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Author Topic:   Powder Coating On A Carb.
Spi-nex
Dirt Forum Racer

Total posts: 88
posted December 10, 2005 01:45 PM  
We bought a Willy's carb this season (used) and recently took it apart. We noticed that some of the powder coating had been eaten away.


Is this normal?
Is it a property of the Alcohol that eats away the powder coat?
Or what?

Thanks for any input guys.

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Jonathon R. Huston
#81 Factory Stock

zeroracing
Dirt Forum Champ
Total posts: 1932
posted December 10, 2005 04:58 PM  
To answer your question yes it is normal. I have been doing some powdercoating for a long time. Powder coat is not going to last forever, and in some cases is not any more durable than spray paint. Chemicals can still eat it up and destroy it.
You can get powdercoat made from different materials, the chemical composition is different between the materials. What this means is simple, some of the materials make pretty colors, but are weaker, some make flat or more basic colors and are harder.
A general rule of thumb is this, the more colorful the powder the weaker it will be and more prone to problems, wheares the more flat or basic colors tend to be stronger. The powder comapines are always coming out iwth new designs and mixes that are better and can defy these rules, but in general the basic colors are harder.
Of course propper prep work comes into play, to do powdercoating to get it to stick good (like one of my cars had almostchrome brake calipers for years without any problems, takes a TON of time, it must be clean enough to eat off of, or use in surgery. also a clear coat will help the strenght of the powder.

You must realize, which most people do not, powder coat will not last forever, it will not take any abuse, just when used correctly it is a stronger altervative to painting.
But it will not last forever and chemicals can eat it up, and it can be chipped just like paint. Also bright color powder loves to fade out.

Alky likes to eat everything it seems, make sure to spray your carb down often with wd-40 to keep the moisture in it down, keep it over the winter in a warm dry place(I cleaned out mine and put it in the closet in our spare room).
Solution go to a gas motor, I push gas power very hard over alky.

Spi-nex
Dirt Forum Racer

Total posts: 88
posted December 10, 2005 05:34 PM  
Thanks Zeroracing.

I don't understand why you would want the powder coat on a carb. Seems that as it came off it would get all caught up in the float bowls.

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Jonathon R. Huston
#81 Factory Stock

dirtbuster
Dirt Forum Champ
Total posts: 2032
posted December 11, 2005 07:46 AM  
we have a carb that is powsercoated on the bowls only and only on the outside. I wouldnt want any coating on the insdie because of fear of if coming loose. I always wondered about those willys carbs that were coated like that if they had any problems. Acctually Im not sure why any carb needs to be powdercioated. The old holley gold color looks good to me.

Spi-nex
Dirt Forum Racer

Total posts: 88
posted December 11, 2005 11:11 AM  
I agree 100% Dirtbuster. I dont understand the need of the bowdecoating inside the carb.

Now to be fair I have talked another person and they have had a Willy's for 6 years and have never had this problem.

I think we're gunna take our dremmel tool and try and strip all that powder coating off.

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Jonathon R. Huston
#81 Factory Stock

chomme
Dirt Freak

Total posts: 315
posted December 11, 2005 06:56 PM  
Powdercoating a carb is cheesy, but to each their own. JMO

Kromulous
Dirt Forum Champ
Total posts: 848
posted December 16, 2005 05:57 AM  
I read where the powder coating down thru the main body and up on top of the venturi area actually increases flow. Due to the smoothness, and slickness of the powder / pain surface.


Krom.

NJantz
Dirt Forum Champ
Total posts: 775
posted December 16, 2005 06:16 AM  
I always heard that powder coating a carb was good for a few hp. Probably because of the reasons Krom listed.

MrHP1
Dirt Roller

Total posts: 11
posted December 16, 2005 07:53 AM  
Powder coating in the main body adds about 8cfm on the flowbench. We did this a while back on a Holley just for kicks. When I wet flow with dye the flow patterns are more consistant too. Maybe Willy's has got something figured out. I'm buying one to do some testing.

NJantz
Dirt Forum Champ
Total posts: 775
posted December 16, 2005 09:33 AM  
wonder if BigHurry will still think its cheasy???? lol

chomme
Dirt Freak

Total posts: 315
posted December 16, 2005 11:09 AM  
Why pwdercoat? why not send off and have some sort of teflon coating put on it, or something along those lines. Smooth, thin.
By decreasing the roughness of the carb can help, but teflon would be a step above powder and less problems with powdercoming off.

Spi-nex
Dirt Forum Racer

Total posts: 88
posted December 16, 2005 07:09 PM  
Now thats slick, I never thought about the surface adding cfm. But it defientally makes sense.

I like that Teflon idea. Would the Teflon react to Alky though?

Boy am I glad I asked. Learn something new everyday on this board!

Thanks Guys!

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Jonathon R. Huston
#81 Factory Stock

MrHP1
Dirt Roller

Total posts: 11
posted December 17, 2005 07:37 AM  
quote:
Originally posted by Spi-nex:
Now thats slick, I never thought about the surface adding cfm. But it defientally makes sense.

I like that Teflon idea. Would the Teflon react to Alky though?

Boy am I glad I asked. Learn something new everyday on this board!

Thanks Guys!


Teflon coatings don't have a slick apearance. With vaporized fuel I think that helps. It may work. I know it works on my cookware. I'll send a main body out for coating and see what it does.


A. Bighurry
Dirt Full Roller

Total posts: 47
posted December 17, 2005 08:44 AM  
Davinci and others have been using a special coating for awhile now, and I believe that it is teflon based. It works well and won't chip off like powdercoating. As far as flow numbers, unless you're restricted to a certain carb, like a 390 or 500 and it has to pass a nogo gauge, resizing the venturi and smoothing the entry area would make more sense than powdercoating a carb to pick up 8 cfm. The powdercoating is to make it look nice to some people. I was just stirring the pot earlier, but if you think about it, the juice isn't worth the squeeze on an unrestricted carb. Now I'm sure that someone will mention losing booster signal by enlarging the venturi, but where it's opened, metering and booster selection takes care of that. We've had a good budget and have done a LOT of testing also, with the help of some good advice.

A. Bighurry
Dirt Full Roller

Total posts: 47
posted December 17, 2005 08:56 AM  
Another point I meant to make is that people will spend hours on here looking for the best air filter to keep debris out of their motor and then put a powder coated carburetor on it. ??????????! I actually LIKE Willys just fine but don't like the idea of powder coat chipping off and ruining a good ring/bore job. And yeah, I've seen several of them with powder chipped off.I don't know how hard on it it would be, but it ain't gonna help! Like I said before, just my opinion and everyone should run whatever they like.

Spi-nex
Dirt Forum Racer

Total posts: 88
posted December 17, 2005 09:29 AM  
I would think if you sent your carb into Willys once a year to be freshend up that they would re-coat the carb. Alky eats it away, but it requires maintainance just like anything else on a Carb. Im pretty sure they also offer a non-powder coat option.

8cfm might not be much, but every little bit helps.

MrHP1
Dirt Roller

Total posts: 11
posted December 17, 2005 03:14 PM  
Yes, the time I tried powdercoating a main body was to get more cfm from a rules deal. They caught on halfway through the season. Davinci has great carbs. I used one on a Bonneville car that was scary fast. I gotta say I still like the BG with changeable venturis. I like things I can adjust. I never show up at a track that is the same twice. Tacky one day, dry slick the next. Just my 2 cents.

A. Bighurry
Dirt Full Roller

Total posts: 47
posted December 17, 2005 05:50 PM  
MrHP1, I think we're on the same page with the flow numbers. SPI-NEX, if you read my previous post carefully, the air flow issue is addressed. Airflow equals horsepower on a carb restricted motor. For the rest of us, it's more about volumetric efficiency, fuel curve, etc. The chipped/eaten away powder coating issue was the reason for your original post. You seemed concerned and mentioned grinding it off. If your last answer to your own post settles it for you, I'm good with that too. Good luck either way.

Spi-nex
Dirt Forum Racer

Total posts: 88
posted December 17, 2005 05:57 PM  
Well we don't have the $125 to send in to have the Carb freshend so we used out dremel and took off all the powder coat on the bottom, but left the Powder Coat alone up in the Venturi area.

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Jonathon R. Huston
#81 Factory Stock

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