Blue Monster has just been returned from the machine shop, and I have some questions.

[the t3d]

Hello everyone. It sure has been a while but I need your input here on the dilemma I'm facing. I just received my assembled short block from the machine shop a few days ago. Upon finally getting the motor on the engine stand, I noticed a few things regarding the head gasket surface of the block. Compared to my old machining job, it just looks like it's not as machined as it could be. It's very smooth but I just remember thing needing to be like a mirror. Here's a couple pictures of the block when it was first assembled...




So upon looking at these older photos, you can see some scoring between coolant pockets on the intake side of the motor. I don't remember this being a huge deal the first time I put this together, but upon receiving my newly machined motor, the scoring seems a little more prominent. I wanna know what you guys think about these, and whether you think they're serious enough where it should've been mentioned that I might possibly need a new block. These guys were good on telling me every other little imperfection so that we were all on the same page, but I'm just wondering if this is not as significant enough to affect my power goals of 450rwhp. I'm gonna shoot them an email regarding these questions, because either way, I want them to say that the believe all is OK for my power goals and whatnot. This time I managed to have the timing cover machined at the same time. And with a mock up, can tell they are even. I plan on running an 1.8mm metal head gasket from Titan. The block was originally machined for a 1.2mm, just to paint a more vivid picture. Here's some pics of the block and the scoring...

 

[the t3d]

I have one more question regarding the piston at TDC protrudes out the bore just a bit, and I'm sure there's a limit, and I have still the 1.8mm of clearance from the head gasket. I just need to know that that is also not a huge deal. Here are those pictures...



Going through questions has almost made me sick to my stomach fearing that this block needs to be replaced, and I would have to source another, and have this disassembled, machined, and then reassembled. If anyone can give me some peace of mind regarding this, it would be much appreciated. I will answer whatever questions needed for further analysis. Thanks for your time!

-Ted

 

[kakanator]

So the first pics with the blue block look good for a mlg just need to get that paint of the deck. For the last 5 pis or so with that much pitting is you run it you will most definitely have a leak in the water passages.

 

[kakanator]

on that piston to deck height on all the 7ms I worked on they are all like that its normal. For the silver block you definitely need to just cut the deck a few thou and you should be good to run a mhg.

 

[the t3d]

Thanks for the reply. I've been running around all day. So, looking at our past emails, he mentioned that the block has been decked already and can't be decked again. Now that I'm thinking about it, I wanna say that they machined it to the point where the timing cover was even. Maybe they didn't want to cut the head surface any further, and just smoothed it out for a mhg.
I do wish there was some filler you could apply to seal the scoring though. I am going to send them the email tomorrow regarding these questions. I just want them to say that they felt they trust the pitting won't leak, and that there's some sort of guarantee of proper function. Thanks for the input. If you have any more, feel free.

 

[kakanator]

If the shop said they cant cut more off the block then go to a different shop because you can. If you are trying to just drive the car and not make hella boost just get a composite head gasket and copper pray it and put arp on and call it a day it will hold up fine.

 

[hvyman]

There is a spec limit to how much you can machine from the block in the tsrm. If you start going too far it will mess with cam and crank timing.

 

[the t3d]

I sent them an email regarding my concerns, and I was pretty thorough as to what I wanted addressed. I even sent them the pictures to refresh their memories, and they said with discussion with the shop manager, that they're sure that for my goals and application it will hold up. These guys have been around forever and have a surprisingly good reputation around the area. I mean, they're also gonna be cleaning up my head, whenever I find one, so if it doesn't hold up I have it documented that they trust their work. I appreciate all of the input from everyone. I'll be updating my build thread soon, and in the near future keeping an update as to how this motor seals and holds up. Thanks again everyone. Also, like I mentioned...I'm in the market for a head in the Tampa Bay area of FL if you know of anything.

 

[kakanator]

Iv been working on 7m for a few years now if you are going to put a metal gasket on the block with the right amount of tq you will most likely get a blown gasket.

 

[suprarx7nut]

I have limited experience with fresh machining for MHGs looking anything like that. That being said... I can't see that sealing with an MHG. Maybe with an OEM composite gasket, but the MHGs really should have a good flat surface to seal on.

Sorry man.

 

[BlackDevilSupra]

Seems like the pitting is around the coolant passages, rather than around the cylinder bores, do you could possibly still use a MHG. Your best option is to use a MHG that also has some type of elastomer on it. I don't remember which brand has this, either the HKS Bead type of Stopper type, Greddy, or Cometic

 

[supraguy@aol]

I thought that they all had a flouroelastomer.
I've had cometic, hks and Titan hg's, and they all had it.

 

[Backlash2032]

Yeah they all have it. Sad thing about that deck surface is, its not even flat outside of the coolant passages. You can see where it was cut and where its original metal... No bueno for a MHG there. Measure it from the deck surface to the main bearing surface (IIRC...). There's a spec in the bible that will say how much you can remove.