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I don't know how you guys can even work in inches let alone design stuff! I suppose it's one of those things that you have to spend your life working in so you can memorize the sizing and learn the relationships. I find I tend to convert it back to decimal inches whenever I'm drawing things which makes it suit my more metric programmed brain.
For example 27/32" I have to spend a lot of time figuring it out if it's larger or smaller than 7/8" or 13/16".
By designing in decimal, not fractional numbers. Fractions are convenient, I guess, for certain things.
I'll probably get a run of 10 of these made at the machine shop that leant me the mill. I need to mount one up and test it all first to make sure it works as it should.
Im currently sorting out the other parts I need to finish the system. I'm not sure if anyone has run the coolant in a reverse flow direction so it will need some testing to see if its effective or not.
I may be interested in 1 or 2 of these if you get them all made. Well this depends on how much shipping from down under is.
Originally Posted by Madjak
I don't know how you guys can even work in inches let alone design stuff! I suppose it's one of those things that you have to spend your life working in so you can memorize the sizing and learn the relationships. I find I tend to convert it back to decimal inches whenever I'm drawing things which makes it suit my more metric programmed brain.
For example 27/32" I have to spend a lot of time figuring it out if it's larger or smaller than 7/8" or 13/16".
It would probably be cheaper to get it machined here than ship it lol
Shipping isn't too bad, at around $15AUD for up to 2KG or $25AUD for 10KG. It's actually far cheaper than getting stuff sent from USA to Aus! There seems to be a bit of interest both locally and overseas so I'll get some quotes from the machine shop to get 20 made. With the low Aussie dollar it might be cheaper than making them in the states anyway.
Won't the water flow in the reverse direction though? Or is that just the toilets?
The sad thing is that our modern toilets are so water friendly now that you can't tell if the myth is correct or not. There is no swirl!
How many of you, if you were looking to run an EWP would want to retain the heater? I think it could be accommodated by a small offshoot loop or even redirecting the coolant to the back of the head through the heater core. This would have the very small benefit of cooling the head even more by radiating heat via the cockpit.
I made a cool CNC machined 'Y' manifold that directly attaches to the Davies Craig EWP. It's made so that I can weld on 12AN bungs on each face with the one facing upwards going to the front of the head and the straight output going to the rear of the head. It's designed the way it is so that it would fit into a small round block of ally I had lying around. I could do this with a 16AN tee fitting and then stepping down to 12AN outputs with a reducer but the total cost of the fittings added up a bit and I would prefer a smoother turn than the 90degree that the tee would do.
I hour on the lathe cleaning up the flange and 5 hours on the CNC mill... here is the end result:
It will have 2 x 12AN bungs welded to the flat faces. I'll probably also drill a 1/8NPT hole in the side to mount a coolant temp sensor.
Bolted onto the Davies Craig EWP.... looks like it was made for it!
A bit of porting with a drill and carbide bit. I really need to get a die grinder! I even added the 'o' ring channel from the Davies Craig flanges.
I'll drop this manifold and also the two head flanges off to the welder to attach the 12AN bungs. I'm just waiting or the AN hoses and fittings to rock up now before I can install it on the engine and test.
With the reversed cooling, are you doing anything with head gaskets and whatnot? Obviously Mazda had a couple different gaskets to address hot spots in the engine. While you are introducing cooled water to both sides of the head, I would think you still need some type of means of controlling flow so that it actually works as intended.
I don't have any experience with reverse cooled engines other than the time I owned a Z28 that had an LT1 which Chevy retrofitted reverse cooling on. Then with a clean sheet of paper on the LS1, they went to a standard cooling arrangement. That decision made me think twice about the benefits of reverse cooling although I have no inside information about why it was done. Obviously, bean counters could have had a ton of leverage on the decision.
Tbh, I don't know if there will be any issues running reverse flow on a BP. I haven't seen anyone do it yet. The gear I'm making can by used in reverse if required but I think one of the benefits of EWP is that you can change the coolant direction. Really I doubt there is any issue with the head unless air bubbles get trapped inside. I plan on running a few tests where I run the coolant through the head in the reverse direction (whist the engine is off) and then reverse the direction of the flow and see if any bubbles come out of the head. If there are I know there is some trapped air.
In terms of head gasket, I figure if most of us run coolant reroutes on the same head gasket I doubt changing the direction will change much anyway. In terms of hot spots the coolant should be cooler as it's coming directly from the radiator so I can't see how it would ever be worse than OEM.
Shipping isn't too bad, at around $15AUD for up to 2KG or $25AUD for 10KG. It's actually far cheaper than getting stuff sent from USA to Aus! There seems to be a bit of interest both locally and overseas so I'll get some quotes from the machine shop to get 20 made. With the low Aussie dollar it might be cheaper than making them in the states anyway.
Posting stuff from Melbourne to Sydney is costing me $15 at AusPost.
I hate the aussie postal service.
Installed... I decided to finish a few projects and instead of porting my head so I figured I'd bolt up the EWP. I still need to wire it up and fill with coolant.
I have room still to mount my small alternator on the hot side in front of the headers. It clears up room under the intake so I can get better access to stuff.
I've just come back from running my car at a weekend event and the EWP ran flawlessly the entire weekend (practice, sprint, track). My tuning map is set up to cycle the coolant slowly (eg 20% PWM) until the coolant temp hits 175F (80C) then rapidly ramp up to 100% by the time it hit's 195F (90C). I also monitored the head temp via a k-type thermocouple and hooked up to an analogue output amplifier to my data logger. Lastly I have it set up so that when I'm back in the pits, the ECU will keep the EWP and thermofan cycling until the temp hits 60 degrees even with the engine off.
The coolant temp rises quickly on idle, lifting up to around 150F within a couple of minutes... it's probably more rapid on my car than stock due to the small radiator and high idle speed. Once out on track the coolant rises rapidly to 175F and then plateaus off at 180 - 185F when at full load on the track. With the engine off the coolant drops back down to under 140F within a minute or so.
Engine wise, I really do think there is some extra power there from 7000 upwards but it might be my own bias effecting me. The engine seems keener to rev and I think I'm shifting faster than before. I dropped over a second off my previous PB at the track but I've made other changes such as adding a rear wing and changing the alignment slightly. Still I've very happy with the end outcome.
The thermocouple head temp sensor should be a default install on any race car with aftermarket ECU. It's cheap, works, and will still measure temp if the pump stops or there is coolant failure. BTW, the head temp trails the coolant temp by around 20F in both the up and down direction.
This is great! Where do you have the thermocouple mounted and are you just using a generic K-Type?
Originally Posted by Madjak
I've just come back from running my car at a weekend event and the EWP ran flawlessly the entire weekend (practice, sprint, track). My tuning map is set up to cycle the coolant slowly (eg 20% PWM) until the coolant temp hits 175F (80C) then rapidly ramp up to 100% by the time it hit's 195F (90C). I also monitored the head temp via a k-type thermocouple and hooked up to an analogue output amplifier to my data logger. Lastly I have it set up so that when I'm back in the pits, the ECU will keep the EWP and thermofan cycling until the temp hits 60 degrees even with the engine off.
The coolant temp rises quickly on idle, lifting up to around 150F within a couple of minutes... it's probably more rapid on my car than stock due to the small radiator and high idle speed. Once out on track the coolant rises rapidly to 175F and then plateaus off at 180 - 185F when at full load on the track. With the engine off the coolant drops back down to under 140F within a minute or so.
Engine wise, I really do think there is some extra power there from 7000 upwards but it might be my own bias effecting me. The engine seems keener to rev and I think I'm shifting faster than before. I dropped over a second off my previous PB at the track but I've made other changes such as adding a rear wing and changing the alignment slightly. Still I've very happy with the end outcome.
The thermocouple head temp sensor should be a default install on any race car with aftermarket ECU. It's cheap, works, and will still measure temp if the pump stops or there is coolant failure. BTW, the head temp trails the coolant temp by around 20F in both the up and down direction.
Yeah its a standard k-type bolt on sensor. $10 on ebay and they sent me two! This is bolted to the back of the head next to the coolant neck in one of the spare bolt holes.
The sensor then runs to an analog adafruit k-type thermocouple amplifier and from there to my ecu. I think the amp was only $15 but you can also get 4 channel ones if you want ro run EGT sensors or other temp sensors. All up its a very cheap and easy setup.
Accuracy wise I'm get a stable reading when the engine isn't running. The ecu is needing to measure tiny changes in voltage as the temp range of the k-type is -270 - 1250 C (over 8 volts) so the temp range we are measuring for coolant is within a few tenths of a volt. When my engine is running I'm seeing fluctuations around 2-3 degrees but then all my sensors do the same so maybe I'm getting noise on my sensor earth or something.
Still even with the noise the logs the temp measurements are very useful.
05-24-2016, 12:41 PM
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