Blue Dream CA78

Very hopeful that tomorrow I get my rebored cylinder back. As far as the heads go, I'll drag along the worst one in case I'm filled with confidence that Randy the machinist can reface the seats relatively soon. The pic is of the worst one with the ridged intakes. the exhausts seem pretty flat or straight. I haven't gotten to the springs yet but hoping I don't have to buy any more parts.

The plan for the better head is to simply lap the vales and seats as is and use that head if the other is going to be awhile.

hIyeXZw.jpg
 
ballbearian said:
Very hopeful that tomorrow I get my rebored cylinder back. As far as the heads go, I'll drag along the worst one in case I'm filled with confidence that Randy the machinist can reface the seats relatively soon. The pic is of the worst one with the ridged intakes. the exhausts seem pretty flat or straight. I haven't gotten to the springs yet but hoping I don't have to buy any more parts.

The plan for the better head is to simply lap the vales and seats as is and use that head if the other is going to be awhile.
Click to expand...


The 2 intake valves in the above picture are very worn;they need to be ground deeply and I'm not sure I would do that if they could be replaced easily? When valves have been ground deeply,it lowers them inside the head,also the springs need to be shimmed in that case as you lose valve spring tension.
 
Last edited by a moderator:
Thanks for addressing that issue, I don't often hear about. Bill Silver says don't grind, replace. Something about the hardening according to him. The depth issue would affect the compression too, I guess.

Amazingly, I have new intake valves in hand so seat dressing is, hopefully, all that's needed. I'd like to find a way to do that myself.
 
ballbearian said:
Thanks for addressing that issue, I don't often hear about. Bill Silver says don't grind, replace. Something about the hardening according to him. The depth issue would affect the compression too, I guess.

Amazingly, I have new intake valves in hand so seat dressing is, hopefully, all that's needed. I'd like to find a way to do that myself.
Click to expand...
Bill is correct about the hardening. It's @ .0002" thick so lapping is a quick way to burn right thru that if not done very carefully. New valves are the best way to go if you want the engine to last more than 3K miles
 
LongDistanceRider said:
Bill is correct about the hardening. It's @ .0002" thick so lapping is a quick way to burn right thru that if not done very carefully. New valves are the best way to go if you want the engine to last more than 3K miles
Click to expand...


+1 for that thought as the valve faces are Stellite coated and usually the stem tips too. It's not a good idea to lap them vs cutting new angles to reface the seats. If the seats are too far worn for cutting then a replacement head is in order. The seats can be replaced, yet I would expect that cost would far exceed a decent used head these days.

Paul recut the seats on my CL77 head using the new valves to guide him in getting the correct 1mm contact patch and did not lap them. He said the two new surfaces would mate and set on their own once the motor is run.
 
Flyin900 said:
+1 for that thought as the valve faces are Stellite coated and usually the stem tips too. It's not a good idea to lap them vs cutting new angles to reface the seats. If the seats are too far worn for cutting then a replacement head is in order. The seats can be replaced, yet I would expect that cost would far exceed a decent used head these days.

Paul recut the seats on my CL77 head using the new valves to guide him in getting the correct 1mm contact patch and did not lap them. He said the two new surfaces would mate and set on their own once the motor is run.
Click to expand...
He's correct, the valves will mate to the seats or vis versa. I used to slam the valves closed 3-4 times with my fingers to give an initial mating before assembly. I haven't lapped a valve since probably 1971 after I was taught 3, 5 & 7 angle grinds, might be '72
 
Just got back from Randy'Mann's Fastmann Racing's shop. My cylinder is on deck, next up. He is a 30 year perfectionist one man band with the best equipment available, even a dyno.
I took my head with the new intake valves and he took a look and gave thumbs up and will do the seats and have it all done next week.
 
Yes, there was a problem with the bore job. I just couldn't waller in PO'd holler, at the time. Lick my wounds and get 'er back on track.
In the pic, 50mm down from the top something happened in the boring process, on the front and back side especially. It is easily felt.

ITCqCJc.jpg


Here are some notes and figuring. It ain't gonna fly. I suppose he thought I could just put it together this way. I paid the bill and left.

0jYLUSy.jpg



Plan B: Spare motor cylinder getting surface sanded and ready to go to new machinist for +1.00mm.

Use the head that has been done already.


THSgmfN.jpg



Maybe Tim McDowell at Classic Honda Restorations has a sleeve left that can be put in the screw-up.
 
Wow, very expensive bore-job. Why it's so expensive ? I pay 125 euro including FAT for boring, plateau honing and a measurement rapport per hole. To me it seems a bore job issue, did he offer to redo the job for an oversize piston ? Or will he do the bores in the next cylinder for free ?
 
jensen said:
Wow, very expensive bore-job. Why it's so expensive ? I pay 125 euro including FAT for boring, plateau honing and a measurement rapport per hole. To me it seems a bore job issue, did he offer to redo the job for an oversize piston ? Or will he do the bores in the next cylinder for free ?
Click to expand...
And pay for larger pistons?

My valve job and bore/hone came to $240 US for comparison.

69 CB350K1/68 CB450K0
 
In this area boring and honing is $150 Canadian per hole, so about $100 US at a shop. The biggest issue is finding a shop that understands Honda specs and not automotive specs. Too many shops bore incorrectly and out of spec using automotive thinking.
No wonder there are few NOS pistons around.... you have them all. ;)
 
Ok, Canadian dollars, that is a different story.

No wonder there are few NOS pistons around.... you have them all.
Click to expand...

No, don't think so. 20 years ago I bought a huge amount of NOS CB72/77 parts, but there where also a few boxes with CB450 parts, mainly pistons, gears, and shift parts.
 
Jensen, my attempt at humour, as I understand you bought a lot of this stuff years ago, or in batches as they became available.

Canada is a huge country with a small population of about 35 million, with our neighbour to the south with some cities with almost that amount of people. So bikes and parts here are thin on the ground, especially bikes from the 60's. Many more bikes and parts are available in the US and Europe/ Britain, so your task is a little easier. I bought many parts for my CL77 from CMSNL and DSS who fortunately have a stash of NOS parts.

I was fortunate in my past profession to be successful and as such have the financial resources now to be able to purchase what I need for these bikes. I realize many on these forums are not as fortunate and need to use whatever skills and parts are available within their budgets.

Sorry to highjack your thread Teebo!
 
No apologies needed. This is what I seek, honest, candid responses. I have a new machinist who charges $50 per hole for boring. He did my CB160 recently. He did quote me $100 for surface milling, so I will continue to surface sand my cylinder tops and heads. I also had him TIG a cracked M8 footpeg stud hole on a case bottom, at $40, I thought that just a bit high (makes me want to get a TIG set-up myself). He also charged $200 for cutting valve seats and valves, also high, I think.

I'll neither use nor recommend the 1st machinist.
As that botched bore job was at the limit of +1.0 mm, I'll probably just get new sleeve(s) at some point. If there were 6th or 7th OS (+1.25, +1.50) pistons available, that would be great. I'll have to check, but believe Bill Silver said stock sleeves can go that far. Again, this is now the back-up or spare motor, so no rush.

My new machinist is Sheeler's Garage in Chambersburg PA.
I thought I'd put this wrap-up of the boring odyssey here as a cautionary tale.
I'm just grateful to have a path forward on this Dream build.
 
I can't call the bore a botched job really, it appears that the cylinder was etched by corrosion more deeply than anticipated. Given that you were already 1mm over there's not much that can be done other than replacing the liner.
 
I can't call the bore a botched job really, it appears that the cylinder was etched by corrosion more deeply than anticipated.
Click to expand...

Maybe, but that could have been detected before starting the job, I think ? It's the responsibility of the company to give an advise, positive or negative before making costs.
 
LongDistanceRider said:
I can't call the bore a botched job really, it appears that the cylinder was etched by corrosion more deeply than anticipated. Given that you were already 1mm over there's not much that can be done other than replacing the liner.
Click to expand...

I know it looks like a corrosion line, but it's not. For one thing I honed these bores quite a bit. The machinists words were " I don't know what happened, it just started chattering ..." IIRC. I wonder if the tooling or cylinder was not locked in tight enough that something shifted or came loose. I posted pics a ways back when I was honing and measuring to assess my options that shows only a few vertical scratches.

Your right though, new liners or doorstop is it's current destiny, regardless of cause or fault.
 
ballbearian said:
No apologies needed. This is what I seek, honest, candid responses. I have a new machinist who charges $50 per hole for boring. He did my CB160 recently. He did quote me $100 for surface milling, so I will continue to surface sand my cylinder tops and heads. I also had him TIG a cracked M8 footpeg stud hole on a case bottom, at $40, I thought that just a bit high (makes me want to get a TIG set-up myself). He also charged $200 for cutting valve seats and valves, also high, I think.
Click to expand...
In 1968 we were charging $6 a hole, to bore & hone. That's about $53, in today's money.
 
Last edited by a moderator:
ballbearian said:
I know it looks like a corrosion line, but it's not. For one thing I honed these bores quite a bit. The machinists words were " I don't know what happened, it just started chattering ..." IIRC. I wonder if the tooling or cylinder was not locked in tight enough that something shifted or came loose. I posted pics a ways back when I was honing and measuring to assess my options that shows only a few vertical scratches.

Your right though, new liners or doorstop is it's current destiny, regardless of cause or fault.
Click to expand...
Given that information then it is a botched job and you should have never been charged.
 
ancientdad said:
Agreed, and though I've never bored a cylinder I've had my share of them done and my first impression was chattering caused it.
Click to expand...

I dropped off the other cylinder for it's +1.00mm bore and hone and Mark at Sheeler's said it sounded like a dull or loose cutter that did the dirty deed. I'll be good to get past the nightmare on this Dream.
 
Did a little 'porting' on my oil pump. There was a pronounced lip and lack of smoothness where the pump exits to the channel so I reamed it a bit for less turbulence. Left is original, right is reamed.

TnPyq73.jpg


Had to make a snake from some copper wire and a bit of scrub pad to clean out the low channel that carries the oil from pump to the rest of the motor. Surprising how much glop was solidified in there and didn't come out with compressed air or even carb spray.

The non standard drain plug boogered the threads so I plan on just going up to 14mm ( still has a 17mm hex head) for the spare motor pump.

57XFJHJ.jpg
 
I took mine apart too to clean and inspect on the CL77 and discovered when I reassembled it that thin aftermarket paper gasket was too thin. The rotors bound when the pump was tightened back up. There should be a little resistance I think, yet this was more than that after the screws were snugged down.
I ended up using a very thin layer of Permatex Motogasket grey on both sides of the pump metal gasket area. Being careful not the get any close to the oil passages. It supplied enough additional thickness that the pump gear rotated better. The old gasket I took out of there was slightly thicker, yet was that from being swollen from the oil, or just thicker originally?
 
That sounds odd. My paper gasket is .17mm. When I laid a straight edge across the gears and inner housing face I was barely able to get a .08mm feeler between both faces. Bill Silver specs .04-.08mm, max .1mm clearance (pg 26-27). I even put one together, tightened down, with no gasket and no oil and was able to spin the drive wheel. My question would be where did you place the two washers?. They should both be on the outsides of the housings on the drive wheel shaft; one between wheel and housing, the other between housing and circlip. IOW's, no washers next to the gears inside the housing halves.
 
ballbearian said:
That sounds odd. My paper gasket is .17mm. When I laid a straight edge across the gears and inner housing face I was barely able to get a .08mm feeler between both faces. Bill Silver specs .04-.08mm, max .1mm clearance (pg 26-27). I even put one together, tightened down, with no gasket and no oil and was able to spin the drive wheel. My question would be where did you place the two washers?. They should both be on the outsides of the housings on the drive wheel shaft; one between wheel and housing, the other between housing and circlip. IOW's, no washers next to the gears inside the housing halves.
Click to expand...

I don't recall as it was months ago, yet I think the washers are on the outside not on the interior as there would be likely no space. I looked a Bill Silvers guide and there is no mention of the washers or the specs you quoted on page 27-28. Are those from the FSM with the tolerance's?

I might have to recheck, as mine was binding with just the new gasket with good resistance. There was still some resistance when spinning the large gear after I used the Permatex, it did not spin freely with extra spinning after I stopped turning the gear.
 
I think now that I did put the washers on the shaft outside, as one was thicker and one thinner possibly as I can best recall. The gears looked decent with no damage or gaoling on the areas around where the gears spin.
 
At the very bottom of page 26 and the top of 27 are Bills three specs. The FSM has 3 specs too but lists packing thickness at .4mm, which I assume to be gear side clearance plus gasket. Mine is .08 +. 17 =.25 , a lot less than .4, for sure. Seems like a lot to me and the one runs fine with no gasket ( just side clearance). I don't know why your's would bind when torqued down, they all have some side clearance like .04- .09 as Bill said.
 
ballbearian said:
At the very bottom of page 26 and the top of 27 are Bills three specs. The FSM has 3 specs too but lists packing thickness at .4mm, which I assume to be gear side clearance plus gasket. Mine is .08 +. 17 =.25 , a lot less than .4, for sure. Seems like a lot to me and the one runs fine with no gasket ( just side clearance). I don't know why your's would bind when torqued down, they all have some side clearance like .04- .09 as Bill said.
Click to expand...

I realized we are looking at a different bike in the download, as I have the CL77 version that I purchased. While it has a picture of the oil pump which is from the FSM I believe there are no specs on my download. When you get yours reassembled I am curious how easily the large gear spins. Mine did spin easily with a little resistance after I did the Permatex treatment vs a lot of resistance with only the gasket. The large gear will not freewheel and really spin easily though with continued momentum.

Bill does talk about not having too much space or clearance, as it will affect the oil pump with pressure loss around the spinning gears?
 
Flyin900 said:
I realized we are looking at a different bike in the download, as I have the CL77 version that I purchased. While it has a picture of the oil pump which is from the FSM I believe there are no specs on my download. When you get yours reassembled I am curious how easily the large gear spins. Mine did spin easily with a little resistance after I did the Permatex treatment vs a lot of resistance with only the gasket. The large gear will not freewheel and really spin easily though with continued momentum.

Bill does talk about not having too much space or clearance, as it will affect the oil pump with pressure loss around the spinning gears?
Click to expand...

I've been referring to his 'engine repair guide', which covers all the 72/77, 250-305's. His restoration guide is probably model specific. But all the oil pumps are the same. Mine are assembled and tightened, one with a gasket and one without, they turn easily with a finger and no discernable resistance, just as they should. They will never spin more than a couple revolutions like that, they don't have to and aren't designed like that. What seemed odd, on yours, is that it should turn easily if there is ANY gear side clearance and if there is not then something is wrong, ie., gears are not fitting in the housing correctly. Did you try flipping over the gears in the housing for the smoothest fit, sometimes tiny edge burs on the teeth can seem to effect the smoothness. Bottom line; the side clearance plus a gasket should provide more than ample clearance for smooth turning, unless something is just plain wrong in the assembly. My warning bells went off when you said that when you tightened it up, it bound up.

Bill is right (of course) that excess side clearance will result in less pump efficiency, but you have negative clearance, if it is binding. Use of a straight edge across the flat mating surface of the pump body and a feeler inserted between it and the flat side of the gears should give .04-.08mm, up to .1 mm max, it is the simplest, universal and traditional method of determining pump gear side clearance. Plasti gauge is not to be used here, as this is not two curved smooth surfaces we are measuring.
 
Ok I need to pull mine and have a closer look, as there was still some resistance where it would not spin easily or freewheel. It will stop immediately when you stop turning the gear I believe.

I have the pump out and just took it apart. The first thing I noticed is the gears don't spin easily on their shafts. I am in the process of dressing the lower gear and shaft and it has already started to spin freer on the shaft. I will work on the upper gear next and then measure the body clearance as you suggested.
I am glad I caught your work on the pump assembly, since mine was not correct as it was currently assembled. Fortunately an easy removal from the motor to address the issue.

Thanks for the alert on this, as my pump did definitely have some issues that took a few different remedies to resolve. It now spins freely when fully assembled. So I just reordered the gasket kit from a Canadian vendor. :)
 
Went to put the valves that got fitted by the 'machinist who shall not be named' back into the seat prepped head. It went well, I think. The spare head will have to wait for it's valve job, etc..
All the cams and rockers look pretty good so far.

Xtry4s3.jpg



Yes, a third and extra advancer was there that I had forgotten about that I bought in June on a whim because the price was great. I guess it's time to admit I have CRS (can't remember s--tuff). My excuse is I was all twitterpated over rebuilding the 160 at the time.

Anyway, I hope Hot Rod Farm Boy sees this cause once I get this one and the spare motor set (or parts grouped) I'll have an option for him that won't cost the current $250 (can you believe it?).

The rain falls on the just and unjust, all the same.
 
I'm trying to make this dream a reality. Here I laid out the cam stuff to get ready for installing. The bearings are interference fit in the head so I don't want to do it more than once.

023dhoG.jpg


Does anybody see a right/left problem here???

CBoytUF.jpg


Maybe it's the dopelganger version of the FSM. Bil Silver's guide and Charles actual bike says otherwise. I'll just call it the Anti-bike image and go with what I know.

Anyway, here at long last is my advancer, incorporating Steve's (66Sprint) brilliant idea for overcoming the loss of the rubber bumpers on the weights, which screws up the full advance limit.

ebJ1aOh.jpg



I re-read my thread here back on page 8 (post 316) and tried to remember the phone conversations with Steve about calculating where to put in the roll pin stops. I think it's pretty close to achieving the goal of having an idle timing that is not too retarded (like zero or T) when setting the limit correctly with a strobe timing light.at 45-48 degrees.

I'll have to get it running to find out if it works Ok.
 
I like it, and it would appear you used the fully extended position to scribe the lines of max travel. Steve is good like that. As for the dyslexia of the cam assembly page, I guess you can write that off as parts guys (or copy editors/proofreaders) aren't engineers or mechanics and seldom the twain shall meet.
 
Cams and advancer are in. Peened/ flared and micro staked the roll pins with my spring punch (very handy for this) and now figuring the end float clearance overall. I may shave a little from the end cap so I don't have to double gasket. Funny how these older engines had minor variations requiring such adjustments. Then again, on one this old it's hard to assume that these are the original cams for sure.

nhe5L73.jpg


EDIT: to include another roll pin mod pic.

ebJ1aOh.jpg
 
Last edited:
O ring options question. Should I use the, supposedly correct, 11x 2mm ones that came in the gasket set (on left), or the nitril generics 2.5mm thick (in middle) ? The used originals are on the right.
Am I being cheap or impatient here? Both, for sure. I just tire of paying one of the family jewels for the official greenies.

rwuzOS4.jpg
 
No picture?

If your talking about the green O rings that seal around the dowel locating pins on the barrels below the head. Those are identical in size to the ones supplied in many full gasket kits for the never replaced valve guide seal O ring in many engines. I have tons of them around and since you have done a few builds you may also have these stashed away unaware that they are the same O ring.
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom