My cylinder head... reborn...

[Jon K]

So as everyone knows I bought a '92 E34 525i and am now getting around to building it. With much thanks to Jay (Multiplex) and his gracious use of cleaning machines and such, I am making this thing look like it never has before.

Here are some pictures of how it looked about 6 hrs ago:

http://blowneuroz.com/newmotor/4.jpg

http://blowneuroz.com/newmotor/mani1.jpg

Then, Jay and I tried out the soda blaster - for those not familiar (and I had never used one until today, though I researched it...) it uses essential sodium bicarbonate (baking soda), water, and air pressure. It's not an abrasive - it has more of a chemical reaction to hitting the aluminum at accelerated speed... people describe it in layman's terms as "exploding on the surface" so basically the soda breaks down as it hits, without ever affecting the finish... and so... this is what I was able to accomplish:

http://blowneuroz.com/mygallery/E34%20525i%20Motor%20Build/head1.jpg

http://blowneuroz.com/mygallery/E34%20525i%20Motor%20Build/head3.jpg

[Jon K]

and most importantly... the combustion chamber! Pay special attention to the valve seats! Freaking beautiful.

http://blowneuroz.com/mygallery/E34%20525i%20Motor%20Build/head5.jpg

http://blowneuroz.com/mygallery/E34%20525i%20Motor%20Build/head7.jpg

I am going to spend time removing the residue from headgasket and intake/exhaust gaskets, but you get the idea.

This head had 180,000+ miles of daily driving. It was formerly in a homemade turbocharged E34... the kid I bought it from said he never head detonation since he was running 7 or 8 psi on a T3, and now I 100% believe him!

[Scott C]

That looks really nice - you getting ready to put more boost into that bad boy?
Scott

[Jon K]

That looks really nice - you getting ready to put more boost into that bad boy?
Scott

Getting there :)

[Dave M]

Wow, thats clean. Makes it easy to sea the hairline crack between the exhaust valve seats.













Bahhhhhhhhhh :D, seriously you do need to see someone about this affliction. Soda blasting did a great job, I've never seen the results before and I'm thinking about having a very old set of rims done, maybe I'll go for it now.

Great work as always,

Dave

[Jon K]

Wow, thats clean. Makes it easy to sea the hairline crack between the exhaust valve seats.













Bahhhhhhhhhh :D, seriously you do need to see someone about this affliction. Soda blasting did a great job, I've never seen the results before and I'm thinking about having a very old set of rims done, maybe I'll go for it now.

Great work as always,

Dave


Haha ass, I was like uhhh what crack... i inspected it earlier....


Thanks!


Soda blasting will probably do VERY little on rims. It's good for cleaning oil/varnish/sludge, but not paint or powdercoat. Bead blast that - but use chemical strip first!

[winfred]

cool, got my short block built today so ill probably be building my head next weekend, unless i get motivated wednesday or thursday night but that's unlikely, i am happy with how my short block came together, everything plastigauged on the tight end of the specs despite the fact that the crank, rods and block all came from different models, and i balanced the pistons and rods to within a 1/10th of a gram of one another, about 2.5 gr between the heavy and light pistons and 4-5 gr between the rods, i read somewhere that a 7 gr imbalance at something like 6 grand turns into like 28 pounds, that'll suck some power

[E34 530]

meh, won't compare to the e30 head that is getting redone from Karl's e30 :p

[Jon K]

cool, got my short block built today so ill probably be building my head next weekend, unless i get motivated wednesday or thursday night but that's unlikely, i am happy with how my short block came together, everything plastigauged on the tight end of the specs despite the fact that the crank, rods and block all came from different models, and i balanced the pistons and rods to within a 1/10th of a gram of one another, about 2.5 gr between the heavy and light pistons and 4-5 gr between the rods, i read somewhere that a 7 gr imbalance at something like 6 grand turns into like 28 pounds, that'll suck some power


Btw winfred - how the hell do you remove the valve seals? I tugged on them with pliers but felt like I was breaking something. Also. do you think putting the valves in a drill and hitting a scotch pad to them is a good idea? I tried soda blasting the exhaust valves and made decent progress it just took a while - gonna soak them in some carb cleaner and try it again next weekend I think.



Andrew - bwahaha this is only the beginning for this head :)

[winfred]

i clean all of my valves on a wire wheel mounted to a bench grinder this gets most of the ****, the most stubborn stuff on the combustion chamber face of the valve sometimes needs more convincing, i usually use the sanding disc on the other side of my grinder but i don't recommend it as if you don't have the right touch you can get into big trouble fast, the way i do it the valve gets pollished, a fine rollock disc on a buffer would be fairly safe and effective

they make a special pair of pliers for pulling those seals, i don't own them despite the large quantity of heads i build because they are so ****ing expensive, i use a pair of end nippers grip it and rock/twist it off with one handle in each hand, i also have removed them with a baby pair of channel locks called cobra pliers, either way ya go they suck to get off and take it easy on the guides, i've never ****ed one up as they are somewhat tough but.....

[rob101]

Haha ass, I was like uhhh what crack... i inspected it earlier....


Thanks!


Soda blasting will probably do VERY little on rims. It's good for cleaning oil/varnish/sludge, but not paint or powdercoat. Bead blast that - but use chemical strip first!
what kind of system do you use, I've been exposed to it at work in an industrial setting and wet blasting its pretty good. won't go through really good paint though. but it is good for blasting paint off welds for crack testing and minor jobs. we use garnet for larger resprays and getting rust off.
soda would be perfect for working aluminium though :)

[Dr. evil]

i'm pretty sure that you have to use an oven to heat the head to the point where they fall out.

i like to take my heads to the machine shop for that, new valve guides and decking.

[Jon K]

what kind of system do you use, I've been exposed to it at work in an industrial setting and wet blasting its pretty good. won't go through really good paint though. but it is good for blasting paint off welds for crack testing and minor jobs. we use garnet for larger resprays and getting rust off.
soda would be perfect for working aluminium though :)

We use an old but good bead blaster for beads with recollection. We use an enclosed closed loop setup for aluminum oxide blasting. the soda blaster is a unit from italy, obviously no recollecting medium.

[rob101]

We use an old but good bead blaster for beads with recollection. We use an enclosed closed loop setup for aluminum oxide blasting. the soda blaster is a unit from italy, obviously no recollecting medium.
ja, that was the big drawback with the soda unlike garnet. you can't reuse the stuff.

[Jon K]

ja, that was the big drawback with the soda unlike garnet. you can't reuse the stuff.

Yah but its clean and green :)

[rob101]

Yah but its clean and green :)
yeah actually that was why they made us use it. Wet blasting you didn't have any airborne stuff to contaminate the land. the EPA went ape on us because we were blasting outside with Garnet. Mind you we couldn't hold a candle to some of the **** that was released from our neighbours. or the mass deforestation that legally took place across the road.

Guess we didn't pay the local council enough under the table. Guess its expected of a construction company to pay everyone off.:p

[Jon K]

Yeah - nothing wrong with getting baking soda all over the place. It does taste funny when you get it in your mouth though