Finally fired the new motor up today! but...
06-22-2008, 04:30 PM
#1
Finally fired the new motor up today! but... It sounded awesome! But, I have a concern. To prime the oil system I pulled the fuel pump relay and cranked it 7 separate times in 15 second intervals giving 5 minutes break in between so as not to burn up the starter. On the eighth time, I reinstalled the relay and primed the fuel system with a few key on/key offs. Then I cranked it. It started immediately which made me happy and oil pressure kicked up immediately as well, which was also good. What made me nervous was oil pressure only rose to about 23psi. I blipped the throttle a little and it jumped to about 45psi instantaneously.
Now, before anyone says that I pinched the O-ring, I doubt very much that I did. I was EXTREMELY cautious and was very, very careful to make sure that I hooked the oil system up correctly. I was well aware that I could have low oil pressure if I hooked it up incorrectly.
I was wondering if this was normal given the mods in sig? Also, maybe there was still some air in the system that hasn't bled out yet? I set up my bearing clearances on the loose side so I'm sure that lowered my pressures a little too. Any other ideas on what it could be?
I was thrown off when it jumped all the way to 45 when I only blipped the throttle ever so slightly, maybe 400 RPM at most.
Now, before anyone says that I pinched the O-ring, I doubt very much that I did. I was EXTREMELY cautious and was very, very careful to make sure that I hooked the oil system up correctly. I was well aware that I could have low oil pressure if I hooked it up incorrectly.
I was wondering if this was normal given the mods in sig? Also, maybe there was still some air in the system that hasn't bled out yet? I set up my bearing clearances on the loose side so I'm sure that lowered my pressures a little too. Any other ideas on what it could be?
I was thrown off when it jumped all the way to 45 when I only blipped the throttle ever so slightly, maybe 400 RPM at most.
06-22-2008, 06:48 PM
#3
Well, I was out there a little later tonight and started it up again to let it run for a little bit. The oil pressure was even a little lower this time. It was down around 10psi. I'm thinking maybe that the O-ring did get me. Every time the idle raises oil pressure raises but down around 1000rpm it's sitting around 10psi cold. Looks like I'll be pulling the front cover to check it. Any other ideas on what it could be besides that? The pump is reasonably new. I bought it last year through TSP. I know that looser clearances could cause low oil pressure but not that low. The clearances were all on the loose end of spec but still looked to be good.
06-22-2008, 07:07 PM
#5
5W30... Should I be running a thicker oil here?
I talked to TSP and I said that my clearances were on the loose end of spec... Something like .0026-.0028" for the mains and around .0023-.0025" for the rods I'm pretty sure. I don't remember exactly but I know they were just on or just a hair outside of the spec for factory. However, I was told this would be okay and that some race motors are setup intentionally with looser clearances?
I talked to TSP and I said that my clearances were on the loose end of spec... Something like .0026-.0028" for the mains and around .0023-.0025" for the rods I'm pretty sure. I don't remember exactly but I know they were just on or just a hair outside of the spec for factory. However, I was told this would be okay and that some race motors are setup intentionally with looser clearances?
Last edited by 98RedBird; 06-22-2008 at 08:25 PM.
06-22-2008, 07:21 PM
#6
I'm just very confused right now because this thing is brand new, bearings and all. I was very meticulous about cleanliness when rebuilding I made positively sure that the oil pump was assembled correctly. Even the oil pump is essentially new. It's only got about 2k miles on it. Prior to the rebuild I was running about 45psi, but I was running a thicker oil as well (Mobil 1 0W40). I'm reading that GM recommends 7-10psi per 1000 RPM, which I'm at, it just still seems to be a concern for me.
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06-22-2008, 08:31 PM
#8
i have nearly the same setup you have, i also use the melling street pump, i think its like 2095 or something like that, not the high volume pump. but i have about 20 PSI at warm idle, and around 45 or so at about 3k rpm. i also made sure the o-ring was not pinched when i put it in.
06-22-2008, 08:37 PM
#9
I think you should take it apart and check the o-ring again. While you are in there you can shim the pump and that will increase your pressure even if the o-ring is not messed up. It is a gauranteed way to increase your oil pressure.
06-22-2008, 09:15 PM
#10
I will definitely be checking the O-Ring, but at the same time I think I will use a heavier weight oil. I'm only using 5W30 right now. I think to break in a motor I should be using at least 10W30 right?
I really don't know what the hell else could be wrong. It's an ENTIRELY new motor at this point.
I really don't know what the hell else could be wrong. It's an ENTIRELY new motor at this point.
06-22-2008, 09:16 PM
#11
i have nearly the same setup you have, i also use the melling street pump, i think its like 2095 or something like that, not the high volume pump. but i have about 20 PSI at warm idle, and around 45 or so at about 3k rpm. i also made sure the o-ring was not pinched when i put it in.
06-22-2008, 09:20 PM
#12
5W30, but im pretty sure the assembly lube thins the oil out a pretty good amount. i took the dipsick out after 500 miles and it was like water running off of it. it was gray in color too. if changing the oil and filter dont help it, im going to take the front cover off and change the o-ring again and shim the pump.
06-22-2008, 09:20 PM
#13
I will definitely be checking the O-Ring, but at the same time I think I will use a heavier weight oil. I'm only using 5W30 right now. I think to break in a motor I should be using at least 10W30 right?
I really don't know what the hell else could be wrong. It's an ENTIRELY new motor at this point.
I really don't know what the hell else could be wrong. It's an ENTIRELY new motor at this point.
06-22-2008, 09:36 PM
#14
Yeah, I know. Dumb moment I guess. I meant 1040 or something of that nature. I was even considering a 2050. I'm hoping it's something like that and it's not a serious problem. Like I said, I'm not sure what else it could be. Checking the o ring is an easy task anyways. Shouldn't take too long to check out.
06-22-2008, 11:08 PM
#15
Something else I just found out was I had the cam bearings changed at the machine shop and I read that most aftermarket cam bearings have a looser clearance than factory. That could effect my oil pressure. I've also got a fram filter on it, just for break in, I've heard problems with those filters causing low oil pressure too...
I just don't understand this problem and am nervous of something really being wrong with this new motor.
I just don't understand this problem and am nervous of something really being wrong with this new motor.
06-23-2008, 07:31 AM
#17
Are the Fram filters really that crappy? I've read that a lot of people have had low oil pressure issues on this forum with them.
06-23-2008, 09:39 AM
#18
What are your clearances set up to? Check that o-ring yet? What clearance did you have pick-up to pan?
I don't like putting a thicker oil in to remedy this situation...it's like a band-aid on a bullet hole (similar to putting a higher amp fuse in when one's blowing).
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COMP - FAST - PACESETTER - DIAMOND RACING - EAGLE SPECIALTY PRODUCTS - CALLIES - COMETIC GASKETS
RAM CLUTCHES - MOSER ENGINEERING - KOOK'S HEADERS - ARP - GM BOLTS AND GASKETS - MSD - NGK
POWERBOND - ASP - AND MORE!
06-23-2008, 10:08 AM
#19
What are your clearances set up to? Check that o-ring yet? What clearance did you have pick-up to pan?
I don't like putting a thicker oil in to remedy this situation...it's like a band-aid on a bullet hole (similar to putting a higher amp fuse in when one's blowing).
I don't like putting a thicker oil in to remedy this situation...it's like a band-aid on a bullet hole (similar to putting a higher amp fuse in when one's blowing).
06-23-2008, 01:10 PM
#20
I hope you figure out whats going on and its nothing major. Thats gotta be the worst feeling ever to put something together and dump so much money and time in it and have this kind of issue. I'm am also building the same kind of setup. 347 with about all the same parts. This gets me worried about mine doing the same thing. Doing all the reading i've done i seem to find everytime the o-ring is pinched. Please keep us all updated.
Good Luck
Good Luck