Topic: 78 CB 550K motor rebuild

[DaveBarbier]

That other hole is nothing.

So far so good! As for that base gasket tear, I also wouldn't worry about it.

[DaveBarbier]

Oh, and not sure if you knew, but the MLS gasket is designed to not use an o-ring in that oil hole. The embossing is said to be enough. Plus the stock OEM sized o-ring won't fit with the gasket installed.

[RAFster122s]

Also, NEVER use any sealer on a MLS gasket.  The coated surface on top and bottom is designed to adhere itself and seal the gasket to the surfaces.  They are also said to be reusable at least once...

[AlekStooge]

Dave: Looks like the O-ring fits, it is from Cycle X top end gasket set. I'll remove it if you say so.



This is the head/block with no head gasket or O-rings in between, looks like it sits flush.





I checked it with a feeler gauges .010mm doesn't fit anywhere but the intake side. As soon as you move it over to the sides of the head/block it doesn't fit. I moved to the next size .012 and it fit on the intake side as well then to.015 and that didn't.

Is this normal for ONLY the intake size to have a slight gap? Should I shorten the pins any?

[AlekStooge]

On a side note what do you guys think of the color scheme? I think a black head with polished fins would have looked better if I've done it over again.

[AlekStooge]

Yes I'm measuring in mm's. Are you saying to measure it with the gasket in now?

[DaveBarbier]

Can you rock the head back and forth (exhaust to intake) and see if it's pivoting on the dowels? Or just remove the dowel pins and see how it sits. That way you'll see if it's the dowels keeping the head off the cylinders.

On second thought, aren't the dowels on the intake side? That could mean, either they aren't fitting in the holes properly due to rust or something else in the holes or that the dowels are too long lifting up the intake side a hair.

I like the color scheme, it'll look even nicer when it's in the frame and all together.

[DaveBarbier]

From Buzz at Dynoman, "The O rings are not used with this gasket, as the embossment around the hole will seal in place of it."

I'm going to do what he says, if you want an o-ring and are confident it won't interfere with sealing or get squeezed into the oil hole, then by all means

[SF]

Ordered oil seals, pucks and O-rings after making a list of OEM part numbers. I will post the list once I know 100% it's correct, so others don't have to go through the cross referencing and hunting.

I'm in the same process right now. Did you post the list? Sorry if you have already but this will be a major help for me.



Sent from my iPhone using Tapatalk

[AlekStooge]

Sorry for not getting back to you guys sooner, busy couple of days and at the end of the day you fall asleep not realizing you did.

Anyways, Cal: Sorry for the confusion my feeler gauges have the SAE measurement and then below that the metric followed with mm on the bottom but not inches. I was measuring in inches but since only mm is listed I got mixed up. Similar to this but written vertically.

I'm going to measure my gasket, I think it was .035 in.

Dave: The dowels do go on the intake side, nothing there is rusted since the block and head were cleaned and the dowels were replaced. I rocked the head back and forth and it didn't rock much. I took the dowels out and the .010 INCH! gauge didn't fit anymore. So now the original question is stands should I shorten the dowels and if yes how does that work since it is only the intake side that has the gap. I mean do I only file one half of each dowel? Cal?

I think my gasket is a Cometic and I think that is what Dynoman sells. Probably will leave the o-rings out.

SF: I have a list written out but I'd like to review it before sending it to you. There are some parts that are obsolete so there is a newer part # for it. When you search for the part number the source sometimes has it listed under the original part number. I'll send it to you sometime between tonight and mid day tomorrow.

[AlekStooge]

My head gasket measures .044 - .046 around there it is hard to measure with the layers flopping around. My largest feeler gauge fits through on both sides of the gasket .026 in.

[SF]

SF: I have a list written out but I'd like to review it before sending it to you. There are some parts that are obsolete so there is a newer part # for it. When you search for the part number the source sometimes has it listed under the original part number. I'll send it to you sometime between tonight and mid day tomorrow.
[/quote]



Hey man, take your time, I'm thankful you have a list that's correct,  I'm going crazy here with all the new part numbers....


Sent from my iPhone using Tapatalk

[AlekStooge]

I did not shorten my dowels. Being that my head gasket is .044-.046 in that will cover the gap. I torqued my APE nuts gradually to 19.5 ft lbs. I'm letting them sit about 24 hours and then loosing and then torqueing again.

[DaveBarbier]

Sounds like a plan!

[AlekStooge]

I'm thinking now does a torque wrench work when loosing? Never tried it that way. I know the manual says 14 to 16 ft lbs but since these are HD studs and nuts I figured I should go higher. Plus I'll be getting more airflow than stock so it's good to have it tighter, I think.

[AlekStooge]

Crank them loose then go down to 14 lbs following the pattern and then 7lbs. Got it!

[AlekStooge]

Head is torqued down. I bought a C5 ignition from a forum member. Missing my sprocket bolts so I ordered new ones once those come in the cam and sprocket will be ready to be installed.

I will take a second look at my clutch plates and discs, I didn't really understand what thickness they should be because one plate or disc is a different thickness than all the others and the manual doesn't specify the spec. I probably will end up keeping them.

[SOHC4 Cafe Racer Fan]

Head is torqued down. I bought a C5 ignition from a forum member.

So that's what became of GV's C5.

[AlekStooge]

Yep, waiting for that, learning how to find TDC with the head and how to degree a cam. Printed out a degree wheel so far...

[AlekStooge]

Got a modified cover.

Made a piston stop

And got everything set up to degree the cam and check valve/piston clearance.


I'm rotating my engine on the points side. When I spin it forward I apply a lot of torque and then it jumps forward and I have to repeat the process. When I spin it counterclockwise it goes easy. Can I do my work this way?

[bwaller]

Cal with no plugs it's ok to turn it from that side. When using a piston stop you have to turn the engine gingerly". That wheel is small, I like double the diameter, it's just more accurate but run what ya brung, at least sharpen your pointer Alex. Use the longest tool you can find, longer allows easier more accurate movement of the crankshaft, but you have to turn the engine clockwise from the right end. If you miss your mark, turn it through & start again.

[DaveBarbier]

Yeah, either tip it somehow with some rubber or at least put it on the bench grinder and make the tip round.

When you use the alternator bolt, just be sure you don't unscrew the bolt as you turn it or the degree wheel doesn't rotate separate from the rotor.

You'll find that the motor sometimes is hard to turn over and sometimes it's easy. When the motor is at TDC/BDC it takes very little effort to turn it because they're very little piston movement. When the pistons are all half way up the cylinder bore there's a lot of piston movement so it's harder. You just have to be steady and work through it.

[DaveBarbier]

And yeah, as Brent says, sharpen the pointer. You want to be able to tell the difference between 32° and 32.25°.

[SF]

You might want to chase those threads too.


Sent from my iPhone using Tapatalk

[MRieck]

You might want to chase those threads too.


Sent from my iPhone using Tapatalk

They are a bit gnarly.