That’s exciting that you made that much power, hopefully I make 850....I would think it should with the build I’m doing. What drive ratio are you running your blower to get 8lbs, and what rpm did you get peak power with the 741 cam?

You'll keep making power up top in spite of the cam due to the blower keeping airflow up.

That’s a big jump, won’t you have to retune for that??

Hogie roll so with a blower motor more cam just gets the desired power earlier??

Don’t worry about hi jacking the thread, I’m learning too!!

power looks pretty good. I don't know why he did 600rpm a sec. it would be nice to see o2 reAdings I see BSFC is very high on the top end may be power there if it's that Rich.

He did not have the ability to hook up o2 sensors so I’ll have to fine tune the rest out in my boat! Still happy with the power for the cubic inches though so far!! 3* timing was worth 50hp!

be carful tuning for power with timing especially dynoing it at 600rpm a second. Watch how far down the ground strap it burns. There is a big difference at 600rpm to 100rpm a second. What heat range plugs you run on dyno?

Ground straps still showed it would have probably taken more timing than we put in it, started at 29* and could hardly tell the tip of the strap was colored then I slowed the blower down and took 2 jet sizes out of front and back of both carbs and made a second pull, it picked up tq and lost a few ho but still had a flat spot around 5800rpm so I bumped timing up to 32* and the motor pulled cleaner and sounded a lot better still shows timing mark before the elbow on the ground strap but that pull picked up another 10tq and 50hp and had a nice smooth power curve with no dips or stumbles so I left it there plan on checking plugs and air fuel ratio once it’s in the boat?

That’s first pull at 10% overdriven with 29* timing and 82 & 86 jets

That’s second pull at 4% overdriven still 29* timing and 80 & 84 jets

Final pull at 4% overdriven with 80&84 jets 32* timing left it alone after this one seemed to be happy there.

Ran a pair of 1050s the timing mark on ground strap changed from 200rpm a second to 100rpm a second went from center of radius to base on plug. Just watch it in the boat 600rpm a second is not a good test for boat engine.

Ok, I’ll check one after the first short run, but isn’t 32* still a mild timing setting??

Mine is 8.2:1 with aluminum afr heads 335cc runners and 121cc chambers

It’s the same short block but with better rods as I had before just different heads and cam, also bigger blower which should cool charge down some?? Old motor ran 33* timing for 6yrs and 100hrs and was goin strong when I tore it down.

Hard to pull the handle back at 600rpm/s :D

That's funny the guy with the turbo motors left my shop and went outside he could not stand to watch it anymore.

First weekend out, motor ran awesome all weekend, but last outing the out drive was stuck in forward gear, broke the shift cable trying to pull it out of gear, what causes them to stick?? Felt like it had a load against it say if rpm were too high when trying to shift out but rpm was at 800 in gear like normal?? Bravo xr drive with 30-40 hrs on it and fresh drive oil before this weekend from bravo shop

Cone clutch is stuck. Did boat catch air and rev high? That'd most common thing to happen.

No air time or over revs on that run took some people for a ride 8 miles round trip and run it up to 5000rpm twice but was easy on the throttle taking off and accelerated a few hundred rpm at a time to 5000 then slowed down the same?? So how do I free the cone clutch?? And now that it happened once will it be a reoccurring thing??

You mean twisted? Or snapped?