Description: Available in several different Hg sizes to custom match your carb setup, Designed for (big window valve) alcohol engines, Features a standard flow Holley 125-75 Standard Flow Power Valve, Size 7.5 Sku # 427125-75 Mfr. Part # 125-75 Condition New Brand Holley Sold Each Details Info Standard flow. Available sizes include: 2.5, 3.5, 4.5, 5.5, 6.5, 7.5, 8.5, 9.5 and 10.5 in hg. High flow 1 Series (big window valve) for alcohol. Available sizes include: 2.5, 3.5, 4.5, 5.5, 6.5, 8.5, 10.5 in hg. For example 427125-145, 427125-135 etc. Application This Part Fits Tech Tip: Engine vacuum will hold the valve closed until vacuum drops below the cracking point, measured in inches of mercury (in hg) at which time, the valve will open and enrich the fuel mix. It is quite common to put very low numbers in multi carb systems. The reason is that if standard single carb valves are used, it will cause the engine to be overly rich. When you are at a part throttle cruise at 55 mph (say, with a 12 in hg of manifold vacuum) and you squeeze into the throttle to go up a hill or pass a car, the manifold vacuum drops (say, down to 7 in hg) and all three power valves open. Normally, this will make the engine soggy & rich, since it has three times the fuel enrichment that it needs. People will put in the lower power valves to delay the enrichment until nearly Wide Open Throttle. At WOT, the engine can normally consume the additional fuel without puffing black smoke or fouling plugs. The problem with putting -45 power valves in, is that it defeats the purpose of a power enrichment system. The enrichment system is designed to provide a slight increase in fuel flow as power requirements increase. If you install -45 power valves and they do not open until WOT, you lose the benefit of adding just a little bit of fuel when you squeeze the throttle a little. A better way is to put power valve plugs (or very low numbers) in the front and rear carbs and use a standard power valve in the center carb. The best way is to put restrictors (PVCR or power valve channel restriction, which are small lengths of stainless steel piano wire) in all three carbs, which limits the amount of fuel that is added, not when it is added. Specs GTIN Code 090127023396 Primary Stage Opening Vacuum 7.5 Reviews I would buy this again. Rated by 1939ford on September 23, 2021 Summary: Used on a dirt race track car Yes, I recommend this product. Just as described Rated by Fred on February 19, 2021 Summary: Worked for application Yes, I recommend this product. Would buy again, went in great Rated by Eric on November 27, 2020 Summary: Had to replace a PV that was blown. Worked good Yes Rated by Pj on October 04, 2019 Summary: Priced Right easy to work on bite again Yes, I recommend this product. I would buy this product again Rated by 111 on July 18, 2019 Summary: Arrived on time. Gave me the power I was lacking Yes, I recommend this product. Related Items / Suggested Parts Holley 26-36 Power Valve Plug and Gasket Tech Support We're here to help before and after your purchase. If you have a question or need assistance with one of our products, please contact us through eBay Messaging and a knowledgeable Speedway Motors team member will be happy to help. About Speedway Motors is America’s Oldest Speed Shop® and has been a trusted source for specialty rodding and racing products and friendly expert advice for more than 72 years. Founded in 1952 by “Speedy” Bill Smith – a racer and street rodder himself – Speedway has grown from a one-man operation to become the world’s largest manufacturer, distributor and retailer of street rod and racing products. Our industry-leading fast delivery is the result of same-day shipping from our state-of-the-art, centrally located 500,000 sq. ft. headquarters. Speedway’s size offers customers unmatched product selection and low pricing, while our excellent technical support and customer service have made us a recognized leader in the rodding and racing industries.
Price: 22.99 USD
Location: Lincoln, Nebraska
End Time: 2025-01-24T14:14:05.000Z
Shipping Cost: 12.99 USD
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Item Specifics
Return shipping will be paid by: Seller
Returns Accepted: Returns Accepted
Item must be returned within: 30 Days
Refund will be given as: Money Back
Return policy details:
Universal Fitment: Yes
Manufacturer Part Number: 125-75
California Prop 65 Warning: Cancer and Reproductive Harm
Brand: Holley