Scotty
Silver Level Sponsor
I know this is a rabbit hole of a topic, but I'm going to ask just out of curiosity. What is the generally accepted break-in oil viscosity used for our 1725's and what is considered the standard viscosity used? I'm assuming the Shell 100X-40 is (in so many and somewhat inaccurate words due to age) a 10w-40. What is the correct or close to viscosity for a car before and after its break-in period?
Mine was rebuilt seven years ago and sat for a few years before I began to put it back on the road. It has under 100 miles total since the rebuild and no one (read: some folks have died since then) seems to remember what oil they had used for the break-in, so I've been using 10w-30 with ZDDP. I ask this question because I have heard this is a correlation between low oil pressure and using the wrong viscosity of oil.
My 1725 is a stock rebuild with the modification of the widening/opening passegeways of the head or block for more oil to pass. I apologize because I forget what exactly it's called but that's essentially what it is and was common to do. I also have hardened valve seats and a few other things.
If I blip the pedal, it races to 40-50 and will come back down. I don't have any issues with the car, it runs like it should and I have been tempted to put in 20w-50 to see if it helps the pressure go to a higher pressure level that isn't <5-10 at the "hot and at stoplight idle".
I have gone through the build paperwork and stack of receipt and my oil pump is within the correct tolerances and the engine on paper was built to spec, yet I have low idle oil pressure after warm up.
I have a brand new steel OPRV installed straight from England and am having the same issue. If I pull the coil and start the car with only the starter turning the engine I get Oil Pressure VERY quick, so I'm of the mind this is either how its supposed to be OR the viscosity for my car is wrong.
I know there are several opinions on this topic, what I ask for is opinions, expertise and knowledge towards my particular situation. If stepping up the oil now would help, I'll do that. If I'm fine the way I am and I'm not risking killing my engine with running 10w-30, I'll keep it there too. I drive mine and I'd like it to last as long as I can get it to.
Please help and educate me. Thanks in advance!
Mine was rebuilt seven years ago and sat for a few years before I began to put it back on the road. It has under 100 miles total since the rebuild and no one (read: some folks have died since then) seems to remember what oil they had used for the break-in, so I've been using 10w-30 with ZDDP. I ask this question because I have heard this is a correlation between low oil pressure and using the wrong viscosity of oil.
My 1725 is a stock rebuild with the modification of the widening/opening passegeways of the head or block for more oil to pass. I apologize because I forget what exactly it's called but that's essentially what it is and was common to do. I also have hardened valve seats and a few other things.
If I blip the pedal, it races to 40-50 and will come back down. I don't have any issues with the car, it runs like it should and I have been tempted to put in 20w-50 to see if it helps the pressure go to a higher pressure level that isn't <5-10 at the "hot and at stoplight idle".
I have gone through the build paperwork and stack of receipt and my oil pump is within the correct tolerances and the engine on paper was built to spec, yet I have low idle oil pressure after warm up.
I have a brand new steel OPRV installed straight from England and am having the same issue. If I pull the coil and start the car with only the starter turning the engine I get Oil Pressure VERY quick, so I'm of the mind this is either how its supposed to be OR the viscosity for my car is wrong.
I know there are several opinions on this topic, what I ask for is opinions, expertise and knowledge towards my particular situation. If stepping up the oil now would help, I'll do that. If I'm fine the way I am and I'm not risking killing my engine with running 10w-30, I'll keep it there too. I drive mine and I'd like it to last as long as I can get it to.
Please help and educate me. Thanks in advance!
Last edited:
