimization that the pump designer does to maximize efficiency. You can have too many or too few.

If "air" appears during a power run, it is either trapped air somewhere in the system that gets dislodged at high flow rates (so you really did not have the system purged) or it is exhaust gas entering the system through the head gasket at high load, or it is steam from boiling in the head. If it is steam than it will re-condense to liquid in the radiator. A really good way to see if it is steam is to put a sight-glass in the radiator return line. If you start getting bubbles throughout the cooling system (including the return from the radiator) at high power, then it is not steam and you have to fix the problem before anything else.

The bottle in the MR2 with the pressure cap is properly called a "hot-bottle" and it is generally considered a premium feature for a vehicle cooling system. The hot bottle continually circulates a small flow of coolant through it and steadily de-aerates the system (if the flow is in the correct direction). So it is normal for the cold level in a hot bottle to drop as air is expelled. A steady coolant level in the hot bottle indicates that you have the air purged. A radiator cap and a overflow bottle is much slower to de-aerate. With that kind of system air only leaves when the radiator cap opens and some air escapes with the hot coolant. When the engine cools down, the relative vacuum in the system only draws liquid back in. After a dozen hot/cold cycles you can expect the overflow bottle level to drop indicating that only hot liquid is expelled when the cooling system develops pressure. This type of system will not self-purge air if the radiator cap never opens.

There are a lot of k-swapped Lotus Elise and Exiges running around now and most see regular track duty. Before you go adding a booster electric pump. why not find out what these guys are doing to get a successful K cooling system.

Dave

 

[dblotii]

so i think i finally got my k20a2 swap's coolant bled. i do tend to agree that the belt driven honda pump seems underdriven, given the difference between a typical short run front engine setup vs. our mid engine setup. i notice a significant increase in flow (via visible coolant temp drop) when the engine is brought above 3800 rpm. i vacuum bled the system. one of the mistakes i was making was overfilling the expansion tank and capping it too early, leaving no room for expansion and purging of the air bubbles. i guess it was my fear that the tank would go empty and suck in air. another thing i read from the 2zz swap coolant bleed tips was to restrict the upper return on the expansion tank. i added a small restrictor, and also elevated that hose before it enters the tank. seems to have helped... maybe let air through the top hose instead of a steady flow of coolant? heat seems consistently warm now. btw i am running the k24 water pump, the one without the water outlet for the k20 oil warmer. not sure if that makes a difference.

What exhaust headers are you using in your K20 swap? My only problem with the PPE headers is that they hang kind of low and will be even lower in a k20 than a k24.

Dave

 

[dblotii]

IF you keep ALL oem lines intact and plug the heater core line coming out of the head (just like the 1zz) and fill it properly, you will have zero cooling issues and it will act IDENTICAL to the 1zz setup

When you start adding a bunch of aftermarket shit, deleting lines, etc. you will run into problems.

The 1zz celica water pump is the same part number as the 1zz MRS pump.

if you plug the heater core line coming out of the head, what do you connect the heater core to?

Dave

 

[dblotii]

The ktuned ram horn I'm using had to be cut and the rest custom, of course. It goes under the subframe.


Sent from my iPhone using Tapatalk

What did you have to cut in the K-tuned Rams horn? Was the lower section approximately correct for clearing the cross-member? I am wondering if the other K-tuned swap headers would need extensive re-working to get past the cross member.

Dave

 

[DDPR]

if you plug the heater core line coming out of the head, what do you connect the heater core to?

Dave

The OE heater core hot / pressure feed on the spyder is a T in the radiator line up at the front of the car. The return from the heater core is the only dedicated line.

 

[gawdzilla]

What exhaust headers are you using in your K20 swap? My only problem with the PPE headers is that they hang kind of low and will be even lower in a k20 than a k24.

Dave

PPE. It does sit a little lower than i'd like. it also comes very close, if not barely touches the OE heat shield for the intermediate shaft. neither should move WRT each other so i guess it's ok.

if you plug the heater core line coming out of the head, what do you connect the heater core to?

Dave

on the K, there are two heater connections on the motor. one that is next to exhaust port #4. I believe people are calling this the feed. The other is a hard pipe that comes up beneath the intake manifold and sits near the transmission pointing rearward. if you trace the hard pipe it connects right by the tstat housing. I believe people refer to this as the return. I'm using the tstat housing connection for heat, and blocking the exhaust port 4 connection with this: https://www.jhpusa.com/store/pc/viewPrd.asp?idproduct=7004