455 acceptable idle oil pressure

Be verry careful about running 20w50 in a BBB during the winter. It gets harder to move and puts a lot of additional pressure on that front cam bearing. I lost a front cam bearing due to running 20w50 once and will never use it again. I've used nothing but 10w30 since and have never had a problem. IMO for a street BBB .002 rod/main clearances are about perfect. Both of mine are set at .002 and I've never seen the idle pressure go below 12 PSI no matter how hot it is outside.

 

Well this makes me feel better!!!! I was concerned at Cruising the Coast last week after all the stop and go traffic and cruising for hours, I noticed my pressure was around 12 at idle. since I knew the rear sees even less, I was concerned...

 

I've run plenty of engines with 10 psi at idle with no problems. Just to second anybody who said it. Get the booster plate on there and set up the correct end clearance with a TA shim kit. That will probably be all you need. If that is not enough run some synthetic 5W-50 or 15W-50. No problems on start up. STP yes. Just remember to keep the revs down until you get some heat in the engine.

 

Wow thanks for all the responses! I think I'll go with the TA cover and I wont have to worry about this hv/hp kit I have on now wearing out the cam, I did not enlarge the port from the sender to the cam bearing as I didnt know at the time it could help, thanks for that info if I ever tear it down again.

Its running at 200 with a 160 thermostat, likely due to the stock 340 rad which is tiny, should probably get the aluminum rad and fan combo from TA at the same time lol! Have lots of time until next year anyways, theres snow on the ground now

 

The rads in those cars are so narrow and even with a thicker rad there still isn't enough surface area. TA's new redesigned BBB water pump is a must, I have used a acouple of them now and saw great results in lowering the water temp all the way around. I am always seeing people on here pushing the 180* t-stats and it drives me nuts because they can't seem to see the forest though the trees. Yes we want to have e final operating temp around 180-190 but in alot of cases you need to use a 160* t-stat to allow the coolant system a head start and sill end up with 200*++ temps. Are cars are not all created equaly when it comes to cooling them, there are different pulley, water pump and rad combos and on top of that are BBB's have tin cylinder walls/blocks and some are alot thinner then others and then you throw a over bore into the mix on a already thin cylinder wall and you end up with a hot running engine no matter what you do. Sorry I didn't to hi jack your thread I just wanted to post this before someone jumps on you for using a 160* t-stat. TA's new water pump is a must in my eyes. I will post some pics to show the differents between the 3 W/P's. There are W/P impellers with 5 blades and that is whats been common to get from the jobbers for many years but buick did use factory 6 blade impellers but they are very hard to find 40 years later, I have been collecting them since the 80's and at some point I will get them rebuilt because they work really good with the small dual pulleys found in cars with cooling packages, AC and smog pumps. Then there is TA's pump that I have seen first hand solve overheating issues on a car that had a new 4 care rad, small dia dual pulley with a 5 blade impeller and proper fan shroud. After the install of the TA pump the car sat in the driveway in the heat of summer idling and the temp never went above 190*. Chris

 

It's all in the clearances, pump and bearings. I personally run a mixed batch of viscosities in my crankcase to achieve the oil pressures I am comfortable with. I do this on all my cars. On my Skylark, straight 10w-30 and warmed up to 185*F and a long highway drive it'll idle at 900rpm at ~15psi, and cruise at ~2100rpm (overdrive0 at around 40psi. I wanted a hair more, so my current batch is 3qts of 10w-30, 1qt 20w-50 and a quart of lucas for it's stickyness. Puts my idle pressure a bit over 20psi and my cruising pressure right at 50psi. With straight and mixed oil at high rpm the pressure caps out around 75-80psi.

 

If your lifters stay pumped up at idle, there is enough pressure.

 

Thank you for the cooling info, that is the next issue I am tackling on it because it is not nearly adequate, will get that water pump now also! I did notice the thin wall casting design of the block while assembling it, it is my understanding this was the first engine GM started casting as such.

---------- Post added at 11:24 PM ---------- Previous post was at 11:23 PM ----------

Yes they do but I am worried as the motor wears some the pressure will go down more!

 

Ok I have to put my drag racing experience in here. I hate low oil pressure in a Buick 455. I don't have alot of money but when I was young i put a high volume oil pump on my 70 Electra and ran the crank out of oil. After talking to Fred C he said .002 clearance on rods and mains. Then he said Kenne Bell booster plate, which was aluminum and in the older covers we drilled a bypass hole in the pocket of the pump cavity and set the gear to cover clearance to a minimum. Then we shimed the spring with a washer to increase pressure a bit. That engine lasted 10 years on the dragstrip. After that on the next build we used the adjustable spring screw. When we broke in the cam we had the pressure maxed past the highest point on the gauge by screwing in the adjuster so the cam wouldn't loose oil on break in. Don't want to hurt a Kenne Bell cam, than I backed it off to have about 80 to 100 at 5000 rpm launch and a little less through the finish line. On the return road I was holding about 30 lbs at 1200 RPMs. I called him and said it's only 30 on the return road and he said "I don't care what it is at idle what is it on the big end". I have never had a bearing failure drag racing with that pressure. I run 5w30 Mobil 1. He want's me to run thicker oil but it works so I am sticking to what I am using. Nobody makes an aluminum booster plate like KB made so when I take my timing cover apart next time I will try to get some made because it has worked for me for years. I hate to take apart something that has wored for 20 years.

 

Is kind of a chicken and the egg thing...if there is enough pressure for the lifters, there is enough pressure so that the bearings won't wear. At idle, there is very little load on them. If the housing bores are true and round and the clearances correct, the bearings should look nearly the same forever. The only "wear" would be on cold starts. I have run performance engines for tens of thousands of miles and the bearings look like new when freshening.
Now, obviously, Buicks have some deficiencies in the oiling system so I understand your concern.

 

Let's get in this deep because when I build my 14 to 1 engine I want to stay the same with the oiling system but modify the block via a 75-76 and keep the high pressure on normal volume. FC says I need High volume for more cushion with the extra compression. I know Chevy's are different but they say I should keep the same system I got now since it works. So I ask them if they went from 10 to 1 to 14 to 1 did the change the oiling system and they said no. Fred said one of the biggest things to keep the 455 or any Buick engine from bearing failure over 6000 rpms is fully grooved main bearings. I think that is a must so if someone has a mill to do it right start selling them but you guys running high compression and high rpm let us know what is keeping these together. I'm so ready to go fast in a Buick and keep it together since I have going slow in the 10's.

 

Might be better to start a new thread for that, as this one belongs to Josh to help address his specific problems.

Devon

 

I agree, new thread. I have some thoughts on the high HP oiling system, and then some things that have worked exceptionally well already.

 

Hello, i know this conversation endet some time ago, but after reading every post i got a question. My 455 make nearly 40 psi at idle with booster plate and new gears. Is there a problem with to much pressure? Or the more the better?

 

40 psi at what rpm?
40 psi at what temp?
What weight oil?

 

40 psi from start at idle constant until 3500rpm, then slowly increase.
From start when engine is cold, nearly no drop when its hot.
10w-40

 

Sounds like you have the stock oil pump relief spring and gears correct?
Stock engine?
If so everything sounds good!

 

Yes, everything Stock except the booster plate. Havent red about that much pressure at idle, thats why i hope this wont last in Problems

 

Its a bit difficult because the engine is not running well because of 40% pressure loss. I need to do a rebuild and just want to figure out if i need to do anything with the oil pump again