OK, this should be fairly simple. On a vacum sec holley, on the back bowl there is the fuel bowl, then there is a metering block which attaches to a gasket which attaches to the main body on my carb. I was looking at a rebuilding manual and it showed that the metering block suppose to be attached to a gasket and then a small plate, and then another gasket and then main body. This small plate. What is it for??? Mine did not have one, neither did 2 more carbs on the shelf that I had, I finally found on, put it on my carb, and it ran like SH**. I have taken it off, but still have not drove it. Just wondering if taking these off is an old speed trick, (thats why it took me a while to find one) or are they important or what? Thanks in advance!!!

I think the manual is trying to show both types of carbs and not doing a good job of it. There are two types of vacuum sec Holleys one uses a metering block like the front and the other a simple plate with drilled restrictions to controll fuel and air.

I understand this. I know that there are 2 different kinds. The kind that I am talking about is the one with the drilled plate. NOT THE ONE WITH THE METERING BLOCK THAT HOLDS JETS. On my carb, behind this plate, about 1/8 inch thick -+, there is a plate of metal with drilled holes in it, about the thinner than a dime. The order is restriction plate, gasket, then this (?) very thin plate, big gasket then the main body. Mine did not have the thinest plate first, I looked at 2 more carbs they did not have it, found one, put it on, then the problem began. The book calls for one, but mine did not have one. This plate does not redirect any holes, nor does it block any. Does it even need to be used.
Robby

Maybe I should have worded this different. I do not meen metering block more like a restriction plate. This "restriction plate" does not take jets, it is a drilled block. that suppose to have a smaller plate, less than the width of a dime, behind it. Mine did not have one, I found one, put it on, carb acts up. What gives

Did you put the gasket between the jet plate and the thin one?

There's no extra plate - there's either a metering block (with jets) or a metering plate (which has a metal plate attached to it with screws) sandwiched between the fuel bowl and the main body. Don't know where you got the other part, but it doesn't belong there. 4150's have the secondary metering block (with jets), 4160's have the metering plate with fixed orifices.

------------------
JohnZ
'69 Z28 Fathom Green

Ok, this will make it easier, I feel like I am talking myself into a corner. Heres a link to Holleys webpage:http://www.holley.com/HiOctn/TechServ/TechInfo/f4150-60.html
When this first starts to load up, on top you will see a exploded view of the "metering block" Part # 151 is what I am try to explain. I did not have this on my car, when I put it on thats when it decided to start acting up. Do you know whats this id for.

www.holley.com/HiOctn/TechServ/TechInfo/f4150-60.html (http://www.holley.com/HiOctn/TechServ/TechInfo/f4150-60.html)

Ball,
I understand what part you are referring to. I have probably had 200 Holley carbs apart over the years and most of them have the plate, but every once in a while you find one that does not. I am not certain what it does, but since all of the fuel metering plates (the part that bolts on top of the thin plate) are the same, I would not think it matters whether the plate is there or not. It might help the gasket seal better ? I always put them back together the same way they come apart and have not had a problem. You do have to use the thin gasket in both cases however.
Hope this helps,

------------------
Bill Koustenis
Owner
Advanced Automotive Machine
Waldorf Md
1971 Chevelle "Heavy Chevy" original owner
1973 Z-28 ..one family car...Brother bought it new in 73

Thanks, this did help. I was just wondering what this did, and since you said that you have found some that does not have them, I feel a lot better. I did not use the thin gasket, I just used the sorta thick one that seals the bowl to the main body. I will make sure to ut the thin one back on. Again, thanks.

It seals the open passages in the back of the jet plate. Use it along with a good gasket or you can get internal leaks. BillK am I understanding you incorrectly or you are mistaken all jet plates are not the same there are about 50 different numbers. If you mean dimensions they are identical.



[This message has been edited by oger (edited 08-20-2001).]