Ok as some of you know I changed the setup on my 1985 f150 300cc . Swapped to the Ds2, installed the cliffords intake ,long tube headers with the weber 2 barrel carb. My commute to work is 52 miles and I have had time to see the changes in mileage compared to how I drive it.( late to work ) .If feather footed, I can get as good as 16.5 mpg, (55)when driving 60-65-70 jack rabbit starts 14 .This truck has the 3.08 gears , 31.5-10.50 -15 tires, 4 speed manual. Before the new set up I couldn't get 15 ,(13-14)and the power lacked. Future I plan to install another carb , edelbrock, motorcraft or holley , The sticker new ,when purchased in 1984 stated 13 city 17 hwy.
Thanks TR

 

FWIW, a 300cc engine is a really small engine. 300cc is a 0.3L.

CC stands for cubic centimeters. The engines in our trucks are measured in cubic inches displacement (CID).

If you wanna use CC's, our 300's are just a hair over 4900cc.

Kinda puts it in perspective with the VW's, mopeds, motorcycles, etc.

Have you run heat to the intake manifold yet? Set your fuel mixture with a vacuum gauge? Set your timing with a vacuum gauge?

With my 1bbl 300 with 3.08 gears, a NP435, and 31x10.5 mud terrain tires, my truck gets right at 18/19 mpg estimated (haven't calculated it yet to be sure). I don't even have any emissions equipment on my motor anymore.

 

Yep 1983, Clifford's has the heat to the manifold in which offy. doesn't .I also used a vacuum gauge in the setup. I am sure I can do better but am satisfied in the power this set up makes. Future ill try another. Carb Tr

 

If I can just ask one question, "which Weber are you using (32-36, 38 , progressive, etc)?" I know others have been curious how a Weber may do (at least a new, modern carb) on an updated manifold as I have been as well.

I have quite a few 2100's that I can tweak, so I may not invest in a Weber right now but for discussion's sake I have a feeling others may want to know what ur' using.

Weber's are great carbs, but like most carbs need to be tweaked for maximum performance so the info you could add would be appreciated I would think.

Good to hear about your successfull Clifford install. When I bought mine "he" was only touting Weber s, but since I have so many Autolites I didn't bite at the time.

"It's all about the tuning"

 

"It's all about the tuning" X2

JMO 2V carbs are a good option for upgrades on our engines whether it be Autolite, Holley or Rochester especially on an otherwise stock engine.

 

Simply put tuning is the key , john I went with the weber - 38-38 carb. (progressive) cliffords long tube headers, the x pipe, dual magnaflow mufflers( turned out behind each wheel)also as suggested by Clifford , fuel regulator turned to 2.5 psi, used a vacuum gauge in tuning . This set up has woke the motor up. Good luck TR

 

It sounds like a good setup for sure. Thanks for the info, I'm sure many will be interested in how your experience works out as you "fine tune" for your driving style. Keep us in the loop as you make any jetting changes...and of course give us a clew how the "mpg" is going..The biggest search here seems to be "mpg"..although for me it isn't the reason I am working with a 300-6... (actually my reason is simplicity, reliablity, and ease of maintenance), but overall performance and reasonable mpg is always good...

 

Just for clarification, I thought it was the 32/36 Weber, which is progressive and the 38/38 is engineered such that both barrels open simutaneously. Can someone add to this? Thanks!

 

Ja, the little 32/36 and 34/34 are progressives and the 38/38 is synchronous.

 

Unless you're smitten with the grannie gear option, I'd look into an OD five speed. M5R2 or something.

If you want to retain the grannie gear, then maybe a ZF five speed.

Tracy

 

Sorry all, not progressive correct 38/38 synchronous, This set up has allowed better fuel mileage overall. Worst I have seen is 14 mpg where best has been 16.5. This truck has never seen 90-100mph but with this set up it will scoot, , better acceleration less downshifting and better pickup from any gear. I have owned this truck from new 1984 and before my install I wasn't seeing 14 mpg(old feed back carb). It was the 2nd carb (feedback)installed in the 530,000 miles on this motor ,John x 2 on the less maintenance simplicity, reliability and good fuel mileage . TR

 

Good update for sure, and the added info about progressive-synchronous availability in that venturi size. There have been so many different Webers used over the years, it's hard to keep up with the different applications. Also good to know that we can find a new, modern manifold-carb combo that can work with these older designed motors (40+ years old) that can be used with relatively little maintenance.

For now I'll probably stick to tweaking the 2100's I have, although as also said here, other 2 barrel carbs can work. I have wondered how the various carbs from a 318 Mopar would work on this motor as well. I also have some Rochesters but I like the simplicity of the single cast body of an Autolite.

Tweaking and tuning, keeping that vacuum signal up...always something to do...

 

John, the 2100 is a great carb( from what I have read about them), also on my set up Clifford does away with the pvc valve.The set up I installed is the 6=8 by cliffords. I actually ordered a holley, but as more reading I opted with the weber. Future , I will test other carbs. Any one having an extra carb (NOT NEEDED ) send it this way lol . TR