Topic: '77 550 Head cleaning questions/ porting???

[youngerthanmybike]

I recently removed and dropped off my cylinder head at the machine shop for the rebuilding of my 550. I don't have much cash, so I told him I just wanted it cleaned up, not totally redone. He looked it over, but didn't clean much except the head gasket mounting surface.

When I picked up my stuff from the machine shop, the owner/machinist explained to me how to remove the old and install new rings. He even made me practice before I left his shop. He was really helpful. He also told me to wipe down the honed cylinder walls with ATF fluid, which has a high detergent content to help remove all of the honing compound. He said that'll help keep my new rings in good shape. I still have a good bit of work left to do to the head, and in hindsight, I'm not entirely sure what I paid him to do, but I can't sweat that now.

He said that he checked the seals of the valve seats and they were good. That being said, I have new valve guide oil seals with my gasket set and the head is still a good bit dirtier than I'd like. It just seems like now is the time to really clean this up.  I'm thinking that I should at least lap the valves, even if I'm not having the entire head redone. Thoughts on that? How clean should this be? The intake ports are clean, but the exhaust ports are filthy, should I be concerned?

Would I be okay to pull all the valves, have it bead blasted, then lap the valves, clean it myself and put it back together? Or should I find a place to soda blast it, or better yet, buy a small gravity feed gun and blast it myself?

[KB02]

I'm not entirely sure what I paid him to do...

Sounds to me like you paid him for some great advice, if nothing else. Deffinately a man that I would go back to if you need more work done.

By resurfacing the head, you'll have a nice, level surface for the gasket to match up to, thus giving a better (leak free-er) head gasket area.

As for cleaning it up, I would have thought he would have run the head through a parts washer at least, but that just gets oil and grime off. The blasting gets all the "age spots" off the head and make it look new again.

As for the other stuff, I'm sure that someone else on this forum wuill better advice than me. 

[youngerthanmybike]

Sounds to me like you paid him for some great advice, if nothing else. Deffinately a man that I would go back to if you need more work done.

As for cleaning it up, I would have thought he would have run the head through a parts washer at least, but that just gets oil and grime off. The blasting gets all the "age spots" off the head and make it look new again.

Yes, there's no question about it- I did get a good bit of education from him which will be very helpful. If he did run the head through a parts washer, there's still a lot of crap left. Most of which is hardened on- the greasy stuff is gone. I think I'm gonna go pick up the stuff to lap the valves and soda blast the head. I don't want to bead blast it, sounds like it's too much to try to clean out of all of the tight spots on the head.

[KB02]

Well, no matter what you blast with, be prepared to do some cleaning. 

[FunJimmy]

If you've got a little time you might want to do some mild porting.
That will really wake things up.

Check out Jonesy's post: http://forums.sohc4.net/index.php?topic=17374.0

Keep us posted.

FJ

[youngerthanmybike]

Ohhhhhh, I don't think you should have showed me that link....
My wife's not gonna like that 

I went ahead with the soda blasting today, it's working out okay. My main problem is my wimpy compressor. It's just a Porter Cable pancake compressor, so it really can't keep up with me while I blast. I probably go about twice as fast as the compressor can. Here's how the cylinders look, and a comparison of two of the exhaust ports:
 




I haven't searched yet, but what else do I need to know if I'm thinking about doing some mild porting?
How many of those bits will I go through? I suppose this depends on how wild I want to go, but am I really hogging away material, or just softening the transitions?

How much messing around with carbs will this require? I've already picked up a 650 cam to drop in when it all goes back together, so keep that in mind as well-

[FunJimmy]

My understanding of what Jonesy did was mainly pocket porting and matching the intake manifold to head.
You can google pocket porting and find lots of info, but basically it is opening up a bowl under the valves.
You don't want to over do it but a nice pocket porting job can make a big differance.

FJ

[fuzzybutt]

as i understand it, unshrouding the valves gives a great increase too. but the one souce on this board that a totally trust for all things cylinder head is MRieck

[paulages]

be careful blasting, as media can clog the oil orifices. i have my heads jet washed and sonic cleaned.

[youngerthanmybike]

be careful blasting, as media can clog the oil orifices. i have my heads jet washed and sonic cleaned.

That's a big reason why I opted to go with soda blasting and not glass, sand or otherwise.

[youngerthanmybike]

Well, I ported.

But I started off with a few other things. First I lapped the valves. Kind of an annoying repetitive process, but I could see the progress I was making, so that helped. Here's a few pics of that. I used a water based compound. The compound and the tool I got at NAPA for about $14.





If you look closely, you can see that I've lapped the intake valve on the right, but not the one on the left. What you'll notice is the slight gray ring that matches up on both the valve and the seat. On the other valve, everything is black.



Then I finished up my soda blasting. Overall, it worked pretty good, not quite as abrasive as I would have hoped, but I think with a better compressor and gun things would have worked out better.

When I finished that up, I found my Dremel (actually my Grandfather's Dremel- it has a build date on it of 1942), realized I had all the bits I needed to get started, and I went to it. The first time through, I just cleaned up all of the casting marks. Even using the steel cutters, I think my tooling marks are smoother than most of the casting. I started on the exhaust ports, figuring those were less crucial if I goofed something up. After I finished round one on both the exhaust and intake, I came back into the house and re-read Jonesy's thread and the "Porting the Honda Head" article on Branch's work. Then I went back out and took a bit more out of the intake ports, especially around the valve bosses. Nothing has been sanded or polished yet, a few of the ports I hit with a scotchbrite wheel, but nothing is "done."

I'd love to hear some feedback on how it looks, what I could do more of or better-

Before:


Round One:


Round Two (intake, then exhaust):

[FunJimmy]

Wow! You don't waste any time do you?
Looks good to my untrained eyes, but didn't Jonesy dig a little deeper around the base of the valve?

Where did you find the Branch Flowmetrics "Porting the Honda Head" story?

FJ

[olds-cool]

I think you can take some more off of what everyone refers to as the football.  It is surprisingly thick in that area.  I wouldn't try going flat but you can smooth it out a bit more.  I also rounded out the areas that go around either side of the seat just a bit more on mine.  Try to avoid sudden drops and keep everything as one flowing surface.  If you look at the picture that shows the valve guide as if you are looking straight through the hole, I see what appears to be a bit of a drop off on either side of the guide.  If I am correct, this will cause the air/fuel to create a sort of pool just under the guide.  This area could be smoothed a bit more into the length of the port and into the guide to avoid this pool.  I wish I could find the pictures that I took of my head to show you what I mean here.  My wife took them off the camera and who knows where she saved them.  Think of a river flowing past a large rock.  If you were to float something around the sides of the rock, there is a good chance that it will swirl around in a pool directly on the other side before it moves on down stream.  I found that my favorite bit during this process was a diamond bit that was cone shaped but with a rounded tip.  That and a ball shaped bit formed probably 95% of my ports.  As others have said, I would trust MRieck's advice on porting.  The man knows what he is doing.  Someone please correct me if I am wrong about any of this.  I could always stand to learn more as I have only done 1 head and haven't ran it yet.

[youngerthanmybike]

I work a bunch of "I'll-call-you-when-I-have-work" part-time jobs, and well, I haven't gotten any phone calls this week. That's good news and bad news. The good news is that I get to work on my bike. The bad news is that working on my bike doesn't exactly put food on the table. Actually, it probably takes it off the table......

Here's the link to the thread I found the article in: http://forums.sohc4.net/index.php?topic=19587.0
The thread has some other interesting thoughts, so I included that instead of just the article.

It does look like Jonesy took a bit more out than I did, but I felt like I did take a good bit of material out. I don't want to go too far, I wasn't sure how close I could get to the base of the valve. Jonesy has the only other pictures of a ported 550 that I've found for equal comparison. MRieck has some posted of a 750, but they look different from the start, so I'm not drawing too much comparison there.

[Jonesy]

The guys are correct, I mainly removed the "football" around the valve guide and cleaned up the casting marks. I also fixed the mis-match between the port opening and the intake tubes.  I didn't really do much with the exhaust ports, although I could have (and probably should have). As HondaMan put it, I could have removed a lot more material, but that would give me tuning headaches I don't want.

To make the nice rounded "valleys" on either side of the valve guide, I used a 3/8 flapwheel. It smooths out the surface and is the perfect size for that area to get the right profile.

Someone on here was working on a more radical "straight-shot" intake for the 550 and had a bunch or photos of cut-up 550 heads. You can see just how thick they are.

It looks like you cleaned up the valve seats nicely. HondaMan also advised polishing the backsides of the intake valves. You can chuck them in a drill and dust off the backsides with fine emery cloth. Don't overdo it, just take off the rough surface.

[youngerthanmybike]

Okay, so I removed a bit more material and softened up that football a bit. I couldn't find those 3/8" flapwheels anywhere, online or not, so I just used what I had. It's not perfect, and it's definately not polished, but it sure is better. I don't want any tuning headaches either, so I figured I'd quit while I was ahead. I cleaned it all up, taped it off and painted it. Yesterday I put the new valve seals in and reinstalled the valves. It looks pretty sharp.

I did fluid test the seals with some WD-40, and for the most part they sealed up pretty good. One of my intake valves had a little seepage, and another had some wetness under it- how concerned about this should I be? Does it warrant taking all the valves out again to re-lap and clean those?

I double checked one of my carbs today, and I do have 90 main jets. Oh, by the way, what does the 90 refer to? With the mild porting I've done and the 650 camshaft, does anyone have a rough idea where I should start with my jets? I'm assuming I should probably increase their size, but by how much? Thanks guys-

[olds-cool]

Depends on your filter and exhaust choices.  I am wondering the same thing for mine but I haven't decided on the exhaust just yet.

[youngerthanmybike]

I'm going to be using the stock airbox, no pods for me. If anything I'd modify it a little to allow more air in.
As far as exhaust, I'm working that out too. I don't think I want to keep the 4 into 4, but that depends on if I can replace it relatively inexpensively. From what I've heard, 4 into 1 works great for high rpms, but not so much for lower/midrange, and 4 into 2 is a good compromise, am I right? I'm looking for a 4 into 2, I'm not all into the speed thing.

[paulages]

the numerical size of a jet is measured in millimeters. a 90 in a main jet is .90mm, a 100 is 1.00mm, a 120 is 1.20mm, etc. the '79-'80 cb650 also used 90 mains (but also uses slightly larger carbs), so i don't think the 650 cam itself will require much larger of an increase. if you're sticking with stock bore, mild porting, 650 cam, stock airbox, and a stock exhaust (?), i would start in small increases-- maybe a #100 or #105.

as for the valve weeping- i'd have had the seats professionally recut on a sunnen or serdi personally, but going the DIY relapping route, i'd relap those valves that don't seem to be sealing well. you'll destroy the seals when you remove them, so i'd have more handy.

[youngerthanmybike]

Cool, thanks for the info about the jets.

I'll have to look into the valves again, I really don't feel like messing with it again or paying to have it done. I don't have extra seals laying around, and that means another week to wait for parts. I'm running out of time to ride this fall! I do understand about doing things right the first time, but there is a line somewhere between dreams and reality.

As far as exhaust, looks like I'll probably be running a Kerker 4 into 1- thanks to Ebay. $110 shipped, needs a real good cleaning and polishing. 

[youngerthanmybike]

Any thoughts or opinions on the above set up with a Uni air filter? I'd love to run a K&N in the stock box, but alas, they don't make one for the 550. Weird, but DennisKirk only listed a Uni filter when I searched for a '74 550, and not for my '77. Any reason it shouldn't work?

[Sporkfly]

The boxes between 76 and 77 are slightly different. The best example I can offer for this is the 76 carbs, frame, intakes etc. do not allow the Emgo conical pods to fit without crushing them where the 77 carbs, frame and intakes do.

And:

1974 -     ELEMENT, AIR CLEANER 17210-374-P00

1977 -     ELEMENT, AIR CLEANER 17210-404-P00