What Power Level Before New Head Gasket

[Badgaz]

What power level are most guys seeing the necessity to change head gasket on an un opened rb25det?

[scotty nm35]

What cylinder pressure do the stock bolts stretch is what you would like to know, but there is no common way to check that while tuning. It would also depend what heat stress the engine was under I imagine. Manufacturers use the stock bolts as a fuse, to let the head lift rather than have a catastrophic bottom end failure when something goes wrong.

I had an MLS gasket let go on the VQ when my wastegate line accidentally popped off. I drove it like that for a year, not knowing what the issue was, just slowly pumping bubbles into the cooling system. It wasn't until I was on the dyno that the head lifted and the weep turned into a mess. Engine out for L19's and a pair of OEM gaskets.

I would say 350kw is around the stock RB's head gasket limits with the stock bolts, but it would depend on fuel and timing. Not saying you can't push through that, you are just living on the edge imo. Some say you can drop new ARP's in without even taking the head off, perhaps it's an option for you?

[Badgaz]

I'd heard different opinion which said factory bolts were less prone to stretch than some aftermarket ones..... Either way it will be tuned to it's next limiting factor. We'll see how far she will go.

[Ben C34]

There's a dude running 600 kw or something nuts with a stock unopened neo with arp studs (replaced with the head still on)

I wouldn't worry about the gasket just blowing due to a certain power level. It's cylinder pressure that does it, and pinging shoots cylinder pressure through the roof.

[Dose Pipe Sutututu]

Lazy timing, loads of boost and E85

I'm putting 1.5bar into my stock motor, hasn't popped yet. Will go to 1.6bar once I sort out this misfiring issue.

[Simon-S14]

boost doesnt kill Headgaskets... cyln pressure does. Well uncontrolled sudden bursts of pressure is what really kills them.

stock gasket and bolts good for 400 rwkw no worries.

[Badgaz]

this is all good news then better beef up my fuel system a bit then.

[Dose Pipe Sutututu]

And screw in more boost!

[Badgaz]

Deatschwerks pump or Walbro?

[Dose Pipe Sutututu]

Walbro E85 pump, they're quiet and seem to be pretty reliable.

One of my mates have had his DW300 fail but another one still has one going strong. Mind you both bought the DW pump before the Walbro E85 450L pump was available.

[Blackkers]

Walbro all the way. Silent

[scotty nm35]

I had the same issue with the DW300 in an e85 Stagea, we replaced it with a 255.

e85 Walbro's are hard to pass on for the $185 they cost.