OMG.... a bad run of "CLAY".

Not bashing by any means, and im sure holley would like to figure that one out if they dont already know.

Like a bad batch of base material at foundry?

I am guessing that was an extremely porous casting and the alcohol in the fuel penetrated the surface pretty deep - I have never seen something that ugly in a Holley - either way its scrap

Over 40 years of fooling with carbs, I've never seen that. Plenty of damage from moisture, corrosion, fuel additives and contamination, abuse, but not cracked to pieces like that.

I've seen this discussed before; evidently during that time Holley was in financial trouble and I believe the flaking and peeling you're seeing is the result of Holley's offshore casting supplier having different standards regarding the metallurgical composition of Zamac #3 casting alloy. The substandard alloy, incorrect temperature/pressure used in the production of thousands of Holley main bodies, metering blocks, and float bowls is the root cause of the problem.

Any moisture present in the fuel or during storage exacerbates the problem.

It's one of their special "HP" metering blocks...... As in "high porosity".

Get one every once in a while but never anywhere that bad.

Ok that's funny right there!!!!

And probably true.

Call holley, they've replaced stuff like that before for others.

Worth a try.

I've seen some carbs that was bought in US having problems here in Brazil. Mainly because we've 30% of ethanol in our gasoline and our ethanol is very different then US ethanol. No issues with my Demon carbs so far, but with edelbrock and old holleys we had some problems with corrosion.

I have had similar issues with 1 carb here in Australia 3(?) years ago there abouts .
Severe delamination/breakup up of the fuel bowls .
Only 1 carb of a new pair used on a blown chev . This was a street motor running pump gas . There was no ethanol in the fuel here at that time .
Swapped on a old pair of spare bowls and away we went no further issues

Tex

Very common with foreign castings, impurities in the casting. Google zinc pest. Fuel has nothing to do with it.

I did a search on the bad Holley casting situation.
Pretty interesting info about how that all happened.

I'm pretty sure that any zinc Holley parts I have were bought before that whole offshore casting situation was happening.

Yeah looks like zinc pest. I worked at a high tech company that did some offshore zinc die casting and stuff like this drove the process engineers nutso. Usually some low ball vendor would buy poor quality materials just to save a few bucks and then we would end up with tons of scrap and a bunch of pissed off customers. Lots of vendors in the far east have zero problems selling garbage to their customers.

I'm going to have to google zinc pest. Never heard of it.

Wow I have never seen one that bad either !! I was thinking the fuel causing it but you say the other two are fine so I bet the others here are right about bad offshore casting ? Ron

I looked up zinc pest and pretty much all the images I see of that look just like my metering block. Interesting, thanks for the info yall!

Good info Andy!

Since it sounds like Holley is willing to do something about for Chip, it will be interesting to see if they do a metering block or the whole carb.

What I'm taking away from this thread, and the stuff I found relating to it is.... I'm going to stay away from Holley carbs made during that 2006-2009 era.

Holley had some issues around that time causing the carbs to flake apart, IIRC it was porosity. One of my friends had bought a new carb around 2006, I never saw it and don't think it was anywhere near as bad as what you have, but he had it apart about a year later, saw the issue, called Holley and the rep at Holley told him they had been having issues and Holley sent him a new one. His was a 770 Street Avenger.

They were hoping you'd send it back before you could post pictures on the internet. No way does that happen if it's cast from the proper Zinc or Aluminum alloy. As bad as it is they probably won't bother taking the carb all apart looking for debris, I expect you'll just get a new carb. Then again, you did post it on the internet...