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My car was warmed up, completely even hot at 95C. I turned it off and back on and it rev'd a little higher on restart longer then normal, not like the usual ISC assistance on start up. I checked the TPS voltage and saw it was right above its home warmed up position. I revd the car to 2k rpm and then the thermowax extended to allow the TPS to be at warmed up home position. This is telling me that the coolant is having trouble making it through the TB at idle and/or low rpm cruising. This may also be why my heater is blowing warm at cruise as well. When I run it at 3k while sitting the heater gets warmer. So I have witnessed flow issues with 0 pressure for the TB line and heater line.
What bothers me is - ....... are my turbos getting the proper coolant flow ??????????
At 0 pressure I honestly feel EVANS is fine for a N/A car or hot rods with simplified cooling systems.
I think I need to find a low pressure cap of maybe 7lbs - then I will start to weep coolant again, but at least the coolant will go where it is supposed to.
Anyone know of any low pressure caps that fit the older style Pettit AST.--- EDIT - found it and installed it last night - STANT 10328 / 7psi
Pettit has a new AST - looks like all the build quality issues have been addressed.
Also I mentioned earlier that my car had a puff of smoke on start up - I accidentally premixed 1.5 instead of 1.25 on 14 gallons. I will add 1.5 gallons of straight gas to help with this since I has already driven it a few miles.
Last edited by rotaryextreme; Dec 15, 2021 at 08:38 AM.
I'm surprised you kept the thermowax. Haven't heard of any similar issues with Evans, but you might get more input in the general sections. Everyone loves a good water based coolant vs NPG thread.
I'm surprised you kept the thermowax. Haven't heard of any similar issues with Evans, but you might get more input in the general sections. Everyone loves a good water based coolant vs NPG thread.
I like the thermowax and ISC set-up, FC Tweak really takes advantage of this if you have your car still set-up with them.
The car warms up and idles like it should, just without pressure and at idle the thermax acts like there is air or not enough coolant flow through it. During warm up the engine is around 1800rpm and there is enough flow to get the coolant through the thermowax but as it idles around 900rpm, there is not enough flow to keep it open to allow the TB to sit at base idle. I am finding out, that for me, 0psi does not work despite the EVANS. I am going to do my rad update, doing another complete engine flush with the 100% SIERRA PG and Prestone, maybe 2X in 1hr and then blow out what I can - thats what she said, and then fill with the EVANs. I will monitor how bad the leak is at 7psi and decide whether or not to just stick with 100% SIERRA.
I really think FC Tweak has brought the PFC to another level of tunability for our cars.
I agree 100% on the water based set-up.
Next I will try Evans with a 7PSI cap to reduce the coolant seal leak until I get the engine rebuilt - then I will switch back to what the whole world does.. lol
In the mean time will use this experience to fine tune my radiator set-up if possible.
0 psi vs 7 psi vs 13 psi - with an engine that has coolant seal failures.
In a nutshell I added I added a 7psi cap to the AST and the car runs cooler longer - this is with a coolant oring failing.
Personal observation.
I had originally drained the coolant to do the radiator modification but I realized I never drove the car with a pressurized cap. I simply saw the leak when it was on the jack stands and the rest is history went down the rabbit hole with the 0 psi stuff.
When I rev the engine at idle I now hear gurgling in the heater core with the 7/13 psi caps, I did not hear this with 0 psi. NOTE - This was after a 10 mile drive.
This tells me that the 7/13 psi caps are providing pressure to get the coolant to flow through the heater core and also my system is not completely bled.
Test 1: - 0 psi, 100% Sierra, 6 x 1/8 holes in t-stat, and dual pass rad = temp continued to rise to no end even when cruising on the freeway approx 5 miles until 100C.
Test 2: - 0 psi, 100% Sierra, cut out the jiggle pin in t-stat only, and dual pass rad = temp continued to rise to no end even when cruising on the freeway but I was able to drive approx 10 miles until 100C
Test 3: - 0 psi, 100% EVANS Performance, cut out the jiggle pin in t-stat only, and dual pass rad = temp continued to rise to no end even when cruising on the freeway but I was able to drive approx 10 miles until 100C
Test 4: - 7 psi, 100% EVANS Performance, cut out the jiggle pin in t-stat only, and dual pass rad = temp settled at 94C after approx 10 miles.
Test 5: - 13 psi, 100% EVANS Performance, cut out the jiggle pin in t-stat only, and dual pass rad = temp settled at 97C after approx 10 miles.
Test 6: - I Put back the 7psi, 100% EVANS Performance, cut out the jiggle pin in t-stat only, and dual pass rad = temp settled at 94C after approx 10 miles. I got on it in 2nd and 3rd a few times and temps drop to 92C unlike before where it would raise in temp.
I believe the 7psi cap is allowing the air bubbles from the compression o ring leak to escape easier into the overflow tank from the AST. With the 13psi cap and my situation I believe the air bubbles are not able to escape as easily as the 7psi cap.
When I removed the 13psi cap to put the 7psi cap back on I noticed more of a foamy look in the AST. The 7psi cap was definitely more clear in the AST.
I wanted to save this observation for the last thing to read because it supports why I want to modify my radiator. In every situation at idle and low RPM the coolant temp continued to rise. While accelerating the temp dropped. This matters tremendously because it shows that without a pressurized system, the pump needs to be spinning faster to get the flow needed to go back "up" the other side of the dual pass.
I feel that if you have a good motor, running 13 psi cap and running the correct coolant / water mixture you will not have this problem. But I am thankful to experience this situation to try and better my product by making it work under worst case scenario circumstances. Realistically the test conditions I have are out of the norm but the goal is the same to provide a better flowing cooling system that can accommodate unusual set-ups.
I do not have any fancy programs to calculate all this, I just go by real world testing. It's just more fun and rewarding. Just like making the brackets in my VM kits, a vice and a hammer...lol.
On to some pictures of stuff I did the first half of Christmas break. I am hoping to have the radiator modified within a few days and hopefully with better results.
Every time I drive the car coolant gets pushed into the reservoir but it cannot get sucked back in because I do not have a good vacuum with my engine coolant o'ring failure. I got tired of sucking it out with my fluid pump and then having to have to throw away the contaminated coolant since I use the pump for all oils on the cars. It was either un-bolt the top clean it out then reassemble, suck the coolant out, poor it into another container and then back into the AST. So that is why I decided to add a drain plug which is cheaper and easier then rebuilding the engine..lol.
I pulled off the reservoir to see how I could add a drain plug without cutting any holes on the top side to get tools in to tighten to top nut. I figured out the size and went to my favorite store to get all the parts to make this work. I didn't realize the straight nipple would be so close to the panel under the oil cooler so I cut a hole for the hose to go through. Next time Im at the store I'll get a 90 degree and redo this. Well, I pieced together the drain outlet by getting a M to F and a Jam nut. I found a rubber washer and drilled a hole to match in a smaller thinner metal washer to provide a backing plate. The jamnut fits through the hole that the grommet goes into for the coolant overflow hose. I used a stepped drill to drill the washer and the bottom of the overflow tank. I put everybody together and put black RTV on the ruber washer where it will touch the tank and on the threads to help keep the jamnut from easily braking free. I put a ziptie through the drain and fed that up thought the hole. I put the ziptie through the jamnut on the top and pushed the nut through the hole and screwed it on by starting it with a flathead screwdriver. Then I used a long reach panel clip remover to hold the corner of the jam nut as I screwed it tight from the outside with a wrench. I was unable to unscrew it by hand so I'm calling it good. I secured some nylon tubing rated for 175F on the nipple, put the grommet back on and reinstalled the tank. I am using a needle valve at the other end with a cap to keep everything clean.
2. - Oil Change
I had originally drained the oil because I was going to have to remove the oil lines to remove the radiator. Well it was do anyways since the oil smelled like gas from all the initial troubleshooting and running rich earlier on. I changed the filter and added some fresh Castrol GTX 20/50. I had to remove the Greddy elbow and piping just to get to the oil filter. Now I know why people make relocation kits for their oil filters.
3. - Adding Coolant - Uh Ohhh
Well, I now have a small inner oring coolant leak - it's getting worse. I have very small bubbles now when adding coolant. I'm sure the overheating didn't help, or all the experimenting I have done either. As I stated before, how can I try to do something when I have not reviewed all the data and/or have missing data. I had no data for driving the car with a pressurized cap so I bought the coolant adder tubby thingy and it make life so easy. as you can see from above, I know have that data). I kept the 7psi cap on the AST so that this time the coolant would not flow into the overflow tank like last time...lol. I only did this at idle and maybe revved the car to 1500rpm. I wish I would have been inside the car while doing this to see if I had the gurgling in the heater core at that point. I let the car cool to see if the coolant would get sucked down and worked on something else in the meantime.
I got an RX8 5-speed shift **** from Jatt. I did post about this before but The **** does not go down as far as the stock one so I put a piece of silicon hose under the boot to prop it up higher. I put the **** back on and the gap is closed now. I always wanted one of these but they are so damn expensive, thanks again Jatt!!!!
5. - Drain Coolant From Reservoir
After the test drive to get the data for the 7 and 13 psi cap, it was time to drain the reservoir. I cut the zip tie holding the needle valve to the tow hook, took the cap off and drained about 1/2 quart out. The interesting thing was it looked more green then the mixture before when I filled it back up. I looked into the AST and the EVANS was more gold. It is almost as if the 100% sierra found its way to the top and separated itself from the EVANS. I poured the green EVANS mix back into the coolant which I drained the EVANS the first time and re-filled the AST with the new EVANS.
And just now I restarted the car and let it warm up and revved it for 3 minutes at 2500 rpm with the heater on the foot position, full heat, and I did not hear any gurgles this time. The temp was barely warm but I was happy I didn't hear any sounds. Also the temp stabilized at 92C, the oil temps however skyrocketed since I was not moving and my dual oil coolers were hot to the touch. I have considered adding a fan on the back of each and running the power to the aux battery. This will be helpful in lane staging, traffic and also in winding canyon roads that go for miles without any straights. The next update should be fun, I'll have results on the radiator mod from dual pass back to single pass.
I know why my damn friggin engine is overheating - it's filled with all kinds of **** and full of I don't know what the hell is inside. When I cut off the water neck on the radiator (the brand new koyo), the tubes were filled with ****, literally ****. Imediately I thought of Rob Dahm's video when he tore apart the FC Turbo engine seen here.
If you have been following my build thread then this will absolutely make sense. 0 psi car ran hot without the ability to cool down, added a 7 psi cap and it showed some stability. But DuuuHHHHHH, it take pressure to force coolant through some clogged *** tubes... just unbelievable. Ok the engine sat for a year, wtf grew in it ?????????
Anyways the plan is to continue the radiator modification, get it all back together, and do a couple of prestone deep flushes and hopefully I can get all the **** cleared out or at least have it run cooler so I can move it around while I save for the rebuild.
Part 1 - Drain Coolant
Part 2 - Lower Radiator Pipe
Part 3 - Check Oil Catch Can
Part 4 - Upper Radiator Pipe
Part 5 - Ready To Be Chopped
Part 1 - Drain Coolant
Every time I drained the coolant I saw little pieces of something, but when I examined it I was able to squish it with my fingers. In the back of my head I was hoping that it would eventually go away. But when I chopped off the upper radiator pipe, all hell broke loose - more on that in Part 4.
Part 2 - Lower Radiator Pipe
I finally figured out a way to get the bottom pipe to work with the fog lights, stock bumper, LRB undertray, and A/C line. This is a change I would like to keep for my VM kits so I had to make sure it would work with everything. I was able to fit a pipe on the opposite corner of the inlet pipe, I will have to cut open the bottom and add another piece to extended over the new pipe. I cut a 45 degree silicon elbow and left just enough room to safely clamp onto the aluminum pipe. Once the radiator is fitted it will be easy to make the rest of the pipe going from the lower outlet to the engine. I have a little more cutting to do but I have the angle that I need.
Part 3 - Check Oil Catch Can
Soooo, I accidentally added about a 1/2 court too much oil. I could smell a faint bit of oil while driving so I decided to check to oil catch can to see if any blow-by was captured, nope it was dry. Later while taking off or the turbo IC piping I saw a little oil in the second turbo charge control area. I took off the second turbo intake elbow to check for play but the turbo felt fine. I guess it was blow by, I hope I didn't screw something up. Anyways I took out the extra oil with my vacuum fluid pump.
Part 4 - Upper Radiator Pipe
The top part of my radiator will be modified back to the orgial single pass design. I will be moving the inlet to the left and removing the add on end tank where the return currently is. I drew some lines for reference before I did any cutting. I remeber how much of a pain it was to get this thing installed because of how tight the rad necks and silicon hoses are to the engine. I wanted to make the install easier and since I knew I would be cutting of the neck I decided to do it will it was on the car so I could pull the rad out without removing the front bumper.
With my confidence at level 10, Risk factor at level 10, I took a skillsaw and cut through the upper pipe while saying over and over again in my head - please don't hit the oil cooler line !!!!! Thankfully I was successful and whipped out the new design for the upper pipe. Both the upper and lower pipes will have individual pieces that will allow easy install and removal of the radiator. I put the IC frame back together and laid the IC core in place to verify my upper pipe set-up clears. Once I had the size correct for the aluminum elbow I rolled some beads on each end with my Vibrant bead roller.
I pulled the radiator off and there was still a little coolant in the hose and it went all over my head, my left eye and into my left ear - oh ****. I still had the radiator in my hands and had to finagle the return neck past the oil cooler lines. With my left eye burning and with the sweet smell of coolant I was able to safely set down the radiator, crawl out from under the car and hobble to the bathroom to wash my brain off. 5 minutes later I was as good as new.
Ok, this is the "What The Fawk Mang!" part.
I go back to get the radiator and I look inside of the hole where the inlet neck used to be and I literally said out loud - "What The FAWK !!!!!!" I had a brand new koyo so obviously it's from the engine that sat for almost 2 years AND / OR my heater core that sat for many many many years while I made VM kits on the car. The tubes in the koyo are blocked with all kinds of ****. Now I am really worried about the coolant passages on the engine and whatever sensitive devices have small passages like the thermowax. It all makes since, everything that I have been experiencing, especially when the car was hot but the thermowax was not fully extended upon immediate restart. I tell you what, I can't wait to cut the other end tank off and see what's in there. No wonder why I saw life with a pressurized cap. Can you imagine if I went with a rebuild and never explored my radiator !?!?!?!. Anyways, I am pressing on with the design change and will enjoy a couple of days with a couple of prestone flushes.
Part 5 - Ready To Be Chopped
I always save old radiators for parts and it looks like I have a donor for the flat section I need. I have everything laid out for the cutting board tomorrow and hopefully everything goes well. I wonder, if there is enough blockage will it blow the coolant oring seal, Did I have a good motor all along and with it sitting for 2 years was it able to grow enough **** to cause this?? Many questions have I, Theories we all have, may the force be with you and to me in this new adventure.
Enjoy the pics.
pics Part 1 - Drain Coolant
Last edited by rotaryextreme; Dec 31, 2021 at 02:06 AM.
Dang, hopefully a couple of heat cycles with the higher pressure cap and those flushes will help.
I almost guarantee you are right. Looks like little bits of corrosion.
Well I have decided to change the updates from "Day" to "Update" which is more accurate.. lol
So, at this point I can give 2 shiets about the leaking from the engine and now my number one concern is corrosion. I had a brand new koyo and it was clogged with all kinds of crap. The car sat for 8 years more or less with the blown motor, then I bought this used engine that sat for another 2 years. I have rusty colored deposits, clear deposits and what appears to be calcified deposits. Some of it I can smash with my fingers and other stuff feels like sand. I am honestly confused on what to put in the car after I do the flush to prevent further corrosion and to reduce leaking from the o'ring. I have read so much stuff about different things it's all a blur now. But for now I am going to flush away with the 13lbs cap, then run 100% PG with the 13lbs cap to clear water out of the system and then run EVANS with the 7psi cap.
The hint was the thermowax. The trhermowax rod should be extended when warmed up enough for the cam to clear the throttlebody roller peg thingamajig, but due to the blockage and pressure it did not stay extended enough even when the car was fully warmed up. I would watch everything act as normal during warm up at high rpm, the thermowax would do its thing and the car would settle to its base idle. When the car was 95C I would shut it off and then immediately restart it but I would see that VTA1 was at 0.50v when my warmed up idle is 0.44v. This caused the car to rev at a higher rpm while coolant flowed enough to get back up to the thermowax. I did notice that with the pressurized cap this issue went away.
Anyhoo let's get on to what I did so far.
Part 1 - New Radiator Top Pipe
Part 2 - Flush Radiator Fan Side Down
Part 3 - Flush Radiator Fan Side Up
Part 4 - Flush The Motor
Part 5 - Reverse Flush The Motor
Part 6 - Chopped Off Radiator Top
Part 7 - Cleaned Parts To Be Welded
Part 8 - Cleaned Radiator Tubes
Part 9 - Welded Flat Top
Part 10 - Radiator Sits Overnight
Part 1 - New Radiator Top Pipe
The top pipe is an easy job since the radiator does not have to be mounted to find the angle. I matched the pipe up to a hole saw, drilled a pilot hole in the radiator and then drilled the hole for the new upper pipe. I couldn't believe my eyes but there was even more shiet in the radiator. I looks as if the radiator acted as a giant filter for all the crap that came from the engine or heater core. Next I matched up a holesaw to the old neck I need to cover, found an aluminum box beam and cut a hole in it. I cleaned up the cap and fit checked it, it was the perfect size. Upon inspection I noticed where I hit the endtank with the skillsaw blade when I pulled it out when it cut through the pipe. No problem, I'll throw a bead on it.
We'll I am definitely rusty at welding, but I got the job done. I welded the cap with some nice fat welds the first time in hope I will have no pinholes. Next was the new top radiator pipe, I found a socket to hold the pipe and used a channel lock to hold it all, I also used the channel lock to apply tension to the pipe against the endtank. I welded it up and did the usual pressure test with bubble solution. I decided to hold off on cutting off the other endtank so that I could use this configuration to flush out as much as possible from the radiator.
Part 2 - Flush Radiator Fan Side Down
OK, So I knew I was going to be having a lot of shiet coming out of the radiator so I wanted to flush it as best as possible before hooking it back up to the motor. I needed to suspend the pump from picking it up. We'll I only use my Turkey Fryer once a year so looks like I'll buy another one because this one's going to get nasty with the radiator cleaner and whatever comes out of it. I put some pipes in the bottom of the big pot and then set the steamer on top of that. I poured 2 containers of radiator flush since it says I need a second one for over 12 quarts. I set the pump inside, poured the 2 containers and filled the pot until the water was level with the top of the pump. I adapted my air pressure test kit to make a feed side and made a return from all the pipes and silicon I have to dump straight into the bucket. I heat the pot up to about 100F and I flush the radiator in both directions for 45 minutes each. When done I poured the liquid out into separate containers to see what I got out, well it was a lot and unfortunately much more was to come. I poured the flush into the radiator and let it sit upright for 30 minutes and then I drained it from the drain plug on the bottom, even more crap came out.
Part 3 - Flush Radiator Fan Side Up
I decided to the flip the radiator just in case gravity was messing with me and going through the lower tubes since I am flushing with flow and not under a pressurized set up. Once again I repeated the process with flushing it through both sides at 45 minutes each, and even more crap came out. I poured more flush solution in the radiator and let it sit overnight. The next day I drained it from the drain plug on the bottom and even more crap came out. I put my hands over my head in disbelief as it just keep coming - that's what she said. At least looking through the new top pipe it looks like it's getting cleaner.
Part 4 - Flush The Motor
I figured that while I am cutting and welding my radiator I could flush the motor in parallel. I removed the thermostat and when I went to put the gasket back in I couldn't find it for the life in me. I searched for a good 15 minutes and finally found it, I set it on the green tape measure which had a black circle sticker on it, perfect camouflage. I had a new OEM gasket that I decided to use since I will not have the metal flange of the thermostat to help with sealing. An interesting thing I noticed is the OEM gasket has a small raised line to help with sealing as compared to the flat surface of the one that was in there. I got the thermostat housing back on and rigged up my flushing system. I flushed it in normal flow path first for about a good 3 hours at 100F. I saw about 45C on the PFC and I verified movement in the thermowax by monitoring VTA1 which went from 0.70v to about 0.67v. This pump is really awesome. I could not find any temperature specs on it so I did not want to go to hot. The directions also say do not run it continuously for fountains, but It seems robust so far. I poured the fluid out into different containers when done and it was clean. I do not know if the heater core can be cleaned like this without pressure but I will take this as a win. Time for reverse flush.
Part 5 - Reverse Flush The Motor
I hooked up the system in reverse and turned up the heat and got it up to about 125F. On the PFC I saw 51C and on VTA1 I saw about 0.65v, full warm up idle is around 0.44v at approx 65C. I let it run for another 3 hours and drained all the fluid and again found nothing, it looks like the radiator captured all the crap after all.
Part 6 - Chopped Off Radiator Top
If you guys didn't know about the different Koyo radiators for the FD, check this thread. A few post down I have the numbers for FC radiators too.
Since I made VM kits the thickness of the radiator affected the angle that could be achieved with the IC core. The newer thinner core is better with more tubes thus having more surface area for cooling. The old core I have chopping the top off id thicker and has 64 tubes. My core is the newer thinner core but has 70 cooling tubes. This also makes it easier to fit the new flat part since it has some overhang.
Time to start cutting some metal - remember kids.... WEAR YOUR SAFETY GLASSES !!!!!
I start with the donor radiator and get warmed up on that since it won't matter if I make a mistake. It's good to get a feel how the tool pulls or how it will move or if it grabs and which way it will spin out. I use a cut off wheel and run it across the endtank a few times making my guideline to cut. I finally get the top off just to see deposits in the donor radiator !?!?!?! I do a quick fit check to make sure the new piece will fit as planned, I needed to cut some of the raised section as well to replace the divider in the old section. Going back to my new koyo I was ready to cut off the top endtank. First I needed to use the skillsaw to cut off the pipe so I could cut of the endtank without risking using the cut off wheel over the tubes. I finally got the endtank off and quickly fit checked the new top piece to see what modifications are needed for welding.
Part 7 - Cleaned Parts To Be Welded
At first glance the radiator looks clean but unfortunately it's still in bad shape. The tubes under the endtank are still filled with crap and I feel only a hot pressurized flush will get everything out, but in the meantime I will continue to flow flush it with the hot cleaning solution until I feel it's safe to put back on the car. I cut the top flat piece to size and sanded down all the rough edges and mating surfaces. Hopefully the edges are closes enough and the gaps will be minimized and I weld it together.
Part 8 - Cleaned Radiator Tubes
I cut the opening for where the bottom pipe will go and noticed more junk in the tubes on the bottom, but it was a different color and I don't know why. Now that I have this opening I wanted to clean out as many tubes as possible. I had some 5052 .032 thickness aluminum which is just thin enough to fit inside the tube. I cut a small strip and slide it through all the tubes I could which was half the radiator.
Part 9 - Welded Flat Top
It was time to weld the top flat part onto the radiator, I tacked it in various places to make sure it was exactly where I wanted it. I put some more nice thick fat welds to hopefully prevent and pinholes. I am unable to pressure test it at this time due to the hole on the bottom of the radiator. I set it down to cool off and started to clean up for the night.
Part 10 - Radiator Sits Overnight
While the radiator cooled I put away the turkey fryer and reinstalled the thermostat with the better gasket with the raised bead. I put the cleaning fluid somewhere safe. I used the air compressor to try and blow out as much fluid from in the motor since we are near freezing temps. It was 40F all day and I work for about 8 hours outside and I am sooo cold.. BBRRRRRRR. I put some plugs on the top of the radiator, flipped it upside down and filled it with the cleaning fluid and let it sit over night. I drained it the next morning and some more stuff had been dissolved and came out. I decided to fill it again and let it sit one more night.
The plan going forward is to test fit the radiator and get the lower pipe made. Then I can do a hot flush on the radiator off the car with my flush set-up and this time I can flush the tube from top to bottom in both directions with the new set-up. Hopefully I will get most of everything out so when it goes onto the car for hot pressurized flushes I'll have less crap to worry about.
