GT6boy Posted September 18, 2009 Share Posted September 18, 2009 Some of you may remember my old 'go-faster' cylinder head made the supreme sacrifice after a skim too far for the moved waterway casting, the head deformed in the area of the fire ring. Heard from the guy doing the new head- guess what happened today.... :X After lashings of expense on flow-bench gas flow work and new valves etc. final skimming of the head revealed painfull issues about thin castings again. Bugger. Going to see the head on monday and hoping there might be some hope of salvaging the situation. It aint through to the water way, but I fear it wont be far off. The head was an un-skimmed item before at 3.300", and the problem became apparrent when skimming off up to -.068" to get the CR to 10.5. Please forward replies to the window ledge- 'cause that's where I am at present. Link to comment Share on other sites More sharing options...
Clive Posted September 18, 2009 Share Posted September 18, 2009 :'( I hope it can be sorted. Specialist welder?? don't know if that is possible...only wish I could help.Makes you wonder how many modified heads out there are perilously thin in places. Link to comment Share on other sites More sharing options...
GT6 M Posted September 18, 2009 Share Posted September 18, 2009 you haveing a tough time Bruce,Its weired this, but it may no be as bad as he is saying,Marcus Link to comment Share on other sites More sharing options...
GT6boy Posted September 18, 2009 Author Share Posted September 18, 2009 I didn't help myself by not decking the block :B. The pistons are 015" below the block, so had I decked the blocked, this would have helped greatly, but the issues of cost associated with doing that just bump up the potential costs still further.(think) Link to comment Share on other sites More sharing options...
Deleted User Posted September 18, 2009 Share Posted September 18, 2009 you can have my knackered engine Bruce!On a serious note, I hope you can sort it mate! Link to comment Share on other sites More sharing options...
Richard B Posted September 18, 2009 Share Posted September 18, 2009 GT6boy wrote: so had I decked the blocked, this would have helped greatly,(think)Sorry Bruce, but you know it makes sense.... :-/ Link to comment Share on other sites More sharing options...
willcolumbine Posted September 18, 2009 Share Posted September 18, 2009 What an absolute nightmare! I feel for your poor wallet... :'( Link to comment Share on other sites More sharing options...
GT6boy Posted September 19, 2009 Author Share Posted September 19, 2009 I'm still on the window ledge- but the wallet has already jumped.... Link to comment Share on other sites More sharing options...
piman Posted September 20, 2009 Share Posted September 20, 2009 Hello GT6boy,I'm a little puzzled that if it is not through, how the machinist knows that it is thin. Unless the metal gets down to just a few thou it won't be visible. (Did they pressure test it for instance?). 0.068" is not a heavy skim, just over 1\16". You say your last head went at the fire ring, there must have been serious core shift for that, as that area is meant to be solid? If it is as bad as you suspect then it is worth seeing about a weld repair? (Assuming only one spot)Alec Link to comment Share on other sites More sharing options...
GT6boy Posted September 20, 2009 Author Share Posted September 20, 2009 Hi Alec. The mk1 head started as a 3.475" 219016 2500S head and was initially skimmed to 3.300" as it was gas flowed etc to fit my 2 litre engine. This was then skimmed further to increase the CR as irrespective of my having asked the company who did the initial skim and gas flow work, to achive a finish CR of 9-9.5/1, it turned out to be 8.1/1. That's when it became apparrent that the core had shifted horizontally across the head, front to back. This limited the subsequent skim I could achieve. As it turned out, I pushed it beyond that. The mk2 head was a GT6 mk2 head, still at its factory depth of 3.300" It didn't appear to have any such visible core shift issues and the final skim total desired equated to .070" to get a good CR of 10.5/1 to get the TH5 cam to function well. The machinist was alerted that something wasn't as it should be when the cutting tool began to chatter as it was facing the head at .068" and the metal in this area seemed to be 'rippling' (his words). He was skimming a factor of .020" in that particular sweep I believe- i have no idea if that is a reasonable amount to skim in one cut, or perhaps that might have been asking too much of the head to accept in one pass :-/? He needs to see a HG to assess where the thinness is in relation to the clampdown forces around the fire ring. He suspects it may only be a matter of 2-3mm from the fire ring :-/. Regards Bruce. Link to comment Share on other sites More sharing options...
tiggrr1 Posted September 20, 2009 Share Posted September 20, 2009 Bruce you and Rob must have all the bad luck in the Triumph world at the moment :(STEP AWAY FROM THE WINDOW LEDGE THIS INSTANT!!!We need you and your beautiful car around the Triumph world, chin up mate you know it will be great when you sort out the head and burn off Royboy66 (evil) (evil) (evil) Link to comment Share on other sites More sharing options...
JohnD Posted September 20, 2009 Share Posted September 20, 2009 Did you post about this elsewhere?'Coz I'm sure I've posted this rteply elsewhere:Kastner writes in the Preparation Handbook (the 2003 one) an article about "Staking the head" to deal with just this problem. The artilcle is about TR3/4 heads, but the engineering would still apply. If you don't have a copy, he describes drilling the head in the weak area through into the water jacket, tapping the holes and inserting bolts that bottom on the opposite side of the jacket. Cut the bolts down and file flat to the head surface. It worked for him!John Link to comment Share on other sites More sharing options...
GT6boy Posted September 20, 2009 Author Share Posted September 20, 2009 JohnD wrote:Did you post about this elsewhere?John I did indeed John :). I don't have a copy of any of Kas' books, so sadly i'm not familier with the items you mention. Are they online anywhere :-/? Link to comment Share on other sites More sharing options...
GT6boy Posted September 20, 2009 Author Share Posted September 20, 2009 tiggrr1 wrote: ....chin up mate you know it will be great when you sort out the head and burn off Royboy66 (evil) (evil) (evil) That's the only thing that's keeping going! ;D Link to comment Share on other sites More sharing options...
JohnD Posted September 20, 2009 Share Posted September 20, 2009 No, but the principle should be clear.Suggest you discuss it with your machinist.If an ordinary engineer needs to see what an extraordinary engineer did, I'll scan the article for you.Pm me, please.John Link to comment Share on other sites More sharing options...
Royboy66 Posted September 20, 2009 Share Posted September 20, 2009 GT6boy wrote: That's the only thing that's keeping going! ;D(tongue) Link to comment Share on other sites More sharing options...
rotoflex Posted September 21, 2009 Share Posted September 21, 2009 I went looking, it's in his Triumph Preparation HandbookYou can buy it online from him at:http://www.kaskastner.com/kasbooks.htmlThese books are great, & seem to be a cottage printing operation which has nice advantages: 1. the spine is one of those curly things which means the book can open flat, 2. when he wants to make a revision it's simple.The article mentions for that particular application on TR3 & TR4 heads using 8 x 32 x 1 1/14" bolts, being sure the head is flat and the drill doesn't wobble "use a drill press", use a #29 drill, drill the hole down until it bottoms slightly to make a seat for the bolt, tap the hole, coat the bolts with 2-part epoxy, run the bolts down into the seat but don't over-tighten, cut the heads off, put a couple of layers of masking tape around the combustion chamber to keep from marking it, & slowly, patiently, file flat. Link to comment Share on other sites More sharing options...
rotoflex Posted September 21, 2009 Share Posted September 21, 2009 Also Bruce:To reduce the anguish of the present situation and to give your wallet a reprieve, why not try to find a used GT6 head in standard, used condition to slap on so you can enjoy the car while you deal with the issue of the go-fast head?Take a break, order a copy of the Kastner book, wait for it to arrive, enjoy reading it and stealing ideas (it's got nice sections on techniques for port matching, etc. among other things), you can drive the car while you plot your course moving more slowly and perhaps inexpensively (many of the things in the book can be done at home with an electric die grinder, drill press, etc.), and swelter in a fume of muttering about how the car may not be hot right now, but you have something you are working on back at the lab, and when it is finished THEN YOUR GENIUS WILL BE EVIDENT TO THE WORLDIt has always been my belief, developed from observation, that the worst things for these cars is being stationary. If you can build up an improvement off the car and swap it in, that's the way to go. Link to comment Share on other sites More sharing options...
GT6boy Posted September 21, 2009 Author Share Posted September 21, 2009 So here we have it. I removed the thin head material that was covering the area behind the squish wall. Really doesn't look promising :'(/ The work done on the rest of the head is 1st class. The core has definitely shifted for this one waterway. It is only .035" for half the area running anti-clockwise from the hole i've made. Old school welding of entire head would render the whole thing a wobbly blob of financial ruin. Any localised 'electric' welding would have to leave the area in the new hole behind the squich hollow, to allow coolant to pass around the head. All is not lost. Chatting with Roy this afternoon, it became apparent that I could make a fetching pair of earrings out of my 2 redundant cylinder heads.... (whistle) Link to comment Share on other sites More sharing options...
GT6 M Posted September 21, 2009 Share Posted September 21, 2009 Okeedokee, Bruce, As you said all is not lost, As the ..man with the hair told ye,.. :-/ :-/ :)BUT , can you clean up around the hole , and see how thin it gets, the further ye get away frae the hole,reason Im asking, is that a lot of heads, have ..redundant.. water holes, so if this can be made into a redundant water hole, and still have enough ..meat.. for the gasket to seal , then ye may be OKtry and open it up, and get some internal caliers, and see how much ye got to play with,it looks to be a bit away frae the fire ring, regards Marcus Link to comment Share on other sites More sharing options...
Deleted User Posted September 21, 2009 Share Posted September 21, 2009 I am sure the area could be cleaned and Tig welded closed and excess tig weld machined to the head level? Have you looked at Tig? I agree Mig/Arc and Gas will bugger it right up but Tig may do the job with the right welder? Link to comment Share on other sites More sharing options...
heraldcoupe Posted September 21, 2009 Share Posted September 21, 2009 796 wrote:reason Im asking, is that a lot of heads, have ..redundant.. water holes, so if this can be made into a redundant water hole, and still have enough ..meat.. for the gasket to seal , then ye may be OKI was thinking along the same lines. Given the time and money already invested, you don't have much to lose in giving it a go,Cheers,Bill. Link to comment Share on other sites More sharing options...
TimW Posted September 22, 2009 Share Posted September 22, 2009 Hey BruceSorry your having such bad luck If you can send it to me i will get my guy to try and tig weld it for you. If the head is scrap anyway would it not be worth having a go?? Link to comment Share on other sites More sharing options...
GT6boy Posted September 22, 2009 Author Share Posted September 22, 2009 339 wrote:Hey BruceSorry your having such bad luck If you can send it to me i will get my guy to try and tig weld it for you. If the head is scrap anyway would it not be worth having a go?? That's a very kind offer- I may take you up on it! I'm off to see a mate who fettles all sorts of odd problems tomorrow. He is gloriously 'old school' and is one of those fellas that the big boys go to to get there stuff done.... It'll be interested to hear his prognosis. :) Link to comment Share on other sites More sharing options...
TimW Posted September 22, 2009 Share Posted September 22, 2009 ;)GT6boy wrote: That's a very kind offer- I may take you up on it! I'm off to see a mate who fettles all sorts of odd problems tomorrow. He is gloriously 'old school' and is one of those fellas that the big boys go to to get there stuff done.... It'll be interested to hear his prognosis. :) best of luck. If he says it's scrap can i have it?????????(whistle) Link to comment Share on other sites More sharing options...
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