Topic: 1973 CB350F "Modest Original" build

[iiAtlas]

Harbor Freight(cheap china)has many products like blasting cabinets,even ones small enough(or just big enough )to where you could do the cyl. head too. I've seen a bench-top style also pictured/owned by a member on another forum.

I've actually found this decent and affordable Eastwood one.  Might pick that up!  In the meantime....


Next steps on the cylinder head were to remove the valves. 



The intakes were up first.  Easy peasy!  I had a helper to keep track of everything.



The valves, springs, retaining clips, caps, and shims all got the "bag and tag" treatment.









The intake valves showed noticable signs of carbon buildup.  I'm glad I have them out so they can all get a decent clean.  I will start with a one hour soak in the Chem-dip.  It seemed above the use of scotch brite was not recommended, I assume due to the fact that it could disrupt the valve guide tolerances.  I suppose that leaves me with soda blasting after the chem-dip?  I will give that a shot (hopefully with the Eastwood blast cabinet mentioned above).  As with the earlier head work, please let me know what tools I have at my disposal to clean these suckers up.  The intake seats looked good.  I'm confident they will "lap" well.



With all four intakes out I moved onto the exhaust.





The exhaust valves, as expected, showed noticeably more carbon buildup.



They will receive the same treatment as the intakes.  Here is a closeup of all the valve seats with the valves removed.



#4


#3


#2


#1


These will all be lapped when ready.  I currently have the entire head sitting in a bath to 2:1 Pine-Sol and Water (2 parts Pine-Sol).  I will leave this be for about 15 hours then give it a look. 





I was going to use the aircraft cleaner but didn't have enough and didn't want to dilute it.  The Pine-Sol was cheap enough and is worth a shot!  I will be using the aircraft cleaner in smaller doses for the valves themselves.  If I end up picking up the blasting cabinet I will probably give a go at soda blasting the entire head itself.  There is some noticeable build up in the exhaust channels.



The intakes aren't as bad but they could all do with a nice polish.  After the soak, what tools do you all recommend for further cleaning?  Dremel?

That's all for tonight!  More tomorrow.

[grcamna2]

The pics are tough to see defined detail on the valves and seats.I would seriously consider taking/sending the head and valves out to see if possibly they should be ground;I did notice some deep rust/pitting on the seats but it might be because pics are never as good as looking directly at the live parts.

[iiAtlas]

The Pine-Sol will likely discolor your head, turning it a dark grey.

Fun...oops!  I think I can mitigate this by taking it out, bathing it in water, then re-dipping.  This is how I prevented the chemical stains on the carbs.  Thanks for the heads up.

The pics are tough to see defined detail on the valves and seats.I would seriously consider taking/sending the head and valves out to see if possibly they should be ground;I did notice some deep rust/pitting on the seats but it might be because pics are never as good as looking directly at the live parts.

The pictures definitely don't do a fair job.  I will go down and give it all a closer examination today.  I believe what looks like rust and pitting in the pictures above is rather little bits of leftover gunk.  I totally see where your coming from with the pictures though!  Maybe after todays soak I will be able to reveal more of the true state.

[grcamna2]

You could also get a soft SS or brass rotary brush for your drill to brush the seats.

[iiAtlas]

The pine-sol worked great!! No discoloration, in fact the opposite.  She is looking shiny and good.  The remaining gunk comes off easily with a nylon brush.  I think a soda blast will really clean this little girl up!  The pine-sol did a really good job at loosening everything up.











I currently have it sitting in warm water just to rinse off any remaining pine-sol.  When I remove it from the water, should I apply any sort of oil (thinking motor oil?) to prevent flash rust?

[sbeckman7]

Wow that looks good man.  What exactly is pine-sol?  Any idea where it rests on the scale of water-to-WMD?

[grcamna2]

That does look clean now. 

[iiAtlas]

Wow that looks good man.  What exactly is pine-sol?  Any idea where it rests on the scale of water-to-WMD?

Pine-sol is kind of like an all-purpose home cleaner.  Mainly used to clean floors.  It's got a pretty strong "pine" scent but I don't think it's TOO evil. 

That does look clean now. 

Highly recommend the stuff! ~3:1 pine-sol to water (3 being pine-sol).  I soaked it for about 15 hours, then checked for any signs of chemical stains.  Nada!  I washed it under warm water to stop the chemical activity, then re-dipped for another 6-7 hours.  I took it out at this point because the remaining grime could be brushed off with my finger.  Soda blast up next! - pending purchase of that Eastwood blast cabinet.

[sbeckman7]

Wonder how good it would be at removing the chipping paint from my cylinders...

[iiAtlas]

Wonder how good it would be at removing the chipping paint from my cylinders...

Cheap enough to be worth a shot! It took about $15 for this whole soak, and I'll be reusing it for the rocker arm cover. I initially intended to use the aircraft cleaner but at $60 a bottle and not being reusable after dilution it seemed overkill.

Took the head out of the bath, brushed it with a nylon brush, dried, and then applied a thin coat of motor oil. There were definitely signs of flash rust but it brushed right off. She's looking good now and should be protected. I've ordered the blast cabinet and will be blasting it when it arrives!

[sbeckman7]

Nice! I'll be painting my entire engine black so I'm not too worried about it.

[iiAtlas]

Eastwood blast cabinet: ordered!  Next up a cylinder hone.  I know you all recommend the "flex-hone" variety.  Have any of you used a specific brand you like?  Need to find a relatively small one to work with the ~1.8" cylinders.  Any recommendations greatly appreciated!

[grcamna2]

Eastwood blast cabinet: ordered!  Next up a cylinder hone.  I know you all recommend the "flex-hone" variety.  Have any of you used a specific brand you like?  Need to find a relatively small one to work with the ~1.8" cylinders.  Any recommendations greatly appreciated!

I've owned a KD brand spring loaded 'glaze breaker' w/ 3 rigid stones for over 20 years that is adjustable for different size cylinders w/ it's spring loaded action and just replaced the stones when I need to;it's adjustable down to just about the CB350F size cylinders.I have the fine stones on it now(which remove the least amount of material but need to be checked for cleaning often) and you can adjust the spring tension to suit the size cylinder you have,like w/ yours I would want the least amount of spring tension because it could remove material from your cylinders if you used it for too long.The style I have needs to be centered while using it all the time and needs an optimum speed w/ the right honing oil to work the best.
I never have owned or used a bead hone(except for brake wheel cylinders in automotive)on cylinders but I've been told that they will work well for just 'glaze breaking' the cylinder surface to allow your new piston rings to 'break-in' ,also they need to be the exact size(size specific) you require for each cylinder.The style of them is a whole bunch of small round abrasive 'beads' right next to each other that are meant to break the glaze inside the cylinder walls,that is their only function.The 'bead hone' has a very forgiving nature to it and won't remove much material from your cylinder walls and even if you get the hone 'off-center' it won't cause too much of a problem with the quality of the honing.. according to what others have told me.

edit: iiAtlas, with the bore measurements you've taken with your precision instruments.. I would make sure to clean out each cylinder bore/hole completely(like w/ an SOS steel wool scrubbing pad)so you're working only with bare cylinder and not carbon which will clog-up your hone stones.I think just enough honing to remove the shiny 'glaze' from each cylinder so you're new rings will 'break-in' would work good.  imo

[sbeckman7]

Next up a cylinder hone.  I know you all recommend the "flex-hone" variety.  Have any of you used a specific brand you like?  Need to find a relatively small one to work with the ~1.8" cylinders.  Any recommendations greatly appreciated!

Flex-hone is the actual brand as well.  Here is the one I ordered, it seemed to work well: https://www.zoro.com/flex-hone-tool-flexible-cyl-hone-boredia1-78in-320grit-bc17832/i/G1267996/?whence=#

The size is ok from what I understand, a little larger than idea but the flex-hone manufacturer site says to use the next size up if yours isn't available.

[iiAtlas]

I've owned a KD brand spring loaded 'glaze breaker' w/ 3 rigid stones for over 20 years that is adjustable for different size cylinders w/ it's spring loaded action and just replaced the stones when I need to;it's adjustable down to just about the CB350F size cylinders.I have the fine stones on it now(which remove the least amount of material but need to be checked for cleaning often) and you can adjust the spring tension to suit the size cylinder you have,like w/ yours I would want the least amount of spring tension because it could remove material from your cylinders if you used it for too long.The style I have needs to be centered while using it all the time and needs an optimum speed w/ the right honing oil to work the best.
I never have owned or used a bead hone(except for brake wheel cylinders in automotive)on cylinders but I've been told that they will work well for just 'glaze breaking' the cylinder surface to allow your new piston rings to 'break-in' ,also they need to be the exact size(size specific) you require for each cylinder.The style of them is a whole bunch of small round abrasive 'beads' right next to each other that are meant to break the glaze inside the cylinder walls,that is their only function.The 'bead hone' has a very forgiving nature to it and won't remove much material from your cylinder walls and even if you get the hone 'off-center' it won't cause too much of a problem with the quality of the honing.. according to what others have told me.

edit: iiAtlas, with the bore measurements you've taken with your precision instruments.. I would make sure to clean out each cylinder bore/hole completely(like w/ an SOS steel wool scrubbing pad)so you're working only with bare cylinder and not carbon which will clog-up your hone stones.I think just enough honing to remove the shiny 'glaze' from each cylinder so you're new rings will 'break-in' would work good.  imo

Flex-hone is the actual brand as well.  Here is the one I ordered, it seemed to work well: https://www.zoro.com/flex-hone-tool-flexible-cyl-hone-boredia1-78in-320grit-bc17832/i/G1267996/?whence=#

The size is ok from what I understand, a little larger than idea but the flex-hone manufacturer site says to use the next size up if yours isn't available.

Great!  I already have the spring loaded type with the honing stones but I think I'll give this flex-hone a shot.  Thanks for the link, and thanks for the info you two!

[iiAtlas]

Tada!  The blast cabinet is here!  Awesome piece of kit and I can't wait to get started using it.







Construction was relatively easy and it feels to be a solidly built item.  Ordered some soda blast media as well, but that has yet to arrive.  Sticking with regular old baking soda for this weekend.

[grcamna2]

I want one ! 

[iiAtlas]

I want one ! 

Yes you do!!

Before:


In the blast cabinet:


A cloud of dust:


Et voila!




That was after what couldn't have been more than 5 minutes - and it was fun!  I just used regular old baking soda - far too fine - but it still achieved results like this.  This was without a soak in anything or even a wash after I took it out of the cabinet.  With the right media (ordered) and the right process I have a feeling this is going to give me great results!  The media is recycled at the bottom of the cabinet so it is quite efficient.  For $139 it is an awesome, AWESOME piece of kit!!!

[grcamna2]

Thank you for the feedback on that Eastwood small sandblast cabinet;I hope you continue to let me know how it performs over the long haul too. What's the model number of it ? and how many CFM(also what size air compressor tank is optimum,could I do it w/ a 10 gal. tank on my small compressor?) does it require from an air compressor ?

[iiAtlas]

Thank you for the feedback on that Eastwood small sandblast cabinet;I hope you continue to let me know how it performs over the long haul too. What's the model number of it ? and how many CFM(also what size air compressor tank is optimum,could I do it w/ a 10 gal. tank on my small compressor?) does it require from an air compressor ?

Here is the Eastwood blaster.  Item #30721.  Picked it up for $139 on sale.  Compressor is this DeWalt 4.6 gal, 1.6hp.  5cfm at 90psi.  It's awesome!  Will keep you all posted on how I like these two together.  So far so good!

You would do well to degrease your parts first before putting in a media cabinet. It saves your media from contamination and allows the blasting to focus on the surface, not the contamination upon it.

Even better, degrease, bake it, wipe down with degreaser, then blast it. A quick Acetone wipe afterwards cleans everything up nice and pretty.

Good tips!  I just wanted to give it a shot and thought this was a harmless enough piece to blast.  I think with a degreaser before and the right media this combo should give me nice results.

[grcamna2]

Thank you for the feedback on that Eastwood small sandblast cabinet;I hope you continue to let me know how it performs over the long haul too. What's the model number of it ? and how many CFM(also what size air compressor tank is optimum,could I do it w/ a 10 gal. tank on my small compressor?) does it require from an air compressor ?

Here is the Eastwood blaster.  Item #30721.  Picked it up for $139 on sale.  Compressor is this DeWalt 4.6 gal, 1.6hp.  5cfm at 90psi.  It's awesome!  Will keep you all posted on how I like these two together.  So far so good!

You would do well to degrease your parts first before putting in a media cabinet. It saves your media from contamination and allows the blasting to focus on the surface, not the contamination upon it.

Even better, degrease, bake it, wipe down with degreaser, then blast it. A quick Acetone wipe afterwards cleans everything up nice and pretty.

Good tips!  I just wanted to give it a shot and thought this was a harmless enough piece to blast.  I think with a degreaser before and the right media this combo should give me nice results.

I read that link for the Eastwood and it looks good;I know what I'm getting once I get some shop space w/ electricity  The required CFM is 10 & I imagine that must be for continous running for the compressor to keep-up.How long do you have to wait for your Dewalt compressor to catch-up? Can you blast steady for 5 mins. before waiting ?

[iiAtlas]

Thank you for the feedback on that Eastwood small sandblast cabinet;I hope you continue to let me know how it performs over the long haul too. What's the model number of it ? and how many CFM(also what size air compressor tank is optimum,could I do it w/ a 10 gal. tank on my small compressor?) does it require from an air compressor ?

Here is the Eastwood blaster.  Item #30721.  Picked it up for $139 on sale.  Compressor is this DeWalt 4.6 gal, 1.6hp.  5cfm at 90psi.  It's awesome!  Will keep you all posted on how I like these two together.  So far so good!

You would do well to degrease your parts first before putting in a media cabinet. It saves your media from contamination and allows the blasting to focus on the surface, not the contamination upon it.

Even better, degrease, bake it, wipe down with degreaser, then blast it. A quick Acetone wipe afterwards cleans everything up nice and pretty.

Good tips!  I just wanted to give it a shot and thought this was a harmless enough piece to blast.  I think with a degreaser before and the right media this combo should give me nice results.

I read that link for the Eastwood and it looks good;I know what I'm getting once I get some shop space w/ electricity  The required CFM is 10 & I imagine that must be for continous running for the compressor to keep-up.How long do you have to wait for your Dewalt compressor to catch-up? Can you blast steady for 5 mins. before waiting ?

Haven't had any issues with running out of air.  I blast it bursts of 2-3 mins with ease.  I was worried about the 10 CFM as well but the 5 @ 90psi has been fine!

[iiAtlas]

Took a quick break from the bike but I'm back in biz and ready to get rocking!  Tonights project was that cylinder hone I've been waiting to get at.  But first, I couldn't get over how beautiful these OEM piston ring boxes were.







It's almost a shame to open them!  Anyways...down to business.





I used a variable speed drill and some 20W-50 (what I had on hand) motor oil.  I kept the drill spinning as it entered and exited the cylinder wall.  I aimed to have a distinct 45° cross hatch on the walls.  Here they were just before honing.



And after



And after a warm water soapy wash



Wow!  Great stuff.  I think they honed up really nice!













For the most part, really good.  However I noticed something not so good...



A distinct score on cylinder 1.







Definitely noticeable.  I can feel it bite in with my finger nail.  I doubt this happened during the honing process, as the line is so perfectly horizontal.  Had it been the hone, I'd imagine it'd be at an angle as the thing is always spinning and moving up and down.  (Someone please correct me if I'm wrong about this).  What do you all think could've caused something like this?  Whats my best course of action?  I assuming this could lead to ring-seating issues once I have the engine back together.  Any other potential outcomes you can think of?  Apart from that, they look good and I'm happy to be back working on the bike!









More soon

[grcamna2]

The hone job looks good. 
That long vertical scratch in your cylinder not so good.I would now measure the cylinder bores and install one of those NOS top piston rings into the cylinder and measure the ring end-gap w/ a feeler gauge.
You did measure your pistons o.d. and the cylinders i.d.'s and recorded them,right? Well,now you can see how much tolerance is there after using the 'bead hone' and possibly use the hone as much as is needed to try to clean-up that long scratch in the one cylinder and just keep honing and measuring while checking clearances.I would check the Honda FSM and see what the recommended clearance 'variance' is on a fresh top-end job;you don't want to go too big and nowhere near the 'service limit';the 'good' is that a 'bead hone' will be very gentle on your cylinders and won't remove too much metal,it takes a while for that hone to remove much material.
I would get some special honing oil so you keep your stones clean;I mix 50/50 kerosene and motor oil and it works well to keep the stones free from metal particles.
I would definitely be concerned w/ that long scratch,as long as it doesn't catch your fingernail even though you might still see 'traces' of it then it can pass;I hope it's not too deep..

[iiAtlas]

Hey thanks for all the great info! Cylinder ID measurements pre-hone are a few pages back. I will measure again to check if I am still within spec, and depending on how much have a go at inching back that scratch on cylinder one. I don't know how deep so I'm not sure what results I'll have, but definitely a concern either way. Was a disappointing surprise, but I'll take it in stride and see what I can do!  Thanks for the list of next steps, will get started on all that Friday. Good to be back!