Bristol Spin-on Filter

[pls01]

Is anyone running a spin-on oil filter with the associated adapter on a Bristol engine?  I believe the adapter changes the oil flow through the filter.  The Volks flows from inside to out where the spin-on flows from outside to inside.  It seems like a lot of porting and potential for flow restriction.  Is there any difference in oil pressure?

[AC Ace Bristol]

Peter
   
   In England,  Tony Byford makes special screw adaptors for Bristol engines....to take small screwon horizontal filter.
   
   email tony@abyford dot  wanadoo  dot   co  dot  uk
   
   
   Alternatively as you are in USA,  Contact :-  Ron Leonard  (Sport & Gt motoring)  he made a couple of Batches of Vertical Screw Adaptor Oil Filters that take Fram HP1  Oil Filters.  BEX333  has had one since July 1997.  Also takes smaller screw on filter ( MOP  P44S2890) I use the Fram as it larger capacity  10 gpm safety vave 22PSI ,  Buurst pressure  500PSI.  This adaptor screws onto existing origonal oil filter housing and allowing one to still run oil cooler as per origonal concept.
   
   Not sure if Ron still produces this piece of kit. Was $240 in July 97.
   
   Tony Byford would be Far Cheaper inclusive of air frieght.especially with the $ to £ exchange rate at present
   
   I change the filter and approx 2 gallons of Millers Competition Semi-Synthetic CSS 20w50 Oil every 3500 / 4000 miles.  and cover 5500 / 7500miles  per annum. Oil pressure remains constant on trips (2141 miles in 8 days) and Sprints, Hillclimbs & racing.
   
   Check out the Oil on www.millersoils.co.uk
   
   Hope the above is of interest.
   
   Cheers 4 Now
   
   Keith

[pls01]

Keith
   Yes, the information is interesting and helpful. I'm leaning towards the HP1 adapter for the larger flow capacity and less pressure drop though the filter.  Lower pressure drop though the filter allows more oil to flow to all the components.  Higher resistance causes some of the oil flow to return to sump through the relief valve.
   
   I am also going to check out the 20/50 oil. I drive my car about 1000-1500 miles a year so most wear occurs at start up.  The multi-vis oil flows better at start up.
   Thanks
   Peter

[Robin A Woolmer]

Why not fit an Oil accumulator for starting which gives a good injection of oil under pressure on starting the engine, i am sure these are available in the USA! It is also a good idea to get a 15 micron or better full flow filter.
   Robin

[GaryC]

I have one of Ron's adaptors and I have a few thoughts.  I haven't run a Bristol before this one but the oil pressure seems high  80PSI at 3,000rpm vs 60 suggested.  I have adjusted the relief valve a few turns and although it drops the pressure, at this psi there doesn't feel like the internal spring is under much compression.  The block is fresh with limited time (1 hour start up and limited driving).  Also with Ron's adaptor you MUST use a specific Fram filter....the oil flow is counter standard and this small filter is unique in that it does not have a one-way valve.  Any comments on the oil pressure??

[AC Ace Bristol]

quote:Originally posted by GaryC
   
I have one of Ron's adaptors and I have a few thoughts.  I haven't run a Bristol before this one but the oil pressure seems high  80PSI at 3,000rpm vs 60 suggested.  I have adjusted the relief valve a few turns and although it drops the pressure, at this psi there doesn't feel like the internal spring is under much compression.  The block is fresh with limited time (1 hour start up and limited driving).  Also with Ron's adaptor you MUST use a specific Fram filter....the oil flow is counter standard and this small filter is unique in that it does not have a one-way valve.  Any comments on the oil pressure??
   
   
   Gary
   
   If your pressure is 80PSI at 3000 RPM when at correct working temperature you will almost crertainly blow the rear Oil Seals when cold as the pressure would be over 100PSI.
   
   Check the spring inside the Filter head and re-adjust the pressure relief valve,  Might be worth checking the Oil pressure gauge as well. Just in case it is not reading accurately.
   
   To adjust  the relief valve only takes a few minutes, I use a stepped very short Ring Spanner braised to a long extention rod terminating with 1/2  inch drive, quick undo,  then use a flexible magnet to carefully withdraw the pin, rotate the capsulated nut, then refit the pin. tighten up......... Test and re adjust if neccessary .....  Job done.
   
   I had a few running hot problems at a few race meetings in 2001, but found the spring inside the Filter head was missing, hence Oil never going through Cooler..... found suitable spring and used a couple of fine washers to get correct operation of bypass to allow Oil to flow through Oil Cooler.  Problem solved.
   
   The Fram HP1 filter is readily available in UK, so must be even easier to buy in USA, It is a very close tight fit and a little too close to the Battery so you might want to consider the Mopar unit reference origonal message. Being shorter it makes life a little easier when removing and replacing the screw on filter.
   
   The flow on these filters is more than adaquate and the flow is in the correct direction for the Bristol engine  / filter head and has prooved very reliable, no problems in the past 8 years ( 39.000 miles ) on long continental runs or during competition
   
   Have a chat with Ron Leonard if the pressure remains at 80 PSI, he may well confirm additional advice and solution.
   
   Keith
   

[pls01]

Oil pressure and flow depend on the components in the system and the fluid.  Oil pressure is readily measured but flow is inferred.  My concern with the spin-on filter adapter is that it restricts flow and reduces lubricant to the engine components.  The oil pressure is measured downstream of the filter and a significant restriction would cause lower hot oil pressure and reduced flow could be inferred.  That doesn't seem to be the case from Keith's experience.
   
   The data is a bit muddy due to the difference in oil viscosity.  A 30wt oil has a viscosity of 11.5 cSt at 100C while 20-50 has 18.8 cSt at 100C.  Since the oil 60% more viscous, the oil pressure will always be high.  High oil pressure is not necessarily good as it indicates high resistance and reduced flow.
   
   Very high oil pressure in cold engine results from thicker oil and insufficient relief valve capacity.  With thick oil, the resistance to flow is high and pressure rises.  The relief valve opens to prevent over pressure.  With thick oil, the relief valve goes wide open and still can not flow enough oil so the system pressure rises above the normal set point.  Once the oil heats up and becomes less viscous, the relief valve can control system pressure.
   
   My engine runs 75-80 psi cold and 60-65 with hot oil with 30wt oil.  Depending on weather, it takes ½ to 1 hour to get the oil to 135 –140F on the oil temperature gauge.  I also notice fresh oil maintains high oil pressure for longer.  Maybe Gary's oil temperature hasn't reached operating temperature?
   
   I stuck with the Volkes filter for this long due to concerns about oil flow and authenticity.  I didn't like an orange filter next to the Bristol engine.  Engine pre-lube systems are great technology, but again disturb the classic sensibilities.  After rebuilding the engine and searching for Volkes filters, I'm re-considering all of this.
   
   Thanks for the help
   Peter S

[AC Ace Bristol]

Peter
   
   You make some valid points regards Pressure / Temperature and Viscosity.
   
   The main piont is Longevity of Our Bristol 100D / 100D2 engines, as time goes on they show more signs of wear and spare parts become more scarce.
   
   Most of us check for wear, whenever the engine is stripped down for regular inspection / maintenance or for more serious reasons pending the use or abuse experienced.  I have found that the Millars oil has coated all wear parts very well and due to regular oil change and Filter change is far superior to the Classic Castrol Oil initially used in 2000 & 2001.
   
   My engine when Hot runs  60/65 PSI at 3000RPM. and takes at least 8 to 10 miles of gentle motoring before I can use 3000 RPM or more.
   When Cold eg Winter with outside temp of minus 5 to Zero, I tend to Run the engine at 2000RPM for 4 or 5 minutes then not exceed 2500 for at least 12 to 15 miles as the Oil pressure would try to exceed 100 PSI.
   
   Mad Dogs and Englishmen ...... We use & enjoy our Aces, Fast, Faster and Flat out all year round as intended, after carefully running in.
   
   Last but not Least .... Peter,  Many Ace Bristol guys on this side of the pond would love to learn of a regular supply of New Old Stock Volkes Oil Filters, I haven't seen a new one for years,  mind you I use Fram HP1 ( Orange ) or the smaller Mopar Black unit.So could be out of touch with the market.
   
   Every one to their own, but seriously..... Where do you get your regular supply of new Volkes Oil Filters, The ACOC could buy say 50 or more units as initial stock for our Ace / Aceca and Greyhound owners - members.
   
   Keith

[Robin A Woolmer]

Flexolite in the UK do a range of spin on filter adapters & have one specifically for the Bristol engine there web site is 'www.flexolite.co.uk' phone/fax 441684 541 941.
   They are £36 each so you might consider that route! They probably can also advise you on lubrication matters on the engine.
   Robin