Chris59 Posted December 12, 2009 Report Share Posted December 12, 2009 Hello, Before Stuart think about kicking my h... , I have tried a search through the search engine, and didn't found anything usefull. I have 3 TR wet liners engines (2, 3 and 4) on the shelf and each extensions + fans have been dismantle at least once in the past, loosing the small balance piece of metal, or reassemble with parts from different sources. I am sure both of these fans + extensions are out of balance, so my question is : is it really necessary to balance these parts ? In my opinion, the answer is yes, but can you please share your experiences ? Cheers, Chris. Quote Link to post Share on other sites
stuart Posted December 12, 2009 Report Share Posted December 12, 2009 Hello, Before Stuart think about kicking my h... , I have tried a search through the search engine, and didn't found anything usefull. I have 3 TR wet liners engines (2, 3 and 4) on the shelf and each extensions + fans have been dismantle at least once in the past, loosing the small balance piece of metal, or reassemble with parts from different sources. I am sure both of these fans + extensions are out of balance, so my question is : is it really necessary to balance these parts ? In my opinion, the answer is yes, but can you please share your experiences ? Cheers, Chris. It is always a good idea to balance any rotating parts, the fans are always a problem as the blades can get bent out of true as well. Stuart. Quote Link to post Share on other sites
Andrew Smith Posted December 12, 2009 Report Share Posted December 12, 2009 It is always a good idea to balance any rotating parts, the fans are always a problem as the blades can get bent out of true as well. Stuart. Hi Stuart I shall be fitting an original ST 6 blade fan to Turk (to 'compliment' the Kenlow ) once I've cleaned it up and painted it - so how do I go about balancing it as suggested above, or am I being thick? - I never did that when I fitted the one on there now (the original 4 blade) , I just fitted all the bits and bolted it on? Cheers Andrew Quote Link to post Share on other sites
Guest ntc Posted December 12, 2009 Report Share Posted December 12, 2009 Hi Stuart I shall be fitting an original ST 6 blade fan to Turk (to 'compliment' the Kenlow ) once I've cleaned it up and painted it - so how do I go about balancing it as suggested above, or am I being thick? - I never did that when I fitted the one on there now (the original 4 blade) , I just fitted all the bits and bolted it on? Cheers Andrew You can diy Andrew think about it Quote Link to post Share on other sites
TomMull Posted December 12, 2009 Report Share Posted December 12, 2009 In theory, the balance of the fan, extension, and hub is critical to the health of the crankshaft and the TR set up is interesting to say the least. Broken TR cranks are not unknown and fairly common in racing. However, in my youth I threw a couple of these together (one from a wreck with a crudely straightened fan) without much regard to balance. We did try to match the position of the weights but if it was apart for a while we lost the reference marks or notes and just guessed. Maybe it was just stupid luck but we put quite a number of road miles on these without issues. Roger Williams suggests drilling a small alignment hole through everything - good advice, after you get things balanced. Tom Mulligan Quote Link to post Share on other sites
jean Posted December 12, 2009 Report Share Posted December 12, 2009 Strange advise in general holes are drilled to balance things, drilling holes later on will probably partly destroy the balance again Quote Link to post Share on other sites
TR 2100 Posted December 12, 2009 Report Share Posted December 12, 2009 Strange advise in general holes are drilled to balance things, drilling holes later on will probably partly destroy the balance again True, but then you would (1) drill any holes close to the centre and (2) being sensible, you don't need a hole, just a small drilled mark. A punch mark would do just as well. Trouble is, the more subtle, and less intrusive, the markings, the easier it is to miss them on re-assembly. When I had my crank, flywheel and clutch balanced, they used a good lashing of red paint to make sure the orientation could not be overlooked. I never did think to check how much the paint would have weighed! AlanR Quote Link to post Share on other sites
Guest ntc Posted December 12, 2009 Report Share Posted December 12, 2009 You should not drill the fan you should add weight Quote Link to post Share on other sites
Chris59 Posted December 12, 2009 Author Report Share Posted December 12, 2009 (edited) Originally, a hole is drilled through the balance piece, then the fan itself, then there is a small mark on the extension, to help during reassembly. But on the ones concerned,no mark because of : - parts of differents sources, - the balance piece is missing. I should try to find someone to balance them locally next week Chris. Edited December 12, 2009 by Chris59 Quote Link to post Share on other sites
TomMull Posted December 12, 2009 Report Share Posted December 12, 2009 Seems to be a little confusion with my suggestion for drilling a hole. 1. The hole is for alignment purposes only, not to correct balance. 2. The hole is small < 1/8 inch (how small can you drill by hand?). 3. If the hole is drilled in the same place on all the pieces balance should not be changed (except for slight differences in thickness). 4. The hole is fairly close to the center of rotation which should minimize any imbalance introduced. If you can make paint or something else work, fine but this a lot better than guessing. Quote Link to post Share on other sites
Andrew Smith Posted December 12, 2009 Report Share Posted December 12, 2009 (edited) Is any of this balancing the fan, drilling holes and concern really necessary? I just wonder if sometimes we forget what these cars are……….. After all, we are talking about a thrown together (and not that well!) sports car of the 50s, 60s and 70s and not a precision thoroughbred like a Ferrari? Cheers Andrew Edited December 12, 2009 by Andrew Smith Quote Link to post Share on other sites
Alec Pringle Posted December 12, 2009 Report Share Posted December 12, 2009 Too easy to get carried away with this stuff, Andrew . . . . The fan can be adequately balanced on a bubble balancer, and it was originally installed with an adjustable balance piece (or pieces, as required) - although the balance piece/s may have gone adrift over the years. I do wonder how many owners even realise the existence of the balance piece ? Cheers, Alec Quote Link to post Share on other sites
PatB Posted December 13, 2009 Report Share Posted December 13, 2009 Just another opinion about the lump up front. I was worried about dropping mine when I added R&P and an electric puller fan so got on Kas Kastners racing site to ask the TR3 hotshoes...everyone of them said drop the lump and don't worry as long as you are going to generally be below redline. Racers balance their engines anyway so not much of an issue, but they noted, and Kas notes in his book that he dropped every fan/extension on all of his cars without issue. Actually, the broken crankshaft issue arrises on cars with the lump/fan in place. I drive mine like it's stolen with oout any difference in vibration. Quote Link to post Share on other sites
Chris59 Posted December 13, 2009 Author Report Share Posted December 13, 2009 (edited) Alec, you now know who am I : not an anorack, but sometimes a maniac "Actually, the broken crankshaft issue arrises on cars with the lump/fan in place." I can't agree, Pat. A friend of mine broke his TR4' crankshaft at the front web, between 1st cylinder and front main bearing, but his car hadn't a fan + extension, but only an electric fan.... I don't say he had broke his crank BECAUSE of the lack of the fan + extension, I just say it was missing on his car Chris. Edited December 13, 2009 by Chris59 Quote Link to post Share on other sites
BrianC Posted December 14, 2009 Report Share Posted December 14, 2009 (edited) "Actually, the broken crankshaft issue arrises on cars with the lump/fan in place." I can't agree, Pat. A friend of mine broke his TR4' crankshaft at the front web, between 1st cylinder and front main bearing, but his car hadn't a fan + extension, but only an electric fan.... I don't say he had broke his crank BECAUSE of the lack of the fan + extension, I just say it was missing on his car Chris. I think Pat meant that the crankshaft can break regardless of whether or not the original fan and/or extension are fitted. FWIW, mine broke and I had the original setup. It also wrecked an extremely nice SAH Stage 3 head in the process I now have Pacet electric fan and plastic fan on my TR3A (belt and braces) but original fan on Lynda's TR4A. Also currently have two spare engines with good crankshafts as spares for insurance. What's the betting another crank will go when I sell these? Afterthought: Has anyone managed to buy a new or second-hand crankshaft recently? Edited December 14, 2009 by BrianC Quote Link to post Share on other sites
ianc Posted December 14, 2009 Report Share Posted December 14, 2009 Why sell those engines, Brian? They are the best form of insurance and will always be worth something when you do decide to sell the car(s) - I hope that will be many years from now, when you can't get the Zimmer frame in! Ian Cornish Quote Link to post Share on other sites
67_gt6 Posted December 14, 2009 Report Share Posted December 14, 2009 (edited) If the extension and fan were originally balanced off the crank, doesn't that indicate that the crank/rods/pistons must have already been reasonably balanced by the factory, as it would be impossible to check the affect on overall balance of adding the extension once the engine was assembled. Obviously the length/shape/weight of the extension must have an impact on the overall crank balance however it would seem reasonable to assume that the length was in order to bring the fan up to the radiator rather than because the crank needed that very specifically shaped mass on the end to avoid self destructing? Andy Edited December 14, 2009 by 67_gt6 Quote Link to post Share on other sites
PatB Posted December 14, 2009 Report Share Posted December 14, 2009 Yes, I meant that the crank has been known to break regardless of the wether the lump was out front. I've also heard (read) that it seemed more prone to breakage at lower lugging speeds in 4th gear which would seem to indicate a weakness in design/strenght rather than a balance issue. I regularly run my 56 TR3 at 85 to 100 mph on our Arizona highways and the motor seems very smooth without the lump/fan in place. Actually the whole car seems to just 'settle' nicely over 90 mph and not a shake or rattle. Quote Link to post Share on other sites
Chris59 Posted December 14, 2009 Author Report Share Posted December 14, 2009 Fully agree this time Pat, my friend's TR4 engine was really far more smooth without the extension and fan ! "Afterthought: Has anyone managed to buy a new or second-hand crankshaft recently?" Brian, yes, me .... Chris. Quote Link to post Share on other sites
Menno van Rij Posted December 14, 2009 Report Share Posted December 14, 2009 Isn't it time to consult seasoned engine (re)builders like Revington and Racetorations? (Or any other well-known TR engine specialist for that matter). This issue pops up every winter when we have enough time to worry about these things I'm sure these engine specialists know a thing or two about these engines! E.g.: if you remove the existing fan and install a small pulley conversion, do you need a dampened pulley or not... Menno Quote Link to post Share on other sites
PatB Posted December 14, 2009 Report Share Posted December 14, 2009 Menno, That's what I did before I pulled mine...I 'chatted' with the TR3/4 racers on Kas Kastners web site. They all drop the lump and Kastner writes in his book "Racing, Winning and other Myths" that breakage is due to fatigue over time and detonation issues (low speed lugging can induce same) and that the TR3/4 cranks tend to break at the number 4 rod journal. The motors were not balanced from the factory, except for the factory racing cars, and the lump is not a harmonic balancer so can't imagine it performing that function. Actually, as it was not balanced it could have the opposite effect. If not familiar with Kastner he raced all of the TR's from the 50's thru the 70's in the US and organized one of the most successful US racing teams...also raced factory supported. Still, like an 'oil' thread lots of conjecture.... Pat Quote Link to post Share on other sites
jean Posted December 15, 2009 Report Share Posted December 15, 2009 All TR3's and 4 racing cars I have seen on the Continent do not use the mechanical fan, but they all run a damper pulley, a rather expensive one. The fan on my TR3A was replaced by a less expensive MGB, sorry dampened pulley, what works well, and drives a thin belt Quote Link to post Share on other sites
JeffR Posted December 15, 2009 Report Share Posted December 15, 2009 I spoke to Revingtons about 3 years ago before I removed the lump on my TR4 engine after a fan blade had sheared due to metal fatigue. They said at the time there was no problem in removing the lump and even sold me a shortened bolt to fasten the crank pulley back on without the fan extension. I agree with the post above, my engine has never run smoother without the lump. JeffR Quote Link to post Share on other sites
PatB Posted December 16, 2009 Report Share Posted December 16, 2009 Most racers here do not if they've balanced their motor, however I did read in 'Improving Your TR2/3/4" that a harmonic comes in at 4800 rpm and again around 6000 rpm that may cause an issue if the motor isn't properly set up. I can hit over 100 mph in 5th gear way under 4800 rpm and I doubt many here regularly drive their half century old cars over redline. Kind of a non issue to spend money on imho. Quote Link to post Share on other sites
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