TD21 Head Removal

Having spoken to various people at the Ickworth event this weekend it looks as if I need to take off the head to my 1959 TD21 to clean the water passages and finally stop the overheating.  I was wondering whether there was any advice available on whether to have it converted to unleaded at the same time, the likely costs and recommended companies within reach of Colchester. Posted by Davenall 16/07/2012 15:44:29

Davenall,  If you intend to keep the car it makes sense when the head is off to do a valve grind, new stem seals and to fit the hardened seats. The seat inserts are only put on the exhaust side and the cost of this given the overall cost is relatively small. As part of the process the head should also be crack tested and if necessary machined.   Whilst the head is off it may pay to remove the block core plugs and  give the block a thorough flush. I found quite a lot of detritus behind the plugs and it was a relatively easy task to flush it out.  Also check your thermostat. In Australia  I use a full flow thermostat as it has a bigger opening. A  71C/160F thermostat works well for me.  All the best. RichardWallach Posted by RichardWallach 17/07/2012 09:47:28

for machining and water jacket pressure test, I can recommend ELB engineering at Sudbury (01787 373055). I had some work done on a Jensen 541 engine a couple of years ago which was carried out quickly and correctly without any fuss. PS you may have to dismantle the big bits for yourself. Posted by DaveT 17/07/2012 13:02:30

Hi Andrew,this is a realy rewarding job.I recommend doing it dry rather than a flush out. Remove head and all core plugs you can access.You then need old screw drivers ,wire, good small troches and complessed air. Block any holes you do not want to blow rusty dust into and the bores.Then just prod gentley,blow out dust ,look with torch and repeat untill you fell steel rather than softers cooked rust crud.If like me, you will find the two re cyclinders coated half way up the outside wall ect.You can talk all day kenlow fans ect but untill this is done your head is in the sky and your feet in the boiling watet!!!! Needless to say this is easyer done on the bench but I'm sure can also be done in situ.Good luck, I founy this a realy rewarding job a zero cost ,it cant get any better for a petrol head!!!Regards TOM Posted by TE McK 06/08/2012 17:52:26

Hi Andrew,  After your overheating problems of last year hopefully you are now touring the UK enjoying the Alvis again  Very curious to know the outcome with the work you did as I am in the process of a head off reconditioning on our 1960 TD.  So far with head off have found  Burn inlet valves and badly worn exhaust valve stems, valve are fine but shafts are oversize  3/8" Blown head gasket between 3&4, probably main cause of overheating. (compressions on 3&4 down to  40-50psi ) Rust in No 3 exhaust port?  Rust slag in head and block but not as much as I had expected. Yet to remove the core plugs.  Oily carbon on valves and pistons. (bore is OK) No chance of Zero cost here ( Tom)  At present still trying to figure out the water flow pattern around block & head, read all I could find on water circulation, in The  Story of Red  Triangle  third edition page 418  overheating was finally cured by modifying a TE 21 head.   So any help you or others are able to offer in what should not be overlooked  in returning  TDs to full health &  understanding the cooling system would be most appreciated.  Best Regards John Speight Posted by john speight 23/07/2013 01:51:55

John  I am not the best person to advise you on the movement of cooling water in the block and hopefully one of our technical experts will respond. I have been told several times that water flow particularly around cylinders 5 and 6 was never good.  My engine responded very well to the Rydlyme treatment which you can read about in one of my other posts.   The head has therefore not been removed and she is running well.  Good luck with your work it would be good to hear how it goes  Regards  Andrew Posted by Davenall 26/07/2013 17:52:32

Hi Andrew,  Thanks for reply.  Still amazed the engine ran at all with the excessive exhaust valve guide wear,(1/16" side play)would only idle on 4cylinders in the end though.  Wear on   No1 & 6 exhaust valves guide  was much less, was this because oil is sloshed over these end guides  when braking?      Oil seals had been fitted to exhaust guides as well as the inlets?  Seals will be fitted to inlets only on rebuild. Engineer  mentioned rings might need replacing as there is a lot of burnt carbon on pistons valves, which I would have expected with this rubbish unleaded fuel we have now. With an oil consumption of approx. 1pt per 1000mls and the bores looking good is this necessary yet? and is a ring job  an  engine out or can it be  done in place?  Head has been crack tested and it appears OK now for a porosity test?  fingers crossed as there was rust in exhaust passage on No 4 . Will let you know of progress and hope this thread attracts other interested 3L owners for their  comments, have found a number of posting most helpful. Also have the about to fly off twin floppy windscreen wipers, for when we get Teddy back.    Best Regards John Posted by john speight 29/07/2013 22:38:37