Options for lowering boost and keeping headgasket intact.

I dont know why those numbers are killing headgaskets.... I know of several oring setups that see far more boost and don't even use studs. are the block and the head flat? Sounds like the surface may be the culprit,
 
dmaxvaz said:
I WOULD GET THE HEAD OR THE BLOCK FIRERINGED AND BE DONE WITH IT
Click to expand...

That's what I did but not until after blowing the head gasket and cracking the head on a stage 3 port job...Everyone told me I didn't need orings when I was building it, just from my mistakes, if it were me on a high horse motor and I was going through a build up, just do it...
 
Timbeaux38 said:
I dont know why those numbers are killing headgaskets.... I know of several oring setups that see far more boost and don't even use studs. are the block and the head flat? Sounds like the surface may be the culprit,
Click to expand...
It's been over 4 years since this head was put on.It was a brand new head at the time. Block had 35k miles on it. Things happen over 4-5 years. I checked the head and the protrusion myself and the head was flat within .0015 and o-ring protrusion was within .001 on all 6. It held fine untill the new pump and cam were installed. More timing, more boost, different cam, no telling why it happened. Trucks in the shop now. I'll get it redone and try it again. I ordered the next size up ex housing and I'll install a wastegate in the hot pipe. Just have to check and see if the head needs to be re-cut. If so, I'll have to get the o-rings re-done also. Fire rings would be a last resort.
 
Ron,

You are on the right track..... How much protrusion on the O-rings do you have? Maybe decking the head a few thou would providing more protrusion along with the 625's would get the job done.

Doug
 
Have you double checked the timing with an injector pulled and pump mm lift?

Almost sounds like the new pump raised timing a bunch. Have you dyno'd the new setup, maybe you're just making 1200 hp now and it just needs better clamping force!
 
Doug.
I'm waiting to hear what Brad finds when he pulls the head. I don't remember what the protrusion was on this head, only what the variance was. I think Piers said they were using .008-.009.
There was a 6 degree difference between the plunger lift method and the timing light. The light showed 24 deg. while the plunger lift numbers showed 30 deg. It was a pain to start untill warm, and even then it needed to be cranked alot more than normal. I've never run that much timing before so I don't know it that is normal or not. I was running 19 deg(using plunger lift method) before and it started instantly. Brad runs 30 degrees on his race truck and it starts easier than mine. That could just be the difference between the 12mm pump and a 13mm. Once it's warm it idles down well and is smooth as heck.

Big Blue 24.
I don't think it's at 1200. More like 750 or so.
 
Ron,

I like .010-.012 for a normal application using ARP 2000 studs. For your setup you might consider at least .012 and even .014, clamped to 150# should hold well. Your timing sounds high by the desciption of how your truck is running, I bet you will like 20*-26 on the street a lot better than 30*! Does the pump in your truck have a custom cut cam?
 
I can tell you that i had to go thru 3 cranking cycles to start to back it off the trailer. I believe its much higher than 30.0 degrees. It sound like you can break glass when you crack the throttle. I am running a little behind schedule. I hope to have a spot in the shop soon. Sorry for the wait Ron.
 
If it's north of 30*, all Ron needed to add was a little nitrous or methanol and he could have windowed the block.
 
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