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TR6 Cylinder head oil leak distributor side


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Hi has anyone had issues with oil coming out between the cylinder head and block the distributor side (not rocker gasket or any were else). I am about to take the cylinder head off for the 4th time for the same problem.


I bought my TR6 a 1972 CP PI in may 2016, took the cylinder head off and got D&G to convert it to unleaded and re work it. I checked the block for straightness all ok. Re fitted with cylinder head gasket after cleaning out all the stud holes fitted with new studs, nuts and washers. Tightened down to 70lbs ran like a dream but leaked oil.


Had a chat to jigsaw who said quite common problem, try heldite round the oil feed channel between block and head, did the same as the first time. Still leaked. Did the cylinder head again with thicker washers and wellseal coated on head gasket block and head plus heldite round oil channel.


Gasket part number I am using is is AJM387, I did a 5 year apprenticeship as a vehicle mechanic any help before I do this for the forth time would be appreciated. By the way this is my first time on a forum so sorry if I have not been clear.



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You have covered all the usual suspects.


im just wondering if the liberal use of wellseal ( generally good stuff) may be allowing too much panting and the head is moving about more than normal


the orig gaskets are normally fitted dry so they 'grip'


mext time try a film of locrite 573 or similar along the side of the follower chest and rear oil feed

this stuff sets,


just an idea pete

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the notorious weep area? where the oilway drillings are to feed the rocker shaft?


There aresome "cures" for this. A friend rills the oilways out and counterbores then, pops a bit of copper tube in and sealant in the counterbore. A faff to do, but works. 

I have usually been OK, decent headgasket and a smear of sealant around that oilway....

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The oil leak was towards the back, by the engine stamp and all along up to the alternator, Mark at jigsaw told me to put Hermotite round the copper washer in the head gasket. At the moment it is leaking from the centre outwards both ways about two inches. I do suspect this oil feed to the rocker. I am this afternoon about to re torque the head down to 85 lbs. if that does not work it will be head off and star again. !!!

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you dont happen to have the external oil feed kit fitted to add more oil to the rear of head rocker feed  ????



if you do remove the head   maybe some careful  checks on head and block flatness is a check worth doing , you seem to be having a lot of trouble and are aware of the main culprits .



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Hi Pete


No I don't have the oil feed pipe fitted, I replaced the rocker shaft and rockers as they were worn. The head as I said above was reconditioned by D&G Engineering so was skimmed. The first thing I always do before re fitting a head is to check the block and head for flatness and all good. Thanks for the thoughts it has got me scratching my head.


I am calling all the tech gus at jigsaw and moss. All seem to think oil way.


Thanks to all of you for your input.

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There is a standard problem with the small four a the six engines where the oil seeps out of the corner of the head/block just above the last sparking plug. Plug 6 on the six cylinder engine. If this is the area where the leak is, it normally comes from the oil transfer hole - from the block to the head. The head gasket needs a small amount of sealer around the oil hole on both sides. Only use a small amount as too much may block the oil hole.



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a good dry off with brake cleaner and a dusting of talc or french chalk along the joint will soon show just where its coming from 

if  you use talc makes it smell nice too  


if its leaks centrally it impossible to track through the gasket  from the left rear corner were the feed enters the head but , it can track along the joint and run out anywhere.

the talc idea should show it up 


if thats a way out of the frustration

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Thanks Pete I'll try the wife's best talc I'll post some pic then.


Dave thanks for the post but as you can see from the thread I have put hermetite around the copper washer on the head gasket that goes around the oil transfer hole I even put wellseal round the whole on the block and head last time making sure it did not block it. I have plenty of oil coming up on to the rocker shaft.

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If the rear cam bearing wears there is loss of the interupted supply and you can get too much or if realy bad not enough.... oil in the rocker box


its only gravity feed back to the sump via the cam follower chest so sealing the gallery side of the HG the

should contain this easily lets hope the wifes talc shows the rear corner to be the snag



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there a few reasons why they mostly leak along the frunt


1, Some gaskets ev a covering of glue,or resin on em,

this stuff is supposed to melt wen engine get hot.


Butt, if the head, block not scrupiously clean it dont stik

And, even though it can be as clean as can be, it still dont stik


As this area dont get hot enuff t,melt the glue, as its too farr away frae the ..heat.

IE, yee,v took a gasket off, and along the frunt, and sides, its no stiking, correct



Butt, aroond the bores, its stuk like sheite to a blanket, correct

this cos the glue  es melted, and its stuk,  and it really does tek some getting off..


this can be got aroond by running the engine wid nee coolant for a while

Yer engine teks aboot 15mins t,get up t,temp,

so running it wid nee coolant will let it get hot quicker , and also let glue melt

In theory at least, as this was what some on Speed talk doo, an them ladds no there stuff

if its good enough fora 1000HP motor, then it should be good enuff for ours,!!!


2, pressure is a cause.

yer gasket aint seal well, cos glue aint set,

so wen yer giv,n it some stik, esp wid a worn bore engine, { most will be !! }

then the pressure int crank case has t,get oot some where,

as that wee 3/8th hole aint gonna let 100 CFAM oot of that wee hole


so what happens it it tries t,get oot of other spots

yer oil seals, other gaskets, filler cap,

it also gets pushed in between the not too good a seal frunt bit


thismeks it leak even moer afterwards, as the oil es nooo got between the gasket an blok / heed

meaning that it,ll never eber seal noo,


3, yer cyl heed gringing is wrong is, even frae factory,!!

look at yer grind marks on heed,  they are in a circular fashion, that go ACROSS the heed,

just wot ye dont want, as the grooves will mek a path for oil t,flow along.


Ye need it t be groove  ALONG the length of the heed / block

this can be done by useing some Wuff wuff productionee paper

and carefully marking it length ways,


wrapping it all around the edges of the block heed, for good measure

as there 2 bigg water ways at each end too,!!



remedies,owa the yers i tried all sorts of things,

some of the so called best stuff ont market


my way noo, and for yoks noo, is t,use the  Blue  Hylomar sealant

put a thin smear on byath sides of gasget, and also ont block, and heed

dont go over board, !!


And, try an get some moer engine breather holes,or mek the one int rocker box { if an alloy one bigger }

or put in another one

ye really need some thing that adds up to aboot an inch or moer,!!


think aboot it, that vent is the same size ona 900 CC original Standard motor, as it is on a 2500 cc car

it dont tek a rocket scientist t,work oot something aint right noo does it,!!

that is, if ye no what the OE size was int fust spot,


I give me car some stik, it gets revved alott up owa 5 k alott in top

this is where yer goona build up alott of internal pressures

and, mine dont leak, just ask some folk that seem mine, or meb,e yeev seen it yer self,

never any oil aboot.



Noo then,  look at this vid clip of a GT ont rollers,

and see, that as revs rise, there aint much  oil smoke

Butt, look at wen its held top gear revs for a wee while,


the smoke is belting oot of the Expansionee tank

its no only belt,n oot of there, butt it,ll be coming oot of other spots ye cant see,


Try this yer sell, tek yer pipe oft rocker box

and rev yer engine, there will most likely be a good ole gale force wind blowin oot of it,

this is just wid the throttle hardly open,

butt, wid WOT, it,ll be 10 time wuss,


hope this es given ye sum food for thowt,

and meb,e try some of me tips yer self.


Vid clips






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Thanks for all that, I'm going to have a play with the breathers today, I have the re toqued the head to 80 lbs, so I'll feed back, if it ever stops raining and I can get it out.


An old mate who I did my apprenticeship with said he had a GT6 and he put a dowel in the oil feed hole on the block, and then fitted the external pipe to feed the cam. He has not got the car anymore so don't know what long term of that fix was, but it sounds like a possibility, before I go that far has anyone got an opinion.




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the original feed is an interrupted supply controlled by a flat on the rear cam journal so you give one squirt for one rotation of the cam  the rockers dont need loads of oil, and the external feed is generally  condemned   John calls it the spawn of satan,   !!!

if  ever its fitted it must be seriously restricted or you flood the un sealed valve stems and get clouds of blue on deceleration

and your diverting pressure from the oil gallery from the much needed mains and ends .


to the answer is dont ever fit one... its an aftermarket myth  for normal road going cars



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Just taken her out for a 5 mile blast, after re torquing the head down to 80 lbs. I also did what Pete suggested and put talk on the block.


Got back no oil leaking out. So great news so far, when the weather is better I will go for a good run and report back, but thanks to all of you for your feedback.


Have a great weekend

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  • 2 weeks later...

Pete and everyone


Ok sorry I have not been back in touch got in trouble for using wife's best talc (johnsons). However I have now done 50 miles over the weekend talking it up to 3000 Rpm at one point. No oil leaks from engine. Great news thanks again for all posts, it really helps. The car runs really well it was worth taking the head to D&G,

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