engine and drivetrain New Engine Rebuild Oil Pressure Problems

[felix_666]

Hello FAQer's.

 

I have been experiencing some problems with my freshly built engine. I have been problem solving with a friend for the past few weeks, but would like the input of those with experience in the area.

 

Background:

• Full nut and bolt restoration
• '74 Block +4200470
• E12 Head
• Engine was completely pulled apart, pressure tested, decked and all the rest of it.
• Over size 90mm pistons, 9.5:1 CR, 292 cam (reground), DCOE 40 webers
• Joe Gibbs Break In oil - 15w50
• New Febi oil pump
• 3 core radiator from W&N
• All other parts new or rebuilt (dizzy hasn't been recurved)

 

It is winter here now and I work in a garage several meters below the ground, its probably pretty constantly close to 12 degrees Celsius.

 

1. First time I started the engine the oil filter seal popped. Figured it was the crappy filter. Mopped up the mess.
2. Second time was shortly after the first, replaced the filter with a new Bosch unit. Filter popped again after 5 seconds of the engine turning over. On these first two occasions I used a good blip of throttle to get the engine to turn over. After many hours of research it seems this combined with the temperature was my problem.
3. After reading many posts about people installing the piston/plunger on the oil pump incorrectly I assumed this was the problem. Pulled the sump to investigate, everything was installed correctly, checked the length of the spring, all good. Stuck on a cold weather high pressure Mann oil filter.
4. Started the engine again the following week, incrementally adjusting the idle so the engine would start but not rev high to avoid high oil pressure. This worked, ran the engine for a couple of minutes, discovered a weeping T join on the carbs, turned the engine off to rectify the problem.
5. Started engine again shortly after the previous time. Once the engine turned over the RPM shot up and the filter burst.................. Scratching my head..... Not sure why the revs shot up as I hadn't touched the throttle, only the idle.
6. TODAY, I started the engine with an oil pressure gauge connected and ran the car for close to 20 min, until the temperature came up. The gauge was limited to 110psi.

• Had the car idling around 800 rpm +-40, ran pretty rough for the entire time
• After 5 min the pressure dropped to 90psi and still cold on the dashboard
• After around 10 min the temp came up to the bottom of the white on the dashboard and the pressure dropped down to around 70-90psi
• After 15 min or so, the temp came up half way (normal) and pressure dropped to around 40-50psi.
• after this I payed with the throttle, working the engine a little, the oil pressure would rise with rpm.
• The entire time the needle of the oil gauge was jumping around a fair bit.

 

It seems these values are too high, aside from the cold, new engine/pump, what else could be contributing to the high pressure?

 

 

VIDEO

 

http://s199.photobucket.com/user/felix__666/media/VIDEO0001.mp4.html

 

 

[FB73tii]

Even though the pressure relief piston, spring etc may be installed correctly, I have occasionally had problems with the piston sticking in the bore, causing the cold filter blowout you mention. This has happened on brand-new oil pumps as well as older oil pumps. My fix is to lightly wet sand the piston with 400 grit wet sand paper. Not saying that is what you should do, but it has worked for me.

 

Best of luck--Fred '69 & '74tii

[c.d.iesel]

good oil pressure readings

[tim385]

I wouldn't say that 110 psi will blow a filter, .on start up mine will run up to 120, I don't think that's all that' uncommon for a rebuilt engine.

After it warms up it comes back to about 90psi.As you rev the engine the oil pressure may come up as well .running it around for a while it ends up 60-70. Your figures are fine .dont know why your blowing filters , or are you blowing the "o"ring out.Are you doing up your filter too tight and forcing the o ring out a bit .Try a little less lube on the o ring.I also believe there is a high pressure E 30 filter avail.

[felix_666]

Even though the pressure relief piston, spring etc may be installed correctly, I have occasionally had problems with the piston sticking in the bore, causing the cold filter blowout you mention. This has happened on brand-new oil pumps as well as older oil pumps. My fix is to lightly wet sand the piston with 400 grit wet sand paper. Not saying that is what you should do, but it has worked for me.

Best of luck--Fred '69 & '74tii

I forgot to mention that I wet sanded and polished the piston from 600 to 2500 after I pulled the oil pan, did so after reading one of your posts. Cheers

[felix_666]

Anyone have thoughts on why the needle of the oil pressure gauge flickered the whole time.

I thought maybe the gauge got damaged when it was stuck on ite maximum for 5 mins.

Or, the relief valve is still getting sticking, making the needle dance.

Going to source a gauge with a higher maximum.

[TobyB]

Sounds like the relief isn't working for SOME reason- this isn't the old 'gear' style pump from 1966, is it?

 

It really shouldn't go over 100 psi ever, even with 50 wt at what, 50f?  And once hot, it should

rise quickly to 60- 65 psi, and hold that.  Maybe 70 at sustained high revs, but

not with anything normal like you're describing.

 

DO make sure you find an accurate gauge, but when it shows 150 psi, nah, something's not working in

the relief system.

 

And the oil filter actually has a square section ring at the bottom- I got some (don't remember the brand)

where the ring wasn't pushed far ENOUGH into it's groove, and they popped out pretty regularly.

The fix was stupidly easy- shove the ring down into the groove solidly, and no more poppy. 

 

t

[AlanM]

I had the same problem with the S14 I fitted to my 2002.  I thought the 700 Kpa (105Psi) gauge was wrong so I took it to work and tested it against a master gauge..It was OK.   So I fitted a 150 Psi gauge to it and it was hitting the end as well. The oil pressure was taken at the oil filter housing.

 

This was using 10/40 Redline synthetic oil. I thought that because I had bought the engine with some parts removed that maybe someone put a rag down the hole for the oil filter housing  and was blocking the relief valve, as it is last in the line of the oil circuit after the cooler.  All OK as I blew down it with compressed air to the oil pump. 

 

I never did find the fault and fitted an external pressure regulator in the line to the cooler (no thermostat in oil filter housing for the cooler)and ran a relief from this into the sump, which fixed the overly high oil pressure.

 

  I had thought possibly that because I had made a windage tray and baffle set up in the sump, and deleted the brace for the oil pump, that perhaps it was getting twisted or flexed enough to jam the relief plunger, which I had out 4 times. I fitted another new pump, comparing the spring to a known OK pump, all within tolerance, but still extreme pressure.

[felix_666]

 

  I had thought possibly that because I had made a windage tray and baffle set up in the sump, and deleted the brace for the oil pump, that perhaps it was getting twisted or flexed enough to jam the relief plunger, which I had out 4 times. I fitted another new pump, comparing the spring to a known OK pump, all within tolerance, but still extreme pressure.

 

Interesting, I too have a baffle from IE installed. Surely this isn't the problem given there are a lot of people running this design. I'm pretty sure the baffle doesn't impede the plunger. However it makes life hell when pulling the pan, don't think I'd put it in next time if the car is for the road.

 

hmmmmmm....

Edited July 22, 2013 by felix_666

[felix_666]

Sounds like the relief isn't working for SOME reason- this isn't the old 'gear' style pump from 1966, is it?

 

It really shouldn't go over 100 psi ever, even with 50 wt at what, 50f?  And once hot, it should

rise quickly to 60- 65 psi, and hold that.  Maybe 70 at sustained high revs, but

not with anything normal like you're describing.

 

DO make sure you find an accurate gauge, but when it shows 150 psi, nah, something's not working in

the relief system.

 

And the oil filter actually has a square section ring at the bottom- I got some (don't remember the brand)

where the ring wasn't pushed far ENOUGH into it's groove, and they popped out pretty regularly.

The fix was stupidly easy- shove the ring down into the groove solidly, and no more poppy. 

 

t

 

Hear what you are saying Toby, but it you gander through the threads you will read plenty of people posting over 100 psi on start up, particularly when its cold and the pump is new. Given I installed the relief valve correctly, then pulled it apart to make sure, with no difference, I'm unsure what to believe.

[DRedman]

Maybe a blockage in oil gallery.  Have you removed the valve cover to see if there is plenty of oil spraying? Our the rocker shafts installed properly? (Open hole in upper rear)? Distributor housing gasket installed properly? 

[tim385]

3 rebuilt engines, 1 new oil pump 1 old but good oil pump, 1 recod pump . All 100+ on start up.

[felix_666]

Maybe a blockage in oil gallery.  Have you removed the valve cover to see if there is plenty of oil spraying? Our the rocker shafts installed properly? (Open hole in upper rear)? Distributor housing gasket installed properly? 

 

Yeah everything is well covered in oil when I lift the rocker cover after running it, can only assume the shafts are correct, will check later this week.

[c.d.iesel]

YOU SHOULD HAVE A 0 - 150 PSI GAUGE AND CORRECT MATCHING SENDER UNIT

[TobyB]

Interesting.  100+ psi at idle cold?  I've only built 4 or 5 motors, but with the new generation pumps, I've never seen that.

 

See if we can get Byron to chime in here, he's built more motors than I've eaten croissants...

 

Given, I guess, that it's usually not that cold here, and we don't race in the winter.

But I DO dd my car, even when it's well below freezing.

 

Now, the cars with stuck valves, those peg 150psi gauges at 2500 when they're not warm.  And I've had a few of those, too.

 

But to your filter problem, I've had it too, and ONLY on cars where the relief's not working.  Not sure why yours isn't,

but given what you've tried with filters, I'd be willing to bet a rusty trunk lid that it's not.

 

what I think,

t

Edited July 24, 2013 by TobyB