head gasket failed TR3a - advice

[Lynx]

Good morning!

The head gasket on my 1960 TR3a failed on Friday and I now have sludgy white oil. What's the best procedure to clean the engine of the fouled oil and the correct steps to rebuild please?

Flush the cold engine now (if so how?) or wait until I've replaced the head gasket etc. run the engine with flushing oil (cheap 20 W50 perhaps?) after replacing the gasket and then drain and fill with good oil?

Any advice most gratefully received

Many thanks

Andrew King

Swanage

Engine TS75430

Chassis TS75982L (converted to RHD)

[Fireman049]

Hi Andrew ~

 

Yes, replace the head gasket then drain the old oil and fill up with flushing oil and run

for some time to make absolutely sure that the engine is thoroughly cleansed.

Drain and refill with fresh oil. Don't forget to change the oil filter.

 

This may be a good opportunity to decoke the head and regrind the valves.

If you're going to remove carbon deposits from the piston crowns only remove the centre portion

and leave the carbon nearest the cylinder walls. This will prevent oil burning.

 

Tom.

 

PS: I'd be inclined to fit a copper head gasket as I did on my 3A.

Edited January 25, 2016 by Fireman049

[Alec Pringle]

First priority is surely to establish WHY the head gasket has failed . . . . . .

 

Cheers

 

Alec

[stillp]

 

If you're going to remove carbon deposits from the piston crowns only remove the centre portion

and leave the carbon nearest the cylinder walls. This will prevent oil burning.

 

 

Tom, I know this is often advised, but I can't see what difference it would make, unless the carbon on top of the piston were to make a better seal than the rings? Leaving a ring of carbon around the top of the pistons might help reduce the amount that goes down between the piston and the liner, but I think I'd either remove it all or leave it alone.

 

Pete

[Don H.]

First priority is surely to establish WHY the head gasket has failed . . . . . .

 

Cheers

 

Alec

 

+1 on this.

[Ian Vincent]

First priority is surely to establish WHY the head gasket has failed . . . . . .

 

Cheers

 

Alec

What are the reasons for head gasket failure apart from overheating or the liners (or one of them) not protruding far enough out of the block?

 

Rgds Ian

[Don H.]

What are the reasons for head gasket failure apart from overheating or the liners (or one of them) not protruding far enough out of the block?

 

Rgds Ian

 

Overheating is probably the leading cause of head gasket failure. That in itself has a number of potential root causes that should be addressed when the gasket is replaced.

 

Detonation or engine knock is another possible cause, and one that could have a number of underlying causes.

 

There are undoubtedly more -- but either one of these could make a repair short lived if the root cause isn't addressed.

[Motorsport Mickey]

You gotta trust your eyes,

 

Have you carried out a compression check ? helps to pin the area for looking for gasket failure. I trust you didn't run far after you realised a head gasket had gone ? If not some other info is needed, how long since the engine has been rebuilt ? It may be that if the liners haven't been out for a dozen years that you will wish to remove them (in situ) and clean out the crud from the water jacket around the liners, worthwhile in service attention. I should be wary of just replacing the head gasket and warming the engine to help remove oil, if the bearings are in decent condition why expose them to more water contamination and possible damage?

 

My recommendation put car on stands or ramps, strip engine down after draining oil and water and find where the gasket has blown. This will start to give you clues and the reason why, remember No4 liner runs hottest, (furthest from water pump therefore water is hottest before arriving and removes less heat ) then No 1 second hottest (closest to the water pump so the water goes too fast past it and removes less heat) then No 2 and No 3 liners which will be about the median temperature which the engine runs at.

 

Your description of sludgy white oil can be arrived at two ways, the liners seal can fail at the top at the head gasket or the bottom on the Figure of 8 gaskets. If the engine has been together since Jehovah used to drive it it's possible the intervening 50 years and multiple hot/cold applications has allowed the block to relax and the liners to "lean" or the cylinder block top surface to lift at the rear of No4 liner (remember it runs hottest), which reduces the liner height above the cylinder surface and therefore the clamp of the gasket causing it to blow there. This area needs examining intently, it's not an uncommon failure point. Also check the top surface of the pistons looking for which one is cleanest, water ingress does a good job of scouring the top surface (it will have likely been leaking in over hundreds of miles before blowing) and cleaning the piston up. Also check around the gasket sealing edges looking for traces of the water or gas travel causing a blow.

 

Enough for now, report back when you have access and can describe better which has occurred. Oh...when you remove the cylinder head clamp the liners down (tube or old gudgeon pins and large washers covering both liners where they Siamese.) so they don't move whilst you are carrying out any engine turning over which maybe needed.

 

Mick Richards

Edited January 25, 2016 by Motorsport Mickey

[Lynx]

Thank you one and all for your comments and advice. I've had the TR3 for a couple of years. She was restored in the 1990's and then SORN'd around 2007 or 2008 and subsequently only had occasional years when she was on the road. Total miles sine the restore and rebuilt engine is less than 10000. I've had her on the road for two years adding only a 1000 or so miles. She's always run slightly on the cool side and has a Kenlow fan. I've had fuel starvation and cutting out problems during my ownership (hence the low miles as I couldn't trust her to get me home!). Just had the mechanical fuel pump restored by David Davis (excellent job!) and was going to fit this in place of the suspect SU pump. Checking cylinder pressures all seemed well last autumn but No1 plug/cylinder always ran very sooty and I had to use No2 with the colour tune. Possible problem here leading to gasket failure I wonder?

Thanks again for your comments.

Andrew

[Lynx]

^Mick,

^{Thank you for your detailed response. It makes me a little apprehensive of what I might find and the need to proceed with caution. I'll have to read-up on the liners and figure of eight gaskets. It's 40 years since I had a head off and replaced a gasket etc. that was on a Spitfire and I was young and gung-ho and just got on and did the job never a care about liners rising etc.}

^{I'm going skiing soon and also have to go to Nottingham next week (and again in March) to support my elderly father who is not well (me and my siblings take it in turns to be with him) so I may not be able to get the head off for quite a while. Mean time I'll do the research and when I get the head off I'll get back with my findings.}

^{Thank you}

^Regards

^{Adrew King}

[Motorsport Mickey]

No problem Andrew, if you can't attend to the TR for a while see if you can at least drop the water out of it to limit any water ingress through the engine.

When you can strip down and advise what circumstances there are with gasket etc any liner and cylinder head gasket problems can be attended to, just a question of identifying and deciding best method. Send me a PM (Personal Message) if necessary for further discussion and advice, click on my Avatar picture and click send a message.

 

Mick Richards

[Lynx]

Took the rocker cover off earlier and discovered three displaced and bent push rods! Three push rods have become dislocated from their rocker arm cups - how on earth does that happen? Looks like this might be a bigger job than anticipated.

Andrew

[Rob Salisbury]

Valves seized in their guides, maybe? Had the head got really hot before the gasket gave up?

Cheers Rob

[Motorsport Mickey]

Carefully unscrew the rocker pillar nuts and let the shaft and rockers slide up the studs, you may have a broken rocker shaft which would possibly explain why you've had some rockers jump the pushrods. If the pushrods contacted on the edge of the pushrod cup it's possible it's pushed the valves down too far and maybe impacted the piston (lets hope not !).

Sometimes you just have to strip and examine and let the circumstances explain themselves, don't try and jump to a diagnosis yet until you get further into it.

 

Mick Richards

[Nick Jones]

Not a wet liner engine expert...... but I seem to be seeing phosphor bronze valve guides and tubular push-rods (spot welds near the top) - are these standard features?

 

All looks pretty clean - has been apart before not that many miles ago IMO.

 

Nick

Edited January 27, 2016 by Nick Jones

[Motorsport Mickey]

"Phosphor bronze valve guides" (often fitted)and tubular push-rods (spot welds near the top)is a standard feature.

 

Mick Richards

[Lynx]

Got the head off today. The head gasket has NOT failed or at least I cannot see any evidence of failure. Fortunately there's no evidence of valves being pushed into the pistons. All valves can now be pushed open and snap shut. The exhaust valve on #3 was stuck but yielded to a sharp tap. This was one of the dislodged/unseated and bent push rods. I wonder if the engine seriously overheated before I realised; there was very little water left in the engine today. The oil is definitely very milky; where would the water have got in? Incidentally none of the head nuts had washers; some are shown in the Moss catalogue. . I guess the next step is engine out and open up the bottom. Perhaps I will get that crankshaft end seal leak fixed! Getting the engine out will have to wait a while I've gone as far as I can before family visits and a holiday. Also need to hire a hoist.

I've attached some pictures and will post another message as I can only get two per message.

Thanks

Andrew

[Lynx]

Additional pictures . . .

[Lynx]

. . .and two more . .

[Don H.]

Around here, there's almost *always* someone with a hoist that one can borrow. There's a guy in our club who has one that I'm not sure has been home for years -- he's just as happy not to store it. Put the word in the local group or your neighborhood out before you hire one.

[peejay4A]

If the water didn't get into the oil through a failed head gasket that leaves the figure of eight seals as prime suspects.

Edited January 28, 2016 by peejay4A

[Alec Pringle]

Hi Andrew,

 

if you're not too far from Mere you can borrow my hoist and engine stand for a week or two . . . .

 

Cheers

 

Alec

[Motorsport Mickey]

I should do a little more stripping before deciding what to do, it could save you a lot of work. When you're back from holiday drop the sump and see what the bottom end looks like, even take a mains (centre cap) off and the conrods to see what the bearings are like.

 

Could be the Figure of 8 gaskets at the bottom of the liners have gone and caused the water ingress, don't forget to remove the head gasket and secure the liners with washers to prevent them lifting, then measure them from block to liner top looking for that 3-5 thou liner height across all the liners. Check them in 4 positions around the liner, you'll then be in a much better position to decide what to do.

 

Mick Richards

[ChrisR-4A]

Hi Andrew, two things will allow the pushrods to jump off the rockers, one is a sticking valve, which you had and the other more common is build up of crud on the rocker shaft allowing a rocker to stick which leaves the pushrod top end floating in air so it falls away from the rocker ball.( ive been there)

Check the rocker shaft when its off by pushing each rocker along the shaft past where it normally runs and see if it goes tight. The other item of concern is no washers under head nuts, this would cause huge ammounts of friction when tightening and make correct consistent torque settings very difficult. Best of luck with getting it sorted.

Regards Chris

[stillp]

Could it just have been over-revved? I've known that cause bent pushrods on a B-series engine.

 

Pete