foster461 Posted August 1, 2016 Report Share Posted August 1, 2016 I'm taking apart a spare TR3 engine, TS 76796 E. The head looks ok with the only obvious problem being a burned #3 exhaust valve. Crank, cam and lifters also look good. The crank has standard sized journals and no serious wear. I could use some help in evaluating the piston and liners. Other that looking for obvious surface issues is this just a question of diameters and ovality ?. At what point do you say the pistons and/or liners are scrap ? Stan Quote Link to post Share on other sites
Motorsport Mickey Posted August 1, 2016 Report Share Posted August 1, 2016 (edited) Hi Stan, Don't get confused here, you'll find the pistons are oval anyway ! they are made like that. Measure around the pistons in 4 positions to confirm what the actual dimension is, (no surprise it's the larger dimension !), then measure the bores on the liners (check for a wear lip at the top). If you're not too bothered about getting 150K out of it you could reuse the components if there is no more than a 5 thou difference, (that's what I take them to when building race units) glaze bust and just rering it using a "ridge dodger" top ring if there's a step on the bore. Mick Richards Edited August 1, 2016 by Motorsport Mickey Quote Link to post Share on other sites
foster461 Posted August 1, 2016 Author Report Share Posted August 1, 2016 Hi Stan, Don't get confused here, you'll find the pistons are oval anyway ! they are made like that. Measure around the pistons in 4 positions to confirm what the actual dimension is, (no surprise it's the larger dimension !), then measure the bores on the liners (check for a wear lip at the top). If you're not too bothered about getting 150K out of it you could reuse the components if there is no more than a 5 thou difference, (that's what I take them to when building race units) glaze bust and just rering it using a "ridge dodger" top ring if there's a step on the bore. Mick Richards Thanks Mick, very helpful. I'll do a quick check with my cheap tools and if it looks like we are in the ball park I'll have the machine shop do a proper job of measuring them and hone the liners if appropriate. I plan to keep this engine around in case I or one of the locals need it so I just need to know what it would take to create a running engine, how much needs to be replaced. Stan Quote Link to post Share on other sites
TomMull Posted August 3, 2016 Report Share Posted August 3, 2016 It will be cool to have a good original 83 mm engine with standard everything, not that many will know. As for ridge dodgers, I've used them on other cars but never seen them for wet liner Triumphs but no doubt Hastings or the like can supply some. I've found that if the pistons will come out without too much fuss the new standard top rings will not cause trouble, in spite of the ridge. I did have an adjustable ridge reamer at one time, but used it only once, I think, and somehow it got lost, probably in the cloud. Sorry I missed DOT. My wife booked me to Nova Scotia (Not in the Herald) Tom Quote Link to post Share on other sites
foster461 Posted August 3, 2016 Author Report Share Posted August 3, 2016 It will be cool to have a good original 83 mm engine with standard everything, not that many will know. As for ridge dodgers, I've used them on other cars but never seen them for wet liner Triumphs but no doubt Hastings or the like can supply some. I've found that if the pistons will come out without too much fuss the new standard top rings will not cause trouble, in spite of the ridge. I did have an adjustable ridge reamer at one time, but used it only once, I think, and somehow it got lost, probably in the cloud. Sorry I missed DOT. My wife booked me to Nova Scotia (Not in the Herald) Tom I do have a slight ridge at the top of the liners Tom, havent measured it yet though (bore gauges arriving tomorrow) DOT was very wet but we had a great time and due to the low turnout and perhaps some sympathy votes my TR6 got 1st place in the late TR6 class Hope you had a good time in NS, and hope to see you both and the Herald in Stowe, VT in September. Stan Quote Link to post Share on other sites
stuart Posted August 3, 2016 Report Share Posted August 3, 2016 I do have a slight ridge at the top of the liners Tom, havent measured it yet though (bore gauges arriving tomorrow) DOT was very wet but we had a great time and due to the low turnout and perhaps some sympathy votes my TR6 got 1st place in the late TR6 class Hope you had a good time in NS, and hope to see you both and the Herald in Stowe, VT in September. Stan Well done Stan! Stuart. Quote Link to post Share on other sites
foster461 Posted August 3, 2016 Author Report Share Posted August 3, 2016 Well done Stan! Stuart. Only three cars in that class Stuart. Pretty much everyone that showed up went away with an award. Quote Link to post Share on other sites
stuart Posted August 3, 2016 Report Share Posted August 3, 2016 Still better than 3rd! Stuart. Quote Link to post Share on other sites
Don Elliott Posted August 4, 2016 Report Share Posted August 4, 2016 (edited) !n 1990 when I was finishing the restoration of my 1958 TR3A, it had 80,250 miles from new. I put in new pistons, rings and liners (plus lots of other parts) to make it a proper rebuild. Since then I have driven an additional 116,000 miles and it still runs like new. I bought the parts from Peter Hepworth in Yorkshire and he told me back in 1989 that these were the last 1991 cc set he had.. For half of the miles since 1990, I was using Castrol 20W50 and then I put in new rings and had the liners honed and I've been running the last 55,000 miles with Castrol 10W30 with little or no oil consumption. Tractor engines just keep ploughing along. Don Edited August 4, 2016 by Don Elliott Quote Link to post Share on other sites
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