rear cylinder removal

[bill-ns]

Any reason why the rear cylinder can't be removed with the engine in the frame?

Bill

[Hordpower]

It'll come right off. Front can be removed in the frame as well.

Hord

[bill-ns]

Thank you sir! Depending on what I find, I may be coming to you for some pistons in the near future.
Good to hear about the front... I figured the rear should be easy (going from memory, the last time I looked at it).

Bill

[bill-ns]

Well... unfortunately I can't justify new pistons.. or rather I can't justify them to my wife!
The cylinder wall was in perfect shape... no wear in the cross hatching, no damage to the pistons, rings are within spec.

Things I've found... The oil ring gaps were within about 10mm of each other, spec is 20mm min.
The compression ring gaps were less than 90 degrees apart, and very close to the oil ring gaps. Spec is 120 degrees apart.

The other odd thing is that there was no difference between the 1st and 2nd compression ring. No bevel, and no marking. Anyone see this before? I don't believe this motor has been cracked open before... maybe it was a friday at the factory?

Intake valves seemed tight... exhaust had some play... will have to check them with a mic.

Original problem was lots of oil being burnt, but the compression wasn't too bad. So I'm going to deglaze cylinders and re-ring. Might as well do both cylinders even though it was only the rear one that was burning (front plugs are nice and clean, rear are caked with oil.) May end up doing the valve guides as well...

Bill

edit... valve seals were done in a previous effort to stop the oil consumptions... if anyone was wondering.

[kip]

but 663 or 700 slugs would be so sweet .

I just went out and checked my original rings. 17k motor with a front cylinder seize, back was decent though. I can't see the bevel of the second ring. I also can't see any markings on them, which seems weird now. The new rings I got from Hord had markings on them near the gap similar to in the manual.

HTH

[bill-ns]

ok... thanks for the info Kip... good to know. Yeah, I wouldn't have been at all upset about having to put new pistons in... But, new pistons, boring, and a future cam... I'm sure I can find another place to spend that money!

So... the front cylinder is a pain in the ass compared to the rear. Would be SO much easier if there was clearance for one of the exhaust studs, and back left head bolt! Anyway, pulled that one off last night, and now they're going to the shop to have the guides/valves checked/replaced.

The car hole looks like a hawk bomb went off...

Bill

[bill-ns]

One sad looking Hawk...

http://www.hawkgt.com/photoalbum/displayimage.php?pos=-4097

Bill

[kip]

but it will be so happy after the rebuild.

Looks good. You are the man for doing that in the frame. Are you zip tie-ing the front cam sprocket to keep its position on the chain? I tried to paint pen mine, but I slipped the chains on the crank in about the first 30 seconds...

When I put the cylinders back on I didn't use a ring compressor, which is how the manual says to do it. Just compressed each with my fingers. Was fairly painful. Curious if anyone else recommends a different method.

[bill-ns]

I noticed by the second cylinder that the cam gear can actually pass through the head and cylinder.... on my old nighthawk I had to seperate the chain and gear because there wasn't enough room.

I dropped the heads off to the local cycle shop. They're going to inspect and replace as needed. Also going to get them to run the hone through the cylinder to help seat the new rings. Not sure that it's needed, as there wasn't any glaze, and the cross hatching is clearly visible, but I'm sure a quick pass can't hurt.

I'll be doing the rings using the same method you used. Sharp buggers aren't they?! Try lining up all 4 pistons on an I4! That sucked!

Hope to get it back together soon... all up to the shop and when parts arrive.

Bill

[Hordpower]

First put the pistons in the cylinder, then slide the cylinder/piston assembly onto the engine, install pin and clip. I think it's easier that way, and less chance of snagging a ring.

[bill-ns]

Have you done this before?

That sounds like a fantastic way to do it. Much easier to deal with it on the bench.

What are your thoughts on deglazing? Recommended or not with new rings? The walls were very clean, nice cross hatching, no ridge... I just want to make sure the new rings are broken in nicely. I was thinking a quick pass with the ball hone?

Thanks!
Bill

[MrDude_1]

Have you done this before?

That sounds like a fantastic way to do it. Much easier to deal with it on the bench.

What are your thoughts on deglazing? Recommended or not with new rings? The walls were very clean, nice cross hatching, no ridge... I just want to make sure the new rings are broken in nicely. I was thinking a quick pass with the ball hone?

Thanks!
Bill

i cant say much for the motorcycle motors, but you ALWAYS want to do that with new rings on automotive motors.
without a FRESH crosshatch on there, the rings wont seat properly.

[balou34]

One sad looking Hawk...
http://www.hawkgt.com/photoalbum/dis....php?pos=-4097

I've been down that road, alltho I took the engine out of the frame, brought it in the basement and work on it last winter. My original plan were a little bigger than just redoing the head gaskets but money was an issue and it got put together stock. There great little engine to work on.

P.S, Bill what ever way you use to put the piston in the cylindre, be carefull not to drop the circlip in the case. I'm sure you already know that.

Good luck.

[Hordpower]

I have rebuilt one or two Hawk engines, yes. Heh.

Yep, I definitely would run a ball hone thru the cylinders. 400 grit works fine.

Hord

Have you done this before?

That sounds like a fantastic way to do it. Much easier to deal with it on the bench.

What are your thoughts on deglazing? Recommended or not with new rings?
Bill

[kip]

Wow. That piston install technique does sound easier. As you guys know, I don't know what I am doing, but I struggled to get the pistons/rings in the other way. The pistons didn't want to go in square and it was surprisingly hard to get good holds on the rings around the studs. Thanks for the tip JD.