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Title: Dellorto 36 jetting advice Post by: baz on February 02, 2017, 17:54:50 pm I have a pair of drla 36s to go on a 1776 motor in a 71 bus. There's a c25 cam in there but the rest is stock including heads.
The carbs I have have got the following ingredients Idles 46 Pump jet 33 Main 118 Vents 32 Air 175 Emulsion 9164.1 I've been searching online for recommended jetting for 1776 running these carbs. The following is what I think I need. Idles 55 Pump jet 33 Main 125 Vent 30 Air 180 Emulsion 9164.2 Can anyone advise on whether this is the way to go? The info I've found is for a 1776 but I don't know if the cam comes into play or the fact it's a bus motor. Any advice appreciated before I start buying new jets. Title: Re: Dellorto 36 jetting advice Post by: DWL_Puavo on February 03, 2017, 09:12:02 am Your new list seems just correct to me, for example:
- Stock heads and C25 won't make good power over 5000 rpm so reduction in aux.vent size doesn't hurt max power. But it improves low end and tuneability. - Emulsion tube ".2" is the most usual one and works well in most VW aircooled engines. Aircooled.net recommends .1 -emulsion tube for center carb application, so it probably fattens low and leans high rpm's. - You may need 130-135 mains but the engine should work well with 125's. - Same goes to idles, but with smaller decrease/increase - maybe 52's or 57's. But the odds are that 55's are just fine :) I would also highly recommend bakelite's or CSP's "pertinax" heat insulation between carbs and manifolds. With hot engine, re-starting may be tricky with hot fuel. http://www.csp-shop.com/cgi-bin/cshop2/front/shop_main.cgi?func=det&rub1=Products&rub2=Engine%2CCarburators&artnr=14457b&pn=0&sort=0&all= Your previous jettings sound like Alfa 1500. About only useable in your list will be the aux.vents. So if it won't operate properly, you can try if the jetting's too rich or lean by switching to those 32 vents. My favorite "real life jet hack" is adding e85 ethanol fuel to lean out - my scooter's running on 50/50 e85/95e because I'm too lazy to change smaller jet in that piece of s**t ;D Puavo / DWL Title: Re: Dellorto 36 jetting advice Post by: PPRMicke on February 03, 2017, 11:28:15 am Buy a wideband lambda
So, you will solve a lot of problems You will see if you have the right mixture and ignition http://www.innovatemotorsports.com/xcart/product.php?productid=16235&cat=262&page=1 /// Micke Title: Re: Dellorto 36 jetting advice Post by: baz on February 04, 2017, 15:24:23 pm Thanks for the help guys. I'll go with the above then, I've got a wideband lambda so that'll come in useful.
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