Pitting on block

[TobyCat]

So I got the head off of my car tonight and came across some problems. On inspection of the HG, Head, Block this is what I found.

- HG was out of round on #1 and #6
- found my exhaust-> coolant leak on #1
- Head looked to be torqued to much, as the head had some sweet indents in it where the gasket was
- block has light pitting around gasket ring

So the question really is: Do I clean up the block as best as I can, use my stock HG with my ARP studs. Slap on some copper seal and call it a day.

Or, the pitting is bad enough to pull the motor, and rebuild it with those pistons I just got from the group buy. Just gotta wait until they arrive (hopefully before summer is over!)

Small pics, sorry. I'll try and take better ones tomorrow.

 

[TobyCat]

I should also say that the head is definitely going to get surfaced tomorrow.

 

[IJ.]

TC: Get some pics when it's cleaned off and I'll give you an answer

 

[Mrbaboon]

Chris, good to see the piccies.

Do the IJ thing and clean that bastard. Scrape scrape. Its the only way you'll know for sure.


I know that when Nashman did his rebuild and I saw the block you can get it pretty damn clean with a bit of effort.

 

[Nick M]

Maximum take off is only .002". That is 2 thousandths of an inch. You would need a thicker metal headgasket, and that still may not work, as you have lost much needed deck thickness to prevent warpage, and future BHG. Look at how many are repeat customers for that event.

 

[TobyCat]

Couldn't find the maximum take-off, but .002" is the maximum warpage?

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=A&P=4

 

[TobyCat]

could somebody post some pics of what "bad pitting" looks like?

 

[jetjock]

Bad HG huh?

http://tinyurl.com/3xzvw6

Note post 7

 

[JustAnotherVictim]

It's like you can see the future!!

 

[TobyCat]

lol Jetjock, I always had this sneaking suspicion that I had BHG but after the symptons went away after what I changed out, I figured it was fixed. WRONG!

 

[starscream5000]

Haha, that was pretty awesome JJ .

 

[Nick M]

If it is warped .002", you can deck it flat. If it is warped .003", you can not deck it flat. Well you can, but it is past the specs.

 

[jetjock]

One time I wasn't happy to be right. I say wasn't because there was no doubt in my mind. There seems to be a widespread belief here that a BHG and faulty cooling system share enough symptoms to cloud accurate diagnosis. That's simply not true. Others will argue this point but they'll still be wrong. It's why I seldom get involved in threads where the BHG thing rages back and forth even though they provide a source of amusement. That one was such an easy call I decided to leave a comment behind.

 

[TobyCat]

Lessons learned from others is often difficult...first hand experience leaves a much stronger imprint :|

The good thing though is that I didn't waste much by changing out coolant/tstat/rad cap.

I'm going to go clean up that block as best I can, take some good pics and see what you all think about its condition. I think that it'll be OK for a stock HG/ARPs.Wish me luck!

 

[TobyCat]

Ok, some better pictures of the block. I went to down with razor blades for a good hour, then some oil/800 grit paper. Didn't push on the block at all, just let the block glide across.

Also, I've got some brutal scoring going on my cam journals. There is quite a bit of aluminum residue from the caps. I'm pretty certain that some scotch bright will get that off the cams themselves, but should I get some new cam caps? This is pretty abnormal wear for a low K car ... dang! I'm going to drop the oil pan and have a peak at my main bearings while all this is going on. If those are getting ugly, well...out the motor comes.

 

[Mrbaboon]

Wow that deck came out nice Chris. Purdy.


The scoring, wow also. Mine weren't that bad were they? (you were the one that cleaned up one of the cams so you remember better than I do.)

 

[IJ.]

TC: Block doesn't look too bad at all but needs to be spotlessly clean before it can be used (Assuming it's flat/true when checked with a straightedge)

Cams look like there's been a lube issue with a few of the lobes bluish?

 

[TobyCat]

Surprisingly none of the lobes were blue, but were all quite scored. It almost looks like whoever did the last HG job torqued down the caps too tight.

The only other thing I can think of is my car is parked on quite a steep drive-way with it's nose pointing down. I keep my car topped up with an extra liter of oil, but could dry sumping the oil pump cause that sort of wear?

Alex: your cams weren't as bad, but had similar deposits of aluminum on them. Scotch bright cleaned them up really good.

 

[starscream5000]

Do quick search on babbit material on here. There's a thread on here explaining why most people see the scored cam journals and caps. The soft babbit material used as a coating wears off. You can always check the tolerances. If they are out of spec, you should be able to resize the caps and polish the cams per the TSRM procedure.

 

[TobyCat]

So that coating on the stock cam shaft acts as a bearing, seeing as the caps do not have any. Seems weird

I looked in the TSRM about polishing the cams but came back empty handed. http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=EM&P=48

I also searched for babbit, and got some threads but there seems to be mixed opinions on what to do with the cams. Is it OK to scotch bright the cam journals (clean off the scored babbit material), then plastigauge them? There was some talk about new cams didn't have this material...