Go Back   The Ford Barn > General Discussion > Model A (1928-31)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 01-23-2022, 08:56 AM   #1
gotthard
Junior Member
 
gotthard's Avatar
 
Join Date: Dec 2012
Location: Switzerland
Posts: 16
Default model b intake diagnosis

I have to change the manifold gasket and took some pictures from the intake and outlet. One intake is a little bit greasy. I can tell, that there was some false air issus since the carburetor flange of the intake manifold was not streight. Is probably this the reason, should I adjust the valves or is there no worries about that? Is there anyone with advice?

best reguards
Attached Images
File Type: jpeg EBB13953-ED10-4826-B6DF-88280AD6D357.jpeg (111.6 KB, 78 views)
File Type: jpeg 535D3591-013D-4D0A-9FF0-D7546874A698.jpeg (94.9 KB, 72 views)
gotthard is offline   Reply With Quote
Old 01-23-2022, 09:22 AM   #2
Gene F
Senior Member
 
Gene F's Avatar
 
Join Date: Mar 2012
Location: Ohio
Posts: 1,915
Default Re: model b intake diagnosis

It is running, right?
Gene F is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 01-23-2022, 09:43 AM   #3
rotorwrench
Senior Member
 
rotorwrench's Avatar
 
Join Date: Jun 2010
Location: San Antonio, Texas
Posts: 16,367
Default Re: model b intake diagnosis

If your tappets are the adjustable type then it's not a difficult task. If they are original type tappets then the job gets a lot more complicated. The old two piece guides have to be driven out to remove the valves on the original design. Valves would be ground on the stems to open clearance up or the valve seat cut for too wide a clearance. If the clearance is close then I wouldn't mess with it unless it would allow the engine to run properly.

The manifold surface should be completely cleaned off after removal of the last two studs there. It can then be evaluated for condition. This is a spot that can have a little bit of material planed off but it would have to be set up in a mill to do that. If the surface only has some minor wear or impact areas then a new copper gasket could likely still be made to seal as long as the irregularities aren't too deep or large.
rotorwrench is offline   Reply With Quote
Old 01-23-2022, 11:15 AM   #4
gotthard
Junior Member
 
gotthard's Avatar
 
Join Date: Dec 2012
Location: Switzerland
Posts: 16
Default Re: model b intake diagnosis

It is a original engine, so I fear there are no adjsable tappets. I will clean the surface, as soon as I got an other manifold, I was able to buy. The actual one has after maching no space left, to install glands. I have to mention also, that I broke the power jet tube, by searching for the reason for high idle. I drove the car during summer anyway and I now was able to fix that, with a modified model a tube. But the engine never run since. Probably I have to do one by one, because there are coming things together. Is it helpful to measure the compression?
Attached Images
File Type: jpg EC675F35-7227-42E5-8782-EAA52A0845DD.jpg (45.0 KB, 64 views)
gotthard is offline   Reply With Quote
Old 01-23-2022, 11:39 AM   #5
Ruth
Senior Member
 
Join Date: May 2016
Location: Glide, Oregon
Posts: 1,334
Default Re: model b intake diagnosis

Quote:
Originally Posted by gotthard View Post
I have to mention also, that I broke the power jet tube, by searching for the reason for high idle. I drove the car during summer anyway and I now was able to fix that, with a modified model a tube. But the engine never run since.
Quote:
Originally Posted by gotthard View Post
I have to change the manifold gasket and took some pictures from the intake and outlet. One intake is a little bit greasy. I can tell, that there was some false air issus since the carburetor flange of the intake manifold was not streight.?

best reguards
A reason for your high idle could be your vacuum leak at the carburetor flange.
__________________
Ruth
"Sometimes you really DO need to read the whole thread"
Ruth is offline   Reply With Quote
Old 01-23-2022, 11:46 AM   #6
Gene F
Senior Member
 
Gene F's Avatar
 
Join Date: Mar 2012
Location: Ohio
Posts: 1,915
Default Re: model b intake diagnosis

Sponsored Links (Register now to hide all advertisements)
What did the spark plugs look like on that end of the engine?

Here is what I recommend. Put marvel mystery oil in the crankcase, and in the fuel tank. Drive the thing. Then pull the plugs, and look in the cylinder with a bright flashlight. She where you are. Costs virtually nothing, and you are no worse than where you are now. Ya know a valve that is sticky might work itself out.
Gene F is offline   Reply With Quote
Old 01-24-2022, 09:52 AM   #7
Chris in WNC
Senior Member
 
Chris in WNC's Avatar
 
Join Date: May 2010
Location: Spruce Pine, NC
Posts: 1,458
Default Re: model b intake diagnosis

don't assume anything about the tappets.
it's a rare engine that has not been apart/rebuilt in 90 years.
take the valve cover off and see what you have.......
__________________
our next Model A is out there in the unknown......
Chris in WNC is offline   Reply With Quote
Old 01-24-2022, 10:56 AM   #8
Dave in MN
Senior Member
 
Dave in MN's Avatar
 
Join Date: May 2010
Location: Jordan, MN
Posts: 1,410
Default Re: model b intake diagnosis

Seeing the oily deposits in the front intake port, I think you may have excessive wear on one or both of the valve guides in this port. If it were mine, I would remove the head, rotate the crankshaft to raise those two intake valves and see if you have excessive lateral movement of the valves in the guides. Grab the top of the valve when in lifted position and try to move them horizontally.
You can check this by taking the valve cover off and looking for the same movement, but it is much more difficult to get to the valve stem to apply pressure.
This condition could also be caused by an intake valve not seating well.
Good Day!
Dave in MN is offline   Reply With Quote
Old 01-24-2022, 11:12 AM   #9
nkaminar
Senior Member
 
nkaminar's Avatar
 
Join Date: Jan 2012
Location: Western North Carolina
Posts: 3,817
Default Re: model b intake diagnosis

Check the valves as Dave suggested. Have the intake and exhaust manifolds surfaced while bolted together. Clean up the block and check for flatness as rotorwrench suggested. Minor imperfections can be filled in with JB Weld and sanded level. Use a sandwich copper gasket like https://www.snydersantiqueauto.com/p...4052&cat=41733
__________________
A is for apple, green as the sky.
Step on the gas, for tomorrow I die.
Forget the brakes, they really don't work.
The clutch always sticks, and starts with a jerk.
My car grows red hair, and flies through the air.
Driving's a blast, a blast from the past.
nkaminar is online now   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 07:06 AM.