So, Zero.
I don`t think that`s going to help much.

Ill just keep dreaming then, i was sure i could But just a little But.

[QUOTE=JaniH;4940290]Ill just keep dreaming then, i was sure i could But just a little Bit. 👺=/QUOTE]

well, you just saved 30k-60k on outdrives.

True 😁. I bought all The bravo tools and made My first upgrade For My xr upper, nothing breath taking But might work at My Current Power level. One season behind and IT seems to Be holding nicely. Any info how The endurance innovation upper Gear test Are going?

Quench clearance....
What is your setup's quench clearance?
I am talking about the distance from the piston's quench pad to the quench area of the cylinder head.
If your piston pad -to- block deck distance is ZERO (we call this Zero Deck), then your quench distance will be the thickness of your compressed head gasket. If your piston is DOWN in the hole .010" then you ADD that to your gasket thickness to get your quench clearance.

A quench clearance of LESS THAN .045" is a SQUISH motor, meaning that as the piston approaches TDC that you introduce significant turbulence into the ignition event, Ensuring a more even and controlled burn.

This ONE factor determines how OCTANE TOLERANT your engine will be.

We regularly run aluminum headed Mopar RB bigblock strokers at 11.2:1 NA with 250@050 cams on 91 pump gas with initial/full mechanical/full vacuum advance numbers of 20/38/54 with no signs of detonation.

Bigblock Chevys respond similarly with tight quench clearance.

If your motor is NOT set up with tight squish, then your octane tolerance is MUCH LOWER than it can be otherwise.

And there is a dividing line between Squish motor and non squish motor.

You get the benefits at .045" to .055", but above .055" you don't benefit at all from the turbulence effect.

So your particular build, your piston to deck setup, your head gasket choice, they all play into this.

Somebody mentioned bowl porting of your heads. You can lower static CR by expertly opening up those chambers properly. But DO NOT ADD HEADGASKET THICKNESS, especially if you are currently operating "in squish". You can also deepen your valve reliefs in the pistons or dish them slightly (both of which will require rebalancing).

5 psi typically raises your octane requirement by 2 points (from 91 to 93 for example).

Comparing two motors with similar configuration and CR, but with one operating in "squish" and the other operating at larger clearances, the squish motor will operate optimally on 2 points LESS than the motor that isnt benefitting from squish.

Hope this is helpful.
M

A Bravo (even an upgraded one) with over 600 ft lbs of input torque is just WAITING for the worst moment to blow up on you.

I have personally blown up stock Bravos with only 450 ft-lbs of input. There are guys on here who will tell you how their modified Bravo lasts forever with their 1,000 HP. I say they are liars or very lucky poker players.

Quench IS very tight ,0.036"-0.037". My Pistons now Have 6.5cc solid dome, so Domes Have to go If lowering The compression IS needed. I always target For 0.039" quench, But this one came really tight.

What exactly are endurance innovation gears ?

They Make XR Gears From better material vs merc junk. Lower Gears Are on The market allready. Not sure about upper Gears. They where searching For people For The upper gear test program while ago.