View single post by SpeedyMitch
 Posted: 11-06-2010 05:04 am
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Joined: 12-17-2009
Location: Hailey, Idaho USA
Posts: 83
For those interested, here is a summary of an e-mail exchange I have had with Dave Granquist @ Red Line Oil.

SpeedyMitch: My Jensen-Healeys stock Lotus 907 motor is a bit 'tired'. The oil pump is worn so oil pressure is slow to build and lower at idle than I would like.

Would Red Line 20w-50 be appropriate for this motor (the manual says the oil needs ZDDP)? Would this synthetic oil help the worn oil pump build and maintain oil pressure faster and better?

David: Thank you for contacting Red Line Oil, I had a Jensen-Healey at one time, it also was slow to build pressure and kept loosing rod bearings. The 20W50 would certainly be a good option to help develop more pressure, though a lower viscosity will help build pressure quicker at start up. All of our oils contain good ZDDP levels, appropriate for flat tappet cam and follower protection.

SpeedyMitch: If my main concern is the slow build of oil pressure and a lower viscosity would help would you recommend a step down to Red Line 20W40 or go even lower viscosity? I am currently using Valvoline VR1 20W50 and it sometimes takes 30 seconds to build pressure after sitting for a few days.

David: I wasn’t able to find the VR1 10W50 data sheet, though generally it would have about 60% higher viscosity at a typical startup temperature (50°F) compared to a 10W40. For quicker oil pressure at start up a lower viscosity will help, the 10W40 would be a good option, quicker pressure build at startup and a reasonable viscosity at operating temperature. The 0W40 for example would have about 25% lower viscosity than the 10W40 at that startup temperature.

Last edited on 11-06-2010 05:09 am by SpeedyMitch