Malbaby Posted August 1, 2023 Report Share Posted August 1, 2023 Looking for a quality head gasket. Engine has been bored out to 40 thou, and it appears the cylinders are not perfectly in line...maybe a variation of up to 5 thou. Would need a gasket that has an internal diameter of the cylinder holes of 77-78mm. Apart from a solid copper gasket, any sources? Quote Link to post Share on other sites
elclem1 Posted August 1, 2023 Report Share Posted August 1, 2023 moss Quote Link to post Share on other sites
Malbaby Posted August 1, 2023 Author Report Share Posted August 1, 2023 (edited) 10 hours ago, elclem1 said: moss Thanks...Moss only has 76.7mm. Edited August 1, 2023 by Malbaby Quote Link to post Share on other sites
Andy Moltu Posted August 2, 2023 Report Share Posted August 2, 2023 If the standard bore is 74.7mm and 40 thou is approx 1.016mm shouldn't the 76.7mm gasket be enough? Quote Link to post Share on other sites
elclem1 Posted August 2, 2023 Report Share Posted August 2, 2023 2 hours ago, Andy Moltu said: If the standard bore is 74.7mm and 40 thou is approx 1.016mm shouldn't the 76.7mm gasket be enough? yes and i thought it was .010", .020" ,060" cuts. Quote Link to post Share on other sites
roy53 Posted August 2, 2023 Report Share Posted August 2, 2023 Talk toTR Shop they have a super gasket with the red sealing that works on plus 60 Quote Link to post Share on other sites
Dave McDonald Posted August 2, 2023 Report Share Posted August 2, 2023 On 8/1/2023 at 8:54 AM, Malbaby said: Would need a gasket that has an internal diameter of the cylinder holes of 77-78mm. Apart from a solid copper gasket, any sources? Racetorations sell 78 mm gaskets which I use on race engine but 78 mm is c. +125 thou so don’t know why you need that. Sit down when you get the price from Daryl. 40 thou oversize is only 75.7 mm. I’ve always been led to believe standard gasket ok up to + 60 thou. Dave McD Quote Link to post Share on other sites
Malbaby Posted August 2, 2023 Author Report Share Posted August 2, 2023 Thanks guys....my bore is 75.7mm...the nos gasket that I have is 76.4 and not suitable. Compounding problems are.... bores are not all exactly in centre line, and the block has been decked so there is now some very minimal piston protrusion...So I will need a thicker gasket anyway. Yes, Racetorations gasket is pricey. I am currently waiting on a reply as to the thickness of theirs. I will check the TR shop....[Their supplier may be the same as Racetorations]. I have now found a couple of sources for custom made composite gaskets [rather than solid copper] here in Australia....Waiting on prices and supply times. Quote Link to post Share on other sites
TonyC Posted August 3, 2023 Report Share Posted August 3, 2023 Just completed a rebuild of engine which has .060" oversize bores and as they were at max. at in good condition the machine shop honed them and machined the top of the block. The bores were recessed so new recesses were machined after the block skim. Pistons were not skimmed so when assembled the pistons were flush with the top of the block rather than flush with the top of the recess, and as such needed to pass through the gasket bore when each was at TDC. This meant that the gasket had to be perfectly positioned to avoid the piston nipping the gasket - ask me how I know! (ruined two gaskets before getting it right). Positioned the gasket and checked with each piston at TDC for interference and then secured the gasket with strategic application of Permatex just above the distributor position as per Roger Williams suggestion in his 'How to restore Triumph TR6' book. I did look for alternative gaskets but could not find any suitable for recessed blocks and really did'nt want the pistons skimmed. Anyway is was a bit expensive going up the learning curve but I got their in the end. Hope it helps. TonyC Quote Link to post Share on other sites
BlueTR3A-5EKT Posted August 3, 2023 Report Share Posted August 3, 2023 (edited) On 8/1/2023 at 8:54 AM, Malbaby said: Looking for a quality head gasket. Engine has been bored out to 40 thou, and it appears the cylinders are not perfectly in line...maybe a variation of up to 5 thou. Would need a gasket that has an internal diameter of the cylinder holes of 77-78mm. Apart from a solid copper gasket, any sources? Is this a flat topped or recessed bore top cylinder block? Get the wrong gasket and there will be tears. and yes +0.060” was the biggest readily available piston I recall from Hepolite. Big seller to Lotus Climax engine builders. Edited August 3, 2023 by BlueTR3A-5EKT Quote Link to post Share on other sites
roy53 Posted August 3, 2023 Report Share Posted August 3, 2023 Get our pistons decked. The PAYEN gasket is ok on +60 TR shop not the same as ractorations gasket Roy Quote Link to post Share on other sites
Malbaby Posted August 3, 2023 Author Report Share Posted August 3, 2023 11 hours ago, BlueTR3A-5EKT said: Is this a flat topped or recessed bore top cylinder block? Get the wrong gasket and there will be tears. and yes +0.060” was the biggest readily available piston I recall from Hepolite. Big seller to Lotus Climax engine builders. Flat top. Quote Link to post Share on other sites
Malbaby Posted August 4, 2023 Author Report Share Posted August 4, 2023 (edited) Thanks for all the helpful comments guys... I checked with the TR shop, they did not have what I wanted. Ordered the "Racetorations" composite gasket last night. I will post my findings when I trial fit it. Edited August 6, 2023 by Malbaby Quote Link to post Share on other sites
nylen Posted August 8, 2023 Report Share Posted August 8, 2023 I have Racetorations gasket on my TR6. Forged pistons 77,5 mm. Works well. Quote Link to post Share on other sites
Malbaby Posted August 9, 2023 Author Report Share Posted August 9, 2023 5 hours ago, nylen said: I have Racetorations gasket on my TR6. Forged pistons 77,5 mm. Works well. Hi Nylen....Forged pistons in a race spec engine? Quote Link to post Share on other sites
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