[n20ta2]

I drove my 461 on its first little outing to a car show yesterday about 12 miles each way. I started out with around 70 psi oil pressure initially when cold at idle and it bumps up to about 85 when on the throttle. When I got to the show engine temp was at 185 and oil pressure dropped to about 15 at idle and rises to around 80 when revved. Idle rpm is about 900, oil is vr1 synthetic 5w40. Is this a safe oil pressure? Car may have 30 miles on it right now so I'm afraid to drive it if it's eating itself, oil pump is a butler 80 psi (I think) blueprint. King bearings,Forged internals and I have all the clearance specs from the machine shop. This is a 400 block. Air temp was about 77 degrees, fans are on a thermostat to come on at 190 off at 180 I think but will double check.

[DOC]

Sounds good to me.

[chuckies76ta]

I couldn't find a vr1 synthetic 5w40. Why you using a 5W oil in summer?

[n20ta2]

It's light initially but it has fine oil pressure when cold. 40w at temp should be more then enough I would think?. I put that in in the spring when Temps were in the 50s and haven't driven it since then while I finished it up.

[n20ta2]

This is the car now as of Monday.

[chuckies76ta]

Wow, that's very nice.

[chuckies76ta]

Originally Posted by n20ta2

It's light initially but it has fine oil pressure when cold. 40w at temp should be more then enough I would think?. I put that in in the spring when Temps were in the 50s and haven't driven it since then while I finished it up.

Yes, I would agree 40 weight oil is probably fine. I run Amsoil 10w-40 in my car.

[78w72]

Those pressures should be fine, is this built to race type clearances or closer to stock/street?

If you dont like the 15psi at idle, consider stepping up to a 10/30 or 10/40 of whatever brand/type oil you like. As long as the pressure jumps up to 60-80 off idle and/or maintains ~10psi/1000 rpms the engine should be fine.

[n20ta2]

Originally Posted by 78w72

Those pressures should be fine, is this built to race type clearances or closer to stock/street?

If you dont like the 15psi at idle, consider stepping up to a 10/30 or 10/40 of whatever brand/type oil you like. As long as the pressure jumps up to 60-80 off idle and/or maintains ~10psi/1000 rpms the engine should be fine.

I think closer to race clearances if I remember correctly. I could post up the clearances when I get home for those curious. I was happy with the off idle psi but was surprised to see it drop to 15 when warmed up. I'm also wondering if 185 is to hot? I wouldn't mind it being around 160 with a max of 180.

[78w72]

Using a 5w synthetic oil Im not surprised its that low... Im an advocate for thinner oils as long as psi is OK... using a 20/50 race oil in a engine built to street specs, especially in climates that have cooler spring/fall temps has no benefits... for a race engine & hotter temps a 20/50 is not an issue.

So if yours is more of a race built engine & you dont like the 15psi idle on 5w oil, experiment with a little thicker until you are happier with idle psi, 10/30 or 10/40 should be fine or try a 15/40? But again, 15psi on a 5w oil at hot idle should not be an issue.

I use 10/30 synthetic in my 467 10.75:1 E-head street/strip engine with a stock but shimmed 60psi pump, reads ~25-30 hot idle, cold start psi is 70-75 and hot cruising or under load remains at ~60.

[Tim Corcoran]

engine fully warmed 15 PSI is what I have on a fresh engine

[n20ta2]

Just checked my extra quart when I got home and it's 10w30. That would definitely thin out a bit woth heat in it. I'm going to change it to 10w40 and that should get me a few more psi with heat.

[n20ta2]

Thanks for all the replies, I could have sworn it was 5w40.

[Don 79 TA]

what oil filter you using? i had low idle/rpm OP readings, but when i went with KN or HP5 filters pressure is much better and higher.
The AC delco filters and wix filters i tried gave me 10-15, just made me nervous, but i'm sure wasn't an issue
regardless of the oil weights i had used
i ran 0-10 a few times when it was cooler out and still had great pressures with KN/HP filters
i run motul 10-60 now since i am in the hotter dessert climate and only use the car in summer/warmer temps
heck 20-60 oil in the summer sounded so thin like it was water in a bottle, sometimes sounded even thinner, but the garage temps were will into the 120s
perhaps its a filter/gauge reading, or if remote filter you have long lines? just other possible options
but you are on pare with what i was getting and i had no issues

[Tim Corcoran]

Originally Posted by n20ta2

I drove my 461 on its first little outing to a car show yesterday about 12 miles each way. I started out with around 70 psi oil pressure initially when cold at idle and it bumps up to about 85 when on the throttle. When I got to the show engine temp was at 185 and oil pressure dropped to about 15 at idle and rises to around 80 when revved. Idle rpm is about 900, oil is vr1 synthetic 5w40. Is this a safe oil pressure? Car may have 30 miles on it right now so I'm afraid to drive it if it's eating itself, oil pump is a butler 80 psi (I think) blueprint. King bearings,Forged internals and I have all the clearance specs from the machine shop. This is a 400 block. Air temp was about 77 degrees, fans are on a thermostat to come on at 190 off at 180 I think but will double check.

That is not unusual to have 15 PSI hot in a Pontiac engine.