Another bhg

[Bomberillo]

So Ive been letting my car sit because Ive been gathering all my parts for the build. But yesterday I decided to take it out for a raping. I let it warm up and decided to turn the boost controller on for the first time since I had the head gasket replaced with a metal one. I put arp's but soon after started gettting huge amounts of blow-by hence the long time with no use. So me and about 700 pounds of friends got in the car and drove it like a bat out of hell. It was pulling pretty good considering it was about 950 pounds heavier than usual. I peaked at about 14 pounds of boost and started to get detonation. It was getting loose in second gear with all that weight. Than I felt it, blown head gasket. The same as before no power same sound. Drove it home leaking oil and coolant comming from who knows where. Oh yeah by the way the moral of the story is dont let a mechanic talk you into a mhg without resurfacing the block. It will just blow again. Do it right the first time or dont do it at all.

 

[AjWit]

Dude thats unfortunate, luckily your rebuilding it. If you could go back would you get an aftermarket OEM HG or just surface the block and stick with the MHG?

 

[daledoe]

resurfacing the block with the MHG!!!~

 

[Bomberillo]

I think I would have gone oem headgasket with the arps. But I was broke then. Now I am going to go mhg with mirror finish on block and head.

 

[sneakypete]

that wasnt a good idea.... i hope for your sake you didnt cause any other damage like warping the head, crack the block, score the crank

 

[AjWit]

Awesome, doing that should be the end to that for a while *fingers still crossed though huh?* I'm thinking OEM with ARP's and 72 lbs right?!

 

[mk3mitch]

My car blew up today. Right when I got it running smooth. Raced a 5.0 last night, then it started over heating. Today I start the car and notice a BIG lack of power and just running really bad. Smoke was billowing out the tail pipe. yay. NEW MOTOR TIME!

 

[Bomberillo]

that wasnt a good idea.... i hope for your sake you didnt cause any other damage like warping the head, crack the block, score the crank

Nah, its all good. I already have a spare block crank and head. So I didnt really care if I threw a rod through the pan or cracked the block. I am going to replace everything that needs to be replaced. But thanks for your concern.

 

[Bomberillo]

Awesome, doing that should be the end to that for a while *fingers still crossed though huh?* I'm thinking OEM with ARP's and 72 lbs right?!

If you cant pull the block than that is the best route to go in my opinion.

 

[AjWit]

That's what i'd like to do when the funds are stable again. You only need the Gasket's, arp's and a Timing Belt right?

 

[CajunKenny]

Awesome, doing that should be the end to that for a while *fingers still crossed though huh?* I'm thinking OEM with ARP's and 72 lbs right?!

Wrong.

ARP's should be torque'd to their specs and 72lbs isn't it. The torque spec for ARP's vary with what you use for thread lube and what type of ARP's you use. Studs or Bolts.

I think all this was covered in a thread you started.

And having your block and head ground to a mirror finish may not be good enough. Each manufacturer of MHG's have their own RA specs that have to be achieved for proper performance of their MHG.

 

[Bomberillo]

Wrong.

ARP's should be torque'd to their specs and 72lbs isn't it. The torque spec for ARP's vary with what you use for thread lube and what type of ARP's you use. Studs or Bolts.

I think all this was covered in a thread you started.

And having your block and head ground to a mirror finish may not be good enough. Each manufacturer of MHG's have their own RA specs that have to be achieved for proper performance of their MHG.

Right you do want to adhere to the RA specs that the manufacturer recommends. And as far as torquing the the Arp's you should have a chart that comes with the arp's to tell you how tight they need to be. At least my rod bolts did.

 

[CajunKenny]

Exactly!

 

[easternguy2005]

Dude I had the head done and cleaned the block deck - threw in a composite HG with arp studs and started blowing coolant within 500 miles. Just pulled the motor/tranny today and getting ready to find a shop to do the block and head. This BHG is getting real old...

 

[Bomberillo]

Dude I had the head done and cleaned the block deck - threw in a composite HG with arp studs and started blowing coolant within 500 miles. Just pulled the motor/tranny today and getting ready to find a shop to do the block and head. This BHG is getting real old...

How reputable was the shop that did the work. Are they familiar with the 7m's. Maybe the block needed some work. Just throwing in ideas as to why it failed. I already know why mine failed. Time to find out why yours failed so that you dont get another one. Especially if its your daily driver.

 

[easternguy2005]

Mine failed for a bunch of reasons. First the compression test shows 185+ so I suspect there's alot of metal missing. Now gonna have it measured.

I looked carefully at the gasket and it blew out at the fire ring into the rear-most coolant channel. Previous gasket blew to the turbo side water jacket.

I know the guys at the shop and the work is OK for a OEM gasket. They aren't capable of the mirror finish I need for the MHG. How do I know ? I didn't like the swirl marks on the head but acceptable for the OEM. Looking at the HG I pulled out today I can see the swirl marks on the gasket surface.

This isn't a DD...but going to have to hunt down a good performance shop this week.

It's failing cause the block has damage (corrosion around water jacket) and may not be flat. The compression is too high.

 

[Bomberillo]

Mine failed for a bunch of reasons. First the compression test shows 185+ so I suspect there's alot of metal missing. Now gonna have it measured.

I looked carefully at the gasket and it blew out at the fire ring into the rear-most coolant channel. Previous gasket blew to the turbo side water jacket.

I know the guys at the shop and the work is OK for a OEM gasket. They aren't capable of the mirror finish I need for the MHG. How do I know ? I didn't like the swirl marks on the head but acceptable for the OEM. Looking at the HG I pulled out today I can see the swirl marks on the gasket surface.

This isn't a DD...but going to have to hunt down a good performance shop this week.
Sounds like you have some work ahead of you. Good luck with it.

It's failing cause the block has damage (corrosion around water jacket) and may not be flat. The compression is too high.

 

[supramk3speed]

I've blown my first, and im not sure if i should do it myself or spend more money to get it done by somebody who could care less about me or my car. Im sure they care for my money though! Im not saying all shops are like that but from the sound of it most people whom take their cars in for repairs find problems later.

 

[CajunKenny]

Here's just one example:

I bought my car from a guy who had the same shop service his car for about 10 years. He had them do EVERYTHING and he kept meticulous records of every transaction.

After I got the car home, I started going through every receipt in detail. I found a receipt from SupraStore.com for the purchase of an HKS 1.2mm MHG. I also found a receipt and work order from his preferred shop for installing the HKS 1.2mm MHG.

So like anyone would, I turned up the boost a little and POOOOF! BHG!!! I pulled the head and guess what I found!?!?! Yep...an OEM Composite HG!

Along with that, I found 5 stripped Exhaust Manifold Bolts!

He spent literally THOUSANDS at this Seattle shop over the period of about 10 years and that's how they treated him in the end.

Granted it may have been just one bad tech; but, you get my point. You just NEVER know...

 

[Bomberillo]

Here's just one example:

I bought my car from a guy who had the same shop service his car for about 10 years. He had them do EVERYTHING and he kept meticulous records of every transaction.

After I got the car home, I started going through every receipt in detail. I found a receipt from SupraStore.com for the purchase of an HKS 1.2mm MHG. I also found a receipt and work order from his preferred shop for installing the HKS 1.2mm MHG.

So like anyone would, I turned up the boost a little and POOOOF! BHG!!! I pulled the head and guess what I found!?!?! Yep...an OEM Composite HG!

Along with that, I found 5 stripped Exhaust Manifold Bolts!

He spent literally THOUSANDS at this Seattle shop over the period of about 10 years and that's how they treated him in the end.

Granted it may have been just one bad tech; but, you get my point. You just NEVER know...

Good job on your dyno numbers. What if after installing the headgasket he got another bhg and had to redo it with an oem from lack of funds. But if he really did pay that much money for them to do a mhg and they didnt, Fuck that. Its shops like those you learn you learn from not to go back to. Sooner or later you find out the shop who just bullshit you and the shop that are lagit who stand by their work.