I have a d16z6 that loves to blow headgaskets. This is the second motor already. I have spent a lot of money and a lot of time into this motor. And yet I cannot have any fun with it. So here's what in the motor:

Head:
2.4 bisimoto cam
bisimoto valve springs and retainers
ferrea valves

Block:
Blox block guard
ARP Head studs
Arias 9.5:1 Pistons
Eagle H beam rods

The rest of the goodies:
victor x intake manifold
RC 750cc injectors
Blox 70MM throttle body
exospeed topmount
t3/t4 turbonetics ball bearing turbo
42mm tial WG
Blitz BOV
Hondata S300
255 Walbro fuel pump
koyo radiator with a fan dat blows 3000cfm of air

The situation:
It will blow the head gasket when I go into boost. Seems like the cooling system is getting pressurized.

What was done to try to fix the problem:
-decked the head.
-make sure the block isn't warped
- cut the dowels
-torqued the head to 60 ft/lbs
-used OEM honda gasket
-used aftermarket gasket
-checked timing to make sure it is correct
-and I am sure we have done more than that, i just 4got already because of the numerous times I have blown the gasket...

My engine builder/tuner is a reputable engine builder and a close friend of mine. He has done many fully built b series and h series engine. Mine would be his first built sohc.

If u have any ideas please feel free to shed some light cuz I am out of ideas, and I am very frustrated with this situation.

 

ARP headstuds!

 

Correct me if I'm wrong but 60ftlbs sounds pretty low for arp's....and are you running a adj cam gear with all this milling? Thicker head gasket maby like cometi...who's Puting the hg in?

 

Not to up on single cam specs but IMO that torque sounds very low for arp headstuds unless that's what they recomend. I know on b series headstuds are tighter than 60ftlbs and that's a VERY easy way to pop gaskets.

 

I torqued mine down to 75 and what kind of HG is this? OE will be your best bet any of the others do the same **** once they see boost leak pop etc. Do you use copper spray. Are you sure both mating surfaces are clean and you are using ARP's right?

 

Ok. Yes both mating surfaces are cleaned.

I torqued the head to 65ft/lbs.

I have used an OEM head gasket before and still it did the same damn thing.

What should I torque my head down too?

 

70ftlb's with Molly lube and a z6 hg...if that blows again you have a head or block problem...buy a straight edge and feeler gauge check it your self

 

so what head gaskets are you using now? chinese ebay gaskets will leak, always. they are ****.

go OEM or made in japan. i use ones by KP gasket made in japan, no issues.

i torque my ARPs to 65ftlb. my sleeves let out before my head gasket. so i doubt its that.


you say you "made sure the block isnt warped", have you had it decked?


what cylinder head are you using?


last but not least how do you know its not detonating? detonation is the most common cause of head gasket failure.

 

When I ws blowing the hg on my sohc I was also at 25-27psi. Found out that the problem was I was slightly lean and too timing in the tune. I street tuned it again with less timing and bigger injectors, got my injector duty cycles down below 85% and it has been fine ever since.

 

If a sohc goes lean for a millisecond it will blow the h.g. Trust me, I have blown 8 tryin to push it too far, but my setup is 6 years old and still running....

 

I was thinking the same as Qwkd16

 

sohc blowing headgaskets usually means its in the tune

 

He even says the guy is use to tuning h and b series. they will take more timing than small bore d series

 

timing issue

 

ok first of all, my friend and engine builder has tuned a lot of d series b4. just mines was the first one he has built. And I do not blame him for anything that is happening. I just want to find the problem and solve it.

I am not running that much boost. I am only up to 15psi. I do not want to push it pass 15psi just yet.

We did straight edge the block and ran a feeler gauge and it checked out ok.

 

Care to shed some light on where the timing and afr should be at all the way up to 8500rpm?

 

try some copper seal

 

Sprayed it wit copper spray still don't work. We even torqed da head down to 70ft lbs. Still da same thing

 

Most D16 have this problem.. Mine does it as well i had the block deck and reassembled everything what a pain and the head was decked new oem gasket y8 honda and then torqued it down to 70 i believe so arps.. and worked great for a while but after you get it going and punch it a few times it will push the compression out of the chambers and in to the cooling system my car runs great but this is just a part of the deal that goes on..Still runs gasket is not blown it just does this when i punch it hard... I wish it would go away but i doubt it... Unless i get thicker studs and maybe re machine the stud holes.. instead of 3/8 run 1/2 and 100ft-lbs also did spray it with copper spray and yeh.. I have pics.

 

My fix atempt is going to be to retorque it to like 80ft-lbs if not more then 80 and larger injectors 1k delphi and stick with e85.. i was at 350whp/315wtq at 17psi and am still..DD

 

I would need a cmm to fix this problem to have the block decked and head and set it all to spec with arps then run it hard and till it leaks like this then take it apart then see where the specs on the cmm are compared to what they were when it was milled.. And see what goes on is it trully flat.. This is a problem with all turbocharged applications the turbo punches the engine so hard it wants to explode and instead of doing that mine just leaks out a little bit of that horsepower.. and dont give me that bs (check for boost leaks)

 

Who out there has had a D16 running 350+ whp DD at like 20-25psi has not had this problem and is it still a problem.. Where is Bisi how is the wagon doing does it have this problem do you Daily Drive it...

 

Plus our cooling systems are really small and combustion cambers are small no place to absorb that punch...

 

So what can we do to upgrade our cooling systems? there has to be way to do it. would external waterpump help this situation?

 

I pulled the head off again today. found the abnormalities on the head gasket. and it shows that it blew all on the intake side.

Would cometic headgasket, 160 degree thermostat help relieve the pressure?