Nelsontr Posted February 28, 2012 Report Share Posted February 28, 2012 I am putting together a 620, I have a lot of parts that are getting ready to be assembled but i will be needing a carburetor. i have been advised that for a single downdraft set up, it would be better off to go with the outlaw 38/38 and run both barrels all the time... But my financial situation would seriously benefit from the fuel economics of the Progressive 32/36 (Progressive) AT LEAST until i have a better looking income... or gas prices go down. I have had the block bored to fit 280zx flat tops and have a w58 peanut, i know that i will not be getting the most out of these high compression parts without the 38/38... but i am not looking to race it as soon as i pull off my driveway... does anyone who knows a bit more than myself (not hard to do), see any glaring issues with my decision to temporarily use the progressive 32/36? other then the loss of potential HP. Here is a pic of the progressive: Quote Link to comment
datsunaholic Posted February 28, 2012 Report Share Posted February 28, 2012 I have and use both. I actually use the 32/36 on the higher-compression engine (it was a peanut W58 but now uses a peanut W53). The 38 is on an open W58. Both are L20Bs. The 32/36 is far more streetable. Compression has nothing to do with it- the 38 breathes more. But you'll only see it at higher RPMs. The 38 bogs under heavy load below 4K. Since I never see OVER 4K in normal driving, that's a problem. The 32/36 never had that issue. The synchronous 38 requires a somewhat different driving style but BOTH Webers are not good for slamming the throttle open. The 38 does eat more fuel. Quote Link to comment
Nelsontr Posted February 28, 2012 Author Report Share Posted February 28, 2012 I have and use both. I actually use the 32/36 on the higher-compression engine (it was a peanut W58 but now uses a peanut W53). The 38 is on an open W58. Both are L20Bs. The 32/36 is far more streetable. Compression has nothing to do with it- the 38 breathes more. But you'll only see it at higher RPMs. The 38 bogs under heavy load below 4K. Since I never see OVER 4K in normal driving, that's a problem. The 32/36 never had that issue. The synchronous 38 requires a somewhat different driving style but BOTH Webers are not good for slamming the throttle open. The 38 does eat more fuel. Thank you much datsunaholic, that answers a lot of my questions. Quote Link to comment
hobbes_the_cat Posted February 29, 2012 Report Share Posted February 29, 2012 I think your driving style will have the most effect on your mileage, I have never checked mileage in my current dime but when I was a lot younger I ran a 510 with a hot l20 and 32/36 carb and couldn't get better than mid teens for mileage, while other guys with softer feet could get in the 20s with similar cars. On a side note I have run a 32/36 converted to syncro and it gave a barely noticeable increase in performance. If your building a hot rod you will probably drive it like one, so just give up on mileage and get the 38/38. :) Quote Link to comment
datzenmike Posted February 29, 2012 Report Share Posted February 29, 2012 You sure you want to run 10.87 compression? Not going to do much without a cam to make use of it. If running stock cam get an open chamber head... still 10 compression but easier to live with. Save the closed chamber untill you get a cam together. 38/38 is a violation of the first rule of carburetion 1/ Never over carb a motor. Over carb in haste.... repent at leisure. 32/36 is far more preferable if driving. Quote Link to comment
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