Oilerfish Posted February 28, 2018 Report Share Posted February 28, 2018 Hi all! New to this Board and hope someone can help out with a Triumph engine question. I recently purchased a factory built 1971 Marcos GT with a 2.5 Triumph engine. This is one of the eleven or twelve that the factory made so not much info on mechanical's on the Marcos sites so hoping for some info here. There was no history with the car when I bought it which is ok but now wondering if the motor may have been hot-rod'ed to a larger degree than assumed when purchasing. Looking at the motor ancillaries the engine has SAH valve cover, SAH carb manifolds, Weber 45 DCOE's, 6/2/1 headers and finned deep sump aluminum oil pan. What I'm wondering about without tearing the motor apart is if there is anyone with any idea of what SAH typically did to the internals (Cam, porting, etc.) when adding the above ancillaries? I have done a bit of googling and very little info on SAH Thanks for any reply, Robert Quote Link to post Share on other sites
Alec Pringle Posted February 28, 2018 Report Share Posted February 28, 2018 The most likely source of reliable information would probably be Rory MacMath at Marcos Heritage Services, given that his involvement with Marcos goes back to the time of the GT and the takeover of Marcos from Jem Marsh by Rob Walker. Most of the Triumph engine cars were, I think, equipped with the carb saloon engine . . . . as opposed to the USA-spec carb TR6 or the UK/RoW-spec PI TR6 engines. I have not heard any suggestion that any factory-completed GT was equipped with a SAH engine. However, at least some cars were sold in kit form to reduce tax, and I'd guess it's possible that one might have been home-constructed complete with SAH-modified engine. Alternatively the engine received a subsequent SAH makeover at some stage in its later life. I can't imagine anyone going to the effort and expense of fitting Webers and tubular headers, or an alloy sump, without having sorted the engine itself . . . . apart from any other consideration, the carbs and manifolds would offer modest benefit indeed if applied to a 'cooking' saloon lump. More compression and a hotter cam would have been the starting point for the engine, together with some serious head work to improve flow. There is no real record of SAH and its activities as far as I'm aware, Sid Hurrell went decades ago and Terry retired prematurely from Triumph Tune as a result of health issues, so no real help there either. There has been surprisingly little crossover from owners of Triumph-engined Marcos cars to the TR Register over the years, it's very rarely that a GT or Mantis has appeared at a TR gathering . . . . I can't recall having seen one since the 1990s. There was a fairly quick GT sprinting and hillclimbing in the 80s and 90s, that had a seriously hairy Triumph 2.5, but I don't know any detail of the car I'm afraid, can't even recall what colour it was . . . . only that it went pdq . . . . Cheers Alec Quote Link to post Share on other sites
Graham Posted March 1, 2018 Report Share Posted March 1, 2018 Robert I'm sure that Enginuity used to look after a triumph 6 cylinder engined marcos late 80's early 90's when they were still based in Trussley road in Hammersmith, at the time I think it was black but apart from that and it was VERY loud can't be any more help. Quote Link to post Share on other sites
Waldi Posted March 1, 2018 Report Share Posted March 1, 2018 Robert, Welcome to this great forum. You can check the cilinder head height, as a higher compression is achieved by simply skimming the head. There are several datasheets with head data available, Chris Witor is one good source: https://www.chriswitor.com/technical.php Regards, Waldi Quote Link to post Share on other sites
Steves_TR6 Posted March 1, 2018 Report Share Posted March 1, 2018 Welcome to the forum Robert Pictures, we like pictures ! Steve Quote Link to post Share on other sites
heckler Posted March 1, 2018 Report Share Posted March 1, 2018 Hi I have a 1974 SAH tuning parts & price list showing what they offered at the time . If you want any details ring me . PM sent. Chris Quote Link to post Share on other sites
Chris59 Posted March 1, 2018 Report Share Posted March 1, 2018 Hi Robert, glad you followed my advice (on PH) to ask your question on this forum, it seems that you've already found some help Quote Link to post Share on other sites
TR 2100 Posted March 1, 2018 Report Share Posted March 1, 2018 Hi I have a 1974 SAH tuning parts & price list showing what they offered at the time . If you want any details ring me . PM sent. Chris And those period SAH catalogues fetch a high price. But - what was available doesn't answer your question as to your engine. I suggest you check compressions first as they may give you some indication of further mods. Also, check how your engine revs when you blip the throttle as that can give you a good indication of a lightened flywheel. AlanR Quote Link to post Share on other sites
Oilerfish Posted March 1, 2018 Author Report Share Posted March 1, 2018 Wow, thanks for all the helpful info! Obviously found the right place to ask Triumph questions:) Have attached a couple pics of the engine bay. All I have done so far to engine is remove all the ancillaries and refurbish. Carbs are DCOE 45s, Type13. Im afraid I dont know enough about Triumph engines to hear the difference between a standard and a lightened flywheel. Will post a video shortly of running engine. My car has always been reddish orange in color as far as I can tell. Believe its factory paint from cowl back. Front fiberglass clip is newer and signs of damage repair on right side of frame where hood is attached also points at front end damage in the past. Quote Link to post Share on other sites
Steves_TR6 Posted March 1, 2018 Report Share Posted March 1, 2018 Good looking car and lovely clean engine ! Quote Link to post Share on other sites
Waldi Posted March 1, 2018 Report Share Posted March 1, 2018 Very nice car indeed. Quote Link to post Share on other sites
roy53 Posted March 1, 2018 Report Share Posted March 1, 2018 where are you located ? Quote Link to post Share on other sites
Oilerfish Posted March 1, 2018 Author Report Share Posted March 1, 2018 And here is the video of motor revving, maybe one of you Triumph savants can determine if it has a lightened flywheel:) Regards RobertE4173EDA-4594-41B3-ABBD-27313A9A5559.MOV Quote Link to post Share on other sites
Oilerfish Posted March 1, 2018 Author Report Share Posted March 1, 2018 I live in Stavanger, Norway. I have spoken to Rory at Marcos Heritage, (great guy and great service) he has no build files for my car. Understand that there was not a huge emphasis put on trying to keep track of car details at the time as they were in financial trouble and I guess just needed to get the cars out the door. Condition wise the car is just ok, needs paint, frame is ok but some surface rust. Interior is actually really good and I think original. Drive train appears solid( drove it a few kilometers last fall before parking it ) No overdrive but felt ok at Norwegian speeds:) Regards Robert Quote Link to post Share on other sites
Alec Pringle Posted March 1, 2018 Report Share Posted March 1, 2018 That sounds to me like an engine that has had proper work done, as opposed to a standard 2500 block and/or head . . . . . Original SAH-built engines were typically painted in a light metallic blue . . . . the red of this engine suggests it was built by A N Other utilising SAH component, or maybe just a later repaint ? Cheers Alec Quote Link to post Share on other sites
TriumphV8 Posted March 2, 2018 Report Share Posted March 2, 2018 WEBER 45 DCOE normally have minimum choke size of 35mm. With 6 of them it is good beyond 200 HP. Normally Weber swaps for the TR6 go opposite route. They use smaller chokes around 28 to 30mm. So I would expect a third party doing the tuning job doing much more on the engine to give those carbs a little bit of sense. If engine runs properly especially on part throttle and fuel consumption is in limits I would do nothing but in any other case I would look after 40mm carbs with smaller chokes. A good indication, easy to get from outside is measuring the valve lift of the cam on overlap TDC. The more the valves are open the hotter the cam. It devides between stock and street and a wilder and hotter cam at around 2mm lift. Quote Link to post Share on other sites
Chris59 Posted March 3, 2018 Report Share Posted March 3, 2018 I live in Stavanger, Norway. I've bought one of my TVR ( a LHD 2500M, so the same engine, gearbox...) from a guy near Oslo, and bring it back home (1900 Km, by Sweden, Danemark and the toll bridges, Deutschland, Belgium and France !) by road in 28hours, with some halts for sleeping. If you decide, one day, to sell your Marcos (can be tomorrow or in 10 years, it doesn't matter), first refusal please, I really love to travel in northern countries ! Quote Link to post Share on other sites
Oilerfish Posted March 7, 2018 Author Report Share Posted March 7, 2018 Thanks all for replies. Will get it on the road this spring and have a proper drive to determine if anything needs to be changed:) Chris59, Ill certainly let you know if I decide to sell the car, that would be a great drive back to France! Regards Robert Quote Link to post Share on other sites
Oilerfish Posted March 7, 2018 Author Report Share Posted March 7, 2018 Thanks all for replies. Will get it on the road this spring and have a proper drive to determine if anything needs to be changed:) Chris59, Ill certainly let you know if I decide to sell the car, that would be a great drive back to France! Regards Robert Quote Link to post Share on other sites
Chris59 Posted March 12, 2018 Report Share Posted March 12, 2018 Thanks all for replies. Will get it on the road this spring and have a proper drive to determine if anything needs to be changed:) Chris59, Ill certainly let you know if I decide to sell the car, that would be a great drive back to France! Regards Robert Thanks ! Quote Link to post Share on other sites
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