Fuel Mileage Tips and Tricks Part 2

[@aylawilson]

Great video. Now I have to find part 1.

[@angelobauza3964]

I have a big duration cam and l put a 3.5 power valve at 2800 the AF gets to 11:9 73 jets in the front as well

[@holleycarbshowtosadvice40y90]

Angelo i need more information what size carb and list# of carb, cubic inch, compression, engine vacuum at idle and at 2800 rpms, are you trying to lean the carburetor out ? Let me know and I'll try to help.

[@b-17wingman37]

Good video ! I like to use a vacume pump to check to see if valve will hold a vacume and at what point first stage opens. A piece of 1/2 braided hose fits over second stake snout then reduce it with a step down T fitting to gage . I have heard that some are defective when new.

[@holleycarbshowtosadvice40y90]

Just about every time I check one for leaking during tear down, I always see some seepage its not uncommon, as long as its not excessive. Hope this helps.

[@gregvanderboom5011]

Learned something new, never heard of 2 stage power valve. Thank you for the video, I appreciate you for sharing this info.

[@holleycarbshowtosadvice40y90]

Greg your welcome, thanks for watching. The two stage pv came on several carbs ( holley 4180 ) is one.

[@ford351cleveland]

Thankyou for the video it makes a lot more since having a 2 stage then one that just open and lets all that feul in at one go. Will this work for my engine that idle at 9 inch vacum if i close the idle mix screws more or wil it be useless??

[@ford351cleveland]

PS. The cashapp is not available in my country... do you have patreon ??

[@ford351cleveland]

To answer the reply from yesterday. thankyou for the reply its much appreciated. I only drive it on the street, its got a 351c with and stock shift kit C4 automatic trans a 3.32 gear ration with 29 inch tall tires with the Holley 1850-4 vacuum secondary manual choke siting on top of a dual plane Eldebrock performer intake with a 1 inch 4 hole spacer and a AEM wide band o2. its got 16 degrees timing at idle at around 650 Rpm my goal is to just cruise around with the best fuel mileage possible I also know that i have a 6.5 power valve in the carb which I think is too big since I only have 9 inch vacuum at idle. Any advice is welcome thankyou again

[@holleycarbshowtosadvice40y90]

No I wish it would, but I believe you would need at least 16 inches vacuum to make it work , but we do have a video on boosters and the main jets coming out in the next few days,thanks for watching.

[@BubbaAyers1969]

Back in the mid 80’s we came up away to keep the power valve from blowing, installed 100’s of the idea in Holley’s, every time we built one (ball point pen and a BB) Great video

[@holleycarbshowtosadvice40y90]

Absolutely, that was a real problem back then the ball check sure fixed it. Thanks for watching.

[@MattsRageFitGarage]

It makes you wonder why most all Holley street carbs don't come with a two stage power valve from the get go other than the cost. You'd think being able to advertise a smoother power/fuel enrichment and being able to run a little smaller primary jet to benefit both fuel economy and drivability would be a good thing.

[@holleycarbshowtosadvice40y90]

I agree, ford used a lot of them in there later model 2bl carburetors but not all of them and in there 4180 holley 4 bl like the gt mustang I don't understand why it wasn't standard on all carbs back then. I worked at a ford dealer for almost 30 years we also worked on Honda cars in the mid 70s , we had a carburated 1976 Honda civic with the cvcc engine with a 3 bl. Carb and a 5 speed manual trans and got 54 mpg highway.

[@MattsRageFitGarage]

@@holleycarbshowtosadvice40y90 So, here's a question. I've got a Holley 1850-5 on a Ford 390. I'm at sea level. I'm running a 6.5 power valve, 67 primary jet, and the secondary metering plate has been modified to flow about a 71 jet equivalent. (got a 4150 conversion kit on the way, it's a bit rich on the secondary side since I reconfigured my centrifugal advance, found it was over advancing to nearly 50* centrifugal) When the power valve opens at 6.5", how many jet size equivalents do you think it makes enrichment wise when it opens up? and which do you think would be a more efficient combo, 67 primary jet with 6.5 power valve, or say a 8.5 or 9.5 power valve with 65 primary jet?

[@holleycarbshowtosadvice40y90]

@@MattsRageFitGarage I would want the 6.5 power valve if it works without causing a lean stumble or surge , opening the pv usually changes fuel enrichment by about 8 jet sizes on the 1850 , you may want to try a two stage pv if your engine is making 16 to 18 inches of vacuum , hope this helps.

[@MattsRageFitGarage]

@@holleycarbshowtosadvice40y90 the 6.5 power valve seems to work great. The engine makes about 13" vacuum at idle and has a very smooth idle to cruise to midrange throttle response. I was just curious as to how much extra fuel the power valve gives when it opens. Thanks for your expertise and I look forward to more videos.

[@Ritalie]

@@holleycarbshowtosadvice40y90 54 miles per gallon? Was that the 1.2 Liter engine in the tiny micro Civic? Was that a stock engine? I am so frustrated that people are not asking for better gas mileage, and are willing to spend $60,000 on an electric car, but not willing to demand 54 mpg gas mileage again.

[@geebopbaluba1591]

Man you need to lay off the coffee

[@holleycarbshowtosadvice40y90]

I know lol.thanks