02WS6SSZ71

Hello all--
New to the forum, new to the Olds game. The subject at hand: '69 Vista Cruiser 350 4 bbl. My issue is related to engine temp, and I'm sure this has been discussed plenty, but was hoping to get some specific advise/suggestions/prior experience. We are leaving on the Power Tour shortly with this ugly creature and I'm getting nervous about Texas heat with an unproven car. For the most part the car runs around 175-180, but on a few of the warmer days (85 deg) we've had in Kansas City it climbs up in the 210 neighborhood going down the highway and holds. It cools back down almost instantly when returning to slow speeds. Stays around 175 at idle. Currently electric gauge, confirmed with manual gauge, and infrared gun has agreed with the current gauge, although it is hard to jump out of the car quick enough to measure when it's running warm because it cools so quick. Factory dummy light still active, never gets hot enuf to come on.

Details on the car: Purchased this winter, 2 burnt exh valves when I bought it, so had the heads gone thru and trued up (took 7 thou to make them straight), I put it back together with Felpro blues. No coolant in oil or vise versa. Stock bore, factory pistons, now has strong compression across the board. Cam unknown, added double roller and new Carter fuel pump. Coolant that came out of the block was surprisingly clean when draining for head work. Built 2.5" dual exhaust with H-pipe, factory manifolds.

Factory 3 core rad was re-cored by a shop that I have done quite a bit of business with and trust. New Murray water pump, new rad cap, obviously fresh coolant 50/50, new NAPA 180 t-stat with bleed hole drilled. Changed to 7 blade fan with new thermostatic clutch. Shroud in pretty decent shape and seals up, lower air damn surprisingly still in tact.

Just rebuilt the carb ('69 QJet 750), maintained setup that was aleadry in the carb other than a mild hanger change for the secondaries. 70 main jets. Plugs look pretty good, a touch rich if anything. I'm being a sissy on the timing due to the compression...swapped to HEI, Crane kit, have worked up to 11 deg initial, 33 all in by 3 grand, 45 with vac advance hooked up.

Sorry for all the details, trying to weed out unneeded suggestions. I am frankly concerned that as ambient temp climbs the car will eventually overheat, and I don't even have the AC up and going (next winter hopefully). My only thoughts are that the rad is somehow messed up, the T-stat is sticking open and not letting the coolant hang in the rad long enough, or I need to sack up and throw some more timing at it. Please share your knowledge, and thanks in advance!

1970cs

Welcome to C.O.! Your right this has been discussed before. Great detail on your post. I and others would suggest on checking to see if all the radiator seals and shrouds are in place and in good condition. Explains the highway condition.

You may want to post pictures of the fan and radiator areas so we can what you are seeing.

Pat

My442

I chased the exact same problem.

It turned out that the mechanical advance weight springs were weak, and allowed too much timing at highway speeds.

A bad timing light will expose this problem quickly.

02WS6SSZ71

I will try to oblidge on that this evening.

02WS6SSZ71

Interesting thought on the springs...they are new out of a Crane kit, one of the light springs, one moderate. I could try another set for sure. Wouldn't this present though as I spin the motor up when checking my timing though? And I'm confused about the "bad timing light" statement....

olds 307 and 403

I think he meant a timing light will show this problem. One light and medium spring should be fine, HEI's advance slow enough and Felpro blues would have lowered your compression a half a point over the stock shim head gaskets. Try 2-3 degrees more timing.and run either 60-40 or 70-30 water to coolant ratio, seeing your in Texas, you don't need -40 protection. Add water pump lubricant if you are worried about corrosion. Another thing to try is the EP Stewart modified Robert Shaw modified high flow thermostat with 3 bleed holes, get it in 160 or 180. I had a bad Mr Gasket high flow thermostat go bad, replaced everything else. Fine around town but would eventually floor the gauge on the highway. Is your water pump a closed impellar type? It has to be limited flow either coolant or air at speed. I had endless issues with my 403, eliminating the super under drive pulleys and chucking the Mr Gasket thermostat finally fixed it.

joe_padavano

You do realize that 210 deg is not unreasonable, right? With a 16 psi pressure cap, the coolant boiling point is over 250F. Certainly verify that the radiator core is not blocked between the fins, but if the temp stabilizes at 210 and the car doesn't exhibit any ill effects (like pinging or misfiring), I probably wouldn't loose a lot of sleep over this.

Do verify that the car isn't running lean at highway speeds, or that advance isn't excessive, as noted above.

My442

I meant to say a DIAL BACK timing light...sorry!

oldcutlass

I agree with your direction, try the changes.

Fun71

Oldcutlass, I think when he said "HEI" he really meant he has an electronic conversion in his points distributor and not an actual HEI distributor. If so, 16-18 initial may be too much for the points weights/center bar as they typically give ~24 mechanical and 16-18 initial would push the total over 40.

oldcutlass

If that is correct Kenneth I agree with you. Different makes of Hei's can be from 18-21 degs of mech advance. So I was going with what he said.

02WS6SSZ71

No prob...figured that's what you were going for! And yes, that's what I use...fantastic tool to own

02WS6SSZ71

Didn't Realize the Felpro was THAT fat! Or should I say the stocker was that thin? I figured by the time they had shaved 7 thou off the heads I'd break even, but that makes me feel a bit better. I'm actually in Kansas City, so I have to be careful on my coolant mix...just in route to Texas this weekend. I will check out that thermostat. The water pump is your general parts store replacement, but it was new, not reman, made by Murray. Open impeller. Looked like a decent unit. Factory pulley setup

02WS6SSZ71

Agreed, I would have zero concerns with 210 if I wasn't coming off the t-stat so far, and if it didn't get worse in warmer weather. 210 is as high as I've seen...so far...max temp 85, but this weekend will be the test. I am running a 16 lb cap in case anyone was wondering

02WS6SSZ71

Now we're talkin! I was hoping someone would chime in and tell me to stop being a wimp on the timing! To clarify, full on HEI conversion, 12v going to her now! Everyone under the sun says 9.5:1 compression max for iron head pump gas in the Pontiac world (where I am more comfortable), so I was going up carefully on my timing here as I imagine I'm still at 10:1 or better. Just scared of inaudible knock trashing this 40 yr old bottom end when I'm 1000 miles from home

02WS6SSZ71

O, and regarding the 175-180 idle...it's a guess...probably 180, but I just have marks at 160 and 190. Still not ruling out the t-stat being junk. And is there any reason to drill a bleed hole with the hose going over to the water pump?

oldcutlass

I know that people have done it, but there is a bypass hose. The small holes don't do much once the thermostat opens. I'm not fond of the dash gauges and usually will run a mechanical set under the dash. They are a bit more accurate. I'm in the camp that you probably have nothing to worry about on your trip. I'd throw 2 bottles of water wetter in there and go.

Fun71

That's similar to what's on my car and it works well in our 115º+ summer temps, so I wouldn't think the pump is causing you any issues.

olds 307 and 403

Fun71 is the ultimate cooling system tester on here. I have seen or had very few issues cooling anything 350 or smaller in the Olds world. The 403 and 455 seem to cause many more issues.

olds 307 and 403

Even with small dish pistons sitting .025"-.030" in the hole, .040" thick gaskets and maybe 66-67 CC head chambers, you have less than 9.5 to 1 compression.

02WS6SSZ71

Thank you all for the help and suggestions. I'll continue the hunt to see if I can make some improvements and update if i find a magic bullet.

02WS6SSZ71

Just an update: Sealed up any little open spots on the shroud with duct tape...no change. Bottle of Water Wetter...no change. Added 3 deg of timing...no change. T-stat change tomorrow. Car was idling at 160 when I was setting timing this afternoon, so my theory is that it's hanging open and overcooling when still and moving coolant thru the rad too quick going down the road...fingers crossed. Good news is I knocked down 16.1 mpg on a 110 mile drive today going 70-75 mph most of the time, which is much better than I ever expected from this pig.

olds 307 and 403

The Olds V8 was an efficient design for it's time. The flat valve angle seems to help fuel economy and torque. The longer intake runners definitely help torque and the chamber likes a lot of timing. I hate how my 9.5 to 1 350 needs the timing slowed down due to pinging, less mileage and just doesn't run as nice as it should. Don't believe that cooling too quickly nonsense, if anything it may be sticking closed at times.

02WS6SSZ71

I randomly today remembered that I had committed one of the worst car forum sins...never updated my own "what's wrong with my car?" post. So, as I left off...


Before leaving on 2016 Power Tour to Texas and back home to Kansas City, the t-stat was swapped out to an EMP Stewart 180 deg $30 job...only result was a more reliable base temp of 180 deg. Added 3 deg initial timing (14 eg) and left on the trip. Each day was hotter than the last, even heading back north...95-100+ deg ambient. Had to dial timing back to 12 deg as it was pinging on occasion. The car continued to climb in temp as we went down the highway, generally making its way to 215-220, but never boiling. Car did well otherwise the entire trip, 2500 miles logged, used 1/2 qt of oil and got us back home in one piece. But eyes were glued to the temp gauge at all times.


For winter 2016/spring 2017 the Vista got new shocks, new ball joints, and every bushing on the car was replaced. Time was also spent on the carb, dialing it in using a wide band 02 sensor...the car had been running a bit on the lean side, and hopes were that this was causing the temp issues. 2 deg was dialed back in, hoping to take advantage of the improved fueling. As summer rolled in and with Power Tour on the horizon, the temps were still behaving in the same way...gradual climb at highway speeds, on the t-stat at a stop and slower speeds.


As a last ditch effort the night before leaving for Power Tour, the AC condenser was removed from in front of the radiator (still hadn't tackled the AC as we were concerned about causing an overheating issue). This instantly cured all of our problems...went the whole trip and the car was never more than 10 deg off the t-stat. This included another 2500 miles of mostly highway driving, hot lapping it on the autocross course and a couple 1/4 mile passes (17.0 if you're curious).


The condenser was thoroughly cleaned when the radiator was out of the car early 2016, fins were in good shape, no apparent obstructions. So, my only conclusion is that the factory 3 row radiator does not have the capacity to support that vehicle for sustained highway driving at 65+ MPH in 85+ deg weather, and likely didn't from the factory since it is still in very good working condition otherwise. I realize the car never boiled, but I feel like adding the drag of an AC compressor to the equation eventually would have caused some issues.


Thanks for reading the long story...hopefully this can help someone else troubleshoot a similar issue in the future.

AZ520

Im in Tucson and its hot and my eyes are glued to the temp gauge as well. Champion 4 row aluminum helps, high flow aluminum pump, 180 t-stat. I think its been said that olds just run hotter, esp overbored rebuilt olds.

rustyroger

Just wondering....
Was the 3 core radiator fitted to a/c cars in the factory?. Maybe they had a 4 core from the production line?. The car is 40+ years old, it may be the factory 3 core you had recored wasn't the original.
One other point, back in 1969 cars were running leaded gas without ethanol, could it be modern fuel isn't helping?.
I don't know, I'm just guessing.

Roger.

Rocketbrian

A/C cars had three row unless HD cooling ordered. Non A/C 455s in Cutlasses only had two row.

olds 307 and 403

I experienced the same thing with a Champion 3 core in my G body with a 403. Fair weather and at low speeds, cooling was OK. Hot weather, especially towing my boat would see 235 degrees at times. The radiator just wasn't big enough. The recored 2 core in my non A/C 70 gets to 190 at idle, 175 or 180 in fair weather. In extreme heat, I would suspect 10 degrees more for sure. I plan on a large core 2 row rad as this one is now seeping.

02WS6SSZ71

A Champion 4 row is in the plans as I've had great luck with their rads in 3 other vehicles. Hopefully that would do the trick for when a/c is added on.


Anything is possible with this old turd, although if they did so they spent the time to change bottom saddles and sourced a 3 row top plate as well.

olds 307 and 403

There is a good pic of the Champion 4 core in Macadoo's Mystery 455 thread, it is a monster. I still believe the 1" core or bigger 2 core will equal or out cool a 4 core just because of the superior air flow and possibly coolant flow.

Firewalker

Possible horsepower VS CFMs

HP = 0.25714 × CFM × No. of Cylinders

Or
http://www.wallaceracing.com/calcafhp.php