external oil feed for no"s 1 and 2

[Lloydpiestate]

ohhh perhaps i should of mentioned that ive got an external rocker feed on mine, works brill, and my understanding is, that if the valve guides are in fine fettle, they are fine to use ??!!

right, topped up to 5mm over the full mark on the dipstick, was doing 55mph ( auto box remember )down the bypass today, glanced at the pressure guage, 85 psi !!! surely that cant be right can it, should i be now looking at the pressure valve, perhaps when the engine was rebuilt, a non standard spring has been put in there ???

[Alec]

Hello Lloyd,

have you access to another gauge to double check the reading? Otherwise, I would think about dropping that pressure. I had the same thing when I first started running my newly rebuilt engine. (I must admit I didn't try another gauge but mine was brand new at the time). I used a dowty washer under the pressure relief valve cap to drop the pressure. That worked in my case.

Alec

[Mike Stevens]

Hi Alec,

Absolutely agree. The external feed also has a metering hole in it so it won't 'hog' all the oil flow anyway. But I think the same as you said earlier, it may not help on an engine that is on it's last legs anyway, but one with good oil pressure and flow should not be affected.

May I'll go and see if Chris still sells them!

Cheers,
Mike.

[Lloydpiestate]

hi alec,

i shall monitor the pressure for a day or two, if it stays as it is at present, i shall do as you suggest with the valve.

the gauge is known to be good, but i do have another here, and if i get 5 mins spare, i will swap them over to double check.

the crank knock has stopped now on my journey up and down the mountain, amazing what 5mm of oil on the dipstick mark will change !!!!

[Alec]

Hello Lloyd,

"the gauge is known to be good, but i do have another here, and if i get 5 mins spare, i will swap them over to double check."

Wet gauges normally are pretty accurate but it just covers the chance you may have an odd rogue one?

Alec

[rlubikey]

... The external feed also has a metering hole in it so it won't 'hog' all the oil flow ...

Mike, I understood that earlier ones had no restriction and, while eking out the life of the rockers, if they or the shaft were well-worn, they would as you say "hog" the oil, accelerating wear of the bottom end. If Chris Witor has a restrictor in the external feeds he sells then that's good. (Does anyone know if other vendors have followed suit?)

Richard

[Jonathan Lewis]

right, topped up to 5mm over the full mark on the dipstick, was doing 55mph ( auto box remember )down the bypass today, glanced at the pressure guage, 85 psi !!! surely that cant be right can it, should i be now looking at the pressure valve, perhaps when the engine was rebuilt, a non standard spring has been put in there ???

Hi Lloyd,

With a direct-acting (mechanical) gauge, once things have warmed-up sufficiently for the oil pressure to have dropped back to 50psi or less on idle, I've found that you can usually see where the blowing-off point for the pressure relief valve is by slowly and steadily increasing the engine speed and watching the reading on the pressure gauge. If it hesitates slightly at one particular point as speed increases before resuming its upward travel, the chances are that is the pressure at which the PRV is beginning to dump oil back to the sump.

One other thought - do you have an oil temp gauge fitted and, if so, what reading is it giving? In this sort of weather, I can be running at 60mph+ with the engine coolant at normal operating temperature for perhaps 10 miles or so before the oil temperature gauge starts to rise above the bottom of the scale (40 degrees C). Just wondering whether the oil might be running slightly cool, and thus increasing pressure, especially if you don't have an oil thermostat fitted to the cooler

Regards,

Jonathan

[Lloydpiestate]

hi jonathan,

i havent noticed any hesitaion in the needle, but then trying too keep one eye on the road and one on the gauge for a while, when ive only got one working eye is a challange, but ill give it a go

no oil tem gauge, but do have the oil cooler therm fitted.

all seems ok for now, but when i get a spare 5 mins, i will fit an oil temp just out of interest.

thanks to all for your replies

[Jonathan Lewis]

i havent noticed any hesitaion in the needle, but then trying too keep one eye on the road and one on the gauge for a while, when ive only got one working eye is a challange, but ill give it a go

Or perhaps just try with the engine running but the car stationary? Seriously, it is only a minor hesitation (twitch?) in the upward travel of the needle as the valve begins to open, so you really do need to be increasing engine speed quite slowly and very smoothly to see it. I don't think you'd notice it under normal operating conditions.

If you've got an oilstat already fitted, then I'd guess you've got little if anything to worry about from the point of view of oil temperature. I only asked as I have heard of some people encountering problems with over-cooled and therefore thick oil when fitting coolers without a thermostat (hence perhaps the origin of the practice of placing the oil cooler tight up against the water radiator).

Regards,

Jonathan

[Lloydpiestate]

" Or perhaps just try with the engine running but the car stationary? "

WHERE"S THE FUN IN THAT