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MG MGA - Experience with new cylinder head
After spending a small fortune to get a cylinder head reconditioned, I am now back to square one - a cracked cylinder head.
My MGA 1600 cracked a cylinder head last fall, during the winter I found a good neat cylinder head from an MGB, after pressure testing, the cylinder head was restored with new Stellite valves, bronze guides,seats etc..
The first time the engine was started - after the installation of the cylinder head, the water began to dripping out of the now visible cracks on the outside of the cylinder head between the cylinders 2 and 3 - Very frustrating!
I have been looking for a new cylinder head that could be suitable for renovation, I have also found a couple of piece - but they proved sadly also to be cracked.
I have seen that it is possible to buy a new manufactured cast iron cylinder head:
It is probably produced in India?
Does anyone have experience with the cylinder head - is the processing and quality OK -it is worth the money?
Or should I rather buy a twice as expensive aluminum cylinder head?
Experiences and tips are greatly appreciated!
|Ivor Searle is a UK manufacturer.|
Comes with a warranty - pretty neat that someone still makes them!
|I bought a Pierce Manifolds assembled alloy head thru a regular seller on Ebay in the US. A tail of woe followed. Firstly it didn't come with the oversize valves as advertised (seller refunded me cost of valves - a big help not!) When I installed on my car I had no compression - found inlet valve seats not cut properly. Valve clearance in the guides was too tight (needed a light tap with a hammer/dolly to removed). Spring caps and valve collets were cut at different angles. Oil retainers where only the basic O ring on the valve stem. Stud holes were not countersunk to depth of first thread so thread lift didn't effect sealing.|
After having all these defects fixed at my expense - $A400 - the cylinder head has now been in operation for 2 years without any issues. Reseller refused to pay any compensation - said he had never had a problem in the past - because of shipping cost back to the US and need to get my car back on the road I elected to wear the costs.
If buying an alloy head I suggest you inspect before you buy.
While not the sort of thing I usually recommend, I know of at least two cars which have been running for 20 years with such cracks, without problem. One of them is cracked from #2 exhaust spring seat all the way down through the center of #2 plug hole.
Put some stop leak in it and drive.
I have had best results with the sort of stop leak that is a silver or black/grey powder; Aluma Seal, Silver Seal, etc here. Or ground black pepper works too - really! I use about half the tube, or a couple teaspoonsful.
|Or just buy a head outright from Peter Burgess in the UK, he advertises on this site and has a reputation without equal.|
|Irontite, Chemiweld and Bars-leak have a good record in Oz for emergency repairs. Irontite is highly recommended.|
|There are many successful methods for repairing heads. I had a flathead head brazed some 45 years ago. Today they can repair by either brazeing, SS welding, pinning....and more. Find a reputable local engine/machine shop, have the head crack tested and ask them for recommendations. I would go that route rather than adding any stopleak/alumaseal/irontite if the crack is contained to the water jacket.|
But honestly, buying a used head may be more cost efficient. Just have it crack-tested BEFORE you transfer the $$.
Here is a website on MGB head cracks and what might be repairable: http://www.flowspeed.com/cracked.htm
|The machine shop that did my seats and guides, refused to do any other work to it before they had magnafluxed it. Considering the propensity for cracks in these heads, that seems like a good policy.|
|I would caution against using any of the so-called "stop leaks", unless in an emergency. They are designed to block small passages, holes and cracks in the motor and so, by their very nature, they will also block your radiator! Voice of experience!|
|I do not know why you chaps are having so much trouble with cylinder heads. I have owned several MGA's over the last 40 years (I still have two 1600's, a coupe and a roadster) and, while they definitely have a propensity to overheat, I have largely overcome this by having the radiators flushed out every four or five years. Are the cracked cylinder heads the result of overheating?|
|Mine was the fault off a failed heater valve diaphragm and then inattention to the temp gauge! - inspection after the failure showed that there had been two earlier repairs to the head. |
This thread was discussed between 20/04/2012 and 22/04/2012
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