What is carburetor percolation..., How can I take care of this annoying problem Options

[nsr-jamie]

Here is the material after I roughly cut it out on the band saw. Than I made a small jig from some scrap metal to mill out the holes for the stud bolts so they are perfectly pitched to keep it positioned well.



This is another jig I made for ones the holes are drilled and it fits into to give it the 2D profile. I did this on the CNC mill after work. Than I bolt it to the jig and mill away in the shape.

[nsr-jamie]

a picture of before and after, sorry picture turned out a bit fuzzy.



The final product all done and ready to go in the car. They turned out better than I thought. It was actually kind of fun making them.

[nathansnathan]

Like I said they are the same, like kleenex and tissue, pretty much.

You may want to use a gasket on top of them too, on the manifold side. The stock fi spacers have a paper gasket adhered to each side, and the CB intakes, the facing where it mates is so far short of flat they have their own thicker gaskets. Just the paper ones don't work, and though the phenolic gives some degree of crush, I have found it better to use both. -not doing this, they will leak slightly.

I've often thought that what people describe as the dellorto howl was just a bad seal there, as it's the only time I've heard it, running paper gaskets. I think the special gaskets without the cutout or the silicone- in-the-recesses trick might be just misled.

[DBCooper]

Another one but close up. Is this really bakelite or is it Phenolic? I believe they are the same material.

You're right, they're the same (http://www.professionalplastics.com/BAKELITE). You couldn't machine the original bakelite, it was always molded, but now it's now made with different reinforcing materials, paper, canvas and linen, that make it machinable.

Right about the Dellorto whistle, too. CB Performance sells a spacer/gasket that covers that gap and eliminates the chirps.

.

[nsr-jamie]

Another one but close up. Is this really bakelite or is it Phenolic? I believe they are the same material.

You're right, they're the same (http://www.professionalplastics.com/BAKELITE). You couldn't machine the original bakelite, it was always molded, but now it's now made with different reinforcing materials, paper, canvas and linen, that make it machinable.

Right about the Dellorto whistle, too. CB Performance sells a spacer/gasket that covers that gap and eliminates the chips.

.

Do you happen to know the part number for this CB performance part? I have been looking over their site and have not found anything....perhaps I am looking in the wrong area.

I was thinking about going with two sets of paper gaskets and sandwhich my new bakelight spacers in between.

[DBCooper]

Hmmm.... not at CB any more but found them on John's site, aircooled.net: Dellorto Anti-Whistle Gaskets

Yes, use regular thick paper carb base gaskets, and note his tip to use chapstick on them to use them more than once. And actually if you put the carbs and manifolds together on the bench you can see the space that creates the whistle. If you want to spend the time you can fill it in with epoxy and file it flat.

By the way I also saw your isolators on their carb page, about halfway down here: http://vwparts.aircooled.net/Dellorto-DRLA...-Jets-s/933.htm Also shows some of the GOOD fuel pressure regulators for carbs.

[nsr-jamie]

Thanks for the links, checked them out and they were helpful. I also finished rebuilding my carbs today and they are almost ready to go.....new gaskets on the way. My spacers fit perfectly. I am going to cut some new stud bolts for them and do some small touches on the following weekend as I only have time to work on the car on Sunday. I can't wait to get my car on the road and drive it finally.

[URY914]

Any chance you sending me some of the scrap material or making a another set of spacers? (IMG:style_emoticons/default/biggrin.gif)

OR do you know where someone could buy about a 12" x 12" piece of it? What kind of supply house would handle it?

Thanks. Great thread. This is one of the few things that I could use on my car.

[nsr-jamie]

Any chance you sending me some of the scrap material or making a another set of spacers? (IMG:style_emoticons/default/biggrin.gif)

OR do you know where someone could buy about a 12" x 12" piece of it? What kind of supply house would handle it?

Thanks. Great thread. This is one of the few things that I could use on my car.

It was a lot of work cause I manually machined each piece...it would have been faster to do it on the CNC machining center and have a program made up. But work wouldn't let me use the CNC's as they are always working and never stop....

The material I came accross from a friend who had it lying around but there is probably enough to do maybe 2 pieces if lucky. I don't know where to get anymore...but I did notice on the link that DB Cooper posted may have them for sale.

http://www.professionalplastics.com/BAKELITE

I designed mine to fit my 40mm DRLA dellortos. I think they turned out very nicely and I am proud of them. There is somebody selling them on ebay for cheaper than I could make them for

[URY914]

Thanks Jamie. I looked at the link and they only sell sheets that are too big. I'll tey to find a supplier locally.

[wndsrfr]

Thanks Jamie. I looked at the link and they only sell sheets that are too big. I'll tey to find a supplier locally.

Try Mcmaster-Carr....they have everything often cut to smaller sizes and it'll ship to your door like overnight even with standard ground service......

[DBCooper]

Or ask that industrial plastics supplier for a 12x12 sample piece.

[nathansnathan]

The Phenolic FI spacers are in the 1.8/ 2.0 elring gasket sets. It's a fun project to make your own, but I can't see going to great lengths to make these.

About the Dellorto whistle, I was saying I think it is a myth, as my Dells only make that noise when they aren't sealing right. CB doesn't make them anymore, like was said. I speculate that those gaskets were a cover up - the literature wasn't going to say, "now buy our gaskets which compensate for how badly machined our manifolds are", so they made up a story about the gaps that had to be filled by a proprietary gasket, when it is just the thickness of the gasket that makes the difference. -just speculating here as I have not tried the special gaskets. My Dells son't whistle, though, without them.

It could be there is some confusion between "Dellorto whistle" and "Dellorto Howl". Mine do howl impressively. (IMG:style_emoticons/default/smile.gif)

[McMark]

But you can buy them pre-fabbed on eBay... (IMG:style_emoticons/default/confused24.gif)

I get why Jamie wouldn't go that route, but the US folk can order finished pieces for less than the time & material would cost.

[ConeDodger]

The Phenolic FI spacers are in the 1.8/ 2.0 elring gasket sets. It's a fun project to make your own, but I can't see going to great lengths to make these.

About the Dellorto whistle, I was saying I think it is a myth, as my Dells only make that noise when they aren't sealing right. CB doesn't make them anymore, like was said. I speculate that those gaskets were a cover up - the literature wasn't going to say, "now buy our gaskets which compensate for how badly machined our manifolds are", so they made up a story about the gaps that had to be filled by a proprietary gasket, when it is just the thickness of the gasket that makes the difference. -just speculating here as I have not tried the special gaskets. My Dells son't whistle, though, without them.

It could be there is some confusion between "Dellorto whistle" and "Dellorto Howl". Mine do howl impressively. (IMG:style_emoticons/default/smile.gif)

Nope. It's real. You have to epoxy up that positioning slot at the base since the gaskets are NLA. My 2270 had Dell's and she tweeted up a storm. I got 'the last set of gaskets' at CB Performance according to the person I ordered from.

[McMark]

Rob's right. Dellorto whistle is a real thing. If you haven't experienced it, great! But some do and when it happens, you know.

[SirAndy]

What about the bottom piece that goes between the heads and the manifold? I think that's even more important than the pieces between the manifolds and carbs.

On my carbed 2056, i ran the stock FI phenolic spacers between the heads and manifolds and just a paper gasket between the manifolds and carbs and i never had an issue with fuel boiling ...

(IMG:style_emoticons/default/popcorn[1].gif)

(IMG:http://www.914world.com/bbs2/uploads/post-8305-1352475296_thumb.jpg)

[mrbubblehead]

But you can buy them pre-fabbed on eBay... (IMG:style_emoticons/default/confused24.gif)

I get why Jamie wouldn't go that route, but the US folk can order finished pieces for less than the time & material would cost.

(IMG:style_emoticons/default/agree.gif) thats what i did....

[URY914]

I'll look for them on ebay

[URY914]

Found them.....


http://www.ebay.com/itm/Weber-44-IDA-44-ID...cbc&vxp=mtr