340 Cylinder Head Gasket

I rally a 1.4 340 in the Endurance Rally events.

Last year we entered the Lombard Rally but only managed 4 stages before having to retire due to what we think was a blown cylinder head gasket.

We had no warning signs, the oil and water were perfectly clean etc....

As a result of the problem we destroyed the engine beyond economical repair, a replacement engine has therefore now been fitted which has done around 70K.

My question now is, do you think I should fit a new head gasket before our next event - obviously this donor engine is showing no signs of needing one, I have no history of the engine etc....

So is it a case of "if it ain't broke don't fix it" or would I be wise to change it anyway and avoid the possible disappointment of retiring from another rally ?

My own thoughts are to change it, maybe I just need some reassurance as my mechanically-minded brother-in-law is certainly of the "if it ain't broke don't fix it" brigade, but then again he has never had the humiliation of retiring from a rally after just 4 stages !!!

Any thoughts ??

Many thanks,


Neil

[ivor940]

Hi, Did you flush out the radiator after last head gasket. Possibly the rad was not working at full effectiveness. Did it cool insufficiently, and cause the head gasket to fail when using beyond normal levels of performance.

ivor940

I think that could possibly have been the cause, I have a feeling that it was more a case of overheating caused the head gasket to fail rather than the other way around - either way the donor engine now has all new hoses and a brand new radiator etc.... but should I change that gasket ???

[ivor940]

Hi, Is the 1.4 340 engine related to the Renault engine in Renault 11 etc. They have cylinders liners with seals. If the head gasket is replaced, will there be problems with the cylinder seals. If you have the time & money, do the head gasket if you can confirm from other owners on the forum that doing the gasket does not lead to other problems. Is the cooling fan electric or direct drive? If its electric, fit a bypass switch so fan can be run full time if the engine gets hot and thermo switch does not work. Most head gaskets I have done over the last 35 years were due to cooling system faults causing the head gasket to fail. I do remember one ( can't remember the car) caused by corrosion of head and one Fiat Uno which had a gasket fail on its own.

ivor940

It is the same Renault engine and it does have liners.

What you say makes a lot of sense, oil is clean, water is clean, no sign of overheating, maybe I should just leave alone for now.

I'll see what any other people come up with.

[ivor940]

BTW, does your car have a carb? I used to look after a 1.4 340 which had a regular problem with the carb top loosening. I finally fitted helicoils and new bolts. The problem was fixed. Info passed on in case it could apply to your car.

ivor940

[classicswede]

I would leave alone tbh as the 1.4 has a bag habit of not going back together properly after removing the head. The liners are a bugger for shifting on head removal.

Thanks for that, I think it looks best to leave alone and act on any of the usual tell-tale signs if they ever show up.

[foggyjames]

Yes indeed - leave well alone. Mine has done 187k, and hasn't blown the HG yet!

cheers

James

[pettaw]

The liners don't shift if you remove the head carefully using the procedure in the book to break the seal. You do, however, need to clamp them in place if you intend to turn the engine over with the head off, cos the liners will then shift and if they do, a complete engine rebuild is in order.

Have you stripped the engine down to determine the cause of the failure? How did you confirm it was the h/g that blew and what happened to destroy the engine?

The 1.4s have a habit of overheating and warping the head, causing the h/g to blow. Later ones were much better cos they fitted the large radiator from the 1.7s. Make sure the thermostat and water pump are in good condition and preferably the thermostat is the correct Volvo one cos the temperature range will be accurate.

If you do intend to change the h/g make sure you follow book procedure 100% so you don't dislodge the liners and also get the head measured and if necessary skimmed at an engineering firm.

Hope that helps.