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Well I joined last week. 5 Laps into the first of two trackdays. Everytime I read about somone doing this I always ask why? So I think I have some answers now. In my case it was twofold. I have a Falicon super crank and crower ti rods. On first check during assembly I had .0028 inch clearence. I wanted .0025 or smaller. I have been told you can live with up to .003. So I did a dryfilm coating which is supposed to be good for taking up .0004 in clearence. David Vizzard who writes for Popular Hot Rodding and is the author of many books says the coating give more longevity but is not sure why. So I wanted to give it a try. I was going to take the engine apart this winter and these two days were to be the last time I ran it this year. I aways cut my oil filters apart to look for metal and also the magnetic drain plug. The motor had 23 superhard trackdays and about 3k street miles which were hard miles also. I am running 14 to 1 compression there are no signs of dentanation and no oil in the airbox and no sign of any oil in the combustion chamber. Valve guide seals are good and ring seal is perfect. No wheelies and synthetic oil from new. Now here is the interesting part. Every picture I have seen from other peoples rod bearing failure there is heat damage. Mine has none. The parts are all shiny clean. The crank journel is scored as are rod big ends but no sign of any heat. Just worn out. One bearing was spun and the other was down to the copper but in place. So what does this say? My motor was just worn out and needed a shorter maintance schedule. The overheated parts I have seen pictures of would say that there was a interuption of oil supply. Oil is what cools the bearings. No oil and heat is the result. Mine failed, but there was a oil supply at all times and no over heating. My ti rods can be resized and the crank journel welded and reground. Its a $400 fix and I keep my good rods and Falicon crank.
 

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Geeze, Art, I think I remember you from the old micapeak list...didn't you do N2's motor too?

What kind of dryfilm? Are we talking PTFE or some kind of microplate/micropolish or what? You don't think that helped reduce the friction that causes the heat for everyone else? Perhaps were you smart enough to turn it off? Some other pics looked like they not only spun 'em but had them both wedge on top of one another piled up on one side, fitting together poorly enough to make a metal-wedge-brake until it wouldn't turn, hardly any wonder that made heat. A big-end failure makes a racket but still makes power until a pretty extreme piont is reached, and some guys just keep going until it stops.

You sure opted for the high-end parts! Now I'm going to pester you with questions or ask for a link to posts about your mill...Opinions on the supercrank? The pics are like porn...the very idea of one with scratched journals is like a supermodel with a chipped front tooth. Do they weld it up with even harder metal? Do Ti rods stretch more, do they need more clearance to the valves or more squish clearance? Do their big-ends deform out-of-round at high revs? Did you do anything to raise the red line? Are your pistons any lighter than stock? What cams are you running?
 

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Same here with big end not heating up, but FAILING, lightly pitted and scored crank journal for front cyl, but nice and perfect on the rear journal, shells for rear cyl in good nick too, a few small areas where i can see a bit of copper though. the rest of the motor is schmick, factory cross hatching in the bores, no chunks of metal anywhere, although a really fine metallic dust (non ferrous) in the oil.
Funny thing for me was the bearing shells that went, looks like they shattered, and then stayed located until i pulled the big end cap off. Note that i only travelled a few hundred feet at light load after the knock started, and shut off.
Sorry about the pic quality, it was taken on a phone camera.
 

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Its a shame they went, but cool that its a fairly easy fix:thumbup

Think the oil pressure just isn't enough to keep the metal surfaces apart on the high performance motor? Any way of increasing oil pressure?
 

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Discussion Starter #5
The bearing coating is a Molybdenum soild dry film. The main reason I used it is because I wanted a small clearence number. I had the biggest shells from Suzuki and they were not big enough. Falicon micro polishes the journel and I think this makes it slightly undersized. I have since learned you can go to a automotive bearing to get a thicker shell. I think the coating may have made it last a bit longer once it started to go. If a plain bearing works right metal never touches metal. Only oil is is in contact with anything. Starting is where most of the wear takes place. My motor now sits for long periods of time between starts. So oil drain down is a issue. The rule of thumb for oil pressure is 10lbs per 1000rpm. Add more pressure than you need justs uses hp to pump the oil. On a race motor a bigger clearence on the bearing can give some power but not last as long. On my previous motors I always set the big end at .002 and they lasted longer and made good power. I still contend that a stock motor with good oil supply and no oil in the airbox(oil in the combustion process is a cause of detenation) and no detenation should last 100k miles. When I repair the crank the rods will be done first and I can call the journel size on the crank and get my .002 with Suzuki bearings. They weld and remachine it. The hardness does not change. I still think failures with heat are oil related vs wearing out. Other causes can be a out of round big end and of course detenation and in rare cases bad shells. (ask early R-7 owners including the factory team) A telling story is that the main bearing look perfect. The Falicon crank is a very nice peice of work. The main reason for their work is one to verify the crank is sound and to rebalence for the lighter rods and pistons. The rods are over 200 grams lighter each and the pistons about 20 grams each. The ti rods streach less that the stock steel so you can go tighter with the squish. This motor was at 9.3mm which works just fine. The big ends do not deform on the rods.There are no carbon deposits at the edges of the piston. I could go tighter but then I would have to lose some compression or else the stock starter motor will not work. At sea level I have to jump it from a car. I have sent the ECM to superchips and got the redlline raised to 10,342rpm(confirmed by a data logger) but peak power is still under 10k rpm. I use Webcam 108/189 cams.
 

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Start ups are the most abusive portion of any engine cycle. I'd look into a pressurized oil container tied into the oil system. Before start you charge the stock system with this external tank of oil. Start the engine, let oil pressure build and fill your tank back up. Shut the valve and remove the external system.

How often was the oil changed? Any damage to your oil pump from contamination?
 

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Discussion Starter #7
There are systems on the market for any engine. They use compressed air in a tank charged by the engine. When you trurn the key on it runs through the oil system before you crank. Then is recharged and set for the next start. Not sure how it would fit in a TL. Any top level car race engine has such a system and the oil is preheated to boot! They still blow motors. I have had factory riders of big twins tell me big end rod bearing faluires are not uncommon.
 

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isn't it usually the front cylinder? Wouldn't this indicate an oiling problem that could be engineered around?
john
 

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i think you are right with your guess that the shells need frequent replacement on your motor,23 track days + 3000 st miles,that would be a record for almost any 150hp 1000cc v-twin from anyone i hope your right with 100,000 miles on a stock motor i have a 98tls with 52,000 miles and i know its only a matter of time untill she pops
 

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cven said:
i think you are right with your guess that the shells need frequent replacement on your motor,23 track days + 3000 st miles,that would be a record for almost any 150hp 1000cc v-twin from anyone i hope your right with 100,000 miles on a stock motor i have a 98tls with 52,000 miles and i know its only a matter of time untill she pops
i managed about 45,000befor my big ends gave up..... hard miles though:devious
 
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