tri-power 250
Well-known member
Has anyone run a temperature probe on the intake manifold, (Log) after a day of driving? I am just wondering how hot a cast iron log gets.
Thanks,
Ken
Thanks,
Ken
Log manifold temperature
- Thread starter tri-power 250
- Start date
No real difference if you couild do an apples verses apples comparison. The head had the non cross flow exhause heat to add to the normal duties, and short intake tracts with small bores and I guess the peak temperatures are the same, but the time taken to heat up is more than aluminum.
The head is designed around a very small intake runner, about half the detachable intake volume, and non cross flows should run hotter at the intake, but the thermal process is tuned to provide target air fuel ratios, and Ford's later versions with detachable intakes ran much higher compression ratios without detonation, but that doesn't mean the iron head intake tract is the culprit.
If someone recast the aluminum intake in cast iron, you'd still then end up with less intake heat because its so much bigger in volume, and would have less heat soak.
Some years, the short intake volume helped Fords emissions (like the 1978-1980 engines that didn't need an air pump in all states), some years (the thermocator years from 1967-1969), it was a negative.
The head is designed around a very small intake runner, about half the detachable intake volume, and non cross flows should run hotter at the intake, but the thermal process is tuned to provide target air fuel ratios, and Ford's later versions with detachable intakes ran much higher compression ratios without detonation, but that doesn't mean the iron head intake tract is the culprit.
If someone recast the aluminum intake in cast iron, you'd still then end up with less intake heat because its so much bigger in volume, and would have less heat soak.
Some years, the short intake volume helped Fords emissions (like the 1978-1980 engines that didn't need an air pump in all states), some years (the thermocator years from 1967-1969), it was a negative.
I've never measured temps, but my best guess would be "not that hot".
Except for the floor directly under the carb, the rest of the log would be no hotter than the rest of the block, or about the temp of the coolant, perhaps a few degrees more in those spots where the intake and exhaust might make contact. The intake floor is supposed to be hot to promote fuel vaporization.
The water-heated spacer under the carb serves two purposes: it keeps the carb warm and helps prevent icing in cool, damp weather, and; it helps stabilize carb temps to the same level as the coolant so the carb doesn't overheat due to proximity to the exhaust.
You actually find similar approaches on many other engines from the 40's and 50's, especially those designed for simplicity and economical operation.
Except for the floor directly under the carb, the rest of the log would be no hotter than the rest of the block, or about the temp of the coolant, perhaps a few degrees more in those spots where the intake and exhaust might make contact. The intake floor is supposed to be hot to promote fuel vaporization.
The water-heated spacer under the carb serves two purposes: it keeps the carb warm and helps prevent icing in cool, damp weather, and; it helps stabilize carb temps to the same level as the coolant so the carb doesn't overheat due to proximity to the exhaust.
You actually find similar approaches on many other engines from the 40's and 50's, especially those designed for simplicity and economical operation.
tri-power 250
Well-known member
Thanks for your replies. I was thinking around ~200 degrees, but hoping for actual numbers.
Thanks again,
Ken
Thanks again,
Ken
After shut down it's going to rise. If you have an electric fan you can put a time delay relay switched by a temp sensor. The relay is needed so it can only run so long regardless of the temp, battery saver. The cooling action of the fan in the radiator will create a natural hydronic convection which will slowly circulate coolant while also cooling the block and dog house with the airflow from the outside.
tri-power 250
Well-known member
Econoline,
Thanks for your reply, you are correct and I didn't think about that. I am trying to figure out what to make my carburetor adapters out of. They will need to absorb the the manifold temperature and keep the carburetor bowls cool enough to keep the fuel from bowling out. Aluminum, phenolic material or wood. I also would like to know which adhesive to use to mount the adapter to log. JB Weld is good to 200 degrees and all materials.....
I'm not a thermodynamisis and, (maybe can't spell it), don't have the education that I need to make these parts, so I have to try a find out.
Thanks,
Ken
Thanks for your reply, you are correct and I didn't think about that. I am trying to figure out what to make my carburetor adapters out of. They will need to absorb the the manifold temperature and keep the carburetor bowls cool enough to keep the fuel from bowling out. Aluminum, phenolic material or wood. I also would like to know which adhesive to use to mount the adapter to log. JB Weld is good to 200 degrees and all materials.....
I'm not a thermodynamisis and, (maybe can't spell it), don't have the education that I need to make these parts, so I have to try a find out.
Thanks,
Ken
Phenolic is the way to go afaik. Wood has too many issues, you may be able to get away with using something like purple heart or hornbeam. As I understand it, the phenolic material is an old type of super dense wood filled resin matrix. We have a 1" chunk, small sheet of it at the shop my boss has been hording for years. I think he picked up at a boeing surplus sale. He's picked up alot of stuff from those over the years. I bet you could make/cast something similar with the right epoxy and wood flour. Most epoxies are probably ok in the ranges we are dealing with. The do soften with heat though, that's how we scrape them at work when needed. What are you doing exactly, carb-wise?
Several years ago I made some carb spacers out of some leftover Corian countertop material. Easy to machine and held up well to the heat and gasoline. Best part was the cost - free!