what does a properly prepped block look like?

[Facime]

Ok well, I saw my block at the machine shop today. I was not entirely sure that the block surface was ready for a Cometic MLS gasket (RA50). The machine shop owner swears its MHG ready but Im not convinced. Since Ive never seen a block that was supposedly prepped for a metal gasket, can someone actually take a picture of one for me? I mean Ive read the description (pretty much mirror shiney right?)

I got tired of sorting through threads trying to find a picture of what RA50 or better looks like.

If anyone can help me out that would be great.

 

[jdub]

Don't have a pic, but if you can feel machine marks with your fingernail...it's not good enough.

 

[cnewingham]

Here are the best photos I have, you can see the lint on the block (not scratches). Hope it helps:

 

[jetjock]

Purty. Not all shops have a profilometer but any machine shop worthy of the name should have at a set of surface roughness standards. They're like what, $80 to $100 for the set? Ask to see those. It'll give you a perfect idea of what it should look and feel like.

 

[Boosted Supra]

Like this

 

[IJ.]

 

[ma71supraturbo]

 

[jdub]

IJ - Not fair! Yours is lapped!

 

[ma71supraturbo]

IJ definitely wins for the most mirror-like block...

 

[IJ.]

IJ - Not fair! Yours is lapped!

Well Weez asked "what's a properly prepped block look like?"

 

[ma71supraturbo]

Here are the best photos I have, you can see the lint on the block (not scratches). Hope it helps:

I had to take off a ton of material to get rid of all the pits/grooves by the coolant passageways -- so much, in fact, that I had to return my 1.4mm mhg and get the 2.0...

 

[speed]

wow, looks like I got some more cleanin to do before i put mine on.

 

[empera]

how much does a machine shop usually charge to prep/lap a block.

 

[Imprezademics]

Damn! Those are some clean ass blocks. Nice work!

Willie

 

[cnewingham]

I had to take off a ton of material to get rid of all the pits/grooves by the coolant passageways

believe it or not you could not feel these areas of discoloration with your finder nail at all. I figured they are just stained (haha)

 

[Facime]

wow thanks guys, those photos (while hard to see some of the detail) really helped. I was actually thinking that everyone had their blocks prepped like IJ's. So when I went to pick up the block today I was concerned that it wasnt smooth enough. The head looked very nice and was much closer to a mirror (I suspect because its aluminum...right?) The thing that has me so concerned is that the shop didnt even know what "RA" was. Granted when I took the parts in to them there was a language barrier but I distinctly heard "diamond cut"

As it turns out, when I went to pick up the block they showed me the pistons and rod bearings...

Junk

So, Im doing a full bottom end rebuild now. I'll take pics when I get everything back, and if its not smooth enough I'll find a shop to fix it. The price I paid for what they did was nothing, and they did it super fast. But like we used to say in the printing business: "You want it cheap, fast and perfect? Pick two and call me back"

 

[Facime]

how much does a machine shop usually charge to prep/lap a block.

I paid $120 for the head and block. And that included taking both apart (basically I gave them a seperated longblock)

 

[tte]

I had to take off a ton of material to get rid of all the pits/grooves by the coolant passageways -- so much, in fact, that I had to return my 1.4mm mhg and get the 2.0...

I just had my head and block machined...The machine shop used a CBN machine and produced finishes esp for metal head gaskets. I cannot feel the machine marks and it is very hard to see them.

Is that stock pistons in your block?
My pistons are stock and have a thermal coating on the top.
IJ told me that genuine toyota pistons come with a coating on top.

Maybe you cleaned yours off.

Cheers,
Roy