High Compression Head

jeepguy1948 said:
I have some pictures but I have never posted pictures on this site and cannot figure out how to do it.
Click to expand...

To post pictures: At the bottom of the thread, click on "Go advanced", click on the paper clip icon (near top centre), Click on "Choose file", double click on the file (picture) that you want to post, after it's name appears in the list, click upload. Simples
 
alexiskai said:
Yeah, the two dots don't mean anything. They're present on many stock heads. If you look at the Burtz head, which was produced from a high-res scan of a NOS head, it also has the bumps. I believe they're artifacts of the casting process.
Click to expand...

I guess I stand corrected. Sorry Marshall, I have never seen those dots on a stock head or any other head besides the 5.5. I just checked the three original heads I have and none have the dots. As far as the Burtz head, I have never seen one. All that tells me is Burtz scanned a Snyder 5.5 head.
 
Y-Blockhead said:
I guess I stand corrected. Sorry Marshall, I have never seen those dots on a stock head or any other head besides the 5.5. I just checked the three original heads I have and none have the dots. As far as the Burtz head, I have never seen one. All that tells me is Burtz scanned a Snyder 5.5 head.
Click to expand...

Why would they scan a Snyder's head? Everyone knows it's the wrong size.
 
I am still unable to post pictures. I get to the point where it says that they are uploaded but I don’t know where to go from there.
 
Marshall V. Daut said:
So, we're back to how to differentiate between the 5.5 and 6.0 heads externally. I had no idea the combustion chambers were so different between them. That's the easiest way to tell one head from the other. But - It's not practical to remove the cylinder head just to see which head is on the engine. Is there a way to differentiate between the two heads from the outside?
M.
Click to expand...


I have seen some endoscopes that have side view capabilities. I would think it possible to slip one into a spark plug hole and turn it upward to view the combustion chamber with the side camera.
 
I thought that everyone who has ever installed one OF those heads knew that they are too short by a noticeable amount. The gasket hangs out the front and head is also too narrow so gasket hangs out the sides also.

Years ago I measured several new heads and compared them to original engine blocks and to 6 or 8 gaskets by various manufacturers and made a table showing this info.

I can not find the table. I guess that it does not matter any more.

Maybe I am just too picky.
 
Last edited:
Here is an example of a 5.5 head that I just installed for a friend last week. I did not notice any gasket overhang anywhere. Maybe differences in gasket sizes? We are awaiting a new exhaust manifold before I can button up the right side of the engine and finish detailing the engine and compartment. Note how the old exhaust manifold was leaking in the back. Lots of black splotches on the gasket and engine block.
Marshall
 

Attachments

  • Crummy_Engine without manifolds_Exhaust leak.jpg
    Crummy_Engine without manifolds_Exhaust leak.jpg
    67.7 KB · Views: 54
  • Crummy_Engine without manifolds_2.jpg
    Crummy_Engine without manifolds_2.jpg
    57.7 KB · Views: 52
  • Crummy_Driver's side of engine_2.jpg
    Crummy_Driver's side of engine_2.jpg
    67.7 KB · Views: 49
  • Crummy_Driver's side of engine.jpg
    Crummy_Driver's side of engine.jpg
    68 KB · Views: 45
Well, Benson may have a point about gasket overhang. There MIGHT be a little gasket overhang in front beneath the water pump. But it was not egregious enough for me to have taken note when I put the head on. Is this the gasket overhang you are referring to, Benson?
Marshall
 
Y-Blockhead said:
You tell me, there are thousands of heads out there without the dots.
Click to expand...


I just went to my shop and took a picture of the first stock head I found. The dots are clearly visible. Notice they’re different sizes even on the same piece; that’s because they’re artifacts of the casting process.

60267ad8c35042d302493c43ed96e6bd.jpg
 
The bumps are probably the result of vent holes in the sand cast die to let gasses escape. They result in a little wire sticking up out of the finished casting that is ground off.
 
Marshall V. Daut said:
So, we're back to how to differentiate between the 5.5 and 6.0 heads externally. I had no idea the combustion chambers were so different between them. That's the easiest way to tell one head from the other. But - It's not practical to remove the cylinder head just to see which head is on the engine. Is there a way to differentiate between the two heads from the outside?
M.
Click to expand...
No!
 
Marshall V. Daut said:
Well, Benson may have a point about gasket overhang. There MIGHT be a little gasket overhang in front beneath the water pump. But it was not egregious enough for me to have taken note when I put the head on. Is this the gasket overhang you are referring to, Benson?
Marshall
Click to expand...

Yes smaller in front and to a lessor extent the rear and sides as mentioned in post 7 and 18 where the word smaller is used in red text on photo and in the text itself of the post.
 
A great discussion thread! The information posted so far will answer a lot of questions readers may have about cylinder heads. In a past issue of "Secrets of Speed", Charlie Yapp showed several aftermarket cylinder flatheads made for the Model A, mostly concentrating on the combustion chamber areas for comparison. This was before Snyder's and the Burtz heads became available. So, if you are interested in what high-performance flatheads hotrod guys ran back in the 40's and 50's, try to locate this article. Copyright issues prevent me from scanning the article and posting it here - besides being saddled with a dead scanner. :)
Marshall
 
Marshall, with you years of experience wrenching on Model A's, I couldn't help but notice the new Float A Motor engine mounts!
Curious minds want to know! How tight do you tighten the through bolts?
Thanks in advance for your reply.
 
You must log in or register to reply here.
Back
Top