Where to Buy Cylinder Head Crack Detection Spray

J and E Engineering Services.

Unit 32, Britannia Mill.

Stoneholme Road,

Crawshawbooth,

Rossendale,

Lancashire.

BB4  8BA

Excessive overheating or extreme freezing are two scenarios that can cause fractures in cylinder heads and cylinder blocks. These fractures can be seen on the surface or they can be inside a casting invisible to the naked eye. This is why it is important to have these components tested. There is no point in using the best parts and spending good money on rebuilding a head or engine only to find there is an underlying fault in one of the main components after completing the job.

Here a hairline fracture can just be made out on the gasket face of this Triumph Stag cylinder head. This is a bad place for a fracture as it leads from a water way into the high stress combustion chamber. This crack was identified by pressure testing and could then be repaired by aluminium welding. This type of crack could be internal and therefore impossible to see without the aid of a pressure test.

This block had cracked all over the deck, some big and some small. Here is an image of two large cracks between a cylinder head stud hole and the cylinders. Again a high stress area. This type of crack would open up when the cylinder head stud was fitted and tightened.

Eliminate any uncertainty and have your blocks and heads pressure tested.

Magnaflux testing is our non-destructive magnetic crack detection method. The iron cylinder head or block is prepared by coating with a contrast layer. The magnet yoke is then placed on the part and magnet turned on. We then apply very small magnetic particles from an aerosol and turn off the magnet. Any cracks or flaws can then be seen as the part is inspected. Cracks will cause a break in magnetic field which will show up as the small magnetic particles disperse around this break in magnetic field. Once identified cracks can be repaired by either welding, metal stitching or replacing a valve seat or cylinder liner for example.

Indications that a cylinder head or block may be cracked are:

Engine oil in coolant radiator or header tank.

Coolant loss via exhaust.

Coolant in engine oil.

Overpressure in cooling radiator or header tank.

External coolant leaking.

Overheating.

Unexplained coolant loss.

Emulsified engine oil or coolant.

Some cylinder head or block cracks will only open up and become apparent during running. This is why it is important to test castings at temperature.

This is our Newclear 150 pressure testing machine. This is where we test cylinder head and block castings using internal air and hydraulic pressure up to 8bar. This is as close as it gets to simulating the actual temperatures and pressures that your cylinder head or block will encounter during service. Baring in mind that the average cooling system pressure when hot would be no more than 1.5bar. Air test is carried out first as part of a multi stage pressure test. The cylinder head or block is placed on the machine and all of the cooling passages are blanked off using rubber fittings. A thick Plexiglas plate is placed on top of the part and tightened to hold the rubber blanking plugs in place. The Plexiglas plate allows us to see the cylinder head gasket face and combustion chamber areas during testing. The part can also be rotated on the machine where the inlet and exhaust ports, valve spring areas can be monitored and checked for flaws. The second part of the test is a cold hydraulic test. The head or block is filled with water and then pressurised while  the part is monitored. A leak or flaw is identified by leaking water and drop in pressure as indicated on the gauge. The final operation is a hot hydraulic test where water is heated and then pressurised. Any leaks are identified by a pressure loss indicated on the gauge and water leaking from any fractures or porous areas.

Here you can see a "C" series cylinder block taken from an Austin Healey 3000 undergoing magnaflux crack detection on the head face. Although the block turned out to be crack free you can clearly see a tiny gap around a portion of the cylinder liner. These liners will be removed and replaced with either a flange or stepped liner.

Our Pressure testing machine in operation. Click to view the video.

In this video you can see an old side valve block from the 1930's mounted on the pressure testing machine. The first air test indicated a pressure leak at around 40psi and although we could hear air escaping we could not see the problem area. We then conducted a cold water hydraulic test as seen in this video. The leak became apparent immediately right at the bottom of the water jacket inside the crankcase. The problem is simply corrosion inside the coolant passages inside the cylinder block due to corrosion inhibitors (anti-freeze) not being used throughout the engines life. This corrosion has made the metal very thin to the point where it has rotted through. This test saved our customer the time and money in rebuilding his engine using this cylinder block. If he had proceeded without testing, the first thing he would have noticed would be a sump full of oil and water and the whole engine rebuilding process would need to be repeated…..

Where to Buy Cylinder Head Crack Detection Spray

Source: http://www.jandeengineering.co.uk/crackdetection.html

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