Guppy916 Posted December 30, 2013 Share Posted December 30, 2013 merry christmas and a happy new year guys, I am trying to trace an engine number I have just purchased a GT6 Mk3 1973 with a 2500 engine I think, can anybody help me The engine number is MG 8631 EBW, I would like to know the year and any other details, also I live near Farnham Surrey is there any body that can recon my cylinder head to unleaded, I have just spoken to Rimmers their recon head is no longer available.thanks Quote Link to comment Share on other sites More sharing options...
andy thompson Posted December 30, 2013 Share Posted December 30, 2013 1970 mk2 2500PI block "132bhp" - if it's still original it might have a cross drilled crank. Of course it might be a rebuilt engine and have a 2000 crank and who knows what else Quote Link to comment Share on other sites More sharing options...
Guppy916 Posted December 30, 2013 Author Share Posted December 30, 2013 Thanks Andy, When i take it apart I will check the crank then, It's in for a rebuild I intend to rework the head, lighten and balance crank,rods, pistons, flywheel, etc add a fast road cam and a pair of 40 DCOE's, I just need to find a inlet manifold first, I then hope it will ready for the road early summer, one more small thing the body needs to be refitted on the chassis. Do you know if this engine is the same as a Mk3 GT6 unitthanks Georgehappy new year old chap Quote Link to comment Share on other sites More sharing options...
TedTaylor Posted December 30, 2013 Share Posted December 30, 2013 lagerzok wrote:1970 mk2 2500PI block "132bhp" - if it's still original it might have a cross drilled crank. Of course it might be a rebuilt engine and have a 2000 crank and who knows what elseI stand to be corrected on this Andy but as far as I was aware only the Mk1 2.5PI engines with a CR prefix which were based on the TR5 engine had a cross drilled crank and were the 'long back' type (larger/deeper 'boss' to carry the flywheel). The TR 250 engines which went to the States were 'long back' type but apparently not cross drilled and are subject to far less wear due to the de-tuning perpetrated on them - I have one of them many thanks to Mark Swingler to rebuild into my Mk1 PI estate because the correct cross drilled long back cranks are like hen's teeth and this crank has minimal wear (to all intents and purposes standard).Mind you if a good cross drilled 'long back' crank came my way for sensible money I would use it but purely for originality because the cross drilled cranks apparently are subject to considerable wear like the one at present in my estate.The Mk2 PI I always understood had the 'common' non cross drilled 'short back' crank based on the TR6.The Mk1 PI engine with the C prefix must not be confused with the later (1973ish?) TR6 engine with the C prefix which is a different unit (and confusing :-/)I am always pleased to be proven wrong in the interests of accuracy and extending my personal knowledge.MUT Quote Link to comment Share on other sites More sharing options...
andy thompson Posted December 30, 2013 Share Posted December 30, 2013 Ted - you are wrong - no hard feelings but the first Mk2 PI and equivalent TR6's had a short back x- drilled crank - I have one at the machine shop.No idea when they were stopped but it's around MG 8500 - I think very early (68?) TR6's had the long back btw.Oh and on the original question - all the blocks are the same but a 2.5 has a deeper sump or a 2000 one with dents Quote Link to comment Share on other sites More sharing options...
andy thompson Posted December 30, 2013 Share Posted December 30, 2013 1526 wrote:I stand to be corrected on this Andy but as far as I was aware only the Mk1 2.5PI engines with a CR prefix which were based on the TR5 engine had a cross drilled crank and were the 'long back' type (larger/deeper 'boss' to carry the flywheel). The TR 250 engines which went to the States were 'long back' type but apparently not cross drilled and are subject to far less wear due to the de-tuning perpetrated on them - I have one of them many thanks to Mark Swingler to rebuild into my Mk1 PI estate because the correct cross drilled long back cranks are like hen's teeth and this crank has minimal wear (to all intents and purposes standard).Mind you if a good cross drilled 'long back' crank came my way for sensible money I would use it but purely for originality because the cross drilled cranks apparently are subject to considerable wear like the one at present in my estate.The Mk2 PI I always understood had the 'common' non cross drilled 'short back' crank based on the TR6.The Mk1 PI engine with the C prefix must not be confused with the later (1973ish?) TR6 engine with the C prefix which is a different unit (and confusing :-/)I am always pleased to be proven wrong in the interests of accuracy and extending my personal knowledge.MUTI heard that one of the reasons for the x-drilled cranks wearing was they are very susceptible to poor servicing and sludging in the oil ways - this wipes out the bearings and crank pins - when they were old smokers and fuel was in the process of going from 25p to a quid and oil was poorer they got thrashed to death Quote Link to comment Share on other sites More sharing options...
DJB_Harvey Posted December 30, 2013 Share Posted December 30, 2013 You learn something everyday I didn't know the early PI Mk2 engines had a X drilled crank .Hmm ... And I know where there's at least 2 H Reg scrap PI's :) Quote Link to comment Share on other sites More sharing options...
Ridgetone Triumph Posted December 30, 2013 Share Posted December 30, 2013 I think they were using up all the x drilled cranks to get rid of them so some of the early PI MK2's draw the short straw :-/ Hmm maybe??? Quote Link to comment Share on other sites More sharing options...
andy thompson Posted December 30, 2013 Share Posted December 30, 2013 That kind of makes sense - The part number is cast in - is it the same on long back and short back? Because you can make a short back from a long back with a lathe and drill Quote Link to comment Share on other sites More sharing options...
mikeyb Posted December 31, 2013 Share Posted December 31, 2013 DJB_Harvey wrote:You learn something everyday I didn't know the early PI Mk2 engines had a X drilled crank .Hmm ... And I know where there's at least 2 H Reg scrap PI's :)My Mk1 PI (ex RichardB) is engine-less, might be interested in acquiring one (engine) if available? I picked up a very early Mk2 block a few years back (MB11HE), this apparently was also originally fitted with a X-drilled crank, but had been long since junked by the time I got it :-/ Quote Link to comment Share on other sites More sharing options...
Ridgetone Triumph Posted December 31, 2013 Share Posted December 31, 2013 MikeyB wrote:My Mk1 PI (ex RichardB) is engine-less, might be interested in acquiring one (engine) if available? I picked up a very early Mk2 block a few years back (MB11HE), this apparently was also originally fitted with a X-drilled crank, but had been long since junked by the time I got it :-/Mark 2 MB???? ;) Quote Link to comment Share on other sites More sharing options...
mikeyb Posted December 31, 2013 Share Posted December 31, 2013 oops MB, that's me - should have read MG ;D Quote Link to comment Share on other sites More sharing options...
Ridgetone Triumph Posted December 31, 2013 Share Posted December 31, 2013 MikeyB wrote:oops MB, that's me - should have read MG ;DThat makes you a MK1 and I thought you were a lot younger ::) Quote Link to comment Share on other sites More sharing options...
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