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Hootowl
| Posted on Thursday, January 23, 2003 - 06:23 pm: |
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Admin, I was unable to figure out how to create this in the KV, so please move this if you feel like it. Today I noticed that I have a small oil leak at the back of the rear head gasket, just under the exhaust opening. I have a set of Cometic gaskets that I bought to replace the rocker box gaskets, so I already have the base and head gaskets, just need to put them in. My question is, can I JUST replace the head gaskets, or will removing the heads screw up the base gaskets because there won't be any clamping force on them? Or will there? I really don't want to deal with taking the pistons out of the jugs if I don't have to. Thanks guys... Jeff |
Budo
| Posted on Thursday, January 23, 2003 - 09:07 pm: |
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Odd, I just had to do that myself. I have a 1998 S1W with 31k miles on it. I did a top end rebuild at 19,324 miles. I had a head gasket leak in exactly the same place as you. I had installed James gaskets too. Well to answer your question. Remove the head very carefully. Gently pry between the head and cyl so as not to break the seal of the base gasket. Then place a socket over the cyl stud and tighten down the cyl stud bolts. I just used two on opposite corners. The pressure of the bolts over the cyl should keep enough pressure on the base gasket to prevent it from leaking. Good luck. |
Ravnos
| Posted on Thursday, January 23, 2003 - 09:08 pm: |
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I've had this same problem before. You can replace just the head gaskets if you are careful. When you remove the "head screws" just make sure the clynder doesn't move or shift. But if you are going to take that much of the top end apart might as well replace the base gasket, it's only a couple extra bucks for the part. Oh yeah don't forget that the "head screws" aren't re-useable, so purchase new ones. Josh |
Mightymouse
| Posted on Thursday, January 23, 2003 - 09:34 pm: |
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Hootowl: As long as you're going in that deep, I would recommend replacing the base gaskets. Beg, borrow, or steal a piston ring compression tool, and you'll have no problems. Besides, this will give you a chance to inspect your pistons, rings, circlips, and cylinder walls for peace of mind. Josh: I've never heard that the head screws are not re-useable. What is your source for this information? |
Spiderman
| Posted on Thursday, January 23, 2003 - 09:39 pm: |
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>>>>>>Oh yeah don't forget that the "head screws" aren't re-useable, so purchase new ones. That is false. You can re-use your Head bolts. You only replace head bolts on cars. It doesn't say it in any manual that Buell has, even the 9R, and the techs in my shop even agree. Also Replace your base gaskets It is cheap insurance. Plus just in case you do loosen them and don't know you don't have to take it back apart and get all pissed off. |
S320002
| Posted on Thursday, January 23, 2003 - 09:56 pm: |
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Spidey, "You only replace head bolts on cars." ??? We don't even do that on Top Fuel dragsters. Of course we use block studs instead of head bolts. Greg |
Spiderman
| Posted on Thursday, January 23, 2003 - 09:58 pm: |
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Yeah, I'm talking about your off the shelf ford or chevy motor. Not a 50 grand top fuel motor. |
S320002
| Posted on Thursday, January 23, 2003 - 10:19 pm: |
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By the way. Most head gasket failures occur near the push rod tubes. Failure is most often the result of nailing the throttle on a cold engine. Greg |
S320002
| Posted on Thursday, January 23, 2003 - 10:29 pm: |
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Spidey, Check the maintenance manual on your average Ford or Chevy. Unless some jackass has decided they aren't selling enough head bolts in the past couple of years they won't call for replacement. Greg |
Spiderman
| Posted on Thursday, January 23, 2003 - 10:40 pm: |
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Well my cousin does heads for a living and has ported heads for funny car teams. He says when replacing the heads to replace the bolts. So I did, Plus OE car head bolts aren't that good any way. BUT back to the original No you do not need to buy new head bolts for your bike Yes replace your base gaskets. |
S320002
| Posted on Thursday, January 23, 2003 - 10:49 pm: |
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Spidey, Would your cousin be nicknamed "Radar" and has he built heads for John Force? If so he drives the fuel car that I have pitted for. Greg |
Spiderman
| Posted on Thursday, January 23, 2003 - 11:37 pm: |
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nope, last project he did for top fuel was through his old shop and it was for the Hawian Punch funny car, obviously a long time ago, now he has his own shop and does private racers and private drag guys. I am slowley getting him into Buell and Harley stuff. |
Dynarider
| Posted on Thursday, January 23, 2003 - 11:51 pm: |
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Ahh Hawaiin punch funny car & Roland Leong. I dont remember who his driver was. And Spidey, I have never ever heard of the replace the headbolts deal. I have read about measuring them for stretch, but certainly not replacing them. |
Spiderman
| Posted on Friday, January 24, 2003 - 12:26 am: |
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On a car? Like I said thats what he told me. And when I replaced the heads on my 5.0, I did. I put in some grade 8 star head bolts. I know for a fact on a Buell or Harley you do not have to. Cause if it were the case you would have to replace the studs as well. |
Hootowl
| Posted on Friday, January 24, 2003 - 12:29 am: |
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Thanks for the input guys. By the way, 38K on the motor. Only been deep enough to change the rocker box gaskets. |
Spiderman
| Posted on Friday, January 24, 2003 - 12:31 am: |
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Nice How did the cylinders look. Check for Y shaped marks buy the stud holes on the cylinder walls. If they are excessive check the cyl. and make sure it is round. |
Newfie_Buell
| Posted on Friday, January 24, 2003 - 08:12 am: |
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You could probably avoid taking the pistons out by getting the piston near the bottom of the stroke and gently popping off the cylinder from the base then remove the piston from the bottom to the point where the wristpin can slide out without actually taking the piston from the cylinder. If someone else can give a better description of what I am talking about please chime in. Seeing you got the heads off it would be good insurance to do the complete top end gaskets. A friend rebuilt his sporty heads last season and never did the base gaskets. About halfways through the season he had to replace the base gaskets. Get the shop manual. If I am not wrong I think the head bolts should also be the TTY(torque to yield) type. When I replaced the head gasket on my 89 Saab 900 the REUSABLE head bolts were TTY. |
Dynarider
| Posted on Friday, January 24, 2003 - 08:18 am: |
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And dont forget that a Buell has very specific torque values for the headbolts. Tighten them till they strip, then back of 1/4 turn |
Aaron
| Posted on Friday, January 24, 2003 - 08:35 am: |
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Newfie's got the right idea. 'Cept do it out in the middle of the stroke. Lift the cyl just enough that the wrist pin can be removed (another 1/8" and the oil rings pop out). Put rags below the piston such that you don't lose the clip if you drop it. Remove just one clip and slide the wrist pin out. Then take the whole piston/cyl assembly off. If it still has the factory paper gasket, it may be a real pain to get it off the cylinder. Use gasket remover rather than scratch it up with a scraper. I'd use steel gaskets. Cometic EST's are the best I've ever used. Replace the circlip you had to remove. Put the new one in by finger, don't use a pair of pliers. |
Anonymous
| Posted on Friday, January 24, 2003 - 08:51 am: |
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Sometimes the piston pin's lateral movements pound a ridge on the opening preventing the pin from sliding past it. You must then use a tool (there is a special Jim's tool, I'm sure, but I use a block of wood with a hole and a threaded rod with a nut and a washer just under the diameter of the pin) to remove the pin. |
Dynarider
| Posted on Friday, January 24, 2003 - 08:52 am: |
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And for that pearl of wisdom you posted anon??? |
Mikej
| Posted on Friday, January 24, 2003 - 09:05 am: |
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I have never once replaced a headbolt on a car engine, Ford, Dodge, Chevy, Mitsubishi, VW, Jeep, Willys, Buick, and have removed or replaced heads on several of each. Never had a problem. Anony, Sounds like the Jim's Tool cuts the ridge, and your method just forces the pin past it. Newfie, What's this TTY stuff? Isn't "yield" the point of strippage? Or are you talking about the types of bolts with the second head that breaks off at a pre-engineered torque-point where you just turn them in and tighten until the upper head breaks off at it's stem? These are used on lots of steering column lock housings but don't have a faced lower head making them a cut-to-remove affair for anyone with the sad job to remove them at a later date. |
Andrewb
| Posted on Friday, January 24, 2003 - 12:01 pm: |
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Both my old merdedes diesels have a torque to X then settle for 15 minutes, then 90 degrees past mark spec in the manual. When (only once) you do the head you're supposed to use new fasteners. Just a info point. |
Bomber
| Posted on Friday, January 24, 2003 - 12:15 pm: |
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ok, this topic clearly needs some more non-aplicable information, and an applicable question many older cars and bikes state to torque the head fasteners to X lb ft, run the engine to operating temp Y times (typically, Y = 1), and then loosen the fasteners 1/4 to 1/2 turn, then re-torque to X . .. . . (I assume this is to make up for any change to the gasket thickness during the first heat/cool cycle(s)) . . . . that's the non-applicable information applicable question . . . .does process apply to sporty motors? I did not see it in the manual, but, as a former manual writer, I know these works to be less than 100% accurate . . . . |
Spiderman
| Posted on Friday, January 24, 2003 - 12:41 pm: |
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Ok here is what the Manual says for the 1200 heads. This is from memory cause I have had my heads off many a times. Alternate bolts in a X patern like on a car. 1------3 4------2 <<in that order for the front head 3------1 2------4 << for the rear tighten in order all bolts to 7 ft lbs then to 18 ft lbs lossen all Tighten in order 7 ft lbs then tighten in order to 18 ft lbs The in order tighten 1/4 of a turn. Be sure to lube bolt with a light coat of oil but not enough to pool. Do not use lock tigh or antiseize on the threads. |
Andrewb
| Posted on Friday, January 24, 2003 - 02:03 pm: |
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ok now I am looking at the '97 S3 manual... cylinder head install: a tighten each to 7-9 ft lbs b tighten each to 12-14 ft lbs c loosen 'em up then: d tighten each to 7-9 ft lbs e tighten to 12-14 ft lbs f reference mark bolt to head turn bolt addition 90 degrees. I think I'd replace the studs after a removal or two. Just MHO, beats taking it apart time and again for pissy little oil leaks. |
Newfie_Buell
| Posted on Friday, January 24, 2003 - 08:13 pm: |
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TTY was a term (torque to yeild) used by a harley mechanic I know. I also had to use the same torquing sequence on the Saab 900 head, torque to two values then go a further 90degrees. I actually have a guage that goes on the end of the bar when doing the final 90degrees |
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