Help with heads

[Scud]

I can't get the RH rocker support off the head. The LH came off easily, as did the head.

 

Why am I doing this?  The LeMans had an oil leak from the RH head (misting my boot and the RH porkchop with oil) and figure I'd just replace both head gaskets, since I already had the exhaust off.

 

The problem - three of the four holes move freely over the studs. The top right is stuck. After about 30 minutes with soft mallets, rocking it back and forth, light leverage (wide screwdriver), and even trying to tap in a wood shim... I managed to get it to move only by the little gap in the photo - and it will not settle back down by hand either - which means if I do get it off, Ill probably have to pound it back on. 

 

I'm tempted to go in there with a lot more leverage - but I'm nervous about damaging the threads on the stud.

 

Any advice appreciated.

[MartyNZ]

My guess would be that there is a little burr, sharp edge, or swaged edge of the hole hooking onto a thread of the stud. If I'm right, you have two choices.

1. Lever the rocker support fitting up with pry bars, trying not to damage the rocker cover gasket surfaces, which means you are dragging the burr all the way through the hole. The aluminum casting is much softer than the steel stud, so any damage will be limited to the inside of the hole in the fitting.

2. Tap the fitting back down, retighten the nuts on all but the stud which is binding, and hook out the burr with a small screwdriver.

I think 2 is better. Before refitting, deburr all the holes where they get mashed by the nuts during torquing, and clear the stud threads of any debris. And fit a washer if it was missing, as torquing a nut against the aluminum casting will smear the aluminum into the threads.

[Scud]

Thanks Marty. I tapped it back down and removed a small semi-circular metal shaving. But I still had a hard time getting it loose. I use gentle leverage, rotating to all four corners - meanwhile wiggling the head to try to move the studs a little. Here's what I found:

 

 

The top right hole is the problem. The washer probably didn't seat correctly. Now I'm not sure what to do with the rocker support. It's kind of hard to make out in the picture, but there is raised lip on the upper RH stud hole - it goes from about 10-o'clock to about 3 o'clock. I suppose I can grind that down. But I can get a replacement part from my spare engine if needed. Keep or replace?  The thread seems good - the nut goes on smoothly.

 

As for the leak, I think the problem was not the head gasket, but the 4 O-rings that go around the studs on top of the head. They were very brittle and some broke when I removed them.

 

Here are pics of the RH head and piston. LH looks the same. I'd appreciate an experienced eye on these. Does it look like I should do anything besides bolt it all back together with new O-rings and gaskets? I was satisfied with the way the bike was running - this was motivated purely by an oil leak.

 

 

 

 

[MartyNZ]

...there is raised lip on the upper RH stud hole - it goes from about 10-o'clock to about 3 o'clock. I suppose I can grind that down. But I can get a replacement part from my spare engine if needed. Keep or replace?

 

...the problem was not the head gasket, but the 4 O-rings.

 

Does it look like I should do anything besides bolt it all back together with new O-rings and gaskets?

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If it was my bike, I'd clear that tight hole with a reamer or drill or a round file, so that it slid on with finger pressure. Then I'd very lightly countersink the top of the hole with a 90 deg or 100 deg countersink tool. No deeper than approx half a mm at 45 deg is necessary. Or scrape a chamfer with a Stanley knife. All that you are trying to do is transfer the tension loads on the studs (that you create by torquing the nuts) into compression loads on the fitting, head, gasket, barrel, & base gasket. A little rework of the hole in the fitting doesn't matter much.

I'd clean the gasket mating faces on the head and barrel with a hardwood or plastic scraper, while being super careful not to get anything down the oil passages in the barrel. The oil passages in the head you can blow out with air or degreaser before installing.

[Scud]

Good advice. I got the heads back on and the rocker support to slide back on smoothly -  no hammering needed.

 

I need one more tip:  how the heck do you get the exhaust gaskets out?

 

I have new gaskets, but if there are gaskets in there now, they must have compressed a lot. I've tried a screwdriver and a pick - there is only a very small lip, which I think could be the gasket - but I am starting to wonder it there is any gasket in there currently.

 

[MartyNZ]

how the heck do you get the exhaust gaskets out?

I have new gaskets, but if there are gaskets in there now, they must have compressed a lot. I've tried a screwdriver and a pick - there is only a very small lip, which I think could be the gasket - but I am staring to wonder it there is any gasket in there currently.

Good question. The parts catalog shows gaskets should be fitted, but you are not the first to find that gaskets were not there.

There have been comments on this forum about exhaust leaks causing tuning problems (like Kiwi Roy's sneeze). Since you have the gaskets, I think you should fit them and tell us if it runs any differently.

There is a step in the exhaust port which is an important part of exhaust tuning, don't be tempted to grind it out, unless your name is Dr John.

[Scud]

Yesterday was the first time in my life that I ever applied a grinder to any part of a cylinder head. I am not remotely tempted to grind out an exhaust port. 

 

I've cleaned out all the angles in the steps with a pick (got a lot of black dust). But I still cannot identify anything that looks like an exhaust gasket - or anything that looks removable. I guess I shouldn't be surprised that it was assembled without. This is my LeMans, in which I have discovered a number of other unpleasant surprises. So - maybe I spent a lot of time fussing with tuning to overcome a lack of exhaust gaskets?

 

Still waiting on delivery of a set of used pipes without crossovers. Then we'll see how she runs.

[footgoose]

It was not easy for me to tell if there was a gasket there in mine. I used a tool my dad made many years ago. An ice pick with an ever-so-carefully bent tip. About 1/4" & 90 degrees. My Yamaha had 2 sets of gaskets in when I changed them out.

[czakky]

I basically found the same thing with my Lemans. Could not find any gasket...

[Scud]

Czakky - did you then use gaskets when you re-assembled?

 

Here's a close-up. New gasket hanging on the stud. Does anybody think there could be a gasket in the head? I feel like I've been trying to remove something that doesn't exist.

 

[JBBenson]

I don't think there is a gasket in there. Judging from the width of the gasket hanging on the stud, will it create a rim that intrudes into the exhaust flow? I don't see how it will seat in there. I am probably not being helpful. Sorry.

 

Wait, I see a tiny "step" from the rusty ring to the darker, innermost ring. Is that the lip you are trying to get a pick under? If that's the "old gasket", it has a smaller width that the new one, right? It might be that the small "step" crushes the gasket and makes a tight seal. The gasket is a softer material, right?

 

Did you try PB blaster to see if the "old gasket" breaks loose?

[MartyNZ]

I think you should fit the gaskets. It looks like there wasn't any fitted before, but as Footgoose said, two gaskets don't cause a problem.

Can you show us a picture of a gasket in place in the head, and against the header? Does it protrude into the gas path?

I'm now thinking that I should take my headers off to check what's in there.

[Scud]

Can you show us a picture of a gasket in place in the head, and against the header? Does it protrude into the gas path?

 

The gasket is about the same size at the face of the pipe that it's supposed to seal - it doesn't protrude. It's fairly soft - I think it's supposed to compress a lot to make a tight seal.

 

 

[Scud]

Thanks guys - I got it all torqued down (31 foot-pounds or 42 newton-metres), new head and rocker cover gaskets, O-rings, washers.  Valves at .008" Intake and .010" Exhaust. 

 

I'm pretty sure I caused the oil leak shortly after I got the bike. It wasn't leaking at the time, but I decided to re-torque the heads during a valve check - and that's when it started leaking. At that time, I must have de-stressed one of the O-rings (4 per side around studs - between head and rocker support) just enough to cause a leak.

 

I swear, the hardest part is getting the throttle body boots back on. But I figured out something - if you start with the RH side it's much easier. That's because the RH cylinder is further forward. With the RH boot on, the angle of the LH boot is close to the intake port. If you put the LH on first, the angle is way off and it's damn near impossible to get the RH boot on.

 

...and another question... since I put in new head gaskets, do I need to re-torque the heads after a heat/cool cycle or a break-in period? I didn't see anything in the manual about it.

[docc]

I've heard a lot about retorquing heads over the years, so I'll defer to the experts.

 

Just make sure you use right head wrench and employ the the proper assistant . . .

 

(link with discretion)

 

http://www.v11lemans.com/forums/index.php?showtopic=19384&p=211501