Oil pressure take off

Technical advice Q&A

Topic author
phoenix
Posts: 155
Joined: Sun Oct 25, 2020 11:49 am
Location: Blackpool
Great Britain

#1 Oil pressure take off

Post by phoenix » Thu Apr 08, 2021 4:51 pm

S1 4.2. I have just turned the rebuilt engine over to get oil pressure. Could not get any. The take off is from the top of the filter take off as in photo. It is fitted with electric and capillary type gauge .When I removed an oil gallery bolt oil run out so the bearings should be getting oil . Is the take off wrong ?
Attachments
20210408_1107261.jpg
20210408_1107261.jpg (98.25 KiB) Viewed 697 times
S1 4.2 RHD Bryan

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

mgcjag
Moderator
Posts: 6220
Joined: Fri Jul 09, 2010 6:15 pm
Location: Ludlow Shropshire
Great Britain

#2 Re: Oil pressure take off

Post by mgcjag » Thu Apr 08, 2021 5:02 pm

Hi Bryan....i could take 30 sec or more of cranking to get oil pressure........top of the filter houseing is correct for an electric or wet guage......providing the correct gasket has been used between houseing and engine.....Some remove a bolt in the gallery and pump oil in useing a garden type spray pump........if your just cranking then remove the spark plugs and disconnect the fuel pump.....Steve
Steve
69 S2 2+2 (just sold) & Building a C type replica

Link:
BBcode:
HTML:
Hide post links
Show post links


Topic author
phoenix
Posts: 155
Joined: Sun Oct 25, 2020 11:49 am
Location: Blackpool
Great Britain

#3 Re: Oil pressure take off

Post by phoenix » Thu Apr 08, 2021 5:33 pm

Hi. yes plugs out even put oil in the top of the filter housing but no joy. I thought it may take a while because the engine has only just had oil put in until then it was completely dry after full rebuild (not me). I have put a little oil in the plug holes. I will try again tomorrow.
S1 4.2 RHD Bryan

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

abowie
Posts: 3116
Joined: Wed Sep 07, 2011 9:15 pm
Location: Australia
Contact:
Australia

#4 Re: Oil pressure take off

Post by abowie » Thu Apr 08, 2021 11:22 pm

In my experience you're unlikely to get oil pressure at all when cranking a new engine using the starter. The battery will probably go flat first.

Consider that on a normal start it may take 5 or more seconds for the gauge to show pressure after the engine has fired, and that's on choke at around 1200 to 1500 rpm. The starter by comparison turns the motor much more slowly.

Your new engine will have all of the critical components smeared with assembly lube which is there to protect them on first start. So they will be fine. If you were still really concerned you could make an adapter up and pressurise the oil galleries by removing a gallery plug and pumping oil in to ensure you have lubricant to the top of the engine.

We have rebuilt a lot of engines over the years and we just start them, relying on the assembly lube to do it's job.
Andrew.
881824, 1E21538. 889457..oops. Jezza the V12 XJS race car.
http://www.projectetype.com/index.php/the-blog.html
Adelaide, Australia

Link:
BBcode:
HTML:
Hide post links
Show post links


christopher storey
Posts: 5168
Joined: Sun Mar 09, 2008 3:07 pm
Location: cheshire , england
Great Britain

#5 Re: Oil pressure take off

Post by christopher storey » Fri Apr 09, 2021 9:00 am

The first thing the pump has to do is to fill the filter canister, and that takes time . Until that happens , you will get no pressure registered . After a filter change, even with the engine started and running at say 800 rpm it can take 10 seconds or so for pressure to be developed and so at perhaps 150 rpm on a new stiff engine on the starter, you are looking at perhaps 50 seconds of cranking

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

Tbob
Posts: 166
Joined: Mon Aug 10, 2015 1:44 pm
Location: Kenton co, ky
United States of America

#6 Re: Oil pressure take off

Post by Tbob » Fri Apr 09, 2021 11:49 am

I pre-oiled my engine using a garden sprayer fitted to the filter housing. Took a few minutes but I actually pumped oil completely through the system. Afterwards it only took a few seconds of starter cranking to see movement on the oil pressure gauge. YMMV.
Bob t

LHD '69 OTS. (Former) basket case

Link:
BBcode:
HTML:
Hide post links
Show post links


paulsco
Posts: 797
Joined: Mon May 04, 2009 5:12 pm
Location: Oxfordshire
Great Britain

#7 Re: Oil pressure take off

Post by paulsco » Fri Apr 09, 2021 1:38 pm

You say you have a capillary gauge.

I had a problem getting oil pressure with mine and it turned out to be that the connecting capillary tube had sprung a leak behind the dash.

Very messy. :shock:

Just something to check.

Paul
65 Series 1 FHC, 68 Jaguar 340

Link:
BBcode:
HTML:
Hide post links
Show post links


Topic author
phoenix
Posts: 155
Joined: Sun Oct 25, 2020 11:49 am
Location: Blackpool
Great Britain

#8 Re: Oil pressure take off

Post by phoenix » Mon Apr 12, 2021 12:59 pm

Now got pressure . Filled the filter with an old washing liquid bottle and now have about 40psi with an old battery. Super
S1 4.2 RHD Bryan

Link:
BBcode:
HTML:
Hide post links
Show post links


tinworm
Posts: 429
Joined: Mon Jan 02, 2012 9:48 am
Location: devon
Great Britain

#9 Re: Oil pressure take off

Post by tinworm » Mon Apr 12, 2021 2:57 pm

Just reading down this thread and I was going to comment that the XK engine will make some oil pressure on the gauge while cranking before you start it for real - I see you have achieved that now - good news!

Barrie
1968 E-type roadster, 1964 E-type fixed head 1995 Ferrari 355 1980 Ferrari 308 1987 V8 90 Landrover 1988 Bedford rascal van 1943 Ford GPW

Link:
BBcode:
HTML:
Hide post links
Show post links


mgman
Posts: 7
Joined: Sun Oct 08, 2017 11:41 am
Location: St Mawes Truro
Great Britain

#10 Re: Oil pressure take off

Post by mgman » Thu Apr 15, 2021 1:55 pm

I got caught out after a rebuild. I turned the car over briskly with plugs out and saw no pressure on the gauge. I was alarmed until I noticed the with the ignition on there was briefly a reading. Then I realised that with the starter engaged the electrically fed instruments appear disconnected.

I use a capillary gauge now as all sorts of irregular readings were reported dependant on the engine temperature.

Stuart

Link:
BBcode:
HTML:
Hide post links
Show post links

Post Reply Previous topicNext topic