LedZep

iTrader: (22)

I posted this in my Intake Thread, but I thought it was important enough to get as many opinions as possible. I noticed this after I completed removal of the throttle bore ridge and finished the curved edge. I was about to get it ready to take off for cleaning and I noticed this inside the venturi.

As in my other thread I have two main questions:

1. Was this a casting defect/mistake when it was made or was this done over time by long time usage.

2. What is the best way to go about fixing it or should I just leave it alone. I had one person suggest to fill it with a material and sand it smooth, but I think if anything I should have both venturis ported slightly bigger.


I am kind of pissed because if I had spotted this earlier I would have modded my other throttle body (I had this one as a spare), now I have hours of labor into getting the throttle body to this stage and I have a defect in the wall of venturi.

Any advice or help would be greatly appreciated.


Throttle Body:

ibmtech

iTrader: (1)

I have seen that before on other types of TB's not just that rochester. It is difficult to know if it was a casting error. Are you worried about it effecting turbulance of air in the engine? I don't think it will make that much that you will ever notice a horsepower difference and unless you are trying to squeeze every ounce of CFM into the engine it won't matter and it is covered with an air cleaner hopefully, so no-one else will see it either.

I have seen that before when condensation gets onto metal for a long time. Not to say that is your case.

LedZep

iTrader: (22)

I'm not worried about squeezing every last bit of HP out of the car, I am just worried this will have some negative effect on say fuel atomization or cause turbulence, stuff like that.

If I wanted to port the venturi myself would I have to figure out some way to be able to get both sides exactly the same width? I'm assuming I would or this would throw off some stuff. How much do you think a machine shop would charge to enlarge the venturis enough to clear the imperfection?

ibmtech

iTrader: (1)

It shouldn't effect air flow, The manifold's and heads design your will cause alot more turbulence than whatever this would cause. I personally wouldn't mess with it. If you do decide that you want to take it to a machinist, You need to get larger throttle plates and IMO will have alot more issues than just leaving it alone.

LedZep

iTrader: (22)

Yea I think you are right, although I'll be interested to see what other users say. I thought about just sanding that area down with a dremel sanding attachment, but that would cause a pit or valley in the venturi wall most likely and cause way more turbulence than that area ever would.

Thanks for your input.

LedZep

iTrader: (22)

I think what I am going to do is lightly sand the area to get it as smooth as possible without taking off very much material and then polish it the best I can with fine grit sandpaper.

Then I'll just leave it alone. That is unless someone has some other advice that is radically different.

ibmtech

iTrader: (1)

I guess no-one else wants to chime in..


I still think you should just leave it alone.. It won't effect your performance.

LedZep

iTrader: (22)

You wouldn't even try to smooth it a little?

ibmtech

iTrader: (1)

NO

I would leave it alone

thomas1976

I would leave it as it is too, doesen't look too bad, if you look in the intake manifold and heads you will see much worse where it actually does matter.

Just make sure to remove any particles that could get loose.

I would not try to fill up the imperfections with anything that could at some point in time come loose.

LedZep

iTrader: (22)

alright I will leave them alone!