Topic: Pseudo-Rebuilding Cylinder Head - a couple questions and I need some suggestions

[SKOL]

Hey guys and girls,

I just removed my valves, springs, retainers, retainer ring, etc. My plan is to soak the head in degreaser, soda blast the cylinder head, soak the valves in berrymans chem dip to remove carbon, scuff the head with scotch brite, paint, re-lap the valve seats, and re-install the springs and valves. I have a few questions before I begin and was hoping some folks would have the answer and offer some suggestions.

1. What is the best way to remove the valve seal? Do I have to? Soda isn't very abrasive.

2. Do I have to remove the spring seat?

3. Do I have to remove the valve guides?

I'm trying not to completely disassemble everything if I don't have to. Not out of laziness, but I don't want to mess with anything mechanical unless I have to. If it was/is functioning fine, than I'd rather leave it be.

I just want clean this baby up more or less and am wondering if I have to completely remove everything. My soda blaster is somewhat under powered to begin with so it isn't as abrasive immediately as other probably are. Am I safe to soda blast the head and pictured below, or should I remove the rubber valve seal? The spring seat? The guide?

If anyone has any answers/tips/suggestions/warnings, I would really appreciate it. Thanks!

[flybox1]

Put the valve cover back on before you blast it.
It would be a shame to damage the sealing surface of the valve cover, and give yourself leaks.
I hope you marked all the valves so they can go back in the same guide they came out of 
You'll want to replace all the valve seals.  just pull them off.

Check out brandEns 'leak free top end' thread.  good stuff there.
http://forums.sohc4.net/index.php/topic,107040.0.html

[flybox1]

And get yourself a copy of Hondaman's book, if you haven't already.

[SKOL]

Put the valve cover back on before you blast it.
It would be a shame to damage the sealing surface of the valve cover, and give yourself leaks.
I hope you marked all the valves so they can go back in the same guide they came out of 
You'll want to replace all the valve seals.  just pull them off.

Check out brandEns 'leak free top end' thread.  good stuff there.
http://forums.sohc4.net/index.php/topic,107040.0.html

Yes I did mark them in separate bags. Do you think it would be alright to soda blast the head with the guides still in? I've seen videos of people soda blast the bottom side of the head where the the valves actually interact with the pistons, but they had old valves in stalled so no soda got into the valve guide. I don't have old valves so that's not really an option for me. A good rinse with water and and acetone wipe down has removed any baking soda residue just fine so far. I probably will put the head back on, though I've read on forums that soda blasting would only damage a mating surface if the blast is left on the same spot for an extended period of time. Not that I want to chance it or anything, but I;m not so sure that soda would affect the mating surface bad enough to cause a leak?

So the valve seals just pull off?

[flybox1]

Yes, the guide seals just pull off.
What are your plans for the head?  repaint?

[SKOL]

Yeah, scuff with maroon scotchbrite and or 400 grit sandpaper and repaint after I remove all the current finish on it.

[754]

Some guys intentionally blast gasket surface to get some bite, for the gasket... no sense in having a gasket sqwooge out and cause a massive leak...

[flybox1]

Do you think it would be alright to soda blast the head with the guides still in? I;m not so sure that soda would affect the mating surface bad enough to cause a leak?

Soda won't harm the mating surfaces unless you go berserk and lose all references to time and pressure applied. Simply move the sprayer across the surfaces, at an angle to the surface, and away you go. Rinse well with Acetone or Kerosene to insure ALL media is vacated from oil passages. And of course prep the surfaces you intend to paint.

^^^  yeah, this is something we have no control over    We dont know OP's experience/equipment.  I was staying on the safe side    acetone and scotchbrite pads is good enough for me.

[SKOL]

Do you think it would be alright to soda blast the head with the guides still in? I;m not so sure that soda would affect the mating surface bad enough to cause a leak?

Soda won't harm the mating surfaces unless you go berserk and lose all references to time and pressure applied. Simply move the sprayer across the surfaces, at an angle to the surface, and away you go. Rinse well with Acetone or Kerosene to insure ALL media is vacated from oil passages. And of course prep the surfaces you intend to paint.

^^^  yeah, this is something we have no control over    We dont know OP's experience/equipment.  I was staying on the safe side    acetone and scotchbrite pads is good enough for me.

An underpowered air compressor with the gravity fed abrasive blaster from Harbor Freight. It barely does the job, even if I use paint stripper before hand.

[flybox1]

Proceed with caution 

[camelman]

Can you heat up the head after blasting and cleaning? Just putting it in an oven at 300F can help dry any remaining water out and evaporate residual oil to make sure your new paint sticks. Paint is a little less susceptible, but powdercoat can be ruined if you don't pre-bake.

[SKOL]

Can you heat up the head after blasting and cleaning? Just putting it in an oven at 300F can help dry any remaining water out and evaporate residual oil to make sure your new paint sticks. Paint is a little less susceptible, but powdercoat can be ruined if you don't pre-bake.

I can, I was going it to give it a good acetone wipe down. I have Eastwood's aluminum prep which is a cleaner/etcher, and their paint prep which cleans really well too, was going to wipe with these after soda blasting and before painting.

[SOHC4 Cafe Racer Fan]

Check out the mating surfaces of the head for evenness.  Many folks deck the mating surfaces so that any warping is eliminated and risk of leaks is reduced.