 What Does the Dellorto Whistle Sound Like |
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| Ansbacher |
 May 8 2017, 04:47 PM
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#1
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Senior Member  Group: Members Posts: 689 Joined: 4-July 14 From: Tampa Bay, Florida Member No.: 17,589  |
I recently rebuilt my Dellorto DRLA-40 carbs. When remounting the carbs, I only had the cheapo type manifold base gaskets to use. Now I have a chirping type noise when under hard acceleration in mid gears. Am I hearing the proverbial "Dellorto Whistle"? Does the whistle sound like a one tone noise or does it chirp like when there is no grease where the points assembly meets the distributor shaft? That's what this sounds like but deeper and louder. Dellorto experts please chime in.
Thanks, Ansbacher '74 2.0L |
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| Jeff Hail |
May 8 2017, 07:41 PM
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#2
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Senior Member Group: Members Posts: 1,141 Joined: 3-May 07 From: LA/ CA Member No.: 7,712 |
Usually sounds like a Type1 with a couple 1/4 inch holes drilled in the fan shroud. Dellorto's will chirp on throttle. Need to use the correct base gaskets that block the passage on the bottom center of the carb body. Double check everything is tight and not moving on hard acceleration including the linkage between the carbs.
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| ConeDodger |
May 8 2017, 08:27 PM
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#3
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Apex killer! Group: Members Posts: 23,589 Joined: 31-December 04 From: Tahoe Area Member No.: 3,380 Region Association: Northern California 
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That's what it sounds like.
I doubt you'll find the "correct" gasket as I bought what I'm told was the last one from CB Performance about 10 years ago. You can plug the notch with silicone I'm told... |
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| Whip618 |
May 8 2017, 10:10 PM
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#4
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Newbie Group: Members Posts: 6 Joined: 8-December 15 From: Albuquerque Member No.: 19,448 Region Association: None |
I don't think you will find those gaskets either but you can use the old stand by "JB WELD" and it works fine. I ran these 40 DRLA's for years with no problems. I was getting more of a chirping sound under acceleration>
36 DRLA on the left with no JB WELD and 40 DRLA on the right with JB WELD filler. (IMG:http://www.914world.com/bbs2/uploads_offsite/www.thesamba.com-19448-1494303014.1.jpg) Phil |
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| bandjoey |
May 8 2017, 10:37 PM
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#5
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bandjoey Group: Members Posts: 4,926 Joined: 26-September 07 From: Bedford Tx Member No.: 8,156 Region Association: Southwest Region |
JB to the rescue (IMG:style_emoticons/default/agree.gif)
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| euro911 |
May 8 2017, 10:49 PM
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#6
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Retired & living the dream. God help me if I wake up! Group: Members Posts: 8,849 Joined: 2-December 06 From: So.Cal. & No.AZ (USA) Member No.: 7,300 Region Association: Southern California
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Curious ... why hasn't the manufacturer changed the design to eliminate the issue? I'm sure they've known about it for some time, seems like everybody else does. My brother ran them on an 1835 in a '69 Ghia back in the 80's
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| Krieger |
May 8 2017, 10:51 PM
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#7
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Advanced Member Group: Members Posts: 4,711 Joined: 24-May 04 From: Santa Rosa CA Member No.: 2,104 Region Association: None
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| Jeff Hail |
May 8 2017, 11:08 PM
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#8
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Senior Member Group: Members Posts: 1,141 Joined: 3-May 07 From: LA/ CA Member No.: 7,712 |
Call em up and see if they still available.
https://vwparts.aircooled.net/Dellorto-DRLA...stle-gasket.htm Attached image(s) 
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| ljubodraz |
May 9 2017, 06:01 AM
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#9
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Member Group: Members Posts: 64 Joined: 4-May 14 From: Chicagoland Member No.: 17,312 Region Association: Upper MidWest |
My DRLA 40 DELLS did not require the special gaskets to eliminate the chirp/whistle.
When I replaced my gaskets to thin gaskets, they began to whistle. I then ordered thicker rubber gaskets (without the special tabs) and the noise went away. My theory is that it's not the cavity itself that creates the whistle, instead its the thin gaskets within the open cavity. The thin gaskets act like a reed instrument that vibrates creating the sound. Like when you blow on the edge of a piece of paper as a kid and you get a whistle sound. Because of this, I am sooooo happy I didn't try filling the voids with any type of filling material like JB Weld. (IMG:style_emoticons/default/chair.gif) |
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| Ansbacher |
May 9 2017, 09:22 AM
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#10
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Senior Member Group: Members Posts: 689 Joined: 4-July 14 From: Tampa Bay, Florida Member No.: 17,589 |
I believe I've read somewhere that Dellorto put those notches in the base to satisfy a particular Alfa Romeo, which used DRLAs extensively. Thanks for all the great info and pics. I will search for the proper gaskets.
Ansbacher |
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| barefoot |
May 9 2017, 12:47 PM
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#11
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Senior Member Group: Members Posts: 1,274 Joined: 19-March 13 From: Charleston SC Member No.: 15,673 Region Association: South East States
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QUOTE(Ansbacher @ May 9 2017, 11:22 AM)  I believe I've read somewhere that Dellorto put those notches in the base to satisfy a particular Alfa Romeo, which used DRLAs extensively. Thanks for all the great info and pics. I will search for the proper gaskets. Ansbacher Yes, after seeing this post, I also wonder why these slots were designed in, must have been some reason that eludes me, did it set up some sonic disturbance to help atomize fuel ???, can't believe it produced higher air flows. Barefoot |
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| ljubodraz |
May 9 2017, 02:39 PM
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#12
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Member Group: Members Posts: 64 Joined: 4-May 14 From: Chicagoland Member No.: 17,312 Region Association: Upper MidWest |
I also read somewhere (probably on the Samba) that those voids are used for a circuit on certain applications and has a hole drilled into them. Just be sure you rule out any intake vacuum leaks which might also chirp or whistle. Depends on what changes you made before the sound started. Good luck.
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| McMark |
May 10 2017, 06:58 AM
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#13
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914 Freak! Group: Retired Admin Posts: 20,179 Joined: 13-March 03 From: Grand Rapids, MI Member No.: 419 Region Association: None |
Those cavities are were the extra fuel from the choke enters the airstream. Most of the Dells you see were never drilled for the choke.
So really, the cavities are vestigial. (IMG:style_emoticons/default/sunglasses.gif) |
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| ConeDodger |
May 10 2017, 09:50 PM
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#14
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Apex killer! Group: Members Posts: 23,589 Joined: 31-December 04 From: Tahoe Area Member No.: 3,380 Region Association: Northern California
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QUOTE(McMark @ May 10 2017, 09:58 AM) Those cavities are were the extra fuel from the choke enters the airstream. Most of the Dells you see were never drilled for the choke. So really, the cavities are vestigial. (IMG:style_emoticons/default/sunglasses.gif) Mark's got the word vestigial trending on Google. (IMG:style_emoticons/default/happy11.gif) |
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