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My TR2 started running poorly miss firing and a lack of power. I suspected a Head gasket failure after running normal diagnostics ignition OK carbs OK.

I took the head off The gasket looks OK as do the valves etc at first look there is a fair bit carbon and oil consumption may have gone up recently.

I intend to take the valves out and examine but this may not be my problem.  Any Ideas I did not do a compression test as I dont have a tester cant do it now.

Cheers

Ewan

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I would have thought it was electrical. Points, condenser, coil related. 
Always the same symptoms , when hot and cold?

Many years ago I had something similar, on that occasion  it was the condenser, when warm.

Iain

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"after running normal diagnostics ignition OK carbs OK."

What were the "normal" diagnostics you carried out. ?

Mick Richards

 

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It was running badley hot and cold very badly at about 1500 revs better at higher and lower engine speeds hills were needing a change of gear and the sound was like a box of bits.

Oily smell .

I checked the sparks and timing and that both carbs with fuel were synchronised all were normal.

I know i was a bit hasty taking the head off but there you are.

Ewan

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Hi, we don't know any details so please provide this info, also do you mechanic on your cars ? or do you have a garage carry out your work ? If you do the work do you have any measureing tools micrometres etc ? 

How long has the engine been together and running OK ? How do you drive it ? easyfooting it at 50mph in top ? or giving it some reasonable work extending through the rev range and working the engine under load in top gear ?

Any idea how many miles have you covered in it ? How long since it's since it's last rebuild, if not you what did the present owner tell you about miles and how long together. ?

Did the engine start running badly overnight ? or did it happen over a length of time ? some weeks or a couple of hundred  miles or more ?

Depending upon what you tell us it may be the engine has glazed bores or even excessively worn bores.

As you've realised taking the head off scuppers you from certain tests which would have helped diagnose the problem, but whilst you've got access you can take some measurements to see what could be the problem. If you have a workshop manual you'll find the following methods inside it.

Take note of which way round the head gasket is fitted (it can be reversed) gasket seams up or down ? carefully remove it trying not to buckle it or damage it.

Can you measure the liner heights above the block surface (clean the block surface first )? They need measureing across the surface on either side...in an X shape and marking on top of the block  or a piece of paper. If you haven't got a depth micrometer a flat edge with feeler guages can do the job, do it carefully...you need to do it at least twice and make sure of your measurements. If you cannot duplicate the dimensions try and getter a better result...they need to be reasonably accurate. Subject to the dimensions being in order we can try something else.

Have you turned the engine over with the head off and the liners not secured ? If not then drop large washers over the head studs and secure the liners, (torque down to about 40 lb ft) they have a Figure of 8 gasket seal on the bottom of them in the block which if they are disturbed by pistons moving up and down can leak water into the sump.

Drop the oil from the sump and then drop the sump. Undo the easiest conrod bolts and push the piston and conrod up and out of the liner, try not to scratch the liner bore. Measure the liner bore accurately, you'll need snap guages or an inside micrometre which covers the 83-89 mm area. Measure at the top, about 1" down the bore and also at the bottom of the bore about 2 1/2" down.

Measure the pistons around their diameter with an outside micrometre, they aren't round so measure in crossection  X  and move the piston around until you can maximise the dimensions. 

Let us know what these dimensions are. If everything is within limits we can try something else. Replace the piston and conrod into the liner bore, the conrods are off set with the join angled, you'll see it on the others fitted, fit yours angled the same way. Carefull as you replace the piston you'll need piston ring compressors, wipe the piston skirts and the rings and grooves with clean oil and tighten the compressor to squeeze the piston rings into their grooves and introduce the conrod into the liner the correct way around, make sure the rings are well into the piston and then press down firmly on the piston crown (top) with the shaft of a hammer and push the piston smoothly into the bore. If it sticks DON'T hit the piston with the shaft, remove and try again

Clean the old copper/asbestos gasket off (you stand a chance you'll get it to seal so you can diagnose correctly) and also the top of the engine especially over the liner tops (with thinners and a sharp scraper), DON'T scratch the liners or block top. Also clean off the cylinder head face with thinners and also make sure the cylinder head studs are clean with no residue gunge on them, again don't scratch any surfaces, then use Wellseal and wipe it over both sides of the gasket (everywhere) and replace the gasket the same way up as you took it off. Replace the head, retorque the head in 3 stages, first to 50 then 80 then to 105 lb ft and then we'll try and see if we can achieve any compression if we can find a gauge for you.

Mick Richards

Edited by Motorsport Mickey
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WOW! That's a pretty impressive response, if I may say so, Mickey.

David

Edited by DavidBee
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9 hours ago, DavidBee said:

WOW! That's a pretty impressive response, if I may say so, Mickey.

David

And a scary daunting one

I’d be surprised if Ewan comes back. 

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I think he's made of sterner stuff Hamish, others have bloomed starting from a similar place.

Mick Richards

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Mickey

Thanks for your detailed response I know what Is did was a big mistake but will find a way back.

I have done all the work on the TR since I got it in 1990 it was a bit rough at the time it ran fine and has been on the road every year.

I have learnt to work on cars from 17 and have basic tools the car is used most days in the summer and driven to the conditions fast when the roads are clear.

I rebuilt the engine in 1991 with the crank reground and new 87mm pistons and liners not much else was changed at the time the head was done later with new valves guides and  seats. I think the engine has done 92000 miles and the head about 60000 since the rebuild. 

I will look to investigate further  I know not to move the crank with the head off but note that the liners look and feel even. I dont think I will take the pistons yet but will measure the bores. 

I note that you dont mention the head I was going to take the valves out to have a look.

Thanks

Ewan

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3 minutes ago, ewan2 said:

Mickey

Thanks for your detailed response I know what Is did was a big mistake but will find a way back.

I have done all the work on the TR since I got it in 1990 it was a bit rough at the time it ran fine and has been on the road every year.

I have learnt to work on cars from 17 and have basic tools the car is used most days in the summer and driven to the conditions fast when the roads are clear.

I rebuilt the engine in 1991 with the crank reground and new 87mm pistons and liners not much else was changed at the time the head was done later with new valves guides and  seats. I think the engine has done 92000 miles and the head about 60000 since the rebuild. 

I will look to investigate further  I know not to move the crank with the head off but note that the liners look and feel even. I dont think I will take the pistons yet but will measure the bores. 

I note that you dont mention the head I was going to take the valves out to have a look.

Thanks

Ewan

Fill the head chamber’s with petrol and observe 

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So we won’t be seeing you and Isabell in The Lakes next weekend then Ewan even if there is a Lakes Weekend which I don’t think there is…..!

We have managed to get booked in at a Premiere Inn an Whitehaven just in case. We will then be travelling up to Oban and then over to Jura.

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10 minutes ago, ntc said:

Fill the head chamber’s with petrol and observe 

+1 with Neil on this.

I didn't mention it previously because I thought I'd given you enough to do !

Mick Richards

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Hi Ewan,

I know this sounds too simple but did you fit new spark plugs to try to remedy the issue.

I have found that many modern plugs do not like our overly rich engines.

Dodgy plugs could give this issue

I use Champion L87 and find these last longer than NKG etc ~ about 5000 miles compared to1500.

Roger.

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Sue 

I got an Email from Wayne yesterday saying the Lakes are cancelled for this year.

Roger Mick 

The plugs looked normal but sooty when I took them out they are NGK genuine.

The problem may be progressive As it did not run well without the choke until fully warm for a while. it would hesitate and misfire until fully warm but there was no lack of power. 

 

 

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4 hours ago, SuzanneH said:

So we won’t be seeing you and Isabell in The Lakes next weekend then Ewan even if there is a Lakes Weekend which I don’t think there is…..!

We have managed to get booked in at a Premiere Inn an Whitehaven just in case. We will then be travelling up to Oban and then over to Jura.

Suzanne, what a whirleind of a tour you have planned! Any chance of posting a few pikkies along the way. I've never been to these places, but it would also be nice to see your TR in ACTION :ph34r:

David

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51 minutes ago, DavidBee said:

Suzanne, what a whirleind of a tour you have planned! Any chance of posting a few pikkies along the way. I've never been to these places, but it would also be nice to see your TR in ACTION :ph34r:

David

I will see what I can do David

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1 hour ago, SuzanneH said:

I will see what I can do David

Oh thank you, Suzanne. I don't mean to create extra work. Just to say that these places you have mentioned sound amazing, and you travelling far and wide across them is also brilliant, and if there is any possibility of taking a few photos I would be very interested. And surely many others too. 

Forgive me if what I wrote came across as intrusive. It wasn't intended that way.

Best,

  David

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David, I hope you didn’t think my reply curt it wasn’t meant to be. My photos will not be pristine photos as others on here post. Mine will be snaps taken with my phone and action photos rather than posed photos of the car.

Roger and I use our TR for touring and like using our TR for bird watching,  nature watching and visiting the more wild places in our beautiful countryside.

We already have photographs of where we are visiting on this TRip all except for Whitehaven which is the only place near The Lakes we could find that had vacancies. As the Lakes Weekend is not on I am hoping to have a good look around Whitehaven as Rogers 3x great grandparents were born there.

 

Edited by SuzanneH
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16 minutes ago, SuzanneH said:

David, I hope you didn’t think my reply curt it wasn’t meant to be. My photos will not be pristine photos as others on here post. Mine will be snaps taken with my phone and action photos rather than posed photos of the car.

Roger and I use our TR for touring and like using our TR for bird watching,  nature watching and visiting the more wild places in our beautiful countryside.

Oh, good-oh, Suzanne!

Just a case of crossed wires. You see, I thought I'd come across as rude without meaning to be.

How inspiring to connect bird-watching and TRs. I have always loved birding myself. I am not a very adventurous person, when it comes to travelling, more a creature of habit which I regret, a little. It's true: some peopke, like Deggers, take amazing photos. But I was just interested and trying to see in my mind's eye all the wonderful places you have mentioned.

Best,

David

 

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Mick 

The liners  for 1 and 2 are about 10 thou        3 and 4    7-8 thou

the bores measured at about mid height with an ancient micrometer  these are in inches but it  was difficult to be accurate I have no experience of using these.

from the front 1   3.431   3.429     2  3.430  3.432     3      3.437   3.427    4    3.430   3.429   the top diameter was consistent at 3.427

petrol in the cylinder heads too a good hour or two  to drain with number 4 faster taking about an hour

I have looked at the tappets they were OK and they did not need adjustment.

 

Ewan

 

Edited by ewan2
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Hi Ewan,

Well I normally leave the petrol in the chambers overnight, you have to wait that long to see appreciable loss out of any failing valves to let you spot the chamber. So a loss in an hour is orrible ! and another after a couple or so hours not much better.

Imagine if you have 160 lbs compression (typical) it finds the slightest leaking area out immediately and your air-fuel mix pushes out around the valve seats and then back into the inlet sometimes burning there. They need sorting out.

The valve guides need checking for wear also, excess wear will allow the valves to rock again allowing the fuel charge to escape.

The figures on the bores are puzzling. The 87mm pistons equates to 3.425 at largest size and an allowable 4/5 thou wear comes out at 3.429 or thereabouts for the liner bores. Your measurement of 3.427 at the top of the bores across all liners is thereabouts the unworn liner dia (I'd expect about 3.4285 as being an unworn liner dia, allowing about 3.5 thou running clearance on the piston). So liner bores showing 3.430 thou upwards would be indicative of excess wear or your lack of experience in measuring (especially when inside the block). Can you spot any wear ridges in the liner where the top ring comes up to ? sneaky little beggars they normally show on the thrust side of the engine where the pistons are forced into the bores. Make sure to check completly around the top circumference of the bores in the top 1" area down, sometimes drawing your fingernails upwards is the easiest way to highlight them.

Bottom line is I'd certainly be dropping the sump and popping a conrod and piston (make it the one worst on the measuring) and measuring more exactly if you can to get the best information.

Having carried out a lot of the labour already what I would do is have the head reworked (at 60,000 miles it doesn't owe you anything) on valve guides and regrind the valves in.

Also at 90,000 miles on the piston and liner set they would be coming up to their expected life end, I would be getting a rering set and rering the pistons (including a "ridge dodger" top ring if available) and carry out a light hone on the liner bores. That stands a chance of maybe another 20-30k before you need start considering options. This would get you back on the road quite swiftly 2-3 weeks ? and with a running engine in decent nick and then see if all is fixed or if not then start the second phase of diagnosis which you can with a running engine. Oh...as Bob and Iain say your gasket looks fine, you could risk cleaning it up and refitting after Wellsealing both sides, but if you don't like the labour fit a new one just to make sure.

Alternatively bite the bullet and replace the piston and liner set which with a reworked cyl head should see you right for more big number miles. We won't go into pulling the cam followers and checking to see wear patterns if getting back on the road quickly is your aim.

Mick Richards

 

   

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