Comments for Thetford Engineering http://www.thetfords.com/blog Experiences in a Vintage and Classic workshop Tue, 20 Mar 2012 08:15:10 +0000 hourly 1 http://wordpress.org/?v=3.3.1 Comment on A Return To The Blog by Pin http://www.thetfords.com/blog/?p=189#comment-54 Pin Tue, 20 Mar 2012 08:15:10 +0000 http://www.thetfords.com/blog/?p=189#comment-54 The bottom line is that with a cylinder head approaching 80 years of age: there is no complete certainty that there will be no further faults. Repairs carried out by welding or stitching specialists are never without some degree of risk but in my experience are very rarely problematic. Internal faults can be hard to find as we experienced with the Bristol, and the cost of repairing these is usually uneconomical. The increasing scarcity and cost of alternative items is an important factor in trying to determine the best course of action. After much discussion with the owner of the car, he decided that repairing the cylinder head was the best option to suit his needs and that the risk is favourably acceptable to him. The lowest risk would have been to purchase a new cylinder head since these are now available for the car, but this is something that the owner wishes to avoid if at all possible on grounds of originality, since the new heads are manufactured in aluminium as opposed to the factory item which is of cast iron. These too are of large expense relative to the car's value and the completed repairs to this particular head have cost around one fifth of the cost of a new aluminium one. The damage to this head is very typical for these cars: Cracked valve seats caused by local overheating and cracks around a guide boss caused by previous careless fitting of valve guides. The small degree of porosity in the top surface which was revealed by pressure testing would almost certainly not have been noticed in service but ceramic sealing was used as a preventative measure. There is no evidence of any previous freezing of coolant which would cause internal damage, although of course one can't easily look inside the casting. I doubt that there are any serviceable second hand heads left for these cars now - believe it or not this was the best item that the owner was able to source in order to replace the one on his own vehicle, which had revealed no less than 14 cracks during pressure testing. This vehicle is in daily use since the owner has no modern car, so the job will certainly be put to the test. I'll keep the blog updated with its progress! The bottom line is that with a cylinder head approaching 80 years of age: there is no complete certainty that there will be no further faults. Repairs carried out by welding or stitching specialists are never without some degree of risk but in my experience are very rarely problematic. Internal faults can be hard to find as we experienced with the Bristol, and the cost of repairing these is usually uneconomical. The increasing scarcity and cost of alternative items is an important factor in trying to determine the best course of action. After much discussion with the owner of the car, he decided that repairing the cylinder head was the best option to suit his needs and that the risk is favourably acceptable to him. The lowest risk would have been to purchase a new cylinder head since these are now available for the car, but this is something that the owner wishes to avoid if at all possible on grounds of originality, since the new heads are manufactured in aluminium as opposed to the factory item which is of cast iron. These too are of large expense relative to the car’s value and the completed repairs to this particular head have cost around one fifth of the cost of a new aluminium one. The damage to this head is very typical for these cars: Cracked valve seats caused by local overheating and cracks around a guide boss caused by previous careless fitting of valve guides. The small degree of porosity in the top surface which was revealed by pressure testing would almost certainly not have been noticed in service but ceramic sealing was used as a preventative measure. There is no evidence of any previous freezing of coolant which would cause internal damage, although of course one can’t easily look inside the casting. I doubt that there are any serviceable second hand heads left for these cars now – believe it or not this was the best item that the owner was able to source in order to replace the one on his own vehicle, which had revealed no less than 14 cracks during pressure testing.

This vehicle is in daily use since the owner has no modern car, so the job will certainly be put to the test. I’ll keep the blog updated with its progress!

]]> Comment on A Return To The Blog by David Dale http://www.thetfords.com/blog/?p=189#comment-53 David Dale Mon, 19 Mar 2012 23:13:44 +0000 http://www.thetfords.com/blog/?p=189#comment-53 I was interested to see the description of the Derby Bentley cylinder head before you decided to put so much time and effort into saving it. With 5 cracks and an area of porosity one could perhaps be forgiven for thinking that trusting this casting to stabilise was a risky venture. My comments are prompted by the fact that I am still smarting from the misfortune that befell me in March 2000 when the cylinder block of my Bristol 403 cracked. Peter and yourself removed the engine and the crack was stitched. Upon replacing the engine, the car covered a couple of thousand miles before a new crack appeared in the block ( between the water jacket and cylinder No. 4 ). Engine out again and the new crack was stitched and engine replaced. June 2000 saw the third crack appear, or more correctly not appear, as we never found out where it was. We had to assume that the crack was somewhere deep in the bowels of the block and, as such, probably inaccessible. The repairs to the first two cracks were still sound and, as the levels of despair were becoming sleep – depriving, we abandoned the block and sourced another with great difficulty and at a huge expense relative to the value of the car. I'm sure that you can explain your faith in this Bentley cylinder head. Having repaired the current cracks and porosity, how can you be sure that the head will be immune to further similar faults ? David Dale. I was interested to see the description of the Derby Bentley cylinder head before you decided to put so much time and effort into saving it. With 5 cracks and an area of porosity one could perhaps be forgiven for thinking that trusting this casting to stabilise was a risky venture. My comments are prompted by the fact that I am still smarting from the misfortune that befell me in March 2000 when the cylinder block of my Bristol 403 cracked. Peter and yourself removed the engine and the crack was stitched. Upon replacing the engine, the car covered a couple of thousand miles before a new crack appeared in the block ( between the water jacket and cylinder No. 4 ). Engine out again and the new crack was stitched and engine replaced. June 2000 saw the third crack appear, or more correctly not appear, as we never found out where it was. We had to assume that the crack was somewhere deep in the bowels of the block and, as such, probably inaccessible. The repairs to the first two cracks were still sound and, as the levels of despair were becoming sleep – depriving, we abandoned the block and sourced another with great difficulty and at a huge expense relative to the value of the car.

I’m sure that you can explain your faith in this Bentley cylinder head. Having repaired the current cracks and porosity, how can you be sure that the head will be immune to further similar faults ?

David Dale.

]]> Comment on A Return To The Blog by Pin http://www.thetfords.com/blog/?p=189#comment-52 Pin Mon, 19 Mar 2012 20:43:14 +0000 http://www.thetfords.com/blog/?p=189#comment-52 Thanks Paul - here's a picture in the next post of some "Proper" cars...... Thanks Paul – here’s a picture in the next post of some “Proper” cars……

]]> Comment on A Return To The Blog by Paul http://www.thetfords.com/blog/?p=189#comment-46 Paul Sun, 18 Mar 2012 20:30:18 +0000 http://www.thetfords.com/blog/?p=189#comment-46 Welcome back to the keyboard Bruv! Welcome back to the keyboard Bruv!

]]> Comment on Vintage Decades by David Dale http://www.thetfords.com/blog/?p=174#comment-21 David Dale Thu, 29 Sep 2011 22:26:44 +0000 http://www.thetfords.com/blog/?p=174#comment-21 >>The sort of complexity which I don’t enjoy is the type which has no benifit for the consumer whatsoever>> Couldn't agree more. A good example is my 2006 Toyota Yaris. Perhaps someone could explain to me why I have to depress the clutch to allow the starter motor to be operated. Why cannot I be trusted to engage neutral before starting the engine ? Needless to say, the cutout switch eventually developed a fault and the car wouldn't start at all - this is progress I suppose. If the fault had cropped up when my car was stalled on a level crossing with the train approaching things could have been interesting. The cutout switch has now been bypassed and, strangely enough, I have not yet attempted to start the car in gear. Back to normal then. >>If someone can tell me what’s wrong with a switch to control the washers I would be very grateful>> My 1953 Bristol 403 w/screen washers were originally operated by the vacuum from the inlet manifold. Problem was that the water hit the screen about a decade after the switch was operated. Thetford Engineering offered me various replacement options. I adopted the well - tried KISS principle ( Keep It Simple Stupid ). I chose a piston in a cylinder located below the dashboard which, when I push the plunger, sucks fluid from the remote resevoir and delivers a healthy splash onto the screen. Fitted years ago and I am still trying to fault it. It works ! David Dale. >>The sort of complexity which I don’t enjoy is the type which has no benifit for the consumer whatsoever>>
Couldn’t agree more. A good example is my 2006 Toyota Yaris. Perhaps someone could explain to me why I have to depress the clutch to allow the starter motor to be operated. Why cannot I be trusted to engage neutral before starting the engine ? Needless to say, the cutout switch eventually developed a fault and the car wouldn’t start at all – this is progress I suppose. If the fault had cropped up when my car was stalled on a level crossing with the train approaching things could have been interesting. The cutout switch has now been bypassed and, strangely enough, I have not yet attempted to start the car in gear. Back to normal then.
>>If someone can tell me what’s wrong with a switch to control the washers I would be very grateful>>
My 1953 Bristol 403 w/screen washers were originally operated by the vacuum from the inlet manifold. Problem was that the water hit the screen about a decade after the switch was operated. Thetford Engineering offered me various replacement options. I adopted the well – tried KISS principle ( Keep It Simple Stupid ). I chose a piston in a cylinder located below the dashboard which, when I push the plunger, sucks fluid from the remote resevoir and delivers a healthy splash onto the screen. Fitted years ago and I am still trying to fault it. It works !
David Dale.

]]> Comment on Cars arriving and leaving by Pin http://www.thetfords.com/blog/?p=159#comment-20 Pin Fri, 16 Sep 2011 18:50:04 +0000 http://www.thetfords.com/blog/?p=159#comment-20 Thanks Daryl - glad to hear that all is going well! I shall definitely be posting about the MKII steering conversion when it happens, since I think that the only alternative would be to blog about Cherine's impending repetitive strain injury from all the shunting in Waitrose car park.... Thanks Daryl – glad to hear that all is going well! I shall definitely be posting about the MKII steering conversion when it happens, since I think that the only alternative would be to blog about Cherine’s impending repetitive strain injury from all the shunting in Waitrose car park….

]]> Comment on Cars arriving and leaving by Daryl http://www.thetfords.com/blog/?p=159#comment-19 Daryl Fri, 16 Sep 2011 10:30:19 +0000 http://www.thetfords.com/blog/?p=159#comment-19 The Scim did look fantastic when I picked it up on Wednesday. Thank Cherine from me for her hard work. The clutch and throttle are really smooth now, makes driving so much more pleasant. Good luck with the TR6 and let us know how the power steering conversion for the MKII goes. The Scim did look fantastic when I picked it up on Wednesday. Thank Cherine from me for her hard work.
The clutch and throttle are really smooth now, makes driving so much more pleasant.
Good luck with the TR6 and let us know how the power steering conversion for the MKII goes.

]]> Comment on More Ford Type 9 Conversion by Daryl http://www.thetfords.com/blog/?p=84#comment-18 Daryl Fri, 29 Jul 2011 16:51:51 +0000 http://www.thetfords.com/blog/?p=84#comment-18 Crispin the adapter plate looks fantastic. even my wife was impressed. Would be good post a link your blog on the Scimitar forum. Fancy doing a few more plates? Crispin the adapter plate looks fantastic. even my wife was impressed.
Would be good post a link your blog on the Scimitar forum. Fancy doing a few more plates?

]]> Comment on Comment Spam and Cars by Pin http://www.thetfords.com/blog/?p=45#comment-12 Pin Wed, 13 Jul 2011 22:12:35 +0000 http://www.thetfords.com/blog/?p=45#comment-12 Given that the promise from the manufacturer was, "Grace, Space and Pace", I'm a little worried that I may start to be offered speed on that premise! Given that the promise from the manufacturer was, “Grace, Space and Pace”, I’m a little worried that I may start to be offered speed on that premise!

]]> Comment on A Dart in France by Ben http://www.thetfords.com/blog/?p=36#comment-11 Ben Tue, 12 Jul 2011 23:32:13 +0000 http://www.thetfords.com/blog/?p=36#comment-11 What a lovely example of both beauties! Great blog, Pin, I am *amazed* you have time... also, will be referring my missus to Cher's regarding present choices - remarkable! What a lovely example of both beauties! Great blog, Pin, I am *amazed* you have time… also, will be referring my missus to Cher’s regarding present choices – remarkable!

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