Jump to content

High Oil Pressure


Guest tr6_guy

Recommended Posts

Guest tr6_guy

First time on the Forum. Thanks in advance for the help.

 

I've a Triumph Stag that I've converted to the Rover V8 approx. 2 years ago. The car has run well with oil pressure running at 50 - 60 psi at 2400 - 3000 rpm. I'm running a TR6 pneumatic gauge. The conversion required a remote oil filter, and I've sorted out leaks in the hoses between the takeoff and remote with aeroquip lines and fittings (3/8 fittings with #8 hoses).

 

Lately, at initial startup, the pressure spikes to 100psi then, and as long as I don't rev the motor, it settles back to around 45-50psi and then drops to 30psi+/- when warm. I've already toasted an oil gauge, and I fear I'm working on my second!

 

Things done to correct -

 

- I've replaced the pressure relief spring (had a performance spring initially)

- Changed to 10w-40 instead of 20w-50.

- Removed takeoff and blew 30psi of air into the spinoff side of oil filter takeoff. Sounds of oil percolating into the rocker covers makes me believe there are no obstructions within the engine.

- Upgraded oil filter to higher flow version.

 

Note: I'm bleeding the oil gauge line by cranking engine to see oil flowing from the line before attaching to gauge.

 

I've read MANY posts about too LOW oil pressure, but what about too HIGH? Is this initial spike in pressure normal?

Link to post
Share on other sites

Hi

The first thing i would ask is where do you have your oil pressure gauge? If it is at the pump outlet & before the oil cooler path then it will see the spike in pressure as you try & get the line moving. If so try relocating it to the other end of the oil cooler plumbing so you measure the pressure into the engine.

Secondly i would suggest the #8 hoses and 3/8" fittings are too restrictive. The #8 hose has a nominal ID of 0.42". i would suspect a #12 (0.64") or #16 (0.88") would be a better bet. Use these with 3/4" fittings.

It is worth noting the Rover V8 relies on high flow rather than high pressure to survive. Indeed the standard operating pressure is something like 25psi maximum. I have found this works best with 20/50 or indeed 10/60 oils. My oil of choice is the 10/60 Castrol RS.

 

hope that helps

Andy.

Link to post
Share on other sites
Guest tr6_guy
Hi

The first thing i would ask is where do you have your oil pressure gauge? If it is at the pump outlet & before the oil cooler path then it will see the spike in pressure as you try & get the line moving. If so try relocating it to the other end of the oil cooler plumbing so you measure the pressure into the engine.

Secondly i would suggest the #8 hoses and 3/8" fittings are too restrictive. The #8 hose has a nominal ID of 0.42". i would suspect a #12 (0.64") or #16 (0.88") would be a better bet. Use these with 3/4" fittings.

It is worth noting the Rover V8 relies on high flow rather than high pressure to survive. Indeed the standard operating pressure is something like 25psi maximum. I have found this works best with 20/50 or indeed 10/60 oils. My oil of choice is the 10/60 Castrol RS.

 

hope that helps

Andy.

Link to post
Share on other sites
Guest tr6_guy

Andy,

 

Thanks for the reply. Yes, my oil gauge take off is indeed at the remote housing, which places it directly in line of the pump prior to oil entering the engine. Is this not where to TR8's tramsmitter is located - at the pump housing?

 

Regarding the "8 hoses. Point well taken.

 

Paul

 

 

Hi

The first thing i would ask is where do you have your oil pressure gauge? If it is at the pump outlet & before the oil cooler path then it will see the spike in pressure as you try & get the line moving. If so try relocating it to the other end of the oil cooler plumbing so you measure the pressure into the engine.

Secondly i would suggest the #8 hoses and 3/8" fittings are too restrictive. The #8 hose has a nominal ID of 0.42". i would suspect a #12 (0.64") or #16 (0.88") would be a better bet. Use these with 3/4" fittings.

It is worth noting the Rover V8 relies on high flow rather than high pressure to survive. Indeed the standard operating pressure is something like 25psi maximum. I have found this works best with 20/50 or indeed 10/60 oils. My oil of choice is the 10/60 Castrol RS.

 

hope that helps

Andy.

 

Link to post
Share on other sites

Hi Paul

For the standard switch location, then you are right, the oil switch or gauge sender is between the pump & the galleries. (before the filter) but with no cooler or external lines.

My thought with that was, because I was presuming you are using a filter take off adapter, the oil gauge was immediately after the pump & before the oil lines & cooler (or half the lines if i now picture your set up correctly) The pump builds the spike of pressure on start up that you are seeing before the oil starts moving through the lines & cooler. If the sender was at the end of the line immediately before the engine, then it would see the pressure of oil entering the engine rather than the pressure leaving the pump. This would have the effect of dampenng the spike you see.

Of course using larger bore lines would also help to reduce the pressure spike.

 

Hope that makes sense as it is not too easy to describe (and i think we agree?)

 

Cheers

Andy.

Link to post
Share on other sites
Guest tr6_guy

Yes, that makes sense, and I do believe we agree. I think what I'm seeing is the uprated pressure due to the 3/8 lines and the proximity of the gauge take off to the pump.

 

I do have one more question - silly as the question is - Should I allow an air "dampener" between the oil in the gauge line and the gauge? I thought this might ease wear and tear on the gauge.

 

Paul

 

Hope that makes sense as it is not too easy to describe (and i think we agree?)

 

Cheers

Andy.

 

Link to post
Share on other sites

Paul

An air damper will do no harm, thats for sure. what you also might consider, if you are going to change your plumbing, is to buy a filter adapter or filter take off with an integral thermostat. Thus the cooler & lines will be bypassed when you start from cold or after an hour or two stopped. it will also help the oil to heat up quicker, but not reduce the good effect the cooler has when it is needed.

 

This is the set up i have to install in my car, the problem i have is the car is so much fun to drive i can't seem to get it off the road to do all the work i have planned for it. oh well....

 

Thanks

Andy.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

Please familiarise yourself with our Terms and Conditions. By using this site, you agree to the following: Terms of Use.