Hey Guys,
After I get the rich A/F ratio figured out, what is the best way to get rid of all the carbon build from running so rich (without pulling the heads)?
Thanks
Original Post
Replies sorted oldest to newest
@Bobby D posted:Hey Guys,
After I get the rich A/F ratio figured out, what is the best way to get rid of all the carbon build from running so rich (without pulling the heads)?
Thanks
What I've always done is just make a few full throttle runs up to redline. You can see the cloud behind you as Elvis leaves the building.
Once, when I was running water/methanol injection on a supercharged miata, I poured the water/meth mix into the intake while holding the engine at around 3000 rpm. It cleaned out the carbon, but the technique seems a little extreme. I kept thinking about what hydro-lock would do to the engine... Hence, not really recommended.
Lots of people swear by “water injection.” Look it up. IIRC, people run their engine about 2500rpm and spray water in the carbs or vacuum port with a household sprayer.
But not if you have a catalytic converter.
None of this applied to cars with converters.
We used to give the old ladies of Tremont, IL the "Italian tune-up" when they'd bring their cars into the Mobil station "running rough" in the early 80s. It involved dropping the car into L1 and heading out on the highway, whereupon we'd run the car up to about 4000 RPM for 30 seconds to a minute. If that didn't get it, we'd do L2 (for more load) on a back road (less chance of a ticket).
If THAT didn't do it, we'd use windshield washer solvent in a small dish soap squeeze bottle down the carb as another guy was revving the engine around 3 or 4000 RPM. Washer solvent is just water and alcohol.
Thanks guys
Just a heads up, Bobby D - you're not carboned up like grandma was carboned up back in the day. A new set of plugs and a few miles on good jetting will burn everything off.
Thanks Stan. I actual purchased a spark plug cleaner a few years back due to rich running.
Would carb cleaner work on something like this is you shot it down the carb?
I don’t think so. Carb cleaner is flammable, water is not. If I understand the process correctly, it’s like a combination of steam cleaning and pressure cooking that breaks up the carbon and blasts it off.
@dlearl476 posted:I don’t think so. Carb cleaner is flammable, water is not. If I understand the process correctly, it’s like a combination of steam cleaning and pressure cooking that breaks up the carbon and blasts it off.
All of that, with this coda: I spray carb cleaner down the throat of the carbs when they start to get varnished from fuel residue.
I do this while the car is running.
Also, you want to follow it up with an oil/filter change.
Hey Guys
Is it me or do these brand new venturis i got from CB Performance look pretty rough?
Attachments
Images (1)
wow, I hope I don't have that issue getting old ones out! I think I am going to have to clean these new ones up. I can't believe a company that claims to cater to "performance" would sell something like these.
I just read the CB Performance description:
**These are Billet Venturi with the exception of the 36mm size, which is a Weber Factory Venturi.**
My bad.
@dlearl476 you have Dells don't you?
What is the actual point of comparing apples to oranges here? (Dells to Webers).
The Weber venturis are castings. Some are very nice indeed(the old Italian ones). Spanish ones are OK but the Chinese junk is, well, junk.
I wonder why CBP doesn't carry billet 36s.
This weekend I am going to pull the carbs and put the 36 venturis in. It will be interesting to see the quality of the HPMX vs the Weber venturis. I will post pictures of the two once I get them out.
Rick
those look a lot nicer than these factory Webers. What do you guys think is the best way to clean this up? with a wire brush in a drill?
@Bobby D posted:I wonder why CBP doesn't carry billet 36s.
I’d take a WAG that 36 is the standard size and as such, there’s plenty of stock. The other sizes they have made from aluminum bar stock. Just a guess.
@Bobby D posted:Rick
those look a lot nicer than these factory Webers. What do you guys think is the best way to clean this up? with a wire brush in a drill?
I think that would be too harsh. I don’t know if those are similar to my Dell’s venturis, but mine weren’t aluminum. They’re pot metal. Your picture looks similar.
Your best bet is scotchbrite, wet/dry, and steel wool. And lots of elbow grease. If you have access to a small lathe, you could chuck them up and save your elbow.
@Bobby D posted:Rick
those look a lot nicer than these factory Webers. What do you guys think is the best way to clean this up? with a wire brush in a drill?
When I port and polish, I've had good luck with an assortment of buffing/polishing heads, metal polish, and an electric drill. I've bought this assortment a couple of time: https://www.amazon.com/gp/product/B07FFWDYW6/
I use a Dremel for stuff like that.
thanks guys
@dlearl476 posted:I’d take a WAG that 36 is the standard size and as such, there’s plenty of stock. The other sizes they have made from aluminum bar stock. Just a guess.
I think that would be too harsh. I don’t know if those are similar to my Dell’s venturis, but mine weren’t aluminum. They’re pot metal. Your picture looks similar.
Your best bet is scotchbrite, wet/dry, and steel wool. And lots of elbow grease. If you have access to a small lathe, you could chuck them up and save your elbow.
They are very thin, I would use caution chucking them in anything less than a 6 jaw chuck.
I would use some 400 grit dry, then some buffing heads in an air grinder.
I would probably hit them with a Dremel, too, with sanding/polishing tips. I have a flexible cable drive for my Dremel that would be perfect for this. There are a number of sanding/polishing tips for Dremel, too, to let you get right in there and make it pretty. Go see the Dremel stuff at Home Depot/ Lowes.
Dellorto makes changing venturiis pretty easy. There is a lock screw that holds the venturiis in place. Loosen that up and they come right out. No hammer needed.
Airflow doesn't like anything too smooth so I'd go easy on the sanding- they're inside where they're never seen so as long as they're dimensionally correct they're fine, even if they look a little mungy- and certainly no polishing.
Well, there you go.
Put the Dremel away and just put ‘em in there!
@Gordon Nichols posted:Dellorto makes changing venturiis pretty easy. There is a lock screw that holds the venturiis in place. Loosen that up and they come right out. No hammer needed.
Easy on the “D” word, Gordo. As Danny pointed out, we’re dealing with Webers here.
ps: two of mine didn’t “come right out.” There’s was enough electrolosis between the aluminum carb body and the pot metal venturis that no amount of DeepCreep/Gibbs Brand would loosen them up.
After the fact Dave or Justin told me they soak them in the (hot) solvent tank then drop a few ice cubes in the venturis and even the stuck ones come right out.
@ALB posted:Airflow doesn't like anything too smooth so I'd go easy on the sanding- they're inside where they're never seen so as long as they're dimensionally correct they're fine, even if they look a little mungy- and certainly no polishing.
Ding! The light goes on!
Get them soda blasted.
Attachments
Images (1)
@dlearl476 posted:Easy on the “D” word, Gordo. As Danny pointed out, we’re dealing with Webers here.
ps: two of mine didn’t “come right out.” There’s was enough electrolosis between the aluminum carb body and the pot metal venturis that no amount of DeepCreep/Gibbs Brand would loosen them up.
After the fact Dave or Justin told me they soak them in the (hot) solvent tank then drop a few ice cubes in the venturis and even the stuck ones come right out.
Thanks Dave!
Same thing with Webers. A set screw and a jam nut. And don't plan on them sliding out easy unless they are brand spanking new in a box.
P.S. when I port heads and manifolds, I leave the surface rough. I know it doesn't seem like it, but rough flows better.
@DannyP posted:P.S. when I port heads and manifolds, I leave the surface rough. I know it doesn't seem like it, but rough flows better.
Rough creates vortices that keep the airflow away from the walls of the intake.
When I ported and polished my AA manifold, I finished up with what we called a “flapper.” A rod like a huge needle that allowed you to “thread” a 1” strip of 180 grit Emory cloth on the end of a die grinder. The finish was far from smooth, but a lot more uniform than the rough casting. Pretty much like brushed aluminum.
like the three on the left:
I have a port and polish kit from the Sears and Roebuck mail order catalog back in the early 80s.
It has all manner of shapes and grits. It also has that rod thing Dave talks about. Works great, still have the kit. I had left it in mom's basement, she asked me to clear out my stuff. I couldn't believe it was still there, along with my Rabbit valve shim kit.
@DannyP posted:P.S. when I port heads and manifolds, I leave the surface rough. I know it doesn't seem like it, but rough flows better.
Porting and polishing advice is similar to advice on the best oil to use. My slightly finer modification to the good advice Danny gives:
- In general, leaving the intake track from the carb to the valves slightly rough (I said slightly) gives the gas droplets that fall out of the airflow more surface area to evaporate from. As long as the roughness doesn't protrude past the boundary layer, the reduced airflow is made up by the better fuel mixing.
- The path of exhaust is dry and doesn't need the extra surface area or larger boundary layer to evaporate fuel. Making the exhaust path smoove (thanks for the great word, Mitch), maximizes the flow and reduces backpressure. There's a lot of science beyond this statement that takes into account scavenging, pressure waves, torque and horsepower peaks that also come into play.
- Airflow is an art as well as a science. To really understand what happens when you make a change, you need to measure it with a flow bench. I don't got one...
- A hypothesis of mine is that you want the intake path up to and including the carb as smooth as possible to maximize airflow. Inside the carb, you don't want turbulence randomly changing the amount of fuel being sucked into the airflow. After the carb, the slightly rough walls slow down the airflow, but make a good tradeoff for even gas mixture delivered to the valves. How much difference does the polishing vs slightly rough surfaces make? Not a lot. Much more effective HP gains can be found by optimizing airflow via port sizes, airflow path curvature, etc at the target airflow rates.
Just my thinking on it. Literally no data to back it up.
A set of rotary burr bits can be a lifesaver if you are doing major surgery. I bought these when reworking my Kadon intakes to balance the ports.
@Michael Pickett posted:A set of rotary burr bits can be a lifesaver if you are doing major surgery. I bought these when reworking my Kadon intakes to balance the ports.
You’ve got to be a real master to lay into aluminum with those in a die grinder. I barely trust myself with the miniature version of them in my Dremel.
These are more appropriate to my skill set.
Attachments
Images (1)
I have a good size ultra-sonic cleaner. Since I am taking the carbs out, I might as well clean them up. What do you guys think is the best solvent for this job?
For home made solutions, use a 50-50 mix of distilled water and distilled white vinegar. It works quite well, especially if you follow it up with a solution of distilled water with a couple of drops of Dawn.
You can also shop around for ultrasonic carb solutions from folks like Royal Purple or Sten's. I'm hear those work great.
Using Kerosene or diesel will clean more than you want, like the whole building off the foundation. Unless what you want is the oportunity to start this whole house/workshop thing from scratch once you get the insurance check don't do it. Seriously, don't use any flamable solvent!!!