Dead cylinder in 1972 2002tii

[TobyB]

I use a carbide scraper, but yeah, clean, clean, clean.  The deck surface should be shiny at the tops of the cuts-

ideally, you'll be able to see the original flycutting evenly, and have uniform brightness across the whole surface.

 

Especially under #2- before cleaning it's impossible to tell, but there looks to be some erosion under there.

 

Since the other 3 were already sealing, no worries there, but since #2 didn't, it needs more careful attention.

 

Oil is never a concern, unless there isn't any.  And coked- up old oil's just a removal hassle.

 

t

would be looking more at the erosion and corrosion.

 

 

[Pablo M]

1 hour ago, OldRoller said:

Looks pretty good. Remove the dowels, move pistons down midstroke. Stuff oil soaked shop rags in the holes, and stuff coolant and oil passages with paper towels with a few drop of oil on'em. Get a flat block, wrap it with 150 oxide sandpaper, and go to town on the surface. Move up to 220 when it starts looking clean. 400 for the final deck polish. Clean it up and pull the rags/towels carefully. 

 

And chase the head bolt holes, and clean them like a doctor after a virus! Q-tips, brake clean, vacuum, air pressure. Stock gasket and Copper Coat it both sides, 2 light coats. And light oil on the head bolts on reassembly.

 

Just my 2 cents, resurrected many old and dead engines. I'm sure others have their preferences. The head deserves maximum attention.

 

58 minutes ago, TobyB said:

I use a carbide scraper, but yeah, clean, clean, clean.  The deck surface should be shiny at the tops of the cuts-

ideally, you'll be able to see the original flycutting evenly, and have uniform brightness across the whole surface.

 

Especially under #2- before cleaning it's impossible to tell, but there looks to be some erosion under there.

 

Since the other 3 were already sealing, no worries there, but since #2 didn't, it needs more careful attention.

 

Oil is never a concern, unless there isn't any.  And coked- up old oil's just a removal hassle.

 

t

would be looking more at the erosion and corrosion.

 

 

Appreciate all the info!

Yes, with the head (and timing cover) at the machinist I’ll focus on the block. Definitely aware how clean this needs to be. All I did now was a wipe down and plastic razor to get crud off. Will go to town as described. Should end up with a bright shiny surface when done. 
Good eye on the corrosion below #2. 

[Son of Marty]

I clean y block using the 2 and 3 inch maroon scotchbrite rotary pads on all gasketed surfaces, but that's just me.

[Pablo M]

Update! 
 

Head is good and can be rebuilt. 
Valve guides are good and don’t need replacing. 
Cam and rockers need replacing though, as do all the exhaust valves. 
 
So I’m thinking of replacing with stock new cam (Ireland Engineering), new HD rocker arms and retainers, new HD valve springs, exh valves and that’s it. 
 

Any opinions on that plan? Should I replace anything else in the head? 
do I also need the eccentrics, rocker shaft hardware, valve stem collets?

Edited October 7, 2023 by Pablo M
Added info

[Son of Marty]

With a stock cam the hd springs only benefit will be to wear your cam out sooner the hd rockers are not needed, and yes new eccentrics and hardware would be money well spent, if your valve guides are still the stock 2002 ones ask your machinist to turn the top down to allow the new style seals.

[tech71]

54 minutes ago, Pablo M said:

and that’s it. 

No new rocker shafts? Are yours still good?

[Pablo M]

1 hour ago, Son of Marty said:

With a stock cam the hd springs only benefit will be to wear your cam out sooner the hd rockers are not needed, and yes new eccentrics and hardware would be money well spent, if your valve guides are still the stock 2002 ones ask your machinist to turn the top down to allow the new style seals.

Yes but the extra west is likely minimal and the benefit is no valve float at very high rpm (which I intend to do-track days). If machinist is taking the old ones out it might be cheaper just to buy later style valve guides and have him replace them. 

54 minutes ago, tech71 said:

No new rocker shafts? Are yours still good?

He told me what I needed and did not mention that so I have to assume no. I can ask him though, to be sure. 

[Son of Marty]

3 minutes ago, Pablo M said:

If machinist is taking the old ones out

They can be cut in place. The springs will not float with a stock cam until you are well past red line and past the power curve.

[TobyB]

+1 for stock BMW springs.  They are very good up to 6800, and they are very durable.

 

I don't know what the latest metallurgy stories on HD rockers are, but in past, they

weren't trouble- free.

The Febi rockers are, up to 7500, if you check for obvious voids.

Even with pretty serious voids, I only broke one by sitting on the 7500 rev limiter for an hour

(ok, 15 seconds, lap after lap, but it FELT like hours)

 

If you're not building a 6500+ rpm engine now, it's not worth putting the 6500+ parts on it.

 

t

 

[Pablo M]

I’ll be hitting the rev limiter quite a bit in my planned use, at least within the life of this head. So I went with the 6500+rpm parts. The HD rockers were cheaper too. 
 

Head will be ready tomorrow! Shame I’ll be out of town. Picking it up Friday when I’m back and the real fun begins this weekend. 😁

 

Just now realizing I still need a head gasket and timing cover gaskets. I asked machinist if I needed a slightly thicker head gasket (I saw on IE website one 0.3mm thicker). He said yes, wouldn’t hurt. He IS going to deck the head, of course. 
Im not buying a gasket set as I have most gaskets new already. 

 

 

[Pablo M]

Waiting on locating pins and gasket for the dizzy housing. Meantime prepping the block. Getting it pretty clean but there are some areas that show corrosion. The areas below the cylinders cleaned up pretty well but still show some corrosion. Feels smooth to the touch but catches a razor dragged across it. Seems to me it’s not a critical area. The area around the cylinders is good. What do you guys think? Safe or keep working it till I get it perfectly shiny? That may take a while. Pulling the motor and having the block decked would be the right thing to do, but not in the cards at this time. 
 

 

you can see it better here.  

 

 

I also chased the head bolt threads. That was definitely the right call. Thanks again. 

 

 

Edited October 18, 2023 by Pablo M
Duplicate photos

[Dudeland]

I would give yourself a little bigger cam.   284, 292.  Nothing too unruly.  For the 95$ I feel it would be worth it. 

 

Unless what you are doing with it doesn't allow it. 

 

Regards 

['76mintgrün'02]

10 minutes ago, Dudeland said:

Unless what you are doing with it doesn't allow it. 

 

It is a Tii, so changing cams is a no-no.

[Pablo M]

20 minutes ago, Dudeland said:

I would give yourself a little bigger cam.   284, 292.  Nothing too unruly.  For the 95$ I feel it would be worth it. 

 

Unless what you are doing with it doesn't allow it. 

 

Regards 

 

8 minutes ago, '76mintgrün'02 said:

 

It is a Tii, so changing cams is a no-no.

Exactly why I went with a new stock camshaft. 

Edited October 18, 2023 by Pablo M

[Dudeland]

2 hours ago, '76mintgrün'02 said:

 

It is a Tii, so changing cams is a no-no.

Shoot, sorry yes, no cam upgrade for you, unless you have a kfish wizard and can channel your inner Alpina engineer.