engine oil priming woes

[Michael]

It's the elementary steps that are the hardest and most disconcerting!...

 

It has been nearly two years since I last started my engine. It had a problem with its adjustable timing chain - the rosette of bolts securing the cam sprocket periphery to the portion bolted to the cam somehow cam loose, and the bolt heads ate their way into the aluminum timing chain cover. In an effort to clean the aluminum shavings, I removed the heads, the timing cover and the oil pan (but did not disassemble the rotating assembly), cleaned what I could, convinced myself (perhaps naively) that no aluminum flakes were present in the oil passages (I did pull one of the rod caps, and it looked more or less OK),... and reassembled the engine.

 

Now, in one of the last steps before firing it up, I'm trying to prime the oiling system. I am using a 14.4V cordless drill and an old distributer shaft.

 

The engine is a 1978 Mark IV BBC, with basically stock rotating assembly, and the following relevant parts (PNs are from Summit):

 

Summit oil filter mount SMU-2015

Moroso high-volume oil pump MOR-22160

Hamburger 8-quart oil pan HAM-1488

Fram generic oil filter

10W-40 oil (8 quarts)

mechanical oil pressure gage plumbed at just above the oil filter boss (stock location)

3/8" pushrods (can't recall manufacturer)

Cam Motion "low lash" (0.007" cold) mechanical roller cam

Comp steel roller rockers

Isky Red-zone roller lifters

 

When I run the drill, oil pressure rapidly rises to around 60 psi - but does NOT rise any further! Max rpm of the drill is around 1200. This is on a 45-degree day.

 

And, there is no oil whatsoever coming out of the lifter oiling holes!!! I spun the crankshaft by hand multiple times (turns over with maybe 30 ft-lbs torque with the spark plugs removed), maybe a half revolution at a time, before resuming running the drill. Before valvetrian assembly I checked that all pushrods were clean.

 

Quesions:

 

1. Why would oil pressure peg at 60 psi, regardless of drill rpm?

2. Why would there be no oil coming out of the pushrods?

3. Would I be a fool to try starting the engine without first doing a complete priming, where oil flows out of every rocker?

[jbk240z]

An idea but, do you have the intake manifold installed? I ask because the dist. body needs the correct spacing to complete the lifter oil gallery circuit.

On my first SBC rebuild, I wondered why only one side of the lifters/rockers were getting oil. I was only using an old pin punch to spin the oil pump. Once I modified an old dist. body, oil both sides!

Anyway, good luck.

[grumpyvette]

Quesions:

 

1. Why would oil pressure peg at 60 psi, regardless of drill rpm?

 

 

because the stock oil pump has a bye-pass pressure relief circuit, thats built into the pump, thats DESIGNED to bleed off pressure in EXCESS of 60-65 psi

 

2. Why would there be no oil coming out of the pushrods?

 

this type above is nearly WORTHLESS

 

this type bellow works just fine

 

 

 

http://store.summitracing.com/partdetail.asp?part=PRO%2D66896&autoview=sku

they are dirt cheap or you can make one from and old distributor

 

 

be sure you turn the engine over at least two full turns while applying pressure to and lubing the oil passages to get full access to all the lifters,rockers,bearings etc.

 

 

"Why is the first one worthless?"

 

LOOK CLOSELY, the top primer has no collar to keep the drive shaft centered over the pump so it can slightly mis-align and bind, Ive seen them bend the pump drive if guys get them mis-aligned and just throw a high torque 1/2 drill on and spin them without checking, the lower primer has an alignment collar that tends to keep things from breaking,,yes both have the alignment collar for the manifold but only the botom one has the lower block support and alignment sleeve that forms the lower oil passage wall, and the drive collar that assure the oil pump drive itself is lined up correctly,keep in mind,the bottom of the stock distributor forms one wall of the main oil passage to one side of the engine, without that passage wall in place you get no oil pressure to one side and darn little to the other due to the HUGE leak the missing oil passage wall presents, the lower distrib is temporarily replaced with that extra aluminum on the lower primer to simulate the correct oil passage config....THATS WHY!

 

3. Would I be a fool to try starting the engine without first doing a complete priming, where oil flows out of every rocker?

 

 

no! it should work without priming but your taking a much higher chance of damaging the bearings , its a whole lot smarter to find and fix potential problem areas before stressing the bearings

 

btw

 

bits of info

 

http://forum.grumpysperformance.com/viewtopic.php?f=54&t=615

Edited March 3, 2009 by grumpyvette

[Michael]

Thanks for the pointers - definitely something for me to think about!

 

This engine has a stock block, crank, rods and damper. Everything else is aftermarket. I'm surprised that Moroso would put a relief valve set at 60-65 psi on what's ostensibly a racing oil pump, but oh well.... And unless memory is playing tricks with me, I recall getting 80 psi or more when revving the engine, back in 2006.

 

Earlier in the assembly process I did the clay-check and found around 0.400" between the pickup screen and the floor of the oil sump. On the Moroso pump, the pickup tube comes pre-welded to the pump casing.

 

Also, I'm using the original distributor's housing to locate the priming shaft, and am using the original distributor driveshaft as the priming tool. I varied how the distributor seats by stacking different numbers of gaskets on the distributor shaft.

 

In desperation I removed several pushrods and found that in every case the pushrod end that mates with the lifter is soaked in oil, but the rocker-end is completely dry. I then methodically blew threw each pushrod with compressed air, reassembled the valvetrain and resumed priming... with the exact same result! There just isn't enough oil pressure to get flow through the pushrods.

 

Follow-up questions:

 

1. Is it worth pulling the pan, disassembling the oil pump, and defeating the relief-valve mechanism?

 

2. Why would 60 psi not be enough to push oil through the pushrods?

[grumpyvette]

60 PSI is MORE than enought pressure,(anywhere from idle to 6000 plus rpm)in fact even at 7000 plus rpm, 60 psi is plenty in as properly set up oil system , pressures of over 75 psi just cause the pump to work harder with little or no benefit to the bearings but you probably have an valve train alignment or lash/preload problem, the lifters don,t line up with the oil feed passages untill they are near the base circle in rotation on the cam lobes so youll need to have a buddy to spin the engine over at LEAST two full rotations with a wrench on the damper bolt durring the priming process to insure oil flow to each lifter and pushrod, and if the lash/preload is too tight the lifter may not get a full charge of oil, check the pushrod guide plates also as its not totally unheard of for them to be binding the pushrods and deflecting them slightly at some point in the cam rotation, & valve lift cycle and causeing them to slightly unseat from the lifter cup, dropping oil pressure in the pushrod to zip, its better to have a bit MORE slack than have the lash or preload a bit to tight and clearances & proper alighnment of the valve train must be maintained for oil to flow correctly

[Cable]

Two years Michael? Shame on you for letting that poor BBC sit around like that!! j/k.

 

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