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oil pressure problems (DONT USE HIGH VOLUME) see pg 2 for rebuild beginnings

broncoman6524

broncoman6524

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In my 383, .030, eagle kit, (crank,rods etc)

With 15w-40 kendall oil in, (8Qt pan) I am getting 5-10 pounds at idle once warmed up. (195t-stat in) Which according to the Temp gauge is 195-200 degrees, with the mechanical sending unit on the top of the intake, next to the T-stat.

Besides the low pressure, it makes lifter noise, Constant rattle at idle. I am almost positive it has a high volume pump in the motor.

Anyone got any suggestions? When i built it, the clearances were tight, tight enough that I had to move bearings around to get enough clearance.
 
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Check bearing clearances and triple check that all the oil gallery plugs are in the right place.
 
I am probably wrong, but my understanding is that 10psi of oil pressure for every 1000rpms is normal. So if warm idle is 600-900rpms, that 5-10psi isn't that far off, as long as the pressure rises with the rpms. Though ticking and/or knocking is bad no matter what the oil pressure is. Sorry, I'm not so helpful.

Was plasti-gauge used when installing the bearings? Too tight will make for lubrication issues, but not at the lifters as far as I know.

Also, was the cam broken in as per manufacturer's recommendations?
 
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broncoman6524 said:
In my 383, .030, eagle kit, (crank,rods etc)

With 15w-40 kendall oil in, (8Qt pan) I am getting 5-10 pounds at idle once warmed up. (195t-stat in) Which according to the Temp gauge is 195-200 degrees, with the mechanical sending unit on the top of the intake, next to the T-stat.

Besides the low pressure, it makes lifter noise, Constant rattle at idle. I am almost positive it has a high volume pump in the motor.

Anyone got any suggestions? When i built it, the clearances were tight, tight enough that I had to move bearings around to get enough clearance.
Click to expand...

Your problem started right there. My guess is because you had bearing clearances too tight you have burned up a bearing which now has too much clearance and you're losing oil pressure. Never install a high volume or high pressure oil pump in a chevy, they already get too much oil up top with a stock pump. The fact that you have really low oil pressure is why the lifters are rattling. Also a rebuilt engine should easily have minimum of 40 psi at idle, mine is 60-70 at idle or cruise with a stock oil pump.
 
Great...

So what would you suggest?

Start with dropping the pan and checking each bearing individually? Then go from there?
 
i am thinking why 15-40 oil. way to thick for this kind of motor?

and if me i would pull it and set it on a stand and start full tare down.
 
I broke the motor in with 15w. 40 then once I started to drive it, I ran 10w,30. That gave me REAL bad pressure..like none...:eek1:

drained that out REAL quick at the same time I put the larger pan on, and put the 15w40 back in.

As soon as it begins to tach up the oil PSI jumps, 20 at 1500, the cruising at 2000-2200 it is ball park of 40
 
like 4x4high said you got problems.

and from what i have seen you break in with reg good quality stuff and if doing big motors you use lighter springs on cams so you dont grind off cam parts and such.

but i am no expert on this like scott 4x4high
 
I was really looking forward to him answering my question, We spoke a while back before I even built this motor, and i've read what he has to say. Much respect for him from my stand point.:bow:
 
well he did basicly answer it in vary short answer. you problem is more than likey in the bottom end bearing specs and the flip floping around before running the motor.

just a little fyi story for ya. my friend years ago got a new forged crank shaft. all speced out good till bolted down the caps on the mains. when all done couldnt turn crank with breaker bar.

long story short he found the crank was shot. cut wrong or stored wrong. the crank was warped from end to end. when bolted in to the block that was line hones and check for stright it would bind up bad.
 
Sorry you didn't get the answer you wanted but you need to tear the engine down and start measuring everything carefully. The whole engine will need to be properly cleaned before trying to reassemble it again.
 
Yeah that makes sense...Guess I have to just suck it up...haha

Was kind of hoping for some answer where everything would be better instantly.
 
broncoman6524 said:
Yeah that makes sense...Guess I have to just suck it up...haha

Was kind of hoping for some answer where everything would be better instantly.
Click to expand...

Send me 5K and i'll pull my engine out for you. That will cure all your problems, you'll get the engine, 454 trottle body and the custom chip. :deal:
 
broncoman6524 said:
If I cut five K's out of the paper and send them to you will that work for ya?

:D
Click to expand...

Nope, but 5000 Franklins will work.

I'm seriously thinking about yanking my engine and selling it as i have another vehicle i want to buy and i need to come up with 6K to buy it. Look for stuff in the for sale section soon possibly.
 
You were right... Hate saying that...

Dropped the pan and Number 5 (thrust) and Number 3 caps...
#3
100_0363.jpg

#5
100_0371.jpg

Kind of hard to tell in the pictures, but on the #5 is more worn in the center and has a few pits, and #3 also has pits.
 
You say #5 thrust are you only meaning there is wear on that bearing or the thrust surface is bad? If the thrust surface of the bearing is bad you have bigger problems.

Did you get all the caps back in their correct position and installed the correct way when you put this engine together? The reason i ask is because you said you had to move bearings around until you had clearance. Each cap MUST go on the same journal it came from and the same direction (bearing tang on the cap must be on the same side as the bearing tang on the block).
 
Correct, when I disasemmbled the motor everything went back exactly where it came from, in the same direction. This was during dissassembly, prior to machining.

There are even little arrows denoting which way they point. :D

I'm not sure where the thrust surface is:blush: If appears that the very center (bottom?) of the bearing is shinier than the rest. Then there are a few little knicks in the surface.
 
Took every thing to my machinist, they both said the crank will polish up and they are going to order me new bearings...and the RIGHT oil pump. haha

Now that I am actually making money, and this upcoming tax return I am thinking bigger.

First set of AFR heads. AFR0916
Second roller camshaft. 08-417-8
I am also considering putting different pistons in. Right now I have -12cc pistons, with my stroke (3.75) and bore (4.030) these with 64cc heads bring me to a C.R. of 9.6 if I remember correctly.

I am thinkin about these pistons. SEA8-KH860CP30
These with the same set-up will net a 10.3 C.R.

Anybody see any problems with any of this? I was already running 93 octane, so the extra coin for gas does not bother me.
 
You should be able to run 87 with that compression, at least theoretically. AL is typically given a 1 point increase in compression over iron due to heat dissipation, and 9.6:1 is completely doable on 87 octane with the "Fast burn" chamber in iron heads, which I assume the AFR chambers somewhat similar to.
 
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