Rebuilt engine oil leak

[haggis]

Hi everyone, you may be aware from previous posts, I have been rebuilding a Mk2 Vitesse HC engine to fit in my Gt6 Mk1 following a disastrous impulse purchase from the dreaded fleabay.

In the process of rebuilding it I have learn't so much from the forum and can only thank you all so far for putting up with.

So, having completed the rebuild and added a lovely overdrive gearbox, it has been rolling road tuned to perfection for the 'running in period' of which I have completed around 200 miles, and with triple strombergs and an extractor manifold is running like a never before and putting a smile on my face every time I drive it even driving it below 2500RPM.

But, it has an awful oil leak on the left hand side of the block on the same side as the coil, distributor etc.

This leak only occurs when the vehicle is hot and driving, when stationary hot or cold there is evidence of the leak but no sign of where it is coming from, its all over the side of the engine between the distributor pedestal and the alternator.

It would seem to be cascading down from the head gasket level as everything above this is oil free.

I have looked at core plugs, distributor pedestal gasket & O ring, along with all the gallery screws, dispstick, relief valve and sump and there is no sign that oil is being sprayed from any of them.

 

The head gasket was a Payen good quality one, the head has been skimmed and the block top faced up in the machine shop, all torqued to correct figures.

 

The plan was to run it in for 500 miles (Santa Pod would have been nice), re-torque head, oil change, valve clearances etc, and then drive it properly. This Triumph ownership thing is mighty frustrating, i'm not sure how we have all stuck at it for so long! (30 years for me).

 

As always any help/suggestions greatly appreciated 

 

Thanks

HAg

 

 

 

 

 

 

 

 

[dougbgt6]

If it was the head gasket I'd expect other symptoms, loss of power or loss of oil pressure or overheating or all three. You haven't mentioned the oil filter. At one time I had the old type which developed a pressure leak on the rubber seal when hot, it vented all the oil and my ex didn't notice the warning light.

.

[haggis]

Hi Doug, no other symptoms, run fantastic with loads of power, 60/70 PSi 2000/2500 rpm. It is fitted with an oil cooler and spin off adaptor to suit with a thermo valve as well (slight leak from this but mended), the leak is right up there at the join between the Block & Head, the engine number flange is wet, the dynamo lump on the block is wet on top and the lugs for the coil too, its coming from the top and working its way down.

 

I'm guessing first stage should be to re-torque maybe? but it has leaked since day one and I know I torqued it up good and proper like.

I have just read another forum post on this and someone was recommending increasing the torque figures by 10lb/ft and to do it while the engine is warm, any thoughts?

 

HAg 

[dougbgt6]

There's a lot of post about how accurate torque wrenches are so this may be your problem. 

[Pete Lewis]

this sounds like spillage from the cam follower chest , so its  a retorque.

have you tried a thin feeler in the gasket face ??   is there gap as not pulled down ?? or not  machined flat !!!!     guess this will be a new gasket and 

some sealer along the follower chest face

 

old trick ..... blow some talc around  the area  the oil will leave a trace where it is coming from,  and if it doesnt work smells nice 

 

Pete

[haggis]

Hi Doug/Pete, I bought a new torque wrench especially as mine was 20 years old, its a 'Teng" which i believe is good quality and fairly accurate, I also double checked with a friends' and my old one too.

I'm guessing first step just to re-torque head back down see if it makes a difference? or is it head off, new gasket & re-torque?. I'll check with feeler gauges, is it worth torquing higher or when engine warm?, I have always assumed cold is best.

I did use existing head studs with some new and some old nuts.

 

Thanks again.

Hag

[Pete Lewis]

did you run a die down the old studs ,   crud in the threads can give you a torque result but no clamping

 

whilst you may maintain the fire ring clamp theres a lot of panting goes on and the extreme edges let leaks out 

 

the head facing may not be as good as you think.  a bead of sealer on the new gasket would be an acceptable solution,, theres no real pressure 

only breathing  down this edge

 

Pete

[JohnD]

This engine has been rebuilt, yes, haggis?  So no crud, Pete.

And it is a Mk2 engine, so no swaged in push rod tubes to leak oil from the 'cam follower chest'  (a new term for me!  but I know what you mean)

 

Quote, " it has an awful oil leak on the left hand side of the block on the same side as the coil, distributor etc.

This leak only occurs when the vehicle is hot and driving, when stationary hot or cold there is evidence of the leak but no sign of where it is coming from, its all over the side of the engine between the distributor pedestal and the alternator.

It would seem to be cascading down from the head gasket level as everything above this is oil free."

 

Dip stick.   Oil is coming out and spraying that area of the block.

It's been rebuilt, but is there still blow by, and excess crank chamber pressure?   This can happen with a new engine, until the rings bed in, or if the bores have glazed.

 

Do a compression test, looking for equality across the block, to ensure that a ring hasn't seized.

And with it warmed up, take off the oil filler and feel the wind coming out - if it is a zephyr, all is well; if it is a mighty wind ......

 

After your first start, how did you drive it?    Initial in-garage run should be 2-3.5K, varying it all the time, for 20 minutes to bed in the cam followers.

Then on the road, foot hard down in third, so that the engine has to work hard - but don't bog it.   This forces the rings against the bores, to bed them in.

And on the overrun keep it in gear with the throttle closed, foot off pedal, engine braking.   This generates the maximum vacuum in the bores, drawing up oil onto the wall and rings to lubricate them.

Brrrrrrrrrrm! and coast down.   Repeat, and repeat, and repeat.  Drive like this wherever possible - eg not in busy traffic, in fact avoid traffic, and do so on more open roads where your antics will annoy no one!

This avoids glazed, polished bores that do not seal and cause excess blow-by.

 

Do this for as long as you can.  200 miles at least.

 

Meanwhile, wrap some rag around the top of the dip tube, and see if I'm right.

 

If not then warm it up, clean the block as much as possible, and drive it to the end of the road.  And back,  Repeat, until you see where the oil is coming from!

Good luck!

John

[haggis]

Hi guys, thanks again for your thoughts, I didn't run a die down the threads but I did thoroughly clean them and blow out with compressed air.

I had considered dipstick, although loose and on one trip found it raised by 10mm, the felt stop was not covered in oil and I assumed this was not the cause, since then it's not lifted.

I do have a triple stromberg set up with a pipe running from the rocker to catch tank and back to the inlet manifold via a PCV (from a 2.0 jeep) as my breathing system.

 

The garage start up involved running til warm, with varying rev's then straight to tune up garage were it was rolling road tested but not past 4000 rpm. Since then I have been taking it easy with gear changes at anywhere between 2 & 3k rpm trying to put some local miles on before re torque.'

 

I couldn't get a feeler gauge in the gap between the block & head.'

 

Think I'll look at dipstick first, re-torque head then see, all the time taking it out on little test drives as suggested accelerating and letting the engine brake.

 

Thanks for your help, I'll let you know how I get on.

 

Hag

[haggis]

Hi again, just had a look at testing the torque values on the head studs, I started by increasing the torque from 26lb/ft to 36ilb/ft to the final figure of 45 lb/foot. They were all fine at 26, 3 moved and torqued up to 36 and finally 6 moved and torqued up to 45. I Was reading the forum and saw that ( I think it was Pete) said you should undo them by half a turn and then torque back up again, should this be done now? And if so do you undo them all in sequence by half turn then do them all back up in sequence to the final torque figure or individually?

Thanks again hag

[Darren Groves]

Definitely should back the nut off when re-torquing, I normally undo a 1/4 turn but as long as you reach your desired setting with a smooth and steady pull then that should be fine.

[Guest]

Hag.

 

I took my head stud nuts back one flat and re-torqued individually - do not undo them all; do each in turn.

 

There was a lengthy topic on here a few months ago about torque wrenches (TW's). If you can get hold of an electric wrench then the accuracy is 99% spot-on. Other types of TW tend to become far less accurate over a period of time and you should always ensure that the TW is set to zero when not in use.

 

There are many different ways of testing, too many to go in to and some are peoples own particular favourites. But if it was me, having it recalibrated properly is worth the money.

 

Better still just buy an electric TW !! 

 

Regards.

 

Richard.

[haggis]

Hi guys, thanks for your posts, mine were not smooth and in fact a bit 'clicky' when I did the final torque, so backing off a bit sounds good. I'll have a chat with my local garage see if they can lend me an electric torque wrench. Hopefully this will stop the oil coming out and save me from removing my head again.

 

Thanks

Hag

[Pete Lewis]

Now you wished you had upped the rebuild with 7/16" studs Ha !!

 

If you have sticky nuts you must back off make sure they are not spreading as too soft,

or diging into soft washers which deform and grip the nut.

Nuts should be a little deeper than a std and be an oiled finish ( canley sell correct nuts

 

if you ever buy a electronic TW make sure it takes std cells not like some wich need a pile and cost more

 

I have a torque to yeild which measures the climb in torqure to the rotation of the nut

but dont have a mk1 to try it on

[JohnD]

"Electric torque wrench"??

 

Do you mean a buzzgun, a cordless impact driver?    Most have no adjustment, or else a crude low/medium/high.  EG http://www.acdelco-tools.com/index.php?route=product/product&product_id=79  "5 torque settings"

No technician would rely on that, but set it low and then tighten with a proper torque wrench.

 

Do you mean an electronic torque gauge?   That goes between a breaker bar and the socket?  EG http://www.justoffbase.co.uk/Torque-Adaptor-Digital-3-4Sq-Drive-100-500Nm-STW292-Sealey?gclid=CPOhjPaTrM0CFfMV0wodJEgLEg  "Accuracy +/- 2%"

 

But you can check your torque wrench, by clamping the drive bar in a vice and weighting the handle with a large object of known mass, hung a measured distance from the drive bar.

 

John

[Guest]

Nope.

 

I was referring along the lines of a Snap-On 1/2" Drive Electronic Flex-Head TechAngle® Torque Wrench (12.5–250 ft-lb)

 

There are cheaper models available.

 

I think 3/4" drive that you have flagged is a tad too large, a lot of home mechanics have most of their sockets in the 1/2" to the 3/8" range; with the latter becoming more popular - except where very high torque setting are required.

 

Cheers.

 

Richard. 

[haggis]

Hi all, and as always thanks. I bought 'uprated' washers & nuts from rimmers, which I thought would be best, can't remember if it's the new items making the noise. I wasn't aware they were upgradable to 7/16" are they the 'torque' bolts you refer to with the built in head and washer?

I don't think I'll be buying a new electronic torque wrench in the near future, hopefully I can borrow one.

Thanks

Hag

[JohnD]

Hmmmmmmmmmm.

" Snap-On 1/2" Drive Electronic Flex-Head TechAngle® Torque Wrench "  https://store.snapon.com/TechAngle-174-Models-2-Accuracy-Ratcheting-Flex-Head-1-2-Drive-Electronic-Flex-Head-TechAngle-Torque-Wrench-12-5-250-ft-lb--P760213.aspx  

$500  for an excellent,long-lifed SnapOn tool, that provides the same accuracy, from the same technology, as that torque gauge.

I showed a 3/4" drive one just at random, yes, "cheaper models are available".  Clarke sell one for £36: https://www.machinemart.co.uk/p/040215238/

 

SnapOn are fantastic tools, well worth it for a pro.

John

[Guest]

John.

 

I've not seen these Torque Adaptor Digital 3/4"Sq Drive 100-500Nm STW292 Sealey before - you obviously have.

 

Have you used / own one and if so what is your view on it ?? 

 

Thanks.

 

Richard.

[JohnD]

They are fairly new, but as I only bought a new, conventional torque wrench a couple of years ago, I haven't got myself one.

 

Nor, as it happens do any of the professionals I know, possibly because they have invested in conventional SnapOn TWs, treat them as precision instruments and have them calibrated every few years!

 

This review of a few devices is complimentary about a torque adaptor, but also shows by testing how im[ortatnt it is the return your 'click' wrench to zero before putting it away:

http://www.hotrod.com/how-to/additional-how-to/ccrp-1304-torque-wrench-testing/

 

John

[Pete Lewis]

Hag, you can upgrade to 7/16 but have to drill and tap the block and open the head stud holes to take the thicker stud,  , its do able 

but never done it.

 

mini or triumph wheel nuts make a good alternative nut , but must be cone up!!!

 

and wont fit under the rocker pedestals 

 

Pete

[JohnD]

Peter,

when you say "open", do you mean to drill out the top thread of the newly tapped stud holes?

 

For Haggis, this is an essential part of the mod, as otherwise when you insert the stud, it will compress the metal around the hole.  No probs, except on the face where the metal can expand upwards.

This tiny bulge can support the gasket and head and cause the seal to fail.

After tapping, the hole should be counterdrilled with a slightly larger bit, just enough to remove the top turn of the thread.

Best done by the machine shop that deals with the block, but remind them of the necessity.

 

John

[haggis]

Hi john, no plans as of yet to do this mod, I have retorqued and wrapped the dipstick, just waiting for rain to stop before going on test drive. Feeling like I should have built an arc not a gt6.

 

Thanks hag

[Pete Lewis]

 A bilge pump is more usable this summer 

 

Pete

[haggis]

hi again, slight query here, can someone out there confirm the torque settings for a late 2.0 6 cylinder HC cylinder head bolts, apparently the later engines have a higher torque setting? I'm currently doing mine up to 46lb/ft.

 

Thanks

Hag