Topic: 1973 CB350F "Freakshow Build" completed! Stay tuned for updates...

[Tim in Ohio]

OK folks...  follow up to the gasket seal issue:  Ta dah!

 

Found at my local Harley Davidson dealer.

OK... regarding the "glass trick"...  Where does one get  some of this "thick glass"?  Does anyone have any pics of a piece of glass rigged up with sandpaper as a visual?

Any guesses on how much it might cost to have a machine shop surface the head?
At some point, for budget reasons I am just going to have to start making some tough choices and say:  I'd love to have a Rolex, but a Timex will do the trick.  You know?   

[Tim in Ohio]

OK friends, I spent a couple hours reading posts and found some encouraging info in a post from "Bunghole":  'I used Ali's Machine Shop in Signal Hill CA, but I only used him for cleaning and surfacing the decks... I paid $110 for cleaning and surfacing of the head and cylinders.'
I'm hoping a local shop could surface my head and the mating deck surface on the cylinder block for around $100 or so...  I guess my budget can handle that.

BIG (noob) QUESTION:  Do I need to remove the valves from the head before taking it to the shop for this operation?  I'm not sure why, but I will confess, I am intimidated at the prospect of removing/messing with the valves.  Talk to me guys.

[scunny]

I've always had my valves out but only because of doing valve work at the same time. I see no need to remove them for skimming, but you will want to remove the dowels.
I'll leave room for other peoples ideas   

[Artfrombama]

If you take the head to a machine shop and tell them to surface it, they will. If you ask them to check and see if it needs surfacing they can do that.
What I'm trying to say is most of the time heads don't need surfacing unless the engine has been unusually hot. A straightedge and a set of feeler gauges will tell the story.

I would be more concerned if the wear + honing moved the piston/cylinder clearance out of tolerance. Did your machinist check the piston to cylinder clearance?
Did you check the ring gaps to see if they were in tolerance?

These things must be checked and corrected if you want an engine to last like new.

[Tim in Ohio]

Scunny: Good to hear from you.

Art: I appreciate the input.  It turns out you are right.  I borrowed some of my dad's machinist gauges/doo-dads...  it turns out that cylinder head and the mating surface on the block are as flat as they could possibly be!  I do mean flat.
About those clearances,

Two new questions for today:
1) Fuel tubes.  My Clymer manual doesn't even mention them.  Sizes? 



I also have a technical question for Two Tired or KGhost or anybody else who is up on the science aspect of bikes.  My local hardware store sells a selection of plastic tubing of different dimensions and types.  They do have some of the black tubing identified as "fuel line" but it is the wrong size.  Some of the clear tubing (meant to carry air rather than fuel I think?) might be close the the right size, but here is what I noticed:  On the placard, the OD and ID is listed as well as PSI.  The PSI specified for the clear tubing has a MUCH lower PSI value than the same size black "fuel line"  (like 45 psi for clear versus 250 psi for "fuel line").
and now the technical question:  Does this vastly different psi factor affect the suitability of the clear stuff to be used as fuel line do to pressure requirements of the system?  Go ahead TT school me on the scientific scoop on that. 

[kghost]

At the start of the fiche for the 350 is a bulk hose Chart.

Thats what you need.

Most Honda shops Don't even know that you can order bulk Honda hose.

Get a roll of that smaller stuff....use what you need and sell the rest here.

Get a Roll of the bigger stuff...I think it was 5 mm for the overflow drain lines.

4 overflows takes almost a roll with a wee bit left over for a repair later.

[Tim in Ohio]

I started to say "about those clearances that Art mentioned..."  and then got sidetracked.

Art.  The machine shop put the new rings on for me.  I don't know if they measured or not...  I would certainly hope so, but now that you mention it...  I guess I should check it while I can.  

I know this probably seems like it should be common knowledge... but how do I measure the piston to cylinder clearance???  

[kghost]

Measure the piston.....Measure the cylinder....subtract.

Sounds simple huh? Its not really.

Its done correctly with a Micrometer and a bore gauge.

I'm betting you don't have a Bore Gauge.....


http://en.wikipedia.org/wiki/Bore_gauge

[mattcb350f]

I didn't even know you could order bulk hose from Honda 

As for the hoses, I believe I used 3/16" fuel hose for my carb fuel line, and used the old vent hoses. 3/16" seems to work fine for me.

As far as PSI is concerned, you won't need fuel line that holds pressure (PSI is the Pounds per square inch pressure rating) since the is no pressure in the fuel system.

..but as kghost says, get Honda and forget finding suitable alternatives.

Not sure if you did already Tim, but check with your machine shop that performed the work for you. They might have checked the tolerances for you already, and if they're real good...they wrote them down somewhere.

 Matt.

[Artfrombama]

I started to say "about those clearances that Art mentioned..."  and then got sidetracked.

Art.  The machine shop put the new rings on for me.  I don't know if they measured or not...  I would certainly hope so, but now that you mention it...  I guess I should check it while I can.  

I know this probably seems like it should be common knowledge... but how do I measure the piston to cylinder clearance???  

A dial/bore gauge is best, measure the bottom of the cylinder (least amount of wear) to the top (most wear) to determine cylinder wall taper but with the piston and some feeler gauges you can get a pretty good idea of the amount of wear.

I believe there is a maximum ring gap specified. Stick the top ring in the bore close to the top, push the ring into the bore with a piston, just enough to square the ring in the bore. Measure the ring gap with feeler gauges.
You can also check cylinder taper this way. Remember Pi? (3.1416)

[Tim in Ohio]

Let's see Art...  Ah yes, "pi."

I remember when Jethro came home from school one day and Uncle Jed asked him what he had learned that day.
Jethro:  "Uncle Jed, today in Geometry class I learned '(Pi)(r) squared'..."
Uncle Jed:  [with a look of disbelief on his face] "Why that aint right boy...  pie are round, cornbread are squared."
 

[Artfrombama]

Let's see Art...  Ah yes, "pi."

I remember when Jethro came home from school one day and Uncle Jed asked him what he had learned that day.
Jethro:  "Uncle Jed, today in Geometry class I learned '(Pi)(r) squared'..."
Uncle Jed:  [with a look of disbelief on his face] "Why that aint right boy...  pie are round, cornbread are squared."
 

Absolutely nothing to do with rebuilding motorcycle engines but;

I remember Jed asking Jethro where Ellie Mae was;
"Last time I saw her she was layin' out there by the concrete pond" (pool)

[boner]Pool scene[/boner]

Ellie Mae, she was "hawt"

[mystic_1]

Uncle Jed:  [with a look of disbelief on his face] "Why that aint right boy...  pie are round, cornbread are squared."
 

Heh, I was waiting for someone to make that joke!  lol

mystic_1

[TwoTired]

Not much clear tubing is fuel proof.  If it doesn't dissolve outright, it seems to harden up to aluminum strength in a year or three.

I'm not certain about the 350 sizes, but the 550 uses 3.5mm and 5 or 5.5 mm for vent lines and fuel lines respectively.  I get it from the Honda dealer.  This tubing lasts 20-25 years, depending on exposure to the sun an weather.  The aforementioned sizes will fit onto the the carb nipples without splitting the rubber or requiring hose clamps for retention.

Cheers,

[mattcb350f]

Not much clear tubing is fuel proof.  If it doesn't dissolve outright, it seems to harden up to aluminum strength in a year or three.

AMEN! the awful clear crap that they push on us to use for snowmobile fuel line is not worthy of such a label.

If used, it needs to be replaced every two seasons. I switched to purpose built black fuel line and haven't touched it since.

 Matt.

[Tim in Ohio]

Matt can you confirm the sizes that TT speculated:  5.5 mm for fuel line from tank to carbs, 3.5mm for vent lines?  Is that true for the 350F?

[Tim in Ohio]

Good news and bad news:  Good news is, I stopped at the Honda dealer on my way home and ordered some 5.5 ID fuel hose and some 3.3 ID vent hose. 
Bad news is it will take 4 to 5 business days. What a drag.  I will have some fuel hose left over and available to sell if anyone needs some.

Matt and Art, I did speak to the machinist about the tolerances.  He said that he did measure the piston to cylinder wall clearance and it was in spec.  Also measured ring end gaps, etc.  He said all I need to do is put a little oil in the cylinders and slide them in.

I guess I just need to spend the next few days getting everything ready and back in the frame awaiting the fuel line.

I checked out YOUNGERTHANMYBIKE's project ( http://forums.sohc4.net/index.php?topic=41139.0 ) I think he's got that engine looking nice and clean.  I was thinking since I have a few days to kill now, maybe I would pick up some polishing compound and get a bit more of a "wow factor" going.  I don't have a buffer or an angle grinder...  wondering if I could use a dremel tool to do the honors?

[kghost]

I'd recommend an assembly lube....

I like lubriplate...

[Tim in Ohio]

Engine goes together TODAY!  First, to put some blue threadlocker on that loose cylinder stud.  Quick:  How much torque do I apply to the studs?

[kghost]

I don't thing they list a Torque for that....

When you torque the nut thats when you'll get the fastener (stud) stretch.

Put it in Tight.

[Tim in Ohio]

Thanks Tim.  I couldn't find a torque value.  So tight will do.  Here we go.  I am going to put the cylinder block on, then put the engine back on the frame before adding the head and cam cover.  (to make it a little less of a wrestling match getting the engine back in the frame.)
Here goes guys...  Now is the time to chip in your "remember to ...  comments"  I will check in between each new assembly that i complete to check for your words of wisdom.
Here goes nuttin!

[kghost]

Remember to be slow and Methodical.....

I've screwed up more stuff being in a hurry then by any other means.....

[mattcb350f]

Remember to be slow and Methodical.....

I've screwed up more stuff being in a hurry then by any other means.....

  me too.

Make sure you put the stud in like the rest. One end has more threads than the other (I can't remember which).

Make sure the base gasket is on.

Ring alignment is critical.

Make sure all the parts for the cam chain tensioner will go on. There is a little rubber cup that goes in the sensioner 'U" shaped thingy. It's easier to put this in if the cylinder is off, but not impossible after.

 Matt.

[Tim in Ohio]

I have the cylinder block and head back on.  I am now trying to recall how that cam chain tensioner assembly goes back together.  Anybody have any good pics of that?

[Tim in Ohio]

Matt, that little u shaped plastic thing you mentioned.  one side of the U is slightly thicker than the other...  any idea if orientation of this little bugger matters?  Thick side in towards the cam or thin side in?