Radiator cap hole

matt92vr4

matt92vr4

Member
Hi guys, I'm new so I apologize if this is a silly question. I've done a little research and cannot seem to find the exact answer. My dad's Model A's radiator cap has a hole in it. I see that some of the cars have a moto meter in place and some do not. I'd like to get him in moto meter in the future, but for the time being do I need to plug this hole or leave it as a purge? Thank you in advance for your assistance.

-Matt
 
The radiator cap should be closed, as in NO vent to the outside. All the pressure and excess coolant should only go out the overflow tube. Sometimes the vented gas cap gets mixed up with the unvented radiator cap.
 
Tom Wesenberg said:
The radiator cap should be closed, as in NO vent to the outside. All the pressure and excess coolant should only go out the overflow tube. Sometimes the vented gas cap gets mixed up with the unvented radiator cap.
Click to expand...

Don't get confused, a big hole through the top is not used as a vented cap.
 
If the hole is small, it's probably a repo gas cap. Get Dad a proper hinged radiator cap made for a motometer. There are 28-29 threaded caps and 30-31 twist on caps. See a parts supplier's catalog.
 
Years ago, when Chief would put an engine back together & was ready for a road test, he would purposely put a spare vented gas cap on the radiator so he would KNOW in advance if it was runnin' a little hot during the test. Our family sedan never had a temp guage, as Chief was atuned to the smell from the overflow tube. I think he was blessed with 20-20 smelling!! Bill W.
 
I hunted around tonight for an overflow but cannot find one. I'll post a picture of the cap in the morning. Thanks for your help.
 
Please see attached picture of the radiator cap. Please let me know what you think regarding the hole. Thank you.
 

Attachments

  • MA Rad Cap.jpg
    MA Rad Cap.jpg
    33.3 KB · Views: 111
It had a motormeter at one time. You can buy a replacement motormeter for the hole from one of the parts houses. Bert's would probably have a good used original cap.
 
Thank you. I'm finding a number of different aesthetic design options. What is the correct motometer for a 1929 Ford?
 
Mine has a possibly not factory gutterbolt in the hole in the radiator cap. That might be an option until you get a motometer.
 
dumb person said:
Mine has a possibly not factory gutterbolt in the hole in the radiator cap. That might be an option until you get a motometer.
Click to expand...
Yo, my faraway Friend,
The Dog:cool: asks, "What's a gutterbolt"?? I wonder if the Dog is building something secret in the garage???:eek: Bill W.
 

Attachments

  • 31 subframe.jpg
    31 subframe.jpg
    80.9 KB · Views: 18
Hi guys, I'm following up on this. I purchased a Motometer from Mac's. It looks great. Thank you for your help.
 

Attachments

  • FMA Motometer.jpg
    FMA Motometer.jpg
    31.4 KB · Views: 30
You must log in or register to reply here.
Back
Top