vic Posted November 6, 2013 Report Share Posted November 6, 2013 I am considering fabricating replacement front and back plates on the 6 engine and seek information on the grade of aluminium alloy to use. I am looking at 6082 T4 which appears to be suitable but would welcome advice from those who have travelled down a similar road or who know better. Vic Quote Link to post Share on other sites
RogerH Posted November 6, 2013 Report Share Posted November 6, 2013 Hi Vic, not an expert on car Ali's but at BA we used a lot of 7075-T6 for structural applications. Similar strength to steel but lighter. Machines easily because it is quite hard. Probably more expensive than the 6068 material though. Roger Quote Link to post Share on other sites
Don H. Posted November 6, 2013 Report Share Posted November 6, 2013 (edited) Joe Alexander of Alexander Racing Enterprises (A.R.E) in the US makes TR6 front and back plates from 6061 T6 aluminum alloy. Front, TR250-TR6 to 1974. $89, in stock: http://www.the-vintage-racer.com/index.php/engine-components/product/43-afp-tr6 Front, 1975-1976: http://www.the-vintage-racer.com/index.php/engine-components/product/44-afp-tl6 Rear, $119, in stock: http://www.the-vintage-racer.com/index.php/engine-components/product/45-arp-tr6 Edited November 6, 2013 by Don H. Quote Link to post Share on other sites
Tom Boyd Posted November 6, 2013 Report Share Posted November 6, 2013 http://www.triumphspecialtuning.com/index.php?route=product/product&manufacturer_id=23&product_id=79 http://www.triumphspecialtuning.com/index.php?route=product/product&manufacturer_id=23&product_id=80 Already made ready to fit Tom Quote Link to post Share on other sites
Peter Cobbold Posted November 6, 2013 Report Share Posted November 6, 2013 Wouldn't the ali plates need to be thicker to have the same 'strength' as steel ? Quote Link to post Share on other sites
RogerH Posted November 6, 2013 Report Share Posted November 6, 2013 Hi Peter, under normal conditions the steel item is probably well over engineered as it is built to cost not weight saving. Many of the Ali alloys have tremendous strength and the tempering can resolve many issues within its useage - corrosion, stiffness, strength etc. 6061 is very similar to 6082 and the T6 temper would give it a great deal of stiffness. 7075T6 would be a little over engineered also. Roger Quote Link to post Share on other sites
Stanpartmanpartwolf Posted November 6, 2013 Report Share Posted November 6, 2013 (edited) Jor Alexander's 6-cyl plates are excellent; I built Josh Files' 2010 Thoroughbred Championship winning TR6 engine with them, & a couple more to boot. The engine also has an alloy sump & contains no gaskets apart from the obvious one. It is oiltight & goes fairly well, I think. As far as I am aware, the 2011 TSCC Championship was won by a "D" Type replica, so the implication in the TRE advert is wrong on two counts. Beware of alloy TR2-4A front plates; titanium works better in this application. Edited November 6, 2013 by Stanpartmanpartwolf Quote Link to post Share on other sites
john.r.davies Posted November 7, 2013 Report Share Posted November 7, 2013 (edited) Did this myself - after all it's easy to use the original as a template. Made them from 6mm sheet when the original steel ones are 3mm. Maybe I chose the wrong alloy, but after a season or two, I had fine cracks around the bolt holts on the rear plate and junked them. After all, these are not rotating parts so its just their dead weight that matters The weight saving is tiny, a kilogram at most, when you can save many kilograms by using GRP body parts. John PS Titanium! Wouldn't you need a whole new set of tools to work that? Edited November 7, 2013 by john.r.davies Quote Link to post Share on other sites
Tom Boyd Posted November 7, 2013 Report Share Posted November 7, 2013 Jor Alexander's 6-cyl plates are excellent; I built Josh Files' 2010 Thoroughbred Championship winning TR6 engine with them, & a couple more to boot. The engine also has an alloy sump & contains no gaskets apart from the obvious one. It is oiltight & goes fairly well, I think. As far as I am aware, the 2011 TSCC Championship was won by a "D" Type replica, so the implication in the TRE advert is wrong on two counts. Beware of alloy TR2-4A front plates; titanium works better in this application. Noted and edited, thanks for your input Jon Tom Quote Link to post Share on other sites
RogerH Posted November 7, 2013 Report Share Posted November 7, 2013 Hi JohnD, various Ali alloys are prone to stress cracking (your cracked holes). There are ways of hardening the surface of the hole to reduce/stop this happening - you can pull a mandrel through the hole that is a few thou bigger than the hole and it compresses the Ali thus hardening it. However if you had chosen your material better in the first place!!! As for Titanium - excellent stuff in the right place. I would have thought a car engine plate is not the right place due to cost and machining difficulties. When playing with Titanium you must also consider any metals coming into contact with it. Electrolytic corrosion can be a problem. Titanium bolts are usually Cad plated etc. But it is there to be played with - go for it. Roger Quote Link to post Share on other sites
Andy Brady Posted November 7, 2013 Report Share Posted November 7, 2013 I've seen used alloy plates with quite a pronounced gouge were the steel tensioner eat into the softer alloy. This concerns me, but I'm working on a fix. Quote Link to post Share on other sites
Stanpartmanpartwolf Posted November 7, 2013 Report Share Posted November 7, 2013 Tom, thanks, none taken & none meant. I've seen no cracking yet; fit the rear plate up with hard plain & Schnorr washers & all should be well. We already have a couple of Ti front plates in use. No problems at all with them. Far from cheap but, as expected, very light & strong. I can supply them to special order. The TR5/6 front plates can be steel inserted, but if you're going to the trouble of building a nice engine, why spoil it with a crappy original style bent tin tensioner? Quote Link to post Share on other sites
Andy Brady Posted November 7, 2013 Report Share Posted November 7, 2013 Is there any available option to the bent tin one? Quote Link to post Share on other sites
Tom Boyd Posted November 7, 2013 Report Share Posted November 7, 2013 There most certainly is. Quote Link to post Share on other sites
Andy Brady Posted November 7, 2013 Report Share Posted November 7, 2013 Don't be a tease... Quote Link to post Share on other sites
Nick Jones Posted November 7, 2013 Report Share Posted November 7, 2013 I've seen used alloy plates with quite a pronounced gouge were the steel tensioner eat into the softer alloy. This concerns me, but I'm working on a fix. I own a couple of steel ones with the same problem...... Also curious to hear of a bent tin alternative as modern tin seems much softer than 60s tin. Nick Quote Link to post Share on other sites
BlueTR3A-5EKT Posted November 7, 2013 Report Share Posted November 7, 2013 A couple of plastic ones from a Mini A+ or the twin row Dol Sprint MGB type tensioner perhaps? Cheers Peter W Quote Link to post Share on other sites
Stanpartmanpartwolf Posted November 8, 2013 Report Share Posted November 8, 2013 MGB tensioner's OK on a 4-cylinder mill. Use on a 6 at your peril. There most certainly is an alternative. Quote Link to post Share on other sites
Andy Brady Posted November 8, 2013 Report Share Posted November 8, 2013 I have been looking at a small block MOPAR assembly as a possibility Still trying to get one, let down by two vendors so far. http://www.hemiperformance.com.au/store2/p_1025_Small-Block-Mopar-Timing-Chain-Tensioner-Mopar-Part-P5007709 Quote Link to post Share on other sites
john.r.davies Posted November 8, 2013 Report Share Posted November 8, 2013 Andy, You made me look around: This one is from a Honda engine, could be attached to the side to the timing cover, and if you could seal it though the cover, is adjustable! http://www.ebay.co.uk/itm/Honda-1980-1982-CB900-C-CB-900-Custom-Engine-lower-Primary-Chain-Guide-Tensioner-/360786687006?pt=Motorcycles_Parts_Accessories&hash=item54008ff41e#ht_749wt_904 Any good?? John Quote Link to post Share on other sites
Andy Brady Posted November 8, 2013 Report Share Posted November 8, 2013 (edited) Andy, You made me look around: This one is from a Honda engine, could be attached to the side to the timing cover, and if you could seal it though the cover, is adjustable! http://www.ebay.co.uk/itm/Honda-1980-1982-CB900-C-CB-900-Custom-Engine-lower-Primary-Chain-Guide-Tensioner-/360786687006?pt=Motorcycles_Parts_Accessories&hash=item54008ff41e#ht_749wt_904 Any good?? John Motor cycle one John, so probably has an external adjuster in an alloy case. I was intrigued by the MOPAR assembly as its a compact aftermarket add on, they don't have a tensioner as standard, and it fits inside a similar tin cover. Stops chain whip and timing drift too, so gives a smoother engine. http://www.hotrodsandhemis.com/Rebuild/HemiRebuildPart2.html http://www.forabodiesonly.com/mopar/showthread.php?t=136340 I'll have another stab at getting one to investigate shortly. Edited November 8, 2013 by Andy Brady Quote Link to post Share on other sites
Andy Brady Posted November 10, 2013 Report Share Posted November 10, 2013 Well fes up chaps! Thats two allusions to a better available option to the bent tin but no pointers. Quote Link to post Share on other sites
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