new motor with low oil pressure?
#1
new motor with low oil pressure?
I just had a entire new motor put together from the rods to the oil pump.
When it is first started it has good oil pressure at idle (just above 40) and will climb above 60 during accelleration. After the car warms up it falls to 20 pounds or just bellow that and will barely get over forty pounds even on hard accelleration. I put the first 500 break in miles on the motor with what i was told was a break in oil.? I was then told to run a dino oil for the first 1000 miles after that before switching to a synthetic. I now have castrol 5w-20w in it. (not sure what the starter oil was) I had the same problem with both so far. As soon as I get to the 1000 miles I plan to switch to mobile 1 15w-50.
When I asked the builder why pressure was low he told me the engine was built that way, that the tollerances were not as tight as a stock motor so it would have more of a coating of oil between parts in the motor. (i cant remember the technical words he used to descride this) He said that this motor was made to be beat on.
This does not sound right to me but, I am looking for some educated opinions on this. The builder is a very reputable place and hasnt steered me wrong yet but something doesnt sound right to me on this.
Thanks,
Getav8
When it is first started it has good oil pressure at idle (just above 40) and will climb above 60 during accelleration. After the car warms up it falls to 20 pounds or just bellow that and will barely get over forty pounds even on hard accelleration. I put the first 500 break in miles on the motor with what i was told was a break in oil.? I was then told to run a dino oil for the first 1000 miles after that before switching to a synthetic. I now have castrol 5w-20w in it. (not sure what the starter oil was) I had the same problem with both so far. As soon as I get to the 1000 miles I plan to switch to mobile 1 15w-50.
When I asked the builder why pressure was low he told me the engine was built that way, that the tollerances were not as tight as a stock motor so it would have more of a coating of oil between parts in the motor. (i cant remember the technical words he used to descride this) He said that this motor was made to be beat on.
This does not sound right to me but, I am looking for some educated opinions on this. The builder is a very reputable place and hasnt steered me wrong yet but something doesnt sound right to me on this.
Thanks,
Getav8
#3
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Join Date: Apr 2003
Location: Lexington, KY
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You only need 5 psi for every 1,000 rpms, 20 psi at idle is more than enough unless you're idling at over 4,000 rpms.
It's not anything to really worry about. You're running a much thinner oil on a non-stock engine, the psi is going to be lower, especially once the oil warms up. You'll be fine.
It's not anything to really worry about. You're running a much thinner oil on a non-stock engine, the psi is going to be lower, especially once the oil warms up. You'll be fine.
#5
Originally Posted by wrencher
Did he say it was excessively clearanced? I wouldnt want it have loose bearing tolerances IMO. I wouldn't run 5w20 either....
#7
Originally Posted by LS1Maniac
You only need 5 psi for every 1,000 rpms, 20 psi at idle is more than enough unless you're idling at over 4,000 rpms.
It's not anything to really worry about. You're running a much thinner oil on a non-stock engine, the psi is going to be lower, especially once the oil warms up. You'll be fine.
It's not anything to really worry about. You're running a much thinner oil on a non-stock engine, the psi is going to be lower, especially once the oil warms up. You'll be fine.
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#9
TECH Senior Member
iTrader: (1)
Depending on your main and rod clearance, yes, that can affect oil pressure. I had to re-line-hone my 1000 mile block when I switched it from a 346 to a 383, the mains were that far out of whack. If your builder didn't set up the mains tight, I could see it. Without the line hone, I was looking at .0035" clearance on the mains with +1 bearings. We decked the caps and line honed it and got .0020 (you want to set it up tight, because the aluminum blocks expand quite a bit when hot).
So check your build sheet for the main bearing clearance, and that *may* answer your question as to why it's a little low. Now what can you do about it? Probably not much. Run a slightly thicker oil. Is it bad? Doesn't really sound like it.
So check your build sheet for the main bearing clearance, and that *may* answer your question as to why it's a little low. Now what can you do about it? Probably not much. Run a slightly thicker oil. Is it bad? Doesn't really sound like it.
#10
Originally Posted by yak
mine used to sit at 40, but I noticed in the warmer weather it dropped to about 20. I think my oil pump may be going. any ideas?
#11
Originally Posted by Camaroholic
Depending on your main and rod clearance, yes, that can affect oil pressure. I had to re-line-hone my 1000 mile block when I switched it from a 346 to a 383, the mains were that far out of whack. If your builder didn't set up the mains tight, I could see it. Without the line hone, I was looking at .0035" clearance on the mains with +1 bearings. We decked the caps and line honed it and got .0020 (you want to set it up tight, because the aluminum blocks expand quite a bit when hot).
So check your build sheet for the main bearing clearance, and that *may* answer your question as to why it's a little low. Now what can you do about it? Probably not much. Run a slightly thicker oil. Is it bad? Doesn't really sound like it.
So check your build sheet for the main bearing clearance, and that *may* answer your question as to why it's a little low. Now what can you do about it? Probably not much. Run a slightly thicker oil. Is it bad? Doesn't really sound like it.
#12
TT-TECH Veteran
iTrader: (29)
Look that low oil presure at Idle is fine if it was set up that way. It's not going to hurt a think and unless he told you to run that 15w50 I would stick with a 10w30 or 10w40. That thicker oil can work against you on cold start up and even when you are getting on it. People are just used to judgeing how good there engine is by it's oil presure whitch has nothing to do with it so don't be afraid just use a good synthetic when you are done breaking it in how every you want.
#13
Originally Posted by Inspector12
Look that low oil presure at Idle is fine if it was set up that way. It's not going to hurt a think and unless he told you to run that 15w50 I would stick with a 10w30 or 10w40. That thicker oil can work against you on cold start up and even when you are getting on it. People are just used to judgeing how good there engine is by it's oil presure whitch has nothing to do with it so don't be afraid just use a good synthetic when you are done breaking it in how every you want.