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Tips
Tips

BJ7 correct oil pressure

Someone else can jump in here, but it would seem to me that the oil pump is not working correctly or there is a blockage, perhaps at the oil filter or somewhere else internally in the block. There should be some evidence of oil where the opening is to the oil pressure line when cranking the starter.
 
chicken said:
Shorn

No on removing the pipe from the block and turning over on the starter with the plugs removed i had no evidence of oil ??? -- I did notice what looked like air bubbles coming through the rocker feed, is this normal.
Rob
Both of these are ominous signs. A little confused though. Oil & air at the rocker arms is not consistent with NO oil at the block with the gage pipe & it's adapter fitting removed.

There may be a serious suction side air leak somewhere on the intake side of the oil pump or pickup. There should be NO air at the rocker arms.

At this point I would remove the sump & thoroughly check the oil pump for proper drive. (key missing from the driving pump gear to it's shaft). Engagement of the pump drive to the cam.

All possible connections between the pump & it's intake screen or the screen itself.

Last or maybe first, the oil level in the sump is well above the pump intake?

The only other possibility is the pressure relief plunger is not seated, which I have already mentioned. This would not explain the air in oil part though.

Sorry you are having such problems,
D
 
Thanks guys, i guess i may have to have the sump of and check over the pump.

One question though, how much oil would the engine take after a rebuild as i seem to remember the dipstick was missing (a long while back) but i managed to find one in my shed !! i'm now wondering if this was a different make and therefore not showing me the proper levels ?

Is there any picture/scetch available showing where all the oil flows round the block, i would be interested in seeing one.

Rob
 
I think the max oil fill level varies a bit from model to model but 6 to 7 US quarts should be adequate. It should show somewhere near full.

I have a detailed oil flow diagram for the Fours but not for the Sixes.
D
 
Dave

well i took the union out of the block and put some more oil in the top, turned it over and after a few cranks some dirty looking oil came out mixed in with the new oil, i then connected it all back up and on turing over on the starter with plugs half in i got about 20 on the gauge so were of and flying now !!

I believe adding the extra oil did the job however my dip stick was allready up to the max level thats why i never added any oil before, can you tell me the right length for the dipstick, mine is 12 1/4 inches from the bottom of the stick to the collar that stops it dropping into the block, is this correct ?

Rob
 
My BJ7 dip stick measures 12 1/4 inches. The pipe for the dip stick measuring from the block to the top is 4 3/8 inch.
 
Hello chicken,hello all

here is a very good link to a oilpump tech.Info. https://www.austin-healey.ch/images/Oeldruck.pdf
But sorry, it is a site from swizerland and it is written in german, but it is specially about the detailed oilpressure problems.

Bye Michel- who has this time a language advantage :yesnod:
 
Dave

I took the sump and pump of the car, before i took the pump to bits i just tried it manually in a tub of oil and it was pumping oil out.
On closer inspection there is a tiny hairline crack just below the shoulder (that holds the pump on) where the drive spindle goes in, i had a good look and it doesn't look like it has gone all the way through but it's a job to see.
Tell me what is the relevance of having a gasket on this shoulder as the drive shaft in the pump has no seal , i'm confused on this, i can understand the gasket going to the fuel filter. Also should there be a gasket where the strainer joins the pick up from the pump.

Now i have it out and with this hairline crack am i as well to get a new pump, at least that would rule something else out.

Rob
 
Rob,
The easy answer first. The gasket at the drive shoulder is likely acting as a spacer to complement the output flange to block gasket thickness so that the pump housing is not in a bind when the pump is bolted down. It "might" even cause a crack in the pump.

There may be a gasket between the pump inlet & the screen. If so, it would prevent the pump from sucking air when the sump level is below the top of the screen housing. It certainly should be sealed with something.

The crack may or may not be allowing the pump to suck air. From your prior description, it sounds as if the pump IS sucking air somewhere.

Regardless, I would not install a pump with a suspected crack in it. Things could only get worse with time. Pump condition is not a good thing to gamble with.
D
 
I had a similar problem. Following engine biuld I had good oil pressure, then decided to change the oil line union from the block with the correct one (small drilling). I'd left the union location open to atmosphere for a week or so and when I reconnected every thing I had no pressure at the gauge.

I was advised to remove the union again and hand prime the pump by using a pump action oil can into the union location in the block. This back filled the pump via the block gallery. Once re-assembled again when the engine was turned over with the plugs out 55 psi was indicated.

Looks like with the circuit open the oil had drained back past the point where self priming at low speed turnover was acheived. Just a thought.
 
Dave

HELP !!

I fitted a new pump as the old one had a suspicious crack in it (although i believed it was allright), i took off the pipe at the gauge end and oil comes out when turned over but with the gauge back on i can only get 20 psi, and on running the engine (for a few seconds) it was still only 20 psi.
Any ideas on this, could it be linked to the carbs not set properly and watering the oil down ?
or i suppose it could be a leak somewhere but i can't see anything on the outside of the block ?
Originally i had the block re-bored, oil passageways cleaned and rebuilt back with the crank & pistons in etc ready for me to fit the head and other parts, the rebuild was done by a company that specialise in this so i can't think they have done anything wrong but perhaps i have when rebuilding the rest, can you throw any pointers on this.

Rob
 
Even fuel diluted oil should show much higher pressure when it is cold.

Did you verify the pump to block gaskets & the pump to intake screen gaskets?

There are a couple of locations where internal oil galley plugs could be missing or leaking, especially if the oil passages were thoroughly cleaned, but it would be a major job to verify now.

DO NOT run the engine even for short times with low pressure. To do so may cause serious DAMAGE to cam, lifters, & bearings. It should build well over 20 psi with starter cranking only. Maybe like 50 psi.

I keep coming back to the oil pressure relief valve plunger not seating. As a test you could put a piece of gasket material between the plunger face & it's seat. Lightly tap the plunger into the gasket, replace the spring & plug, crank it for a few seconds.

I'm about out of ideas on this. There are a few shops that could connect an external pressurized oil supply to the engine & with sump removed, observe the engine internals for amount of oil flow/leakage & make a diagnosis. Not a simple job & very messy.

I see no place where you have consulted with the shop that did the original machining. Maybe time to have a chat with them? Or time for professional "hands on" help.
D
 
Dave

I tried the gasket on the end of the plunger and that made no difference, however i was a bit nervous about losing the gasket inside the block so did not tap it in place.
So where are we up to:

a new pump was fitted so that rules that out

the pressure relief valve to me seems ok

on turning the engine over the needle on the pressure gauge shows 18-20 psi but is not constant but keeps flickering around 18-20psi

although the gauge was reconditioned i guess this could be faulty (i have known supposidly reconditioned parts not to be correct before), is there a way of testing this or the pressure from the pipe by another method ?

i guess if there was a blockage one of the oil ways then would the pressure not rise higher as effectively it would be pumping against a dead end ?

on looking round the block there doesn't seem to be any visible signs of an oil leak, which i presume if oil was seeping out would obviously cause a reduction in pressure.

would the oil filter have picked up some old residues still in the engine and become slightly clogged up, i guess it's worth a change anyway, i have fitted the spin on canister to mine.

Any more thoughts.

Rob
 
You can check the gage via another gage (could be an air gage) & a source of adjustable regulated air pressure. Simple air pressure regulators are readily available. The gage works the same whether it is operated by air or by oil.

The leakage I was refering to would be internal. There are several plugs that intentionally block internally drilled passages. This would be impossible to detect by casual inspection.

The spin on filter adapter could possibly be installed incorrectly or be the wrong adapter for the engine. Hard to describe, but the adapter should have a "source" passage that aligns with the outer diameter of the filter & block, & a return passage that aligns with the centeral part of the filter, & block. The two adapter holes must fully align with their respective block holes & the gasket must not block either hole.

An incorrect filter cannister "could" block oil flow. Remember, multiple outer small cannister holes, align so that oil can flow from the outer block hole to these holes. The center oil return hole, filter to block, would be hard to misalign.

There have been several different adapters made. One of the more common is the Moss adapter which uses a K&N # HP2009 filter cannister or equivalent. Not sure which your's might require.

As I mentioned, maybe time to get professional hands on help. It's very difficult to diagnose some problems by mail. If the pressure is truly low, each cranking test that you do is likely to cause damage to the bearings, or especially to the cam & lifters.
D
 
Dave

I think i have an old air gauge so will try that, also better have the filter adapter off and thoroughly check as well as speaking with the guys that did the recon for their pointers.

Thankyou for your ongoing help.

Rob
 
Dave Russell said:
The spin on filter adapter could possibly be installed incorrectly or be the wrong adapter for the engine. Hard to describe, but the adapter should have a "source" passage that aligns with the outer diameter of the filter & block, & a return passage that aligns with the centeral part of the filter, & block. The two adapter holes must fully align with their respective block holes & the gasket must not block either hole.

An incorrect filter cannister "could" block oil flow. Remember, multiple outer small cannister holes, align so that oil can flow from the outer block hole to these holes. The center oil return hole, filter to block, would be hard to misalign.

Dave

I just took my adapter off and how it was put on was with the lower "outer" hole that goes to the pump aligning with the center core in the filter, is this correct, previously when i looked at it i didn't believe it could be put on wrong. However on looking at it now if i turn it then the lower hole from the block feeds the small outer holes in the filter with the center hole from the filter going to the center in the block, if that makes sense !!
I believe this is what you described above, please can you verify before i bolt it back on.

Rob
 
Rob,
Yes it makes sense. If the filter flow is backward, most cannisters have a one way valve that prevents oil from flowing out the outer circle of holes. Anti drain back valve.

The hole from the pump MUST feed the outer circle of holes on the filter.

Hope the puzzle is finally solved.
D
 
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