weber 38 too much cfm for stock 258?
- Thread starter hoobness
- Start date
I recently put the Weber 38 carb on my stock 258, and it makes a world of difference. I have had to lean it out pretty good, in fact, I am still adjusting it. Not that it's difficult, but I have very little experience, and these things take time with me. I have a noticeable increase in torque and horsepower, and fuel economy seems to be the same. Maybe when I get it dialed in properly, fuel economy will improve. Overall, I am very pleased.
Inspector-Gadget
New member
Hello hoobness,
The "Holley" carb web page offers a good tutorial on matching an aftermarket carb to a given engine.
I fully realize that you are interested in adapting a "Weber" carb to your engine, but the mathematics involved in the carburetor to engine matchup are name brand neutral.
The principals will apply regardless of the carb manufacturer.
That tutorial can be found here:
http://www.holley.com/HiOctn/ProdLine/Products/FMS/FMSC/FMSC.html
Regards,
Gadget
The "Holley" carb web page offers a good tutorial on matching an aftermarket carb to a given engine.
I fully realize that you are interested in adapting a "Weber" carb to your engine, but the mathematics involved in the carburetor to engine matchup are name brand neutral.
The principals will apply regardless of the carb manufacturer.
That tutorial can be found here:
http://www.holley.com/HiOctn/ProdLine/Products/FMS/FMSC/FMSC.html
Regards,
Gadget
hoobness
New member
i just went to the holley link, and calculated the recommneded CFM for the 258, given a max RPM of 4500, ....Ive never had it past 4000, feel like it gonna rattle itself apart!
Anyway, the figure I got was about 336 CFM, 270 at 4000.
ticks me off cause the carb (32/36) just arrived after ordering it 8 days ago, and now I debating on wether or not to send it back... for the 38, any advice?
BTW - can I achieve similar performance w/performance jets or something?
Anyway, the figure I got was about 336 CFM, 270 at 4000.
ticks me off cause the carb (32/36) just arrived after ordering it 8 days ago, and now I debating on wether or not to send it back... for the 38, any advice?
BTW - can I achieve similar performance w/performance jets or something?
Deerhunter30
New member
How many CFM is the 32/36 Webber? You cannot achieve more from a carb by bigger jets. That will only richen up the mixture costing in both fuel economy and power. If that 32/36 is 300 CFM or close to that, I would say that it is adequate for a stock 258.
