Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) 1956 Plus 4 Tr4 Head off

Cant help but think that to just bung in a new gasket and hope is not the right way to go. Gaskets dont fail without a contributing factor, and its quite easy and not expensive to get a head checked for flatness and cracks. Likely there is a local engine machinist in the nearest big town who can do just that for you. If then there was no problem with the head and bearing in mind what others have said about the liners, I would have the engine out. Again it isnt a big issue having gone as far as removing the head anyway.

Stick the head back on and hope might work but most likely in my experience wont work.

The driving factor here will be cost to repair. I remember years ago, we'd go to numerous lengths to get the car running again as we simply needed it to get to work and back every day. This is one reason why older cars and bikes seem to have suffered such massive bodges and neglect.

These days, not only are they now in the hands of caring owners, but those caring owners have spare cash and time to do the job like it should be done, the end result being they become 'enthusiasts' or car fanatics and the world of specialists blossoms again.

If money is tight, you'd stick something together and sell it on pretty darn quickly..! When I was younger and the family were all pre-school, the MoT was something you used to treat like a visit to the dentists. I've thrashed nails down kingpins just to get that twelve month ticket, and made sure we could get to the shops the next day.

I digress. Good luck whatever, Rob.

Rob

As an addendum to my earlier post I would look very carefully at the new head gasket you use, and ensure you don't have any small areas protruding into the bores. It is difficult to see from the photos but the old one does appear a trifle marginal in a couple of places.

The TR engine came in 2 bore sizes for 1991 and 2138 capacities , and the head gaskets were different at the time , they have probably been amalgamated by now and only use the bigger bore diameter one. It probably wouldn't cause overheating , but it will cause pre-ignition.

great advice will get my vernier out and measure bore diameter ...then Im thinking a steel gasket as is needing less height from the liners?

Not convinced that a steel shim gasket will work any better. In fact trying to seal both the oil and waterways could prove more difficult than using the standard type gasket.

From what you have said my feeling is that the problem is one or more of the following causes: corroded area in the bottom of the block where the wet liner seals sit, faulty fitting of the seals, insufficient protrusion of the liners above the block face (from recollection 4 to 6 thou, but check the Haynes manual), a sub-standard head gasket or incorrect torqueing of said head gasket. Sorry to be so disheartening.

I'm not an engineer but have rebuilt two TR engines in the last few years using the Haynes manual. Luckily there is a motor engineers in Bridgwater who do engines for Revingtons and are familiar with TRs. In both cases they cleaned the blocks and set the liner protrusions. Expensive, but worth it.

So, the choice is to remove the engine, strip it and take the block and liners to a reputable motor engineers or you could have a go at it in situ. If you choose the former, it's recommended that you remove the gearbox first or risk bending the front propshaft/jackshaft when trying to wiggle the engine out. Having a go in situ could be worth a punt providing you don't mind lying on your back under the car removing the sump, oil pump, conrod bolts etc, popping the pistons out and then hoping that the wet liners will come free. Incidentally, one of the TR suppliers stocks the wet liner bottom seals (known as figure of 8 seals) in two different thicknesses which could give you the correct wet liner protrusion if the liners are currently level with the block face.

As advised, use Wellseal on both the figure of 8 seals and the head gasket. It's horrible messy stuff but excellent.

I feel for you.

Tony Quinn

Sounds like good fun to me. And an interesting challenge.

Get the engine out and do the job properly. Do it right and do it once.

A few more thoughts after having slept on it.

Is the oil milky or otherwise showing traces of water? You might be able to ascertain this from looking at the dipstick or draining the sump. If the oil looks OK, then the figure of 8 seals at the base of the wet liners may well be OK. If so, re-check the protrusion of the liners using the edge of a good quality metal ruler across the liner and try to insert 3 to 5 thou feeler gauges between the ruler edge and the block, but check the Haynes or Triumph manual for the correct figure. If they do protrude a little you might get away with replacing the head gasket, but it's worth buying a good quality one from a reputable source.

The tightening sequence is in the Haynes manual too. The correct torque figure is 105 ft lbs! Yes, really. It's possible that whoever rebuilt the engine may not have torqued the head nuts to the correct figure as it seems unreasonably high. You'll need a good quality accurate torque wrench. Not sure if it's the correct procedure, but I tighten in three 'circuits' of the nuts: approx 60 ft lbs, then about 85 ft lbs, then 100 to 105 ft lbs. always clean and lubricate the threads and nuts with an appropriate gloop, available in small sachets on eBay or, failing that thin oil such as 3 in 1.

If there is no protrustion, you might consider removing the liners and fitting thicker ones. Revington TR sell them in different materials and three thicknesses, see https://www.revingtontr.com/product/112789cu/name/figure-8-gasket-copper-0018

I have found Revington to be very helpful on the phone in selecting the correct product.

If the engine hasn't done many miles the liners may well pop out by turning over the engine. Otherwise they can be tricky, but worth a try.

All the best,

Tony Quinn

I replaced liners and pistons with +4 on jack stands. Crank shaft still in place. Liners can be driven out from the bottom. I used a piece of ash and knockoff hammer to drive them out. Make sure the surface for the figure 8 gaskets are squeaky clean.

Not sure if this is easier than pulling the engine.