stevie_b Posted February 3, 2012 Share Posted February 3, 2012 The 7M is a different engine though (and you know this). Either Toyota have improved their head gasket design when building the 2JZ, or a lot of people on this forum are covering up the head gasket failures that they've suffered. Which scenario is correct? Anyway, we digress... To remove the bad bits, you have to identify which bits are bad. Otherwise you'll replace literally everything. You also have to be satisifed that the replacement bits are better than the originals. Sometimes they are, sometimes they aren't. If the head gasket was weak on a 7M, it doesn't mean the crank dampener on a 2JZ is. Quote Link to comment Share on other sites More sharing options...
Dnk Posted February 3, 2012 Share Posted February 3, 2012 Quote Link to comment Share on other sites More sharing options...
Kirk Posted February 3, 2012 Share Posted February 3, 2012 You asked about the Titan pulley and I answered. Clearly you didn't listen so I'll say it again. Its the same as the ATI but has a Titan logo on it instead. The pulleys are made by the same company just with difference brand logos on them! The only advantage of those pulleys is the ability to add on a crank drive adapter to drive a dry sump pump. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted February 3, 2012 Share Posted February 3, 2012 clearly you folks just don't know me. are you trying to tell me that 1000 bhp supra's are running the standard oem pulley. i plan on a new engine for my car next year and it will be insanely powerful so i want something better. how do the titan one work, has anyone here had one? Now why would an increase in BHP affect the pulley, it merely damps the crank and drives ancillaries via a belt. If it's balanced (and they are pretty much spot on from the factory), it will be happy with more RPM. Let me ask you this, who do you think has done more R&D on torsional vibrations in a 2JZ-GTE engine, Toyota, with one of the best research centres in the industry, or ATI who make generic dampers with different hubs and belt pulleys for umpteen different engines? What reason is there for a 1000 BHP engine NOT to run a stock damper unless some drag racing body insist on a damper constraint system? I don't know you, so I have to ask this.... Quote Link to comment Share on other sites More sharing options...
Nic Posted February 3, 2012 Share Posted February 3, 2012 Budge up :Popcorn: Quote Link to comment Share on other sites More sharing options...
garethr Posted February 3, 2012 Share Posted February 3, 2012 This (from the unpublished, except on a blog, autobiography of Roland Pike, who developed the Gold Star clubman racer for BSA) is about a bike engine about 60 years ago, but it illustrates what vibration can do (and why sharp edges are bad). Whilst working at BSA Dennis Lashmar carried on racing my old 'Pike BSA' with the alloy twin engine. I think he had one good win on a wet day at Snetterton, when it ran cool enough not to blow up. Latterly whenever we went to Silverstone or anywhere to watch him, he finished up sliding along on his backside at about 100mph with a broken crankshaft. This was too dangerous, I considered. Once, just after the massed start at Silverstone, with the pack all bunched up and approaching Woodcote corner at over 100mph, the engine suddenly seized and he was sliding along with bikes all round him! I told Mr Hopwood that if we could not do something about the crankshaft breakages we should drop the racing twin. He pointed out that as far as Lashmar was concerned it was his own bike and he could do what he liked with it, but the policy of the factory was to make a twin. I felt we should make a new crank for it to which he agreed and wanted to know if I had any suggestions. By this time Group Research were in the picture at BSA and they demonstrated to me in ten minutes what I had suspected for years. They came up with some very good ideas. One was that the crank needed larger crankpin journals which would make it stiffer and get away from the frequency at which it now vibrated. Mr Hopwood agreed that their suggestions were fine for 1955 but at that time we had to use what we had. He was interested to know if any other suggestions and Group Research said to put a rolled radius around the ends of each crankpin. They demonstrated by putting a standard crankshaft on vee blocks over the top of the electro-magnetic vibrator they had built. They started some sort of motor generator. The noise was like standing next to a jet engine at the airport, it went into a scream and from a scream to an outer pitch sound, on to another phase even higher, then they brought in the electro-magnetic vibrator and the whole place began to buzz. The frequency of the vibrator was adjusted to a multiple of 6,600, the crank vibrated with a high speed buzz, inside ten minutes there was a loud bang, the crank fell in two parts, broken at the usual point, showing the same sort of fracture that we had experienced after three hours running at 6600 RPM. It was a much quicker way of testing a crankshaft and without wrecking an engine. Next they set up one of their special cranks, with the rolled fillet radius on the crankpin, it was subjected to the same test, buzzing away on the vee blocks, ten minutes passed, thirty minutes and it was still in one piece. I got tired of waiting and asked to be informed when it broke. It did not break and after one hour it was still good. I was very impressed and so was Mr Hopwood, but the factory again did not seem interested, perhaps they could not believe it. This rolling process consisted of applying a ball ended tool to the radius under high pressure in a big lathe. A few cranks were made, some for research, some for use on the dyno. It seemed fantastic that this simple process could make such a difference. Many years later, when I was working for Volkswagen in the USA, I discovered that they cured a rash of broken crankshafts on the 1965 truck engine by the same procedure, except that they did not use a ball, but a small roller, to form the radius. Quote Link to comment Share on other sites More sharing options...
Digsy Posted February 3, 2012 Share Posted February 3, 2012 The bottom line with torsional vibration dampers is that in OEM world they are specifically tuned to the engine, or a faimly of engines. A generic aftermarket damper will not be. I am willing to be proved wrong but its an involved process requiring computer simulation and physical high speed vibration measurements made on a running engine on a proper engine dyno, so I simply do not believe that aftermarket parts are made specfically for each engine in the same way that OEM ones are. Having said that I have worked on plenty of engines that had power levels "around" OEM (certainly within the realms of BPU) that used carry over dampers without issue. However, if you plan on doing something extreme, like significantly increasing the input pulses to the crankshaft or significantly increasing the RPM (both to get more power) then you run the risk of putting the cranktrain outside of what the damper is designed to handle, or bringing a new resonant frequency inside the engine rev range. I'm sure there are loads of high power engines out there running with all sorts of setups but unless a tuner out there has access to OEM levels of development then I can virtually guarantee than none of the setups will be properly tuned. All engines have an achilles heel (whch the MK3 head gasket quite obviously is) but the logic doesn't extend to "OEMs don't know any better than aftermarket". It costs tens of thousands of pounds and a lot of skilled people to develop a cranktrain. Incidentally, the stock pulley has a torsional and a bending damper. None of the aftermarket ones I have seen do. Quote Link to comment Share on other sites More sharing options...
Digsy Posted February 3, 2012 Share Posted February 3, 2012 A few cranks were made, some for research, some for use on the dyno. It seemed fantastic that this simple process could make such a difference. Many years later, when I was working for Volkswagen in the USA, I discovered that they cured a rash of broken crankshafts on the 1965 truck engine by the same procedure, except that they did not use a ball, but a small roller, to form the radius. Fillet rolling is an extremely common process now. Even "cooking" engines use it. It raises the material's fatigue limit by putting localised compressive stress into the most highly loaded parts of the crank. In order to initiate a crack, the loads must first overcome the built in compressive stress to create a tensile stress. Quote Link to comment Share on other sites More sharing options...
little num Posted February 3, 2012 Share Posted February 3, 2012 (edited) Lovely looking engine there bud, would love to see how much power you get once its fitted. I love my 1JZ and also have lightweight pullys except the crank pully as i went with a new OEM 1, same pully for both the JZ engine's. Edited February 3, 2012 by little num (see edit history) Quote Link to comment Share on other sites More sharing options...
hagar Posted February 3, 2012 Author Share Posted February 3, 2012 it's only in it for about 1 year then it is out when i have the new engine, that engine in the pic's will then be going into a mk1 escort shell. Quote Link to comment Share on other sites More sharing options...
Hellstrom Posted February 3, 2012 Share Posted February 3, 2012 (edited) Well the mk3 7M engine dont have MLS head gasket 2jz has it stock. Also the headbolts used on 7M where torqued too low thats why the eats headgaskets. Also the bottom end takes alot of punish due to this matter from mixing oil and water. The 7M bottom end is awsome if you get the oil pressure up and fixing the gasket. About the crankdamper i cant say if ATI is better or worse the OEM However the ATI Will not split oem could do hence they are needed in some ET's. If you rather want a fluid/gel based damper you should look towards Fluidampr --- I am here: http://maps.google.com/maps?ll=57.729305,11.786229 Edited February 3, 2012 by Hellstrom (see edit history) Quote Link to comment Share on other sites More sharing options...
CanisLupus Posted February 3, 2012 Share Posted February 3, 2012 I honestly don't think that a NEW stock Damper will split. All the cases I've heard of them splitting were old dampers.... Quote Link to comment Share on other sites More sharing options...
hagar Posted February 3, 2012 Author Share Posted February 3, 2012 have you guys seen this, it will take a while to get through. http://www.supraforums.com/forum/showthread.php?558853-ATI-vs-Fluidamper Quote Link to comment Share on other sites More sharing options...
dude Posted February 3, 2012 Share Posted February 3, 2012 Now why would an increase in BHP affect the pulley, it merely damps the crank and drives ancillaries via a belt. If it's balanced (and they are pretty much spot on from the factory), it will be happy with more RPM. Let me ask you this, who do you think has done more R&D on torsional vibrations in a 2JZ-GTE engine, Toyota, with one of the best research centres in the industry, or ATI who make generic dampers with different hubs and belt pulleys for umpteen different engines? What reason is there for a 1000 BHP engine NOT to run a stock damper unless some drag racing body insist on a damper constraint system? I don't know you, so I have to ask this.... I always run a BL or Titan damper............................................................because I have to, the stock ones do not pass scrutineering otherwise I would run one. Quote Link to comment Share on other sites More sharing options...
Hellstrom Posted February 3, 2012 Share Posted February 3, 2012 I honestly don't think that a NEW stock Damper will split. All the cases I've heard of them splitting were old dampers.... Yeah for obvious reasons and old used one will be in alot worse shape then a new one. i just stated that some ET's require you to have SFI/FIA or W/E and i dont really think it will split either however if someone plan on getting loads of power out of the engine you will probebly need to rise the rev limit as one would want a bit wider register. so when revving 8.5-9kRPM who know for how long it will last. i would probebly go for either OEM or Fluidampr. but thats just me. Quote Link to comment Share on other sites More sharing options...
Nic Posted February 3, 2012 Share Posted February 3, 2012 (edited) clearly you folks just don't know me. are you trying to tell me that 1000 bhp supra's are running the standard oem pulley. i plan on a new engine for my car next year and it will be insanely powerful so i want something better. how do the titan one work, has anyone here had one? Who's building this insanely powerful engine? Edited February 3, 2012 by Nic (see edit history) Quote Link to comment Share on other sites More sharing options...
Ian C Posted February 3, 2012 Share Posted February 3, 2012 I used to run an unorthodox crank pulley and it made no difference at all. After talking to Digsy about it, I put the stock pulley back on. If the aftermarket one doesn't change the way a car feels to drive, why bother? Quote Link to comment Share on other sites More sharing options...
Lude Posted February 5, 2012 Share Posted February 5, 2012 (edited) does anyone know what the cost of one is from toyota? just called them and the parts dept is shut today (sunday) just working out how it compares to the whifbitz one (£219) EDIT: called toyota, £290. will be going for the whifbitz Edited February 6, 2012 by Lude (see edit history) Quote Link to comment Share on other sites More sharing options...
superdooper Posted February 12, 2012 Share Posted February 12, 2012 just get a origanal and spray it blue nobody will notice wen ya engines in it will still look sweet Quote Link to comment Share on other sites More sharing options...
superdooper Posted February 12, 2012 Share Posted February 12, 2012 If ya damper splits, if you have beans going on, it could fly forward and go through your radiator , and if you are going some ud never know until its too late, same on supras, if you get rid of the origanal fan, the fan acts a safety belt n braces device, the loose damper hits the origanal supra fan you see, and it stops it flying forward in to the rad. Its better to chew a fan blades then loose a radiator or a engine. just idea ok...think of it ok. Just advisary, becose wen the lett go ...they let they let go. If you get rid of your fan to gain a 2-5 H.P it up to u. Quote Link to comment Share on other sites More sharing options...
Nic Posted March 6, 2012 Share Posted March 6, 2012 You have really answered your own question, without realising it The crank at the front gets the impulses from just the no 1 cylinder, and as you move back along it the crank gets the torque pulses from more and more cylinders, until the last main bearing section is seeing all six firing pulses. So you have differential torque loadings along its length. Add to that the pulses are sometimes unequal, but a straight six is pretty much OK in that regard, which is why they are normally such sweet running engine formats. Then, and this is the bit you answered yourself, you have differential inertia. The front of the crank just "spins" and maybe drives some ancillaries. the back end has a dirty big flywheel to give inertia to the engine for added smoothness and easy starts, both as in firing the engine up from stopped, and driving smoothly away from a standstill on the road. Add the pulses, the unequal torque loading along its length, and the unequal inertia, front and rear and the crank is constantly twisting and untwisting (literally, but fractionally) all the time the engine is running. At certain RPM's and loadings it will twist a LOT relatively speaking. These are the crank harmonics, a BAD thing. The front damper's job is to calm these motions to stop the thing fatiguing and eventually failing catastrophically. Now, that's a pretty simplistic explanation, but basically the damper tries to damp down twisting movements, the same as the dampers on the road springs dampen the car body's oscillations up and down. If you have knackered, or no dampers (shock absorbers as they are so often wrongly called), the car's body vertical motion is violent, uncontrolled and potentially dangerous and unstable. By removing, or sometimes just altering the crank damper, you are basically doing the same to the engine, albeit the results are not usually immediately obvious. HTH. Happened across this today and wondered what your view was Chris. http://vibrationfree.co.uk/?page_id=863 Quote Link to comment Share on other sites More sharing options...
JamieP Posted March 6, 2012 Share Posted March 6, 2012 OP looks like he is going for plenty of power, On a high reving, big bhp engine is it worth the risk running a stock pulley? I remember seeing the damage done to L33's single supra when the oem pulley let go, Ive ran Titan crank dampers for as long as ive had supras. Quote Link to comment Share on other sites More sharing options...
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