Jump to content
Sign in to follow this  
TRsixchris

New TR6 sngging starts!

Recommended Posts

OK I have picked up my TR6 an have already got a list of things to do. (Snagging rather Sngging)

 

I drove the car home, about 120 miles and it was great. There are some issues however. The oil pressure is very low. I knew this when I purchased the car and the PO was completely up front about this. The odd thing is that the engine was only overhauled less than 10,000 mile ago by CTM. I have so far removed the external rocker oil feed and have ordered a new spring ,plunger and washer for the oil pressure relief valve. I may go to the trouble of changing the oil pump as I know there are some poor ones out there. If I go down that route I can inspect the bottom end bearings and measure with plastigauge. The engine is also a bit leaky so I may just bite the bullet and pull the whole thing to sort out.

 

The electric are in for some improvement. I will be attending to items such as the Kenlow fan whose connections have obviously been getting hot and there doesn't appear to be a relay in sight. I will also fit a relay to control the Bosch fuel pump. The headlights will come in for the same treatment as although they are Halogen they are nothing like as good as the relay controlled units I had on my GT6. The foot dip is difficult for me to use with big feet so I may move that to the column.

 

So plenty to keep me occupied but at least after having a more detailed poke around the car seems to be in good structural condition.

 

I would like to get hold of an original engine driven fan assembly if anyone has one they no longer require.

 

Regards

 

Chris

Edited by TRsixchris

Share this post


Link to post
Share on other sites

Chris

 

Congrats on picking up the car, pleased u r happy with it. As you know they re a continual labour part enjoyment, part trial, part achievement, part frustration. But when they sing the feeling is wonderful

 

Just had a Sunday driving through the hinterland (old volcanic remnants from eons ago) of northern NSW near the Queensland border and still smiling

 

Enjoy

 

Graze

Share this post


Link to post
Share on other sites

Congrats on the new purchase.

 

What do you mean by "low" oil pressure?

 

My recently rebuilt 2.0 6 pot has lower oil pressure than I would have liked at 20psi hot idle (800ish rpm) and 50 psi at 2000 rpm. This is ok by the book, but actually less that the 150k miler old engine (which had bad oil habit). I was especially disappointed as I took alot of care with this one. Oil pump clearances were all very good, VP2 bearings plastigauged and well in spec, cam bearings fitted and no external rocker feed. The only deviation from standard oil system is an external feed pipe from the main gallery feed above the oil filter to the drilling at the front of the main oil gallery to give a ring main feed effect. A 2.5 engine I built last year ran 30 psi hot idle and 65 - 70 psi at 2000 rpm. I've tried different springs and plungers to no effect at all.

 

Nick

Share this post


Link to post
Share on other sites

Hi Nick,

 

It's very low. Starts off fine at between 75-100 psi but once hot idles around 5-10 psi and only gets to 25 psi at 2000 and doesn't get much higher even at 3000 rpm.

 

I rebuilt my gt6 engine and that idled at 25psi and maintained 65-70 when hot at 2000rpm and that was just a bearing refresh without a new grind.

 

This hasn't come as any surprise as I had driven the car with the previous owner and seen the low oil pressure. The engine sounds fine with no knocks or rumbles but I think it will need to come out for a full investigation. I will try the simple things first just to eliminate them. My limited time driving the car so far was great so I want to make sure that I have an engine that I can use as I wish with no worries of mechanical failure. It is quite surprising how much the oil pressure varies from engine to engine but I guess it can only be due to a combination of the tolerances of different components.

 

Chris

Share this post


Link to post
Share on other sites

You may find the dashboard oil pressure gauge is inaccurate showing high or low, especially if it is the original. I replaced my original gauge (cica 1969) with a dual oil water/oil version and tested the pressure against my PI pressure gauge when I found the reading was noticeably dropped less on the new one.

 

In my case I found the old gauge was reading between 10PSI high, which was a bit of a shock! But the actual pressure was within the Triumph specification/limits.

 

Mark.

Share this post


Link to post
Share on other sites

I'd also suspect the gauge - because its a freshy rebuilt engine.

£13 , plus an adaptor fitting, could save a lot of work:

http://www.ebay.co.uk/itm/UNIVERSAL-2-52mm-PSI-BLACK-DIGITAL-LED-OIL-PRESSURE-PRESS-GAUGE-Meter-CAR-UK-/291035804701?hash=item43c315f41d

Peter

Share this post


Link to post
Share on other sites

Well I am certainly not looking for a reading anything lower than what I have now :(

 

One of my elimination tests will be to connect a different pressure gauge. I have a known good item stashed in the garage somewhere.

 

chris

Edited by TRsixchris

Share this post


Link to post
Share on other sites

I have spent today getting better acquainted with the underside of my TR6. As stated above the oil pressure was very low. Having removed the external rocker feed and replaced the oil pressure relief valve I decided I would have a look at the oil pump and crank bearings

 

post-13559-0-91181600-1440263309_thumb.jpg

 

I put the car up on ramps and removed the sump. I then removed the oil pump. This looked as though it had been pumping sand!! With the pump in this condition I didn’t hold out much hope for the rest of the engine. With some trepidation I removed one of the centre mains – it was perfect as was the crank. Exactly what you would expect for an engine of this mileage. The bearings were VP2 as well. I checked a few more crank bearings and they were all perfect.

 

I fitted a new Chris Witor supplied oil pump and cleaned up and refitted the sump. New oil and filter then off for a test drive. The oil pressure held 50 psi hot @ 2000 rpm, around 20 psi @ 800-900 rpm and still made 75psi @ 3000 rpm after a blast. So really chuffed. I could also see evidence of the crank balancing which was mentioned on the bill for the engine rebuild.

 

Everything else looked OK except the CAM whose lobes looked worn and pitted. I will fit a new CAM and followers at some point. Any recommendations? I was thinking Newman PH1 or standard CR if they are available – the engine is a MK2 Pi Saloon but already had a different CAM.

Next job is the electrics with a new 10 way blade fuse box and some relays for the high power items

 

Chris

Edited by TRsixchris

Share this post


Link to post
Share on other sites

Chris,

I think the stippled surface may be the result of cavitation not sand. Perhaps a dpo used a high viscosity oil to try to raise oil pressure and that cavitated.

Peter

Share this post


Link to post
Share on other sites

Hi Peter,

 

Not too sure. If you look at the shaft of the worn rotor that too is badly scored.

 

Chris

Share this post


Link to post
Share on other sites

Chris,

 

When the cam and followers on my TR4A failed, the pump showed the same damage as yours. I assumed that the metal removed from the cam/followers had done the damage to the pump. I did a full engine strip and clean to remove any contaminants.

 

Cheers

Graeme

Share this post


Link to post
Share on other sites

Hi Graeme,

 

Yes I think the demise of the CAM has wrecked the oil pump. I would be interested to know what caused the CAM failure. Reading around it doesn't seem uncommon for CAMs to fail at low mileages. I think I will get a CAM and followers from the same source, probably Newman and not do anything silly with valve spring rates.

 

Peter, the wear on the outer rotor on my pump looked more scratched as if hardened particles has been dragged round the pump, not dissimilar to the pump in the link. Luckily the oil filter seems to have done a good job in protecting the crank. I will see what the top end of the engine looks like when I remove the head to fit the new CAM.

 

Chris

Share this post


Link to post
Share on other sites

Welcome to the forum Chris, great to hear you've improved the oil pressure with some basic fixes :-)

 

Electrics on a 40 year old British car can be fun..... I removed about 20 metres of wiring from mine when I bought it, all added over the years by various POs, including one unfused live wire hanging loose in the boot near the fuel tank :-o

 

Look forward to hearing more from your restoration !

 

Steve

Share this post


Link to post
Share on other sites

Yep, lost material from the cam has killed the pump. Rest of the engine protected by the oil filter. Cam damage probably occurred within the first few minutes of the engines life.

 

You've got me worried now...... Sump much harder to remove on a Vitesse (chassis X-member in the way) and I'm supposed to doing the Club Triumph 10 Countries run in less than 3 weeks..... Mind you, my oil pressure is alot better than yours was to begin with - just not where I'd like it to be.....

 

Good news that it is now sorted

 

Nick

Share this post


Link to post
Share on other sites

If it helps.i rebuilt my 1968 6 cylinder Aston Martin DBS engine a few years ago (i also sold it a few years ago and regretted is ever since) and i used comma 20/50 oil in the engine and i was supprised when the oil pressure was about 20psi under what it should be so after a few miles i changed the oil to GTX 20/50 and stright away the oil pressure shot up to what it should be and stayed there,Have you tried a different oil?Paul

Share this post


Link to post
Share on other sites

Having replaced the oil pump which cured the low oil pressure I thought I would have a look at the worn camshaft. I hadn't realised just how much car you have to dismantle to get it out! Any way I have learned a lot about the my car this week and had my first play with the lucas PI. I have now fitted a 308778 pattern cam with slightly more lift on the inlet from Chris Witor and replaced the very strong valve springs with an original style and spring rate set.

The cam I took out was a Kent TH1-26 which is supposed to be a high torque cam. Some of the lobes were only about half the height they should be and the followers were very concave and chipped around the edges. I agree with Nick that the cam probably failed when originally fitted during the engine rebuild - not sure why though.

So today with the injection retimed and everything reassembled the car is back up and running. A bit of fine tuning required but hopefully the engine should be fine for several tens of thousands of miles.

 

Chris

Share this post


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...
Sign in to follow this  

×
×
  • Create New...

Important Information

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