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damunk

no oil pressure with starter motor only  

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damunk

what's my next step. worried about oil temp going well over 6 bar on proper start up, considering it went to 5 bar on starter motor alone.

 

do i take oil out , heat it up and put it back in the engine and give it another starter motor crank or shall i just go for it and start up engine and run for 20 minutes at 2000 rpm 🙂

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kwijibo_coupe

All engines I've fitted oil pressure gauges to have pegged the gauge to maximum on start up. I've only ever used gauges that go up to 5Bar but I believe the pressure peaks around 7-8Bar on start up.

Once the oil has a bit of heat in it you'll notice it drop off and once warm you should see around 1Bar at idle.

 

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damunk

thanks so much for this.. my gauge goes to 8 bar. hopefully if cold start does take it that far thats not enough to blow out the oil gallery plugs

 

its a rebuild with new cams so i thought cus clearances might be tight. it's up to me to pre-heat the oil now or just give it a go as it is,

 

 

Edited by damunk

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dvderlm

I confirm with cold oil and block (no preheater) my gauge goes over 7 bar at first start. Once warm it idles at 1 bar, but stays over 3 bar at 1700+ rpm unless there is an oil leak (for example at the rocker cover gasket or the mechy fuel pump blanking plate).

 

Your cams have roller rockers so the lobes don't need as much hardening as for mechanical finger rockers.

 

Does it have new piston rings in newly honed bores?

Running for 20 minutes at 2000 rpm with no load will get hot and will not press the new piston rings hard against the bores to bed them in.

The engine needs to do work.

http://www.mototuneusa.com/break_in_secrets.htm

 

http://healey6.com/Technical/startup.pdf

 

 

I was not running in a cam, but with new rings.

Once I was happy it ran with no leaks at 2000  to 2500 ish for 5 mins I tried a poor man's dyno. Lifting front wheels off ground and accelerating against the disc brakes and varying engine speed up to 3000 rpm. This was not easy and I stopped after 2.9 miles on the odometer, preferring instead to drive around quiet roads of my estate including decelerating down a mild slope for about 5 miles up to 3rd gear not over 3000rpm, then a proper 40 mile round trip.

 

(I also put neodymium magnets on the oil filter to try to catch any ferrous particles and changed oi and filter after ~500 miles. I used the Millers running in oil for 500, then a mix with 1.5 liters of Millers and  10w40 semi-synth and finally just my usual 10w40 after 1000 miles).

 

 

Edited by dvderlm
(removed dead link : leverfamily PDF), missed a 0 in 3000rpm

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damunk

yeah new rings n new cams. walls honed criss cross. 

 

how long is it safe to stay over 7-8 bar. 5-10 minutes?

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dvderlm

I'd definitely expect it drop after 10 minutes, but I'd also be watching the engine temp. 

 

Oil pressure should be already dropping when coolant has gone over 70 to 80 degrees - which In this cold weather could take more than 5 minutes with bonnet open.

If pressure stays high then it's not circulating everywhere.

https://dannysengineportal.com/oil-pressure-low-high-faq/

That's why I suggest run few mins at 2000 ish , turn off close bonnet wait for latent engine heat to spread through block, open bonnet, repeat run for a bit longer.

 

Rather than emptying, heating and refilling oil , could you put a fan heater facing the sump beforehand so the oil is pre-warmed, even if the block starts at ambient? 

 

In the summer I did my rebuild I faced the opposite problem -  I put a household fan blowing cold facing the radiator grille to keep it cool during the first runs.

Though I  did start with 60degree coolant preheater.

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damunk

Might take ten days heating it up with heater :P. it's gotta get through metal although those sumps are very soft metal. (thin).  I will give that a go. Got a small fan heater. 

 

"If pressure stays high then it's not circulating everywhere." ...   regardless of oil circulating anywhere, the relief valve is always at the pump so it should open up regardless of where oil is pumping as it opens up on pressure reading only.

 

 

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