Every fresh engine is primed after oil pump is blueprinted. Appears you have a real issue somewhere. Our initial primes are always at least 60psi cool at 1500rpm with 10w40 oil. You should feel resistance holding the drill after the first couple seconds and pressure should be shown on gauge. You are hemoraging oil somewhere. Leaking gasket, end clearance, scored thrust surface, too much gear clearance all play a role. I'd change the gasket plus install a booster plate first and then set end clearance.
My guess was that either 1. The pump tolerances are allowing too much blow by and not allowing pressure to build, or 2. There is Something wrong on the suction side like a bad pickup gasket or 3. Both. I have a new gasket on the pump cover and there are no external leaks. I also tried two different pressure senders and they read the same thing on my external oil pressure gauge To isolate #2, I overfilled the crankcase by a few quarts and nothing changed. If it turn the pump slowly by hand like 90* at a time, I feel a little bit of resistance after a few rotations and I can generate about 10psi by hand this way. Turning continuously with the drill - either slow or fast - gets me only 2-5psi. Also I am using a 3/8 drill which in theory should be undersized for this job but it’s having no issues I didn’t think loose pump tolerances could be so sensitive and digital on a cold engine with cold oil. Next stop is to get some new gears (since he old ones seem to have some decent tooth crown wear) and set up with the correct end tolerance
Quick update here on a few more diagnostics. probably overthinking it but why stop now? 1. Pulled the oil pump and checked a few things: a) the high-pressure relief valve was working as its supposed to. with the spring in and bolt tightened, no oil is able to get through the inlet cavity on the bottom. if I start to back off the bolt and relieve spring tension, oil starts to flow into the cavity. 2) gear side spacing is in spec. - it is at or below 0.005 according to feeler wires 3) the end spacing (between face of gears and housing cover) is way out of spec. The gears are flush with the flange and with *no* gasket, I can turn the pump gear by hand with moderate resistance. This is probably at least part of my no-pressure problem. 2. Before I pull the pan and tear into things further, I wanted to take the oil pump, timing cover and pickup tube out of the equation to see if I have an internal leak somewhere else. Maybe its far-fetched to think a gallery plug or head gasket is the issue but wanted to convince myself. To do this, I created a block off plate out of sheet aluminum in the shape of the oil pump cover. this gets sandwiched between the pump cover and timing cover with a gasket. I connected a garden sprayer to the pressure sender port on the block with a quart of 10w30 and started pumping. I pumped the sprayer up to what seemed like a lot of resistance and the oil very slowly drained into the engine (maybe over a minute for a quart) I didn't see more than a few psi on my gauge (external gauge running off the factory sender with a tee) but I don't think these hand pump garden sprayers generate too much pressure (thoughts?). I haven't pulled valve covers yet but I did not see oil in the rocker arm area on the driver side (through the fill hole) doing this. there are also no leaks from my fittings or block off plate. So the head scratching continues. Here is the order of operations from here - please weigh if you think I am chasing windmills. 1. pull valve covers (need to do this to check for pass side pressure no matter what it seems) 2. get a mechanical oil gauge (I tried two senders but will get an inexpensive gauge just to rule out a bad gauge) 3. set up pump to spec with new parts, pack vaseline, run with drill. if I get pressure and top end oil, mission complete 4. if insufficient pressure, pull the pan and check the pickup for suction leaks or screen clogs 5. if pickup is ok, check main and rod clearances thanks everyone for the input! seems like a simple problem but its not something I've dealt with before.
I pulled the pan which was not too painful in the grand scheme of car wrenching. The pickup looked pretty clear but there was about 1/2” of jello-ey sludge in the pan - I couldn’t tell if this was blocking the pickup. I removed the pickup and the gasket looked intact. About enough metal grit in the pan to reconstitute into a dimes worth of volume. While I have the pan off, what is the best way to confirm that the pickup gallery in the block is not - eh hem - blocked? I tried pipe cleaners but they don’t seem to turn corners well. Blowing compressed air was inconclusive to me (maybe I’m missing something). It would be great to confirm the passage is clear while I’m this deep into the motor. Thanks for the tips!
Nice car - Lack of rust on a '73 is key. Hopefully some of the more expert engine builders than I will chime in on your pressure issue but it sounds like you're working through it methodically.
Unfortunately I didn't - the pan hadn't been off this motor for 15+ years so it didn't strike me as a concerning find. Thanks. Even after all the pre-lubing I attempted with the drill at first, the inside of the pickup tube and the suction gallery seem a little too dry (just a feeling) so I want to chase down the idea of clog in the block before I move on.
Update. Oil pressure at last! There was no single smoking gun but the combination of excessive pump gear end tolerance and gelatinous sludge submerging the pickup were probably the reason. I also think my external gauge is junk. No matter what, it does not go above a few psi. However I have a lot more resistance in the drill and oil coming through all 16 pushrods so I think I will call this ‘good.’ For the setup, I went with a Mellings 5/8” pickup and new gasket, TA booster plate and adjustable regulator and new gears. I measured the gear “stick out” Two different ways and ended up with 0.003 to 0.004 inches. Adding the specified 0.004 for the booster plate gave 0.007 to 0.008”. I set up the gaskets on the low end of that range and gears were spin-able by hand so that was that!
Just to close the loop with some actual empirical data, My external electronic gauge was indeed bad! I hooked up a mechanical gauge under the hood with a Tee fitting to the electronic sender for the dash gauge. Cold idle oil pressure was 70psi and warm was ~40. I have the TA adjustable regulator so I will need to dial it back but I am very happy to have that issue taken care of! Next step is the interior. I pulled the seats out and took them to a local upholstery shop. I pulled out the 47yr old carpet to replace w new pieces in the original color (Black) from ACC. unfortunately I found some rust at the low points of the front footwells likely from water coming in from bad window seals. There is no rust on the bottoms or rust-through but the pitting is pretty bad and I think I will have cut out some areas to replace with patches. ugh.
Personally I would not cut the metal just for scale? If there are no holes, I would hit it with a wire brush (motorized if possible) and see if there are still no holes? If the metal has no holes I would just scrape as much rust as possible using the wire brush, then clean it really well and treat it with a rust converter product, followed by paint. It’s going to under several layers of stuff, so the visual imperfection of the scale is not a problem. I have jumped up and down on my floor pan which has some pinholes through it and it isn’t going anywhere...
Was it difficult pulling the seats? This is something I'll have to do further down the road on my '75 with bench seats and I've been dreading it for some reason. Driver seat is the only one that's getting a little worn/torn
@theroundbug, It was super easy on mine. the car has been in the west for its whole life and the the bolts were not rusted. interestingly the seat belt weight sensor wiring on the passenger side was in good shape. for the rear seat, you need a T-50 TORX bit to remove the seat belt retractors on the bottom to free the upper seat foam. @Max Damage - I hear you. I don't want to be a surgery cowboy knowing all the tweaking and iteration that will be needed. There is scale but it looks pretty bad even after wire wheeling. will see if I get to clean metal and then make the call.
Hey All, Been MIA for a while on this form so wanted to post some activity over the last few months. Last time I posted, I had the carpet and interior out for some floor pan fixes and seat re-upholstery. First, here is the 'Before" picture
Second, here is the floor cleaned up , rust patched, and tar paper removed. On top of this went second skin MLV and closed cell foam for sound and heat insulation
Finally the finished product with new color matched seat upholstery from a local shop here in OC. haven't yet cleaned up the dash and door panels though
Been enjoying cruising around with my son. But when you start to spend some seat time, you start to notice all the little things that need work! Next step was to work on the front suspension and a few related things. I noticed that the steering was wallowey out of the gate with weird clunks from the front end going over bumps and driveways. To the naked eye the control arm business looked "OG" and were all crumbling. Ball joints seemed ok wiggling the wheel assembly with the car in the air but who knows. I also noticed an exhaust leak and that the fuel lines were touching the header collector on the pass side. Not good! I decided to go with QA1 upper and lower control arms - they ended up being only ~20% more than pressing out and replacing all the bushings on the stock arms. Had a local shop re route the fuel lines away from the headers as well. The exhaust leak was a hole in the header itself that came from a torn engine mount allowing the pass side to rock into the upper control arm bolt. DOH! I should have checked the mounts more closely before dropping the motor in. Will chalk this up to rookie inexperience.
"Finally the finished product with new color matched seat upholstery from a local shop here in OC. haven't yet cleaned up the dash and door panels though[ Who did you use for the upholstery? I'm in Fountain Valley and working on a 64 Skylark wagon that is going to need interior at some point. Thanks!
WELCOME!! What a rad ride! Cant wait to see the progress. Im in SoCal too (San Diego) looks like we are getting a great west coast presence and must set up a cruise soon!!
