Cool running! Or how I dropped 20+ degrees by spending $$ and scraping knuckles

Oh good grief! Another hot car thread? Well kind of but more a 'what worked for me' thread.

I've been following most of the 'hot engine' threads with interest and finally set to to do something about the Electra. Since fitting the gauges I could finally tell how hot the engine was running. In 90* ambient it would run around 200* until stop-start or crawling traffic would push it up to 220* from which it would never drop.

I decided to replace the radiator and fit a 180 thermostat.

Chose the "Champion Cooling Systems All Aluminum Radiator 1968-85 GM (28" Core)" from Jegs

https://www.jegs.com/i/Champion-Coo...uw_FtdqUvLhcnLY2Ic1eJ1jSHqB77GchoCW3YQAvD_BwE

I flipped and flopped on whether to do a complete system flush and finally flopped and decided not to. (I can hear the groans already!) My argument for not flushing was that doing so might just force all the crap in the old radiator around the rest of the system. Removing the old radiator would probably take the worst of the crud with it.

The old radiator came out without a hitch and even the trans cooler lines undid without too much effort. Pre-soaked with WD-40 and used a good beefy flare nut wrench.

The old radiator weighed a ton (no I didn't measure it) and by comparison the new one was a featherweight. It dropped right into place on the old pads which were in good shape and in no time was locked down and hooked up.

Thermostat replacement was an equal breeze. What came out was a super clean 195* rated thermostat. This was obviously contributing to the hot running. Popped the new one in, new gasket, torque up, hos eon and Bob's no relation.

Checked all the hose clamps and filled up with Prestone 50/50 premix. Time to spin up and see if anything leaks.

Fired up and backed out of the garage. Stuck my head under the hood to witness trans fluid hemorrhaging out of the cooler line at the cross-member clip. Eeek! Back into garage and shut down. Drip pan and lots of wiping of smoking exhaust pipe.

It looks like the old lines had rusted where they were held by the clip and the flexing caused by the radiator removal was enough to induce a tiny split. I'm just glad it happened when it did and not while miles from home.

Decided to go braided stainless lines but hose end crimping is not my favorite task so I stumped up for a pre made pair that came with the correct adapters for both the trans and radiator ends. Paid extra to get them by Friday so I could have the car on the road for the weekend.

The old lines came out with only a bit of stubbornness at the trans end and the new ones went in without incident. Except... the only length them came in was 7 ft ! I don't know why 7 ft but that's about two too many!

Made up an aluminum clip to mount on the fender lip and resorted to zip ties to keep the lines positioned as best I could to avoid the exhaust system.

With a single pipe system there is a crossover pipe from the drivers side and this means the trans cooler lines have to route between this and the passenger side downpipe. In anticipation of this I also bought some heat shield wrap. This opens up fully length ways and is held closed by a strip of Velcro that tuns the length of the wrap. It looks kind of clunky but should help reduce cooking from the exhaust.

Top up trans fluid and coolant. Ready for some heat!

Well today hit a high in the low 80's and I had some of she-who-must-be-obeyed's family over for a visit so I took us five adults out for lunch at Bub's Bar-B-Que in Sunderland, MA Slogan: Pig out in style!

Car warmed up to 180* and held there or a little over until we hit some traffic. Crept up to 195* but dropped again when moving. For the most part it hung in around 180-200* the entire time so I'm pleased with the result. Next big test will be a 90+* day.

Bob

So pictures. There have to be pictures.

 

Glad to hear the new radiator is kicking butt! Just bought myself a Champion radiator as well, and can’t wait to install it.

Did you buy the braided lines from Jegs as well?

 

Not to hijack this Bob, but I did the same job last winter as far as the trans fluid lines were concerned. On the XGS with a 455/400 and headers, the old steel lines were pretty cooked and have repaired leaks in the distant past. No fun on the side of the road. I changed over to AN6 blue silicone hose with push on fitings and adapters. I ran 2 - 120* fittings from the trans BACK to the top of the cross member and across to the frame, then up through the frame rail to the nose and out right up to the radiator. Completely clear of everything . No runs, no leaks, no errors! Each hose was almost 12 - 14 feet in length.

I dont know how the PO did it, but the steel jobs passed in between header tubes and were even "pinched" pretty well between a few. All that added to heat transfer to the ATF and the AF. I had to cut each line 3X to remove them. ws

 

I got the lines and insulation from Summit Racing. Lines were not cheap but I wanted fit and forget for now. An engine rebuild is in the future so I'll have the luxury of time to do a better routing job.

Lines: https://www.summitracing.com/parts/ADD-23-1501
Insulation: https://www.summitracing.com/parts/SUM-350135-1

The radiator itself was a drop in replacement. I went with all aluminum over a less expensive plastic and aluminum because I was concerned about how well the plastic would hold up under repeated heat stress on sunny but frigid New England winter days.

Bob

 

Now that looks like the way to go!

Braided steel lines would not work for this because the minimum bend radius is too large. Could you post links for the tube and fittings you used for future reference? Thanks!

I'm going to fit a dual exhaust system and that will eliminate the crossover tube making for more clearance. If I stick with stock headers when I get the engine done I'll get shorter braided steel lines made up. If I switch to shorty headers I will probably follow your lead and go the long way around!

One thing to note for other radiator and or trans cooler line swappers is you'll need to check and top off trans fluid after you're done. Especially if you end up fitting longer lines.

With the slight loss of fluid from the old steel lines and the longer, larger bore steel lines I had to add a quart of ATF to bring it back up to full.

Cheers!
Bob

 

Glad that you got the heat issue worked out. I had a similar experience and am also a big fan (no pun intended) of the aluminum radiator's results.

 

Thats pretty neat on the big car routing! On mine I was fortunate that the frame had a big (lifting lug for assembly??) hole right at the front inside that lined up perfectly with the radiator. My guy at the motor parts/truck parts store ordered all my stuff and even had one chunk of hose (by the foot) for one side and ordered a 25 foot coil for me for the other which I returned like 12 feet of for a refund.
I know my steel lines were not right, plus the PO had one of the trans fittings cross threaded (inverted flare side) and just kept tightening it until it "almost" quit leaking har har... THAT was a chore to unscrew.
The trans AN6 fittings are 120* to point to the rear and are almost perfect. They just clear the dipstick tube too. I also did a fluid and filter job PLUS a governor inspection and used almost 2 gallons of ATF to refill it. ws

 

Update on new cooling performance. Passed with flying colors!

Was a 90* day for another trip to Bub's (Pig-out-in-style) Bar-b-que with she-who-must-be-obeyed's father for fathers day lunch.

Car ran a steady 180-185 until slowed down for traffic and stopping for lights and turns when it crept up to 200. Once moving free of traffic it dropped right back to 190 and stayed in there.

Bob

 

The creep up at idle could be a few things. What is your idle rpm? If the timing cover is worn a bit, low rpm won't move enough coolant. After the engine is nice and hot see that the fan clutch has some good resistance to it. Is your vacuum advance hooked up to ported or manifold? If it's hooked up to manifold, going to ported may help (over advanced at idle putting heat into the engine). Too much advance with an overly rich carb will cause hot idling, but this can be hidden by good coolant and air flow.

 

Thanks for telling about that.

 

Retarded timing at cruise will put more heat in the system, at no load idle advance allows more heat into the cooling system. It's all about piston loading and where the heat can go (exhaust vs metal). I can change my coolant temp at idle by 5ºF by sweeping the timing low to high. Most modern cars idle with timing in the single digits. My car's hang around 10º-12º timing at idle.

 

Agree to disagree. I read it. It cools more from engine increasing speed (water pump and fan). What does that same service manual say to set the base timing at for idle? When the TCS is off, aka no vacuum advance until 3rd gear or getting hot and needs more rpm?

Check your Riviera's timing after it's been warmed up. Timing at idle is added during warmup, to both increase rpm and add heat to the system.

 

Nicely done!

 

I'm still of the opinion that the faster water pump and fan speed correct the cooling more than the timing. I have my idle rpm increase 200rpm automatically, without increasing timing, if it starts getting warm on an extra hot day and it's always brought the temp back into line. That's a bunch of timing at idle, was the A/C on?

Of course NOx is less with retarded timing, NOx forms from high-temperature combustion and retarding the timing at idle lowers combusion temperatures because the exhaust valve opens before all the fuel can burn and peak combustion pressure happens well after the piston has started its travel down, which causes rough running. So the solution is having the throttle opened more to lean it out to complete the burn of less fuel (and heat) before the exhaust valve does open, and keep the peak combustion pressure around ~10º ATDC, which smooths the engine pulses out.