| Author | Message | ||
     Preybird1 |
What the heck i torqued the head bolts to the factory spec and i got a head gasket leak, Yes i put a new gasket in. I followed manual to the letter tightening the head in 3 stages what am i doing wrong here! I am going to go back in and see whats up! | ||
| Jos51700 |
How tight did you tighten it? | ||
| Ratbuell |
Did you oil the bolts? IIRC they're supposed to go in wet with motor oil... | ||
| Jos51700 |
There's a VERY specific procedure. Oil threads and head-seat with clean motor oil, torque up in steps 7, and 14 ft-lb, and turn 90 degrees, in an N pattern. | ||
| Blackm2 |
Remember mine did that a few months back Jos? I had to go through the whole process again Preybird. As stated, just be sure you step in the correct sequence, also make sure the head is seated on there flat when you start tightening. I chalk mine up to a faulty gasket. Blew off a big chunk of the silver material. | ||
| Preybird1 |
I followed the book exactly oiled up all the bolts torqued to 11 nm as my wrench doesnt read foot pounds, Then to 18-20 nm and loosen them all again, And start over same steps left em at 19 nm. I was just noticing that the last step is a 1/4 inch turn. Im just no realizing i didnt turn the bolts the last 1/4 turn so. I am going to go back and start all over to get it right. What torque is the head at after the last 1/4 turn anyone know? | ||
| Buellistic |
REMEMBER THIS: you are dealing with ALUMINUM HEADs and CYLINDERs !!! This is how the FIRST STAGE should be done: TORQUE in a cross pattern(as best as you can since you are dealing with 4 studs) ... Do 3 ft.lbs , 6 ft.lbs., 9 ft.lbs. ... SECOND STAGE: Do 4 ft.lbs, 8 ft.lbs., 12 ft.lbs. ... THIRD STAGE: 1/4 turn ... 12 inch pounds equal 1 foot pound ... | ||
| Jos51700 |
Note: It's 90 degrees, not 1/4 inch. I think you typo'd, but wanted to clarify. I'd suspected that's what happened. I've seen the 1/4 method verified, and it changes every time, but usually in the 75-85 ft-lb range. | ||
| Jos51700 |
I've never known how there would be a significant difference, but HD specifies an N pattern, with a specific starting point. I've always followed it, and had no issues. | ||
| Buellistic |
Basic TRIG., 360 degrees in a circle, 1/2 of a circle is 180 degrees, and 1/4 of a circle is 90 degrees ... Very good on the "N" pattern, although it would sound like "BUELLschitte" to some ??? | ||
| Preybird1 |
Hey thanks jos and bullistic. Sounds like i didnt finish it correctly and i need to go in and re-do? Or would you guys suggest just turning them the rest of the 90 degrees or just start over! thanks for the help (Message edited by preybird1 on November 08, 2008) | ||
| Ducxl |
but usually in the 75-85 ft-lb range. I simply do not understand that comment.IF you're stating that the studs end up around 75-80 foot pounds of torque you're WAY,WAAAAAAYYYYYYY off. I think these studs would break off at 50. When i torqued my Ducati heads on last February i could FEEL the studs stretching at the final 38 foot pounds of torque.I know if i'd tried to end up at 75-80 i'd have long ago broken the studs. But i really feel i misunderstood your post. Explain,please?? | ||
| Buellistic |
IMHO taking apart is more important than putting together ... No one ever uses reverse SPECs. to take apart and it is never mentioned in any SERVICE MANUALs that "i" have ever got a hold of except "FORD" !!! If you back off and start over make sure you have the cylinder that you are re-torquing on TDC(no valve spring pressure)... | ||
| Blackm2 |
Is it leaking oil or is it blowing air Preybird? Mine was blowing air, it sounded like a train whistle, blew off the silver material, so I had to re-do. If it is just leaking oil, you may get away with re-torque, but either way I would probably re-do. | ||
| Preybird1 |
Yeah im gonna do a redo. Its air not oil and it was squeaking kinda like a train whistle! I was tying to figure out what the hell that was!! | ||
| Jos51700 |
and 1/4 of a circle is 90 degrees I know, but he said 1/4 turn and 1/4 inch in the same post. **************************************** And, I am exactly stating that the studs end up that high in torque. Let's say for example, that a bolt can stretch .005" for each inch of it's length, before it breaks. If it's 8 inches long, it can stretch .040" before it snaps. Remember, the studs are stretched even more when the engine heats up, due to the expansion of the aluminum in the cylinders and heads. This is why these motors like to develop gasket leaks and pop head gaskets when run hard while cold. It's because the bolts aren't at their final "torque" (used loosely) while cold! The aluminum cylinders grow much more than the steel cylinder studs. Another way to look at it. Mark your head bolt, and torque to 7 foot pounds. Make a reference mark. Torque to double that, 14 foot-pounds, and see how many degrees the bolt actually moves (Very few, 5-10). Think: The last step of this sequence is NINETY DEGREES, and you were already 14 ft-lbs tight! | ||
| Spiderman |
I used a tourqe wrench the last time i did the ol' 90* turn and it ended up being like 65 or so ft lbs. | ||
| Ducxl |
Oh.Your last paragraph makes sense.My factory Ducati service manual(and Kyle Thompson) states the final torque at 38 foot pounds torque.Different.I guess. It's been a few years since i last torqued a set of XL heads (Message edited by ducxl on November 08, 2008) | ||
| Buellistic |
Learning to be "MECHANIC's" are we !!! You'll are never going to trust a technician ... | ||
| Jos51700 |
You'll are never going to trust a technician I'm a technician. You don't trust me? | ||
| Sloppy |
Make sure you're using the latest gasket design -- the original gaskets were ka-ka. | ||
| Preybird1 |
Man i trust you jos51700 you helped me not fux my bike up sloppy got all new updated stuffs. So here is the verdict. I went through it again and the same problem happened again!! SO I WENT THROUGH IT AGAIN!!!...and this time we just kept turning the bolts until they stopped moving at 50fp they felt tight and didnt move easily....Then the 1/4 turn, They made the same creaky sound as they did when they cracked loose, They felt just right. Finally got it all back together and ready to fire up! DRUM ROLL PLEASE AS WE TEST FIRE........and nothing rear only firing checked spark and wire. WOW ZAP! this coil hurts worse than a car. used different wire tested ok, Plugged the sparky port with the old thumb. Ahh a little blow by ok put some oil in the cylinder. We had just cleaned it totally up before putting it together needs oil. OK DRUM ROLL AS WE TEST FIRE!! BAM IT FIRES UP YESSSSS IT LIVES . runs good..A little backfiring at 4000. At steady open throttle but i think it will get better but could get worse. Idle was off wouldnt stay idle. Adjusted idle screw it held. So i got to do the oil change tomorrow and maybe a test ride! | ||
| Jos51700 |
That's wicked tight on those studs. I'd be afraid of pulling threads out of the case with that kind of torque! Given the issues that TWO different members of the site have had, I'm wondering what is going on here. I've done a few hundred head gaskets, and none twice. | ||
| Sportyeric |
That sounds like a really bad idea. When that engine gets up to running temperature, there will be more strain on the studs than they were designed for. If you are getting a head gasket leak when following the recommended procedure, I would think that there is another issue, like maybe a warped head? | ||
| Preybird1 |
jos dont say that! what should i be at! I was skeptical it seems to be ok this factory manual seems to be vague. Man it was a hand held torque ratchet and Then a 2' torque bar! | ||
| Sportyeric |
Do you have the rubber O-rings in place on the locator pins? I'm no pro but I've always just followed the manual and haven't had an air leak on start-up. | ||
| Ratbuell |
Shouldn't need a 2' torque bar on a set of Buell heads. Those studs go into an *aluminum* case... Did you use new bolts, or reuse your old ones? From my years playing with 2.2 turbo Dodge engines (also a torque-to-yield setup - that last 1/4 turn stretches 'em on purpose), I always put in new un-stretched bolts. Overkill? Maybe. But cheap insurance. I'd pull it down again, and take the head and cylinder to a competent machine shop to have the gasket surface checked for flat. If they have to deck it more than a couple thousandths, I'd pull the other one and have it decked to match. | ||
| Blackm2 |
When I did mine, I followed the manual to the t, and it blew. Second time I did the same thing. The next time I have to do it, the only thing I would change is exactly what Rat says, get new head bolts. All of my bolts turned easy except one was creaking, which I'm sure was screwing with the final torque value | ||
| Buellistic |
"i" prefer anti-size compound on the threads over engine oil !!! | ||
| Ducxl |
I've never had a leaker.I use graphite Anti-Seize on the threads too |
