I am boosting 15psi at 340hp at 8300 rpm. I has tried calling bisi but no luck in trying to reach him. I would really love to resolve this problem for my sakes and everyones sake that are going through this same problem.

 

I have my timing around 14-15* at 27psi and havent had any issues. Make sure the afr's are in the 11's. I run 11.5-11.8 making near 400. I daily drive it for 6 years now.

 

My boss had the block drilled out to 12mm headstuds from a Cummins diesel. He ran it lean ONE time and the h.g popped, but he made 450whp.

 

Hmmmmm, this throws me off even with the OEM Headgasket! Have you thought about trying one of our multiple layer steel heat shielding intake gaskets?

To me it does not seem to be the tune potentially cooling system, maybe just a knack in the motor, remember guys although the motors are techincally the same there are always variances and differences in the motors that we cannot see so it may have to do something with that!

If you are interested in the multiple layer steel headgasket shoot me an email!
Randy@bisimoto.com

 

I very well doubt it... If you have had the block decked flat and the head at 70ft-lbs on aprs and it is pushing coolant then i really dont know what to to next.. If i could torque the studs more then that could be a potential fix.. The gaskets never go bad it just presses the air out pass it.. Gaskets are allways in good shape.. I also did use copper spray torqued it to 70lbs I was gonna go more but others say its bad and my tuner said he would of done like 85ft-lbs

 

Randy,
I have been trying to get a hold of someone there at Bisi to maybe shed some light as to how I might be able to resolve this matter, but I have had no luck in getting in contact with anyone.

 

Well as far as what I read on the ARPs, torqueing them pass the required limits does more harm than good... But Idk. Some people say they torque it to 80ft lbs, others say 70ft lbs, and some says 60ft lbs is ok... I am really confused. The last time we torqued it down to 75ft lbs and the gasket still blew...

but anyways i got new studs coming, and the thermostat, plus I will use the oem gasket, and try it again i guess...

 

Shoot me an email:

Randy@bisimoto.com

describe the issue so I can print it off and show our tech staff!

 

so your tech staff is bisi him self..

 

No, I jus figured I ask them...

 

After 4 years of running with a Dseries and studying and watching a bajillion builds and whatnot, I've found one thing to be very very similar with the Dseries.

And that similarity is, if there's too much timing, they will blow headgaskets like no tomorrow. Doesn't seem to matter what anyone does, torquing the headstuds down doesn't help, it just keeps the engine from getting headlift.

I have my ideas as to why, and it's just simply physical gasket size is so much smaller than that of a Bseries or a Kseries or anything like that. The blocks are smaller, the heads are smallers, and so the headgaskets are smaller. It's simple physics, you're going to need x amount of material to withstand x amount of pressure and a heavy pressure spike from a lean mixture or too much timing on the edge of a tune will almost always pop the sucker.

OP, do you know what kind of timing you're running at full boost? What kind of gas?

 

This is what i was getting at is there is a limit on the D series cuz of the size at least if you plan on daily driving it but if its a drag car where it sees the boost few times a year then your good till you have to fix it... I dont think my gasket is bad its just need to be torqued more.. The steel gaskets dont go bad now if it was composite gaskets then yeh they let go fast..

 

Yesss!! I was reading this thread and could not believe nobody mentioned this yet. The sohc cannot typically take the timing advance like some other B,H and K motors can. I would be willing to bet if the timing was changed significantly this problem will go away, blowing a metal gasket is extremely high cylinder pressure spikes!!

 

Ive never blown the oem steel gasket mine just leaks over or under the gasket and i know that cuz last time i looked at the one i pulled out i could see carbon on the green part of the gasket where the coolant passages are.. If i melted the gasket i would probably freak out... Mine just leaks like its not torqued down enough..

 

Thread jack much? Start your own topic. Let the OP have his own topic

 

I said this from the beginning.....

 

 

x2

It's tough to read when people assume all day