3b to 3bt, head gasket didnt seal (1 Viewer)

[bj70bc]

So first off the truck is an 86 bj70, around 322k km on the truck, i just put a td04 13t turbo on it but havent yet turned up the fuel. I wanted to baseline it first to see everything working after i put it all back together. The head was cracked a wee bit when i took it off to replace the precups so it was replaced with a new unit, injectors were rebuilt at 1850 psi, injection pump was retarded about 1mm.
I put a frozen boost water to air intercooler on it. Head was decked at the machine shop.

So after the first drive i realized that the coolant overflow was slowly spitting out some fluid, i figured that it was just burping some air so i filled it up after it cooled and drove it the next day. Same thing the next day too, and the bubbles coming from the overflow tube were fairly constant. The water temps started to climb as well about 200+, and it got up to 220 or so for a very short period, so i pulled it over and let it cool.
The egt's were higher than i figured they should be as well, especially having an intercooler installed and no fuel increase.
I'm starting to think the head gasket didnt seal, classic hg symptoms......
I used a toikio (probably mis-spelled) MLS gasket from radd cruisers, looks identical to the toyota one.
What are some reasons that it may have not sealed? Could this issue be something else?

 

[BramJan40]

Might be a silly question, but after you put the head back on and topped off the coolant. Did you let it run with the rad cap off to let all the air bubbles out?

Did you also re-torque the head after a full engine heat soak? I believe the mls gaskets need to be re torqued 2, if not 3 times. I did 3 times just to be safe.

Im running the same turbo on my b engine. But I think mine is the td04hl 13t. I have it set to about 18psi. Max egts on a 30C+ day I’ll get is 1100 doing the coq at 70 kph

hope this helps. pm me if you have more questions.

 

[-MaTTi-]

What headgasket is installed?

 

[bj70bc]

So....
I believe what had occurred was i bought the tokiko head gasket instead of the toyota one (first mistake), The tokiko was 1.37mm thick and toyotas is 1.54 mm thick, (unbeknowenst to me at the time) and the accepted crush range is around .2mm so the head essentially contacted the top of the liner fire ring protrusion and didnt allow for a full crush.
Also i used oil to lube the bolts instead of the moly head bolt torque lube, this could have introduced oil film between the head and block and skewwed torque readings and helped to botch the install.
I took it all apart cleaned it all 10x better and since have installed the toyota head gasket, and all seems to be well.
I have not re torqued the head gasket though......
Running around 20 psi

 

[bj70bc]

Might be a silly question, but after you put the head back on and topped off the coolant. Did you let it run with the rad cap off to let all the air bubbles out?

Did you also re-torque the head after a full engine heat soak? I believe the mls gaskets need to be re torqued 2, if not 3 times. I did 3 times just to be safe.

Im running the same turbo on my b engine. But I think mine is the td04hl 13t. I have it set to about 18psi. Max egts on a 30C+ day I’ll get is 1100 doing the coq at 70 kph

hope this helps. pm me if you have more questions.

How much extra torque-ing did you see when re-torquing the bolts ?

 

[BramJan40]

How much extra torque-ing did you see when re-torquing the bolts ?

Some bolts I definitely noticed a quarter turn. But I’m going to double check with steve at EBI. But I may be mistaken. I believe you need to loosen all the bolts in the correct pattern and then re torque but I could be wrong. Been a couple years since I rebuilt my engine. I’ll get back to you on it tomorrow.

 

[Eurasiaoverland]

You went to the trouble of rebuilding the engine with a new head, and wanted to save a few dollars / days of waiting by fitting a non-genuine gasket? Of all the things to cut corners on, surely the head gasket is the absolute last thing to consider?

You say you got a new head, but you got it decked. Why would you do that? Or do you mean 'new to you' as opposed to truly new? Was it decked with the pre-cups in? Have you checked the pre-cup protrusion with a dial indicator? Has the block been machined? Was it checked for being perfectly flat?

 

[bj70bc]

i was under the impression there was no difference in the gaskets, lesson learned.
new head decked to skim the precups for proper protrusion (ie 0.0-0.1 as per the manual) and ensure flatness.........
new gasket is in and good now buds

 

[Eurasiaoverland]

i was under the impression there was no difference in the gaskets, lesson learned.
new head decked to skim the precups for proper protrusion (ie 0.0-0.1 as per the manual) and ensure flatness.........
new gasket is in and good now buds

Glad to hear that, and that no damage was caused.