Project Deimos: An LS '65 Coupe Build: Engine no longer overheating!

[jemorgan3]

Id consider a coolant filter, like diesel engines have at some point in the circuit. I cant imagine all the sediment that is discoloring the water will extend the lifespan of the water pump any, not to mention the passeges in the radiator!

[PMD24]

Wondering if the AN hose material is compatible with the specific coolant used?

[JimStone]

Thanks for the feedback and thoughts guys

You might try a power flush like this video demonstrates:



The guns are relatively inexpensive on Amazon.

I've been doing something similar, using a radiator adaptor cap and using compressed air to blow out the system.


Today, I used Prestone coolant cleaner, filled the system, and ran it for 10-15 min.


This is what I drained afterwards

(our nightly bucket photo)







No sediment at the bottom.

Doesn't necessarily look it on the photo, but it is clearing up.

Id consider a coolant filter, like diesel engines have at some point in the circuit. I cant imagine all the sediment that is discoloring the water will extend the lifespan of the water pump any, not to mention the passeges in the radiator!

I have thought about the filter, but I'd have to alter my AN coolant lines and I'm not super thrilled about doing that. I'm going to flush a few more times tomorrow, then just call it done.

I'll plan to do an early coolant change after 100 miles / a few hours on the engine.

Wondering if the AN hose material is compatible with the specific coolant used?

Good thought. I used braided CPE hoses for all the coolant lines. Per my reading, this is definitely compatible with Dex-Cool coolant. Perhaps not as long-lasting as EPDM or Silicone, but not because of reacting with coolant.








I've been running it without the thermostat the last few days. I'm going to re-install and hopefully I won't have the issues I had previously with the thermostat never opening and the engine overheating.


I did realize today that I had my radiator fan wired backwards, so it was pushing instead of pulling. Fixed that issue, but I don't think it's related to my previous problems.

[JimStone]

Family and I are on vacation at the biggest tourist traps in the world: Disney and Universal Studios. Then onto another mindless vacation staple - a Caribbean Cruise. The kids love it.

I'm more of an off-the beaten-path kind of vacationer.


Gives me time to post about things unrelated to where I'm at on the build.


For instance, I put my 3D printer to use making car stuff that won't go on the car









And a headphones stand with the Deimos logo.









I'm also looking into making Project Deimos T-shirts if anyone's interested (probably wii be just me)






ChatGPT did a pretty good job, but just could not get the radiator tunnel exit right. Also struggled with, then gave up on the F14 wheels

[JimStone]

Last week jemorgan3 requested some more details on my AN coolant lines. I only briefly mentioned them earlier in the thread when they were installed.

So here goes






I'm not a fan of plain rubber hoses. Just an aesthetics thing. So I essentially changed everything to braided stainless or nylon hoses (either CPE or PTFE, based on the use) with AN fittings. The only exceptions are the A/C lines, which there really are no braided hose substitutes. To dress those up, I covered them in these carbon fiber braided sleeves: https://www.racetronix.biz/p/loom-ca...299-cal0-75-bk


For the heater hoses, I used 12AN hoses and fittings from Evil Energy. I used the "full flow" versions of the fittings.

I know Evil Energy is considered the "budget" brand for AN products, but I think their stuff is good quality with excellent value, and I haven't had a single failure. Plus I like being able to buy a single fitting when needed on Amazon and get it the next day with free shipping.

I had been using all Fragola hose and fittings for systems I completed previously (reservoir lines, power steering, steam vents, PCV/ventilation), but I had 3 failures in their fittings. And, of course, more expensive.


By far the biggest challenge I had with the heater hoses was self-created because I wanted the heater control valve moved into the footbox. Space is really tight in there with the AC evaporator box. I tried a bunch of various configurations that wouldn't fit, but ultimately what I ended up with was to use the kit supplied rubber hoses inside the footbox passing just through the footbox aluminum via NotcHead Firewall Rings. Then used I used barbed to AN adapters to begin the AN hose lines.













The heater hose connections to the LS required tapping the water pump for 1/2" NPT threads for adaptors.







I used this Summit Racing tank for the "surge tank" with a T-fitting at the bottom to connect it to the heater hose circuit:
https://www.summitracing.com/parts/SUM-300118

[JimStone]

The radiator hoses are 20AN in size. They're pretty stiff so need to be precisely made or the fittings won't line up and thread on










The hose end fittings are from Racetronix. AutoPlumb is the "big" name in the radiator hose AN conversion game, but everything is quite pricey. The Racetronix fittings seem perfectly fine.




I did use AutoPlumb water neck adaptors. Needed 3 of them. I'm not aware of any other company that makes adaptors like these. I haven't had any leaks thus far, although I have limited engine run time.




Besides the 3 AutoPlumb adaptors, I also needed an LS3 thermostat housing with a 20AN connection. AutoPlumb has them, but I went for a generic that probably is made at the same factory but 1/2 the price: https://www.amazon.com/Flashpower-Bi..._rpt_ba_s_5_sc




The 20AN nylon braided CPE hose I got from Amazon. Way less expensive than AutoPlumb and seems really nice to me (no expert): https://www.amazon.com/Autoutfit-Nyl...rpt_ba_s_30_sc






For my LS3, the upper radiator hose is a simple straight-ish shot

[JimStone]

The lower radiator hose is much more difficult, thanks to the ill-thought out angled water neck on the radiator that points directly into a frame member. Also in the way is the sway bar, battery, and a bunch of other frame rails.





I pieced together a pathway out of aluminum tubing from Amazon, silicone couplers, connected by Gates Powergrips. The aluminum tubing has beads on them, otherwise I think the connections would slip. This was primarily trial and error until I got something that would fit.












Then the last leg to the thermostat housing is the AN hose










Looking back to do this write-up, it's no wonder it's taken me forever to get to my current stage in the build.

[PNWTim]

Thanks for sharing Jim. You are fortunate there are so many options for LS engines. I think this can be done with a Coyote but it would be a challenge. I really like AN fittings as well but they seem to go up exponentially in price once you leave behind -8 sizes. Looks great.

[Blitzboy54]

Just exceptionally good looking stuff.

[460.465USMC]

Just catching up on your excellent thread, Jim. Whoa! You're getting your fair share of challenges, and then some. I know the coolant flow issue won't slow you down for long. Hang in there! Thanks for bringing us along. I'm learning right along with you, and appreciate all the forum wisdom.

[JimStone]

Thanks for the kind words guys. I appreciate the encouragement





------------------

To close the chapter on two recent head-scratching issues:


1) I figured out why my two Wilwood brake master cylinders have leaked at the outlet

I used Wilwood 1/8" NPT to 3AN adaptors to hook up the MC to my brake lines (used 37 degree/AN flares on my stainless brake lines). Paid a premium for the Wilwood name brand to ensure there would be no issue

https://www.summitracing.com/parts/wil-220-6956

You can see below that the NPT threads on the Wilwood adapter (bottom) are hardly tapered at all, compared to my generic replacement (top)



Without the taper, the interference seal never was solid. My cheap replacements adapters didn't need to thread in as far before there was resistance.

This is really annoying, because I initially assumed that I was the problem and over-torqued and broke the first master cylinder that leaked. I bought a whole new replacement MC.

Turns out it was just junk fittings from Wilwood


I have 3rd Wilwood master cylinder. That one uses a 1/8"NPT to 4AN fitting. It also was from Wilwood, but looks perfectly fine (adequately tapered). Fingers crossed.










2) Figured out why my two coolant sensors were reading dramatically different coolant temps. (...long explanation below - short version is it was the wrong sensor...)

My engine came with one coolant sensor already installed from Blueprint on the driver's side cylinder head. The second sensor came with the Holley Terminator X, which I installed in the passenger side cylinder head.

The Holley sensor clearly went to the Holley. The Blueprint one was already installed and had the correct connection to the Speedhut gauge cable, so I just hooked it up.

I actually had a 3rd coolant temp sensor that came with the Speedhut gauge, but it didn't seem like I would need that.



When running the engine, the Holley sensor was saying the coolant was heating up (actually overheating) but the Speedhut gauge's needle would hardly move. The thermostat clearly wasn't opening correctly (as per my previous posts), but was the coolant also not circulating through the engine?

I used an infrared thermometer to check for hot spots and the engine seemed to be heating symmetrically.

I tested and compared the resistance output coming from the two sensors and the readings were similar.

Only after I took the Blueprint sensor out and showed ChatGPT a picture did I learn the issue.


Below is a picture of the Blueprint CTS (right) and Speedhut sensor (left). Chat GPT informed me that I was trying to use an ECU sensor when a gauge sensor was needed. ECU sensors have a lower resistance range, thus why my Speedhut gauge was only very slowly rising compared to what I was seeing on my laptop in the Holley software.




So, there are two different coolant sensor types. You all probably knew that. Now I do too.

The Speedhut sensor did require a 1/4" NPT to 1/8" bushing, but got it installed and now both measurements are similar.

This was confusing, but I am very relieved. Means my engine isn't F-ed!

[Papa]

Good news all around! Glad you got those issues resolved. Looking at the brake fittings, the thread pitch looks completely different.

[PNWTim]

Glad you got it squared away. Not sure where or how you are getting your oil pressure but that is a dedicated Speedhut sending unit as well. It should have come with your gauge set. They are proprietary to Speedhut (just like the water temp sending unit) so confirm you are not using Blueprint's standard Chevy sending unit.

[JimStone]

Good news all around! Glad you got those issues resolved. Looking at the brake fittings, the thread pitch looks completely different.

Thanks Papa


Yeah, I'm wondering if it was a bad batch. I believe it came labeled correctly in its baggie, but that was two years ago so who knows...

Being one of the earlier parts I installed on the build, I didn't have a Spidey sense that something wasn't right. I'd like to think I would catch that now.

Glad you got it squared away. Not sure where or how you are getting your oil pressure but that is a dedicated Speedhut sending unit as well. It should have come with your gauge set. They are proprietary to Speedhut (just like the water temp sending unit) so confirm you are not using Blueprint's standard Chevy sending unit.

Oh man, I had no idea their sensors were proprietary. Explains a lot!

Yes, fortunately I did use Speedhut's oil temp sensor and it seems to be working.

Thanks Tim






Clearly a lot of my mistakes are due to inexperience, which could be minimized if I knew to ask a question before making the mistake.

But some stuff just seems so straightforward and obvious that I couldn't possibly screw it up!

[PNWTim]

Thanks Papa


Yeah, I'm wondering if it was a bad batch. I believe it came labeled correctly in its baggie, but that was two years ago so who knows...

Being one of the earlier parts I installed on the build, I didn't have a Spidey sense that something wasn't right. I'd like to think I would catch that now.















Oh man, I had no idea their sensors were proprietary. Explains a lot!

Yes, fortunately I did use Speedhut's oil temp sensor and it seems to be working.

Thanks Tim






Clearly a lot of my mistakes are due to inexperience, which could be minimized if I knew to ask a question before making the mistake.

But some stuff just seems so straightforward and obvious that I couldn't possibly screw it up!

That old saying "you don't know what you don't know" is never more true than when building one of these cars. Even when I know I still forget and have to redo things. Went to install my headers last night, knew the DS wouldn't install with the alternator in place but guess what? I had forgotten that tip and reinstalled the alternator. Live and learn I guess.

[JimStone]

Finally, my engine is working properly!


I had been having issues with "overheating" and the thermostat seemingly never opening (lower radiator hose was never getting hot).

Turns out, everything was fine. Except I had the wrong temp sensors.

Tim pointed out that Speedhut's temp sensors are proprietary. They give a different resistance range than does a typical coolant temperature sensor. I didn't know that when hooking the Holley and Speedhut gauge wires. I had them reversed.

Net result: The Terminator X thought the engine was about 50 degrees hotter than it was, and Speedhut gauge thought it was 50 degrees cooler. Had me going nuts trying to figure out why one side of the engine was hot and the other cold.

Took me waaaay longer than it should have to figure this out, but got those sensors switched.

After filling with coolant for the nth time, then doing some short "burping" runs, everything ran great. The engine got up to temp, the fan ran for a bit, the thermostat opened (warm lower hose), the temp went back down, fan turned off, then repeat.

Turns out I was just shutting the engine down before the thermostat had the opportunity to open because I was being fooled into thinking the cylinder heads were about to warp.

I'm very relieved by this. Now onward to first Go Kart!










Pinewood Derby:

The kid's school has a pinewood derby each Spring, which the boys get really into. Of course, I also get a bit (too) involved with the car builds.

This year my 8 year-old wanted an F1 car and my 5 year-old a Porsche GT3 RS. We have the 3D printer this year, so will be adding some printed parts to the wood carvings.



















Not sure the GT3 looks exactly like a GT3, but pretty awesome nonetheless and the kids are thrilled.

Will update when printed parts and painting is done.

[PNWTim]

That's great news on the engine front, good job figuring it all out.

Don't forget the strategic addition of lead...