Well, I started to clean up the 3810 main body for assembly and I noticed a very funny thing. I'm blowing out all the holes and orifices in this original 3810 body with compressed air,after recoloring, and then I find that one high speed air vent on both the primary and the secondary side will not blow out. Here's a picture of the main body:
So I figured that I must have plugged up the main vent holes in all the torture I put this main body through. Tried to blow it out again and then cleaned off the suspect vents in the air horn. Found that one vent in the primary and one vent in the secondary had never been drilled.
Then I looked closely at the primary metering block (a 4743 also stamped 3810), and I found that the place where a corresponding hole would be drilled for the second main vent was not drilled.
I then tore apart a replacement dated 3810 which I had installed a new (NOS) 4743 metering block and placed the two metering blocks side by side. Sure enough, the NOS metering block had both vent holes drilled, whereas the original one had only one vent hole drilled. Here's a picture of them side by side with the main body:
The metering body on the left is the NOS one and has two holes drilled for the main vents. The metering body on the right is the original one. THe track where the point of the pawl is, is a place where a hole should have been drilled but was not drilled.
I was wondering why this metering body was fitted with #62 jets instead of the holley spec of #65 jets, could this have anything to do with it? Perhaps I have the super-economy version of the 3810 which was changed later.
And the question for the carb experts is: Should I drill out the second vent in the main body and metering block, or put it back together as is with #62 jets?
What would be the difference in performance or economy?
Still having fun,
Jerry Fuccillo
#42179
So I figured that I must have plugged up the main vent holes in all the torture I put this main body through. Tried to blow it out again and then cleaned off the suspect vents in the air horn. Found that one vent in the primary and one vent in the secondary had never been drilled.
Then I looked closely at the primary metering block (a 4743 also stamped 3810), and I found that the place where a corresponding hole would be drilled for the second main vent was not drilled.
I then tore apart a replacement dated 3810 which I had installed a new (NOS) 4743 metering block and placed the two metering blocks side by side. Sure enough, the NOS metering block had both vent holes drilled, whereas the original one had only one vent hole drilled. Here's a picture of them side by side with the main body:
The metering body on the left is the NOS one and has two holes drilled for the main vents. The metering body on the right is the original one. THe track where the point of the pawl is, is a place where a hole should have been drilled but was not drilled.
I was wondering why this metering body was fitted with #62 jets instead of the holley spec of #65 jets, could this have anything to do with it? Perhaps I have the super-economy version of the 3810 which was changed later.
And the question for the carb experts is: Should I drill out the second vent in the main body and metering block, or put it back together as is with #62 jets?
What would be the difference in performance or economy?
Still having fun,
Jerry Fuccillo
#42179