Help needed troubleshooting V 11 Sport

[bigbikerrick]

Thank you guys for educating me on the proper way to do a leakdown test. I had never done one before, and just put the piston at TDC on compression, then filled the cylinder with compressed air.  I am thinking in this case with the compression test showing almost no compression on one side, head removal is in order, to see whats going on.
I appreciate the advice and suggestion, guys. Much appreciated....Espe cially yours, Guzzisteve!
Rick

[Shiny Hat]

Haven't had any issues hitting valve at BDC  in over 50yrs so I don't think I'll have one. I'm out, if your an expert like the rest here, you fix it. NO WONDER every tech leaves this place, the TROLL factor is terrible.

You didn’t say do it at BDC, you gave no specifics.
Simply put it’s bad advice and you have to consider a newbie reading this and think it’s ok to bang a valve open.
I guarantee you the cause would have been long ago solved if the bike was in front of me.
If I gave incorrect advice then correct that, I know why you posted what you did and that my friend was trolling.
Reread my post I gave advice as to why he could be having an issue with the leak test and gave him things to check, that’s not trolling.

You were incorrect in your advice and rather then admit it was a mistake you played the troll card.
Not cool.

[bigbikerrick]

Hey Guys, I was laying in bed,awake last night thinking about this. This is so strange, the way the bike would run great at high speeds, but not idle, etc at lower speeds. Incredible that would happen with almost no compression on the right side. I guess its possible once the engine is spinning up to speed.  The V 11 sport is at my "retirement" home in Green valley south of Tucson, where I am at only on weekends. The plan is to trailer the bike to the owners home a few miles away, and I will help him remove the head/cylinder there. From what I gather, with this bike it looks like its been ridden hard and put away wet, as they say. I had a hard time getting the oil dipstick back in, it was very "finicky", and had to find a hole to go into way deep in the engine. I realized the bike has had a sloppage plate of some type installed. You can see the alloy plate between the sump spacer, and the block. almost all the alloy bits on the bike have been powder coated black, etc. You can tell the bike has been taken all apart,and "messed with" alot.
Rick.

[bigbikerrick]

Wrenching on these old bikes, sure is a learning experience! I have to keep reminding myself "check the simple things first" If I would have had the presence of mind to do a compression check first, I would have avoided the owner from spending money on the crank sensor, wires, caps,  TPS,etc.  Live and learn, fellas! Its all good, though. I view it all as part of the learning curve. Once we get the head and cylinder pulled, I will take photos,and follow up with you guys here as to what the findings are.
Thanks to every single one of you guys that have helped me. You guys rock!   
Rick.

[Shiny Hat]

Wrenching on these old bikes, sure is a learning experience! I have to keep reminding myself "check the simple things first" If I would have had the presence of mind to do a compression check first, I would have avoided the owner from spending money on the crank sensor, wires, caps,  TPS,etc.  Live and learn, fellas! Its all good, though. I view it all as part of the learning curve. Once we get the head and cylinder pulled, I will take photos,and follow up with you guys here as to what the findings are.
Thanks to every single one of you guys that have helped me. You guys rock!   
Rick.

Here’s a really simple test for compression, use your thumb. If you can hold your thumb over the spark plug hole it most likely doesn’t have enough compression to fire. If it blows your thumb off and you hear the air pop it will be enough to fire. Not exact science but it is a quick simple thing to do. Unplug the coils before doing this.

[John A]

You didn’t say do it at BDC, you gave no specifics.
Simply put it’s bad advice and you have to consider a newbie reading this and think it’s ok to bang a valve open.
I guarantee you the cause would have been long ago solved if the bike was in front of me.
If I gave incorrect advice then correct that, I know why you posted what you did and that my friend was trolling.
Reread my post I gave advice as to why he could be having an issue with the leak test and gave him things to check, that’s not trolling.

You were incorrect in your advice and rather then admit it was a mistake you played the troll card.
Not cool.

 
He said bdc in the first sentence. No edit. It’s the only place to stake a valve safely. it’s useful to blow seat/valve interface in case there is crud there. It also checks the sealing of the valves without having to hold the crank. The advice is correct.

[guzzisteve]

You didn’t say do it at BDC, you gave no specifics.
Simply put it’s bad advice and you have to consider a newbie reading this and think it’s ok to bang a valve open.
I guarantee you the cause would have been long ago solved if the bike was in front of me.
If I gave incorrect advice then correct that, I know why you posted what you did and that my friend was trolling.
Reread my post I gave advice as to why he could be having an issue with the leak test and gave him things to check, that’s not trolling.

You were incorrect in your advice and rather then admit it was a mistake you played the troll card.
Not cool.

My bad, I do an extreme test at bottom cause it should be tighter(rings). No trolling, I shouldn't be on computer anyway.

[Shiny Hat]

 
He said bdc in the first sentence. No edit. It’s the only place to stake a valve safely. it’s useful to blow seat/valve interface in case there is crud there. The advice is correct.

True, he did say set to BDC after TDC then bang the valves open? I stand corrected. Still not good advice and doesn’t blow out what the engine running or cranking would normally do. Look at the big picture, the engine was operated for days with claimed speeds up to 100mph and there might be crud between a valve and seat causing the issue which can be cleaned? At that point the crud valve is toast. Also noted to unloosen the adjusters and remove the push rods to perform the bang valve cleaning. Applying the same logic you would remove the valve actuation on an overhead cam 4 valve head to bang on valves? Get into 3, 4, 6, 8 cylinder engines and it’s taking a simple test and adding way more than you have to. The OP has 30 psi in one cylinder, you could bang on the valves all day.

[Shiny Hat]

My bad, I do an extreme test at bottom cause it should be tighter(rings). No trolling, I shouldn't be on computer anyway.

I’m willing to learn, why are the rings tighter on the bottom? I would think you would want to test where they would be loosest to not skew the leak test, if the rings are tighter on the bottom? Is it a comparison between TDC and BDC? That’s a spec I’ve never seen, indication of cylinder taper? Curious.

[Moparnut72]

In the aircraft shop after a run in on an overhauled radial we did a leak down test. It was always done at top TDC. I don't know why but that's what was done. Those engines don't have a cam as we know them the but used a cam plate. Had to hold on to the prop and it was surprising how much force there was even at only 80psi.
kk

[John A]

In the aircraft shop after a run in on an overhauled radial we did a leak down test. It was always done at top TDC. I don't know why but that's what was done. Those engines don't have a cam as we know them the but used a cam plate. Had to hold on to the prop and it was surprising how much force there was even at only 80psi.
kk

Yep , those big suckers will kill you . Let a blade get a little off dead center and it’s time to pay very close attention…

[73 sport]

  Gentlemen, thanks for your comments on working on aircraft. I worked on Stearmans, Twin Beech, up to Connies. I enjoyed the recips. The jets are wonderful,   but the prop jobs have a different soul.

[Shiny Hat]

In the aircraft shop after a run in on an overhauled radial we did a leak down test. It was always done at top TDC. I don't know why but that's what was done. Those engines don't have a cam as we know them the but used a cam plate. Had to hold on to the prop and it was surprising how much force there was even at only 80psi.
kk

It’s done at TDC compression because the valves are fully closed in this position. You need this to do a leak down test.
You can’t do it at BDC because, depending on the stroke, a valve will be opened. This is the reason Steve removes the push rods so the valves will be closed. It’s an unnecessary step for a leak test but if that’s your thing go for it.
When the cylinder is pressurized the piston can move down. It can go either way and rotate the crank backwards or forward depending on the rod position. Once the piston is pushed down a valve will open and the test is not going to be accurate and can actually lead you to believe there is a leak past a valve because you are unaware the piston moved.
If there is a leak past one of the valves it can still be hard to determine which on. Once the air gets past the valve it enters a high volume low pressure area and the velocity slows. If you hear the leak open the throttle and listen for a sound change. On the exhaust block one of the mufflers if it uses a crossover and listen to the other or light a cigar and blow the smoke at the muffler end.
My posts aren’t to argue or troll it’s to help the OP and anyone else unfamiliar with a leak down test. It’s a simple test, try and keep it that way.

[cowtownchemist]

I realized the bike has had a sloppage plate of some type installed. You can see the alloy plate between the sump spacer, and the block. almost all the alloy bits on the bike have been powder coated black, etc. You can tell the bike has been taken all apart,and "messed with" alot.
Rick.

That sounds like the "Pete Roper sloppage plate" designed by one of the forum members here and over at https://www.v11lemans.com/forums/.  You may consider posting your problems over on that forum as it is specified to the V11 with some very knowledgeable and helpful people.  It is a small community, and considering the bike has SpeedHut guages and the Roper sloppage plate, both of which seem to have originated from members of the V11 forum, it is possible that you may find the previous owner of the bike there in order to get background information.

[Chuck in Indiana]

I've always done a leak down at TDC ready to fire on that cylinder. Staking the valves at that position (with a copper hammer) will many times blow off carbon/corrosion/crap from the valves, and compression will come up.

I guess its possible once the engine is spinning up to speed.

Yes it is. I've seen cylinders with little compression running fairly normally at cruise rpm.

[bigbikerrick]

hey Guys, I pulled the head. The cylinder looks good, I believe. The area of the head, around the  exhaust valve  looks blackened. I turned the head upside down ,and filled it with water, water ran out the exhaust port. no water came out the intake port.  You can see the water dribbling out in the second  photo.
Rick. 

[bigbikerrick]

Check out the area around the exhaust port in the rocker box. it is all blackened. What do you guys think of that?  The area around the intake port looks normal.  This is the right side head. The left side is where I  originally found the valves had zero clearance.
Rick

[Chuck in Indiana]

Like I mentioned a long time ago.. a proper leak down test would have told you if the rings are bad, too. (shrug) Now, you don't know.. you may just get the head done, put it back together, and find out the rings need to be replaced. (I'm guessing they are ok, though)

[Shiny Hat]

hey Guys, I pulled the head. The cylinder looks good, I believe. The area of the head, around the  exhaust valve  looks blackened. I turned the head upside down ,and filled it with water, water ran out the exhaust port. no water came out the intake port.  You can see the water dribbling out in the second  photo.
Rick.

Looking at the pictures it looks like the piston kissed the exhaust valve.
You’re pulling both heads to have the valves done?

[Shiny Hat]

Like I mentioned a long time ago.. a proper leak down test would have told you if the rings are bad, too. (shrug) Now, you don't know.. you may just get the head done, put it back together, and find out the rings need to be replaced. (I'm guessing they are ok, though)

With a leak at the exhaust valve a leak down test would not help him determine if the rings were worn. To determine if the rings are worn the valves would have to seal. Would work on the good cylinder but not the one reading 30 psi.

[Shiny Hat]

Check out the area around the exhaust port in the rocker box. it is all blackened. What do you guys think of that?  The area around the intake port looks normal.  This is the right side head. The left side is where I  originally found the valves had zero clearance.
Rick

Yeah that got warm. I imagine when that cylinder would fire at higher RPM’s the leak caused excessive heat. Just curious are the exhaust header pipes a different color right and left?

[pressureangle]

Leakdown test is performed at TDC because that's where ring seal matters; there is no meaningful or useful cylinder pressure in the bottom half of the stroke. IIRC peak cylinder pressure is around 20* after TDC, but you can't do a leakdown there unless you have the means to restrain the crankshaft against the pressure, which as stated by others is a lot harder than one might think.

[Chuck in Indiana]

You have to be *right at* TDC. Otherwise, pressure will just push the piston down, and you have to start over.

With a leak at the exhaust valve a leak down test would not help him determine if the rings were worn. To determine if the rings are worn the valves would have to seal. Would work on the good cylinder but not the one reading 30 psi.

I respectfully disagree. I can hear 30 psi. at the breather without an issue.

[lucian]

Check out the area around the exhaust port in the rocker box. it is all blackened. What do you guys think of that?  The area around the intake port looks normal.  This is the right side head. The left side is where I  originally found the valves had zero clearance.
Rick

  combustion gasses are being forced up through the valve guide as the exhaust valve is not sealing .   Time to pull that valve and inspect valve guide clearance as well as valve and seat conditions.   

[Shiny Hat]

You have to be *right at* TDC. Otherwise, pressure will just push the piston down, and you have to start over.I respectfully disagree. I can hear 30 psi. at the breather without an issue.

I think we are on two different pages.
When the OP did the compression test the right cylinder was 30 psi, the leak down test was 0.
He could never build any pressure in the cylinder to do a proper leak down for the rings due to the pressure loss out the exhaust valve.
If the valves sealed properly and he was able able to get the tester to 90 psi and showing a loss of 30 psi then yes you would hear that in the breather, dip stick hole, etc.

Kind of past that now, he does have a problem with the exhaust valve leaking so that will be his area of focus.

[LowRyter]

as a mechanical nitwit.  given a burned valve, what next?  new valve? new seat in the head?  both?  something else?

you guys have all done this but me?  I haven't.  The suspense is killing me.   
 

[bigbikerrick]

We will see what the more knowledgable here recommend. I bought a valve spring compressor,and  plan to remove the valves today, and take a look at the valves and the seats, and check the play in the guide. 
Rick

[lucian]

Make sure that if you disassemble both heads at the same time that you keep track of which valves belong to which head. Common sense I know, but easy to get them mixed up especially on 4v heads , I am still a bit skeptical about the rings , It looks from the bore photo that there is a bit of corrosion ?  At this point may be worthwhile to have a look.  could have a stuck compression ring

[bigbikerrick]

Make sure that if you disassemble both heads at the same time that you keep track of which valves belong to which head. Common sense I know, but easy to get them mixed up especially on 4v heads , I am still a bit skeptical about the rings , It looks from the bore photo that there is a bit of corrosion ?  At this point may be worthwhile to have a look.  could have a stuck compression ring

I have not cleaned up the top of the piston, and the cylinder yet, but from what I saw, the crosshatch marks are still visible in the nikasil coating, and there is no obvious signs of cylinder damage. That makes me hopeful the rings are intact. for sure a broken ring would cause some cylinder damage, I would think.  I cant get the valves mixed up here, they are different sizes, but thanks for the heads up.  I will post some photos, for the group to see, when I remove the valves.
thanks
Rick

[Shiny Hat]

The exhaust valve in the right head is bent, piston hit it, slight but bent none the less (you’ll know more when it’s removed).
Replace that valve and have a machine shop do the heads, they will also let you know if the seats, guides and intake valve are ok and useable.
I would recommend to do both, you will have one redone with clean dressed valves and the left side will have build up on the valves. You will have to compensate for that with balance, chase it.
I would rather start with both heads being done and all things being equal. If it’s a budget job you can probably leave the left alone, the choice is yours but there are unknowns (you didn’t ask but if you did I would not do one without the other).