Q:  Will the VFF conversion change my oil pressure?

A: The regulator in the VFF adapter will assume control of the system pressure, and should yield the same pressure as the original regulator if the installation was done per the instructions. If the pressure is higher than it was before the conversion, it indicates that the original regulator was likely affected by a weak or broken regulator spring. If it is lower, but still within the correct range, it is possible that the original regulator spring had been replaced with one of higher tension or had been shimmed to produce higher than normal pressure. This is usually an attempt to correct poor pressure at low rpm but will not do so since the regulator is out of play under those operating conditions anyway. 

If your oil pressure was low before the conversion and is still at the same level, this usually indicates that the bearings have excessive clearances or there is some internal leakage in the oiling system beyond the pump's ability to overcome. It may also indicate excessive clearance in the pump itself.

Q: Do I need to do anything to my pump?

A: A routine inspection of the pump as outlined in the appropriate manual for your engine is certainly encouraged, but no modification to it is required except as noted in the installation instructions for the Hudson-built pumps. This is simply installation of a cup-type plug in the discharge port as outlined in the instructions.

Q: What filter should I use in the VFF system and why didn't I get one with the kit?

A:Any good quality filter is fine and largely a choice made based upon the user's personal preference. There are a wide variety of filters made that share the same specifications that may be used, but generally, a filter for Ford or Chrysler spin-on applications is acceptable. Examples include NAPA 1515. Pennziol PZ-1, Fram PH8-A. Since these are readily available and many users have a brand preference, we didn't believe it made sense to include one.

Q: What oil do you recommend?

A: Any good quality oil is fine and also largely a matter of personal preference. Conversion to the VFF system has the added benefit of allowing the correct use of contemporary, multi-grade, detergent motor oils without concern for that old notion that you shouldn't use detergent oils in these old engines. Decisions regarding viscosity should be made commensurate with your driving conditions and aren't related to the type of filtration system.

Q: Will any component in the VFF system interfere with my exhaust headers?

A: Clearance issues with any given set of headers is a determination that will need to be made by the customer. We will provide any dimensional information that you may need to help you make that decision.

Q: I've heard that I can achieve an enhanced level of filtration if I use a bypass type filter in addition to the full-flow filter. Is this true and, if so, what should I use?

A: It is true if the micron rating of the bypass element is sufficiently lower as to provide additional "polishing" of the oil prior to returning it to the reservoir. Bypass elements in the 10 micron range are common and have the capability of removing particles less than half the size of the typical full-flow element but are low flow-rate filters. Some manufacturers of modern industrial engines use a special combination filter that does both jobs in one element. Of course, it's a system designed specifically to accomplish that, but you may utilize the original type bypass filter for your engine or upgrade it to a more modern spin-on type bypass element. This does not include the employment of a simple "conversion" to a spin-on base and full-flow type of element!! If you wish to ad a spin-on bypass filter, it must be a bypass type element with a restrictive orifice no greater than 1/16 inch (.063") in diameter or serious loss of oil pressure may result.   


Q: I'm nervous about altering the original pressure regulator. Do I really need to disable it?

A: Disabling the function of the original regulator is a necessary step in the installation of the VFF system. Failure to do so would allow the original to assume control of pump output, essentially cutting the VFF adapter's regulator out of the system. The result would be that the pump output would revert to unregulated flow, sending it's entire gross output through the filter at all times. This scenario would almost certainly overwhelm the filter media, causing the filter to go into internal bypass mode letting unfiltered oil straight through without first being filtered. The filter's internal bypass valve is a necessary feature to prevent rupture of the media under certain conditions.

Q: My engine previously had a bypass filter but I don't want to use it. What should I do with the ports that were part of that system? Should I connect them with a hose?

A: If you have removed the original bypass filter canister and hoses, simply thread the appropriate pipe plugs into the ports.  DO NOT connect them with a hose. To do so would cause a drastic loss of pressure under most operating conditions since the regulator would view it as a huge leak.

Q: My engine had a bypass type filter on it and I'd like to retain the original look of that set-up. Can I leave it in place?

A: Yes, as long as it retains its original restrictive orifice. It's questionable that it would perform any useful function but it won't hurt anything. Installation of an element with a finer micron rating (numerically lower than the full-flow unit) would yield an enhanced "polishing" of the oil to some degree, depending on that rating.

Q: I like the idea of adding a bypass filter with a low micron rating but don't wish to deal with the mess of changing elements in an old canister type. Is there something in a spin-on unit that will do that job effectively?

A: Yes. There are spin-on elements available in the 10 micron range that have a built-in restrictive orifice, making them a good choice for this application. They have 5/8-18 mounting threads so that they cannot be interchanged with the 3/4-16 mounts in the typical full-flow element. An adapter for the 3/4-16 to 5/8-18 is available through WIX Filters.

Q: My regular cars are Chevrolets and  I would like to use the same filter elements on the VFF system so that I don't need to keep two different filter on hand. Can I use those instead of the Ford/Chrysler units if I get a spin-on base with the correct filter mounting threads?

A: NO. With one exception that I'm aware of, there are no GM filters that utilize an internal filter bypass (not to be confused with "bypass filter"). This internal bypass is an absolutely mandatory feature for any filter element used in the VFF system. In the absence of that valve, there exists a real danger that the filter media could be ruptured in a high flow or high oil viscosity situation. Such a breach of the media would allow unfiltered oil to pass, likely scouring accumulated debris off of the media and into the lubrication system. Worse yet, you wouldn't be aware that it had happened. 

If you have additional questions or have reason to disagree with the information shown here, please feel free to email or write to me through the "Contacts" page.

Frank Hughes

Owner "Hughes Machine" and "Vintage Full Flow"

 Frequently Asked Questions