Summershandy

Straight 8 engine overheated at idle

Recommended Posts

Cool, I just got my thermostat in. Is this how the configuration of thermostat and ring sit in the housing?

 

 

IMG_7953.JPG

  • Like 1

Share this post


Link to post
Share on other sites
17 minutes ago, Summershandy said:

Cool, I just got my thermostat in. Is this how the configuration of thermostat and ring sit in the housing?

 

 

IMG_7953.JPG

yes

 

  • Like 1

Share this post


Link to post
Share on other sites

I trimmed the retainer ring flush to hold the thermostat in. It ain't stainless either or it wouldn't cut so easy. 

 

IMG_7957.thumb.JPG.ba816eabb7f0aace8375f6afe1ed0dfa.JPG

 

 

Good to see the ring can't actually fall into the cylinder hole even if you squeeze it and try.

 

IMG_7959.thumb.JPG.c2385c20e73987fa92a41b96c0d2b240.JPG

 

 

  • Like 1

Share this post


Link to post
Share on other sites

Everything is put back together so I went for a cruise today. 82 degrees out. Cooling system worked well for an hour drive....until we went to a drive thru burger joint. It was slow today being Sunday. The temp gauge rose to just over 3/4 high. Started to drive again and the needle went back down. Guess I have to accept the fact this is how the engine's cooling system operates. But, I did just remember that last year I had removed the inspection covers thinking I could get more air flow. Think I'm going to try that next time. Wife & I think that in 1954, there were less cars, less lights, no car shows and no slow drive thru burger joints.....

  • Like 1

Share this post


Link to post
Share on other sites

Just a thought, hows the timing ? Wonder if a few degrees of advance might help. have you ever set timing with a vacuum guage ?

 

Beyond that maybe just bump the idle speed up a bit.

Share this post


Link to post
Share on other sites
Posted (edited)

That sounds pretty normal. With old gauges, it's hard to know what's accurate and it sounds like those in your Pontiac don't even have actual numbers, correct? Drive it some more and you'll get a feel for what's normal and how it behaves and you won't worry about it anymore. As long as it cools off once you're underway and doesn't go critical sitting in traffic, it's all good. If the cooling system is in good order--and it sounds like it is--then it should reach a saturation point when it's sitting still where the radiator can reject just enough heat to stabilize at a certain temperature. It won't be as cool as when you're underway, but there will be an equilibrium point between the heat the engine is generating at idle and what the radiator can reject.

 

In addition to the vague factory gauge, I have a modern mechanical gauge with clear numeric markings on my '41 Limited and it's connected to the thermostat housing so I know it's as accurate as possible. Underway, it shows 160 degrees but if I get stuck in traffic, it'll go up to 190 or so, but it always stops there and goes no higher. Once I'm moving, back to 160 in a matter of minutes. I think that's pretty normal for any old car with a healthy cooling system.

 

I think you've got it solved. Now go enjoy!

Edited by Matt Harwood (see edit history)

Share this post


Link to post
Share on other sites
9 hours ago, Matt Harwood said:

With old gauges, it's hard to know what's accurate and it sounds like those in your Pontiac don't even have actual numbers, correct?

 

When I got the car it had an under dash aftermarket numbered gauge. I had installed a 180 degree thermostat and the gauge read 180-190 operating. 

I just dug out the work order for my rebuilt temp gauge and found this drawing at the bottom of the sheet which I hadn't noticed before. 

Guess this was part of Abbott's calibration. Wonder if the lines drawn were intentional because the line for the 190 degree is on the right side of the dash mark. That would mean 180 is smack dab in the middle to me. Also good to know what the hot mark reading is.

 

 

 

 

IMG_7964.JPG

Share this post


Link to post
Share on other sites

Dang antifreeze weeps out from the housing and head now. I made so sure of the clean surfaces and added a super thin coat of sealant to the paper gasket. One surface side was a bit pitted so I wanted to account for it. After a heat cycle the bolts were able to tighten a bit more. Maybe the retainer is a little too long and preventing a perfect tight seal? It's not a major thing and I'm leaving it for now. I'll look at it again this winter when it's project time again.

Share this post


Link to post
Share on other sites

i was thinking that the retainer did look a bit too long after it had been trimmed.

Share this post


Link to post
Share on other sites
11 hours ago, pontiac1953 said:

i was thinking that the retainer did look a bit too long after it had been trimmed.

 

Took it to a show yesterday. Under a 5 minute line up to register. Drove around before I went home. Cooling system ran good. 

 

Checked this morning and the weeping coolant is very, very minimal. Actually is too hard to see against the dark green engine color. 

 

I'll take it apart this winter and file it down and clean up the surfaces again.

 

 

 

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...