Some pics of blown MHG with ARP studs, any ideas why?

[SC61 MK3]

Purchased the "rebuilt" motor almost 2 years ago and have not had any problems until I started losing coolant with no other signs. It would sometimes run hotter than normal on my autometer gauge but nothing crazy and it never spiked the stock gauge. Finally one day it stalled and had trouble running and blowing white smoke so I pulled the head. Here are some pics, any ideas why it went? Also 2 of the ARP studs fully unscrewed instead of just the nut when I pulled the head, were they installed wrong?

 

[IJ.]

Was the deck surfaced?

Was the timing case done at the same time?

Did it get a retorque?

 

[hvyman]

Closer pics of the gasket would be better too.

How is it tuned also?

For pouring white smoke its funny that you dont have a clean cylinder.

 

[laotionracer101]

+2 ij

 

[SC61 MK3]

I was told the head was resurfaced and rebuilt, the bottom end previously had rod knock so the crank was machined and got new bearings. I am not sure what was done to the block besides that and I am not sure about the timing case but it was done at a supra shop who seemed knowledgeable.

I never did a retorque, remembered reading it was not required

---------- Post added at 02:29 AM ---------- Previous post was at 02:25 AM ----------

Closer pics of the gasket would be better too.

How is it tuned also?

For pouring white smoke its funny that you dont have a clean cylinder.

If you click the pics again when it the window opens it will maximize it.

I was not running high boost (13-14psi) but it was around 12:1 under boost

Ya I was disappointed I at least wanted a free engine steam cleaning with my bhg

 

[Moy]

Improper assembly or improper machine work. Or both. Hard to see in the pictures as said above, closer pictures of the headgasket, cylinder head's HG surface and block's HG surface would help.

 

[SC61 MK3]

Click the pic again when the new window opens and it will maximize the picture.

I might add I have already taken the head to a machine shop and had it resurfaced, it was also pressure tested. It was warped and he has the exact amount that was taken off written down I think it was something like .008. He did say that it had been resurfaced before.

 

[IJ.]

I was told the head was resurfaced and rebuilt, the bottom end previously had rod knock so the crank was machined and got new bearings. I am not sure what was done to the block besides that and I am not sure about the timing case but it was done at a supra shop who seemed knowledgeable.

I never did a retorque, remembered reading it was not required

---------- Post added at 02:29 AM ---------- Previous post was at 02:25 AM ----------



If you click the pics again when it the window opens it will maximize it.

I was not running high boost (13-14psi) but it was around 12:1 under boost

Ya I was disappointed I at least wanted a free engine steam cleaning with my bhg

Personal opinion based on experience, it's always needed....

 

[SC61 MK3]

Was the deck surfaced?

Was the timing case done at the same time?

Did it get a retorque?

So when I put this back together I absolutely have to get the block decked? I really would like to avoid having to disassemble the bottom end myself...

 

[IJ.]

Unless you use a composite....

Even then the fact it's blown a HG at all I wouldn't reuse it as is but that's just me I try not to build grenades

 

[SC61 MK3]

Personal opinion based on experience, it's always needed....

So for future reference on the retorque do I crack each one lose and tighten one at a time or crack them all lose first than tighten all of them, of course using the correct pattern

 

[IJ.]

One at a time so you don't get Coolant and Oil under the HG.

 

[SC61 MK3]

Unless you use a composite....

Even then the fact it's blown a HG at all I wouldn't reuse it as is but that's just me I try not to build grenades

I have a oem toyota hg but I'm afraid it will won't last with the bigger turbo

and thanks for taking the time to help me out!

 

[hvyman]

What i meant was pics on 1-2 so you can actually see each cylinder. All yours pics are of entire block. Can not see where if any damage was done to hg.

So something warped. You should have a hardness test done.

With new arp's they need to be retorqued as the heat cycles breaks them in,when you reuse it is not needed but insuance(Have seen and heard from friends of them backing out with oil on assembly) and they have to have each hole on the block tapped all the way to the bottom. There is about 1/4in that is untouched stock.

 

[IJ.]

I have a oem toyota hg but I'm afraid it will won't last with the bigger turbo

and thanks for taking the time to help me out!

Be surprised how well a Composite will hold up with a solid tune, my TT V8 in the 240z ran 30psi all day on them.

 

[SC61 MK3]

What i meant was pics on 1-2 so you can actually see each cylinder. All yours pics are of entire block. Can not see where if any damage was done to hg.

So something warped. You should have a hardness test done.

With new arp's they need to be retorqued as the heat cycles breaks them in,when you reuse it is not needed but insuance(Have seen and heard from friends of them backing out with oil on assembly) and they have to have each hole on the block tapped all the way to the bottom. There is about 1/4in that is untouched stock.

Do you think there was a problem with the 2 arp studs that came out with the nut still on them. I was able to spin the nut off by hand off the stud

edit: The nut was not loose at first. I had to crack them loose and they didn't seem any different them the other. All but 2 of them the nut came off the stud by itself and on 2 when I thought I was unscrewing the nut off the stud, it was the stud unscrewing from the block with the nut still threaded on it

 

[hvyman]

So what exactly are you tuning with? A bigger turbo needs a standalone not a afc.

If the nuts were loose than yes.

 

[SC61 MK3]

Be surprised how well a Composite will hold up with a solid tune, my TT V8 in the 240z ran 30psi all day on them.

Well maybe I'll give it a go, I would like to reuse my arp studs. I am going to measure each one with a caliper to make sure they didn't stretch and I have some new arp assembly lube also. Anything else I need to know to reuse them?

---------- Post added at 03:17 AM ---------- Previous post was at 03:13 AM ----------

So what exactly are you tuning with? A bigger turbo needs a standalone not a afc.

If the nuts were loose than yes.

The nut was not loose at first. I had to crack them loose and they didn't seem any different them the other. All but 2 of them the nut came off the stud by itself and on 2 when I thought I was unscrewing the nut off the stud, it was the stud unscrewing from the block with the nut still threaded on it

 

[IJ.]

Unless they've been torqued to 130+ft/lbs I wouldn't be too concerned at the ARP's, I used to replace the Nuts every 5th tear down.

You need to run a chaser down each bolt hole in the deck, I use a tiny smear of assembly lube on each stud and spin them in by hand, more assembly lube on the washers and nuts before torquing them in 3 incremental passes in sequence. (lube helps to hold the washers in place in the head before you drop it down over the studs, can't get the washers in if the head goes on first)

Have a really good look at the Steam holes beside the head bolt holes for cracks, it's quite common on earyl/light blocks.

 

[SC61 MK3]

OK thanks for the tips.