What is the average running temperature of a 1928 using a infrared thermometer? The return hose to the radiator is around 160 and 212 on the head at the #4 cylinder. This is after 20 minutes of driving at 5 mph or so. I had a gush of 50-50 coolant come out when I shut the engine off but the level was just a 1.5” below the cap before driving and my overflow container is just a 20oz beer bottle which apparently isn’t large enough. This is the longest I’ve had it run since getting it running last fall.
I wish I would have seen this before now. I drove my 1926 for the first time this year earlier today and I could have pulled temps for you. I will likely drive it again this week if the weather is nice...
5 MPH isn't very quick, but I imagine the temps in PA are similar to the 50F-70F that we've had in Ohio recently. What is the condition of your radiator and water pump? Where was your timing at while you were running it? I think the '28 heads have a thermostat. You may want to check that it's not stuck closed.
As long as you're moving in these cool temperatures, you shouldn't be boiling over.
Very similar weather. Today it was just around 70 or so when I had it running. My ”˜28 was converted to a doodlebug tractor back in the 40s and I recently converted it to what I guess you could call a truck. Since it has a ford TT rear, it’s max speed would be 15mph. I’ll mostly be putting around the house in 1st or 2nd gear at low RPMs. I know that’s not ideal because there is little to no air movement besides what the fan can create. I’m not sure what the timing was and I don’t believe it has a thermostat. I didn’t see anywhere one would go when I had the head off. I’m pretty sure it would be in the return water housing. I can’t remember exactly, but I think the capitals didn’t have them?
The ”˜28s originally had a bellows style thermostat in the return housing set for 168F. A couple things to consider:
1) If your cooling system is non-pressurized as they were originally, modern 50/50 antifreeze has a tendency to foam up and not cool effectively. A lot of us will run water with a bottle of “water pump lubricant” which has corrosion inhibitors in it but does not foam up like modern antifreeze. If you need antifreeze coolant, you can use a 50/50 mix of water and glycerine as was originally specified
2) if you have not check already, make sure the baffle plate on your water pump is still in tact, these are often rusted away and adversely affect pump performance
3) Assuming you have the thermostat housing, you can easily install a modified modern thermostat
Also, you can find the whole 1928 specifications here:
The original bellows type thermostat opening temperature,according to the '28 service bulletin was 140 degrees F.Most would people would run a 160 degree F,as long as the entire cooling system is in peak working condition.I chose to run a 155 degree bellows type thermostat out of a mid '50's Pontiac 6,due to our climate here in Australia,and it works fine.According to the accessory steering column mounted Motometer gauge on my '28 truck,at normal speeds it runs just below 160F.I've got the sensor bulb fitting fitted into the back of the cylinder head,behind the rocker cover to get a better idea of the temp in the hottest part of the cooling system.
I'd go with CPJ's temp values, taking a closer look at the spec book linked above, at 168F the thermostat was to be fully open, the nominal operating temp was probably closer to the 140F - 160F range.
I have a 170F thermostat in mine which is probably a bit higher than it should be, however, it also has a new higher capacity honeycomb core and rebuilt water pump.
Thanks for the replies. I attempted to pull thermostat housing this afternoon and broke one of the bolts. I stopped after trying the second one because it felt the same so I assume it might break as well. The bolt was really rusted and looks like it broke right below where the threads start. So the bolt is about an inch and a half long that came out. Since it didn’t break at the head of the bolt, I won’t be able to weld another bolt on. What are my options? Are there any threads inside the housing its self? If the second bolt were to break in a similar spot would I be able to take a putty knife along the housing and ”˜pop’ it off? I’m so frustrated that I broke it off. I thought that being hot from running would be enough to loosen it up and that was not the case. Thanks for your time and I appreciate any help.
That's really common, I did it myself so don't worry! The housing itself does NOT have threads and the bolt is exposed to the coolant (not the best design) so they often rusted away and often break when trying to remove. The following blog pages show the housing removed:
Based on your description of where the bolt broke, I would CAREFULLY cut/grind off the other bolt head holding on the housing so you can pull the housing off exposing what is left of the bolts. I would spray the threads with PB Blaster or your favorite penetrating oil and let it soak for a couple days and see if you can back the bolts out, if there's enough of the bolt left, use some vice grips to back them out or if needed use a bolt extractor (). If they're still not budging, you can heat it up with a torch to help loosen them up just be careful.
If all that fails, I would take it to a machine shop.
Another technique for lubricating stuck threaded thingees is to heat up the assembly with a propane torch and melt some paraffin (use a candle bottom) into the threads. The wax will wick down into the threads and act as a lubricant.
If you need to use a bolt extractor, I suggest using a square-type extractor rather than one of the twisty ones. I've had better results with the square extractors than the other types.
When I rebuilt my '28 engine a couple of years ago, both of the bolts for the thermostat housing broke off. Luckily, part of the bolts were left sticking out of the block so I could work them out with vice grips attached.
BTW, I used brass replacement bolts to help prevent the rusting of the bolts in the future.
Your posts make me feel much better and give me hope! Thank you! I was really disgusted and slightly discouraged yesterday.
Now knowing the length of the bolt, and seeing the pictures I should be able to figure out how much of the broken bolt is sticking out of the head. It looks like from TJPlatts' pictures only the last 1/2" or so of the bolt is actually in the head? I plan on pulling it in the garage this afternoon so I can work on either heating up and attempting to pull or cutting the head of the other bolt and begin soaking the threads.
Home Depot should have carry brass push plates that I pick up to make a similar thermostat bracket like Dean's. Do all thermostat housings have the two inside screw holes? Once this is all done I'll drain the antifreeze/coolant and switch back to water w/ water pump lube as suggested and check the temperatures again. I had only switched to the 50/50 antifreeze/coolant when I moved it down to my shed for the winter. Good to know that I'll have to rotate between the two depending on the season. I haven't been keen to antifreeze with a dog around anyway. If everything checks out I would love to take it down the road for a 20-30 minute ride at a slightly higher speed. Hopefully, an orange triangle and a 5-gallon gas can in the back is enough to convince the local sheriff that it's a 'Tractor' should we come across each other.
Thanks for the suggestion on brass bolts. I would also suggest anti-seize on the threads. I have two 28 heads that I need to pull the housings off. Fear of breaking the bolts off is what has held me up from doing it.
Last edited by Mark_Gregush; 05/05/2006:44 PM. Reason: Removed what might be wrong info
Congrats on getting the bolts out! ;-) I learned the wax trick not too long ago from a friend who is a high school auto shop teacher.
Before you go through the effort of making a thermostat bracket, check with Gary Wallace (http://www.earlychevyparts.com/). One guy in my engine build thread mentioned that Gary had the brackets.
Cheers, Dean
Dean 'Rustoholic' Meltz old and ugly is beautiful!
Dean, My neighbor helped me fabricate a thermostat bracket based on your pictures. We used a piece of 2” aluminum bar stock with stainless bolts and a 160 thermostat from a 1967 Mustang. We also cut down new stainless steel bolts (local hardware store only had 3” or 2.5”) so I should be able to re-mount everything tomorrow. I appreciate all the info, help and ideas everyone has shared.
I took the doodlebug for a short drive down the road this morning. The ol’ girl ran like a top! I think my round trip was 2 miles and It was running for about an hour and a half after stopping to talk to a few neighbors. Of course it’s cooler out today but I think the thermostat is going to do the trick.
Here’s a few pictures and two videos. One video is 2nd gear and the other is third. I need a seat cushion and my brakes parts to arrive before attempting 4th.
When the social distancing is past and car shows start happening again, take it out and show it! I guarantee that the public will be fascinated by your doodlebug.
By the way, does it have a name?
Cheers, Dean
Dean 'Rustoholic' Meltz old and ugly is beautiful!
Thanks! A couple neighbors told me the same thing about the car shows. Funny, I only thought about taking it to tractor shows.
No name yet, it’ll probably just be the ”˜doodlebug’ which is kinda fun/funny to say. When I get it out, I ask my 1yr old if he wants to go ”doodlebuggin’” or “do you want to doodlebug around?” He’s already hooked!! Of course his vocabulary is minimal but his reaction says it all. When my wife rides with us he only wants to sit on my lap and hold the steering wheel and push the horn button. There’s no horn but thanks to summit racing an ah-oog-ha horn will be here Thursday
