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Engine block drain tap


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Sorry but it's me again.

 

This is probably blindingly obvious, having removed the engine drain tap "to drain the block" I find no water coming out.

 

Have poked about in the hole left by removing the tap I find it completely blocked. Before I make an expensive mistake can I just tap away at the crud, ie poke a screwdriver in the hole and tap away at what seems to be very solid crud or does the the water enter the drain from and angle?

Engine and pistons still in the car so I can't properly see what I am bashing / scraping away at.

 

 

 

sorry to have to ask such daft questions David

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a screwdriver is fine to break the crust then waggling inside with a welding rod is better, you can go deeper and remove more crud. From above also since the head is off... It's a very common issue especially around cyl 3 and 4 where the crud accumulates due to engine slightly tilting backward

Edited by Geko
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Hi David ~

 

Here are photo's of my block before and after. I had the block chemically cleaned

and I used a Dremel parallel burr to open up the drain hole to make it much bigger.

The block is painted with Frost's 'Glyptal' paint to prevent the build up of corrosion.

 

Tom.

 

Edited by Fireman049
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Just a point, if you have then engine in the car and the battery connected be sure you don't allow whatever you are prodding the **** out with to fall across the live terminal on the starter solenoid auxiliary...it hurts ! Disconnect the battery.

 

Mick Richards

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The guy who rebuilt my engine (Mark Macy of Macy's Garage, a pretty well-known TRiumph shop in the US) as a matter of policy refits the block drain as a "cosmetic" restoration. His experience has been that they're pretty hard to reliably restore.

 

He cleans out the blocks during rebuilding, of course, but he doesn't make the tap functional when it goes back on.

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I cleaned mine up, polished it, chipped all the crud out of the block. Problem was that when I braked hard, the weight of the operating handle swung it forward, opening the valve and leaking my nice clean water out!

 

I had to wire it shut until it got a bit cruddy again. Works nicely now.

 

Pete

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Thanks all

I am a coward at heart and make very sure the battery is out of the car when shifting heavy metal bits about.

I intend to put the drain back in, it seems in very good nick, but as a precaution I'll wire it shut.

My main concern was that I was not going to knock lumps out of the block now reassured that that it's a straight bored hole. I'll keep on tapping away at the crud 'till it gives up then have a good waggle with a bent rod...........with the "stuff" knocked of.

 

Thanks all for the advise

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I don't think the drain needs to be wired if the mickey mouse spring provides enough pressure which i found doesn't with the wear.

Edited by Geko
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In the 1960s, we found that the block drain tap on my brother's TR3 was open permanently, but no coolant had flowed out because there was so much limescale etc inside that blocked the exit! Back then, many owners used anti-freeze solely in the depths of winter, so limescale build-up was common.

We dug out the crud and made the tap work properly, setting it to the closed position.

Ian Cornish

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Having read a lot about this on the interweb, I have to wonder just how important it is. The consensus of opinion seems divided between those who say don't trouble, it will only silt up again within a few months and those who feel it's worth doing.

While I have the head off I am cleaning up the top of the pistons and notice they are marked +020, is that a good thing? What does it mean? the bores appear to measure 87mm (I don't have a way of measuring......anything very accurately.)

 

Thanks for all you help. David

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It simply means the bores have been machined to increase the nominal dia by .020", & the pistons are chosen to match that.

.020" (20 thousanths of an inch) is very nearly 0.5mm, suggesting your bores are either 87.5mm, or 86.5mm.

 

Bob.

Edited by Lebro
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I think the value of the tap is proven by the fact that it silts up so quickly. All that 'silt' can flow directly out of the tap when it's open, instead of having to find its way through the block and bottom hose to the radiator drain.

 

Pete

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Hi David

 

Glad your are finding something to do while you are waiting for the new head gasket to arrive!

 

From what I saw of your engine last week and looking at the cylinder head yesterday I think previously a new set of +20 pistons & liners were fitted but certain works were not carried out the way they should have been.

 

I know you did not go into detail on the "non starting" thread but I am sure you will not mind if I let people know what I found when I came down to look at your problem. I have given you some of my ideas of why the engine is as it is but others on here may have another take on my opinion & that could save you time.

 

History.

 

When I went down to see David last week he told me he had done no work to the engine and had relied on the PO saying it was a good running unit. Fair enough.

 

While trying to sort out the non starting issue I removed the rocker cover and set the engine to TDC on the no 1 firing stroke and found the ignition timing to be 180 out. I then noticed that the valve clearances had not been set by the PO - they were around 10mm!!!!. Corrected that & timing and got the engine to run briefly but on cranking the engine was pressurising the cooling system and pushing coolant out of the rad. A compression check by David later showed a variance from 100-165 but only an even 10lb rise across all 4 with a squirt of oil in the bores.

My 1st diagnosis was a blown head gasket and valve seating issues.

 

David then removed the cylinder head and brought it up to me yesterday for examination.

 

I put a straight edge over the head and could find no warping.

 

A 20min leak down test showed more than acceptable valve seats.

The head gasket showed no signs of a blow but David told me the head bolts did not seem to have been bolted down to anything approaching the usual torque figures.

I have not had the opportunity to examine the block with the head off so can make no comment on that

 

Certain aspects of this do not make sense to me for the following reasons.

The PO offered to get the engine running when David collected the car but he declined as he intended going over the whole car during his restoration.

Obviously the car would not have run as it was.

Did the PO undertake engine work that he had forgotten he had not finished? Did he think he had finished and then realising he was going to lay the car up for several years decided to open up all the valve clearances to make sure all valves were closed and no moisture would get into the cylinders?

I am concerned about any bottom end issues but can understand why David is reluctant to pull the engine just yet.

 

Having done a fantastic job of fitting out the engine bay and the interior to a very high standard David is reluctant to pull the engine just yet so I have suggested he refits the head in the next couple of days and torques down properly and then takes another set of compression readings and we then go from there.

 

Any other comments guys?

 

I hope you don't mind me posting this info David but there are lots of guys on here far knowledgeable than me who can pass on their knowledge.

 

Steve

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"A compression check by David later showed a variance from 100-165"

 

¨100" is a strange figure that would suggest cocked valves/seat or daft rings. Was the compression test taken WOT with enough battery charge ?

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Hello all

Steve I have no worries at all about your posting your findings, even if it does make me look a bit of a dipstick......which is fair enough :D

Just for the sake of accuracy the readings I took with the engine dry were 1-120 2=160 3=160 4=150 (don't think I tightened up the fitting properly on 4)

with the addition of a few squirts of 20/50 the readings were 1 = 130 2=170 3=170 4=170.

 

Having then unbolted the head all too easily I have to wonder if at least some of my problems ie compression and waterworks my well have been caused by the head if not being loose certainly not being tight down?

 

New head gasket should be here in a few days and it will be interesting to see how we get on from there.

 

Once again thanks all for your invaluable help and advise, and to Steve C for his hands on help.

 

The infernal optimist David.

 

Sorry this post is rather more relevant to previous post............(the most basic problem)

Edited by david c
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Hi Stef

 

Nope. As far as I am aware battery fully charged. 3 readings around 160 and 1 at 100

 

Even change to ring pressure across all 4 at 10psi with a couple of squirts of oil.

 

As stated earlier, checked the head yesterday all valve seats good and holding under leak test.

David said yesterday head not fully tightened down when he removed (did not have stuff with me to compression check etc when I visited as I assumed just a timing issue)

 

Problem is I have not seen with head off but main concern is why the engine was left this way.

 

I think the real aim here is to get the car running and enjoyed.

 

The detail can come later.

 

Steve

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Take the Engine Out,Strip the whole thing down get the Block Cleaned Out properly and Rebuild as you don't know what the previous Owner has done.

Wise words - that's where I am now (but with a TR2 engine).

 

I thought my engine had been rebuilt (it may have been, but not well). It was gradually destroying itself from the inside apparently and finally gave up on the way to/back from the NEC last year.

 

Just back in after total rebuild. Not too much damage though and managed to have the crank reground, but at least I know what is in there is good now.

 

Roger

Edited by Pogo
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At 105lbs ft torque on the 4 cylinder head it takes quite a bit of grunt to pull and so it's unlikely that the threads have suffered stripping (I've never yet found a stripped block thread in over 20 X 4 cylinder rebuilds). I've stripped a deep thread but only when doing "unusual" modifications to the block for racing purposes which caused the problem.

More likely the engine hadn't been retorqued after initial rebuild and the head had relaxed releasing the max pound ages needed.

 

Mick Richards

Edited by Motorsport Mickey
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The reason I suggested looking was because one of my deep bolts has pulled out the thread whilst torquing the head.

Was during rebuild with top quality torque wrench set correctly

Maybe already damaged but think the head had never been messed with before.

I still have to rectify this problem, maybe thread insert

Gary

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Update to my sorry saga.

I did get the engine to fire this afternoon, with a squirt of easy start. I some ways I wish I hadn't. the two seconds the easy start took to burn off was quite enough to convince me that the engine needed major surgery, ominous heavy rumble from the bottom bit. So out it comes, minus the gearbox and overdrive, there is no way I can manhandle that lot out in one even with my shiny new engine crane.

On the plus side at least I will be able to sort out the drain tap.

 

Thanks for all your help and advise, got a feeling I will be back.

 

David

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The reason I suggested looking was because one of my deep bolts has pulled out the thread whilst torquing the head.

Was during rebuild with top quality torque wrench set correctly

Maybe already damaged but think the head had never been messed with before.

I still have to rectify this problem, maybe thread insert

Gary

Gary,

 

Check out the search function, I remember a stripped deep stud being discussed and how to recover it probably about 2 years ago.

Oh me...how did I sort out my stripped thread. Well I had an imminent race (48hrs) so I bought the nearest up size taps from my local engineering shop (16mm )and made an oversize head stud from some steel stock (actually two, one for a spare, still in my toolbox), climbed into the engine bay of my TR 4 with my Black and Decker and drilled out the stud hole the tapping size to suit and tapped it in situ. Opened out the clearance hole in the head screwed the stud into the block, slid the head over the studs, and never had any further problem with it, that was in 1988 and I saw the same engine In the same car with it's new owner win it's race at Donnington in 2014.

Art of coarse TR engineering fixing number 44 in the fabled "double digit" series.

 

Mick Richards

Edited by Motorsport Mickey
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