940 hp 565" A-460 ..... finally !!!!!!!

Specs:

4.606 bore x 4.25 stroke = 565 actually 567" 13:1 comp
A-460 Block
Crower/Ford Motorsport crank 4.25 stroke ( .020 under)
Crower rods w/ BBC journal 6.536"
Modified A-460 heads flow 450 cfm at .750 lift ( 2.40 ti intake)
Crower Roller cam (Danny Crower) 278/285 @ .050 with .433 lobe lift
T&D Shaft rockers 1.8 ratio
Manton Push rods.
Arias pistons, gas ported
Akerly & Childs ring pack .043, 1/16th, 3/16th with a Tool Steel top ring
Stephs oil pan w/ kick out
Kaase oil pump
Pro System 1,200 cfm carb
MSD crank trigger:

Engine was built by Greg Gosset at Total Performance in Santee Ca. His attention to detail is awsome.


C-12 with 31* timing is black line, Blue line is C-12 with 27* timing, Red line is Av gas blend with 27* timing.


Engine lost 10hp running av gas blend with 4* less timing vs C-12.

Max Power pull: with 1,050, engine made 5 more hp with the 1,200 Pro System, but the Old 1,050 was a better over-all carb.


Best pull with the 1,200....running 30wt Kendall:



Av Gas blend run with 27* timing 2:1 100LL blended with 91 octane. Works great for pulling the kids on the tube and skiing. It beats the hell out of burning $12.00 gas C-12


We made 16 pulls, burned up just 9 gallons of fuel, 5 gals of C-12 and 4 gals of av gas blend that we did the 10 minute break-in with and power pulls. Carb spacer changes and last couple of runs before the av gas we dumped the 30wt Kendall and swapped in 15/50 Mobil 1




Just might go back this Winter and play for a day or two: just might have to find an Old " Holmes" tunnel ram too ???????



A couple of build shots:








G-

Jon

Nice build Jon............

very nice build love the comparison with the av gas ....very cool

Did you try straight Av Gas?

IDT-572 wrote:Nice build Jon............

thanks Blake,


No on the avg gas I didn't make a straight av gas pull and I had meant to have Steve make a pull to 6,800 and see the numbers. Sicne we had pulled through peak trq without detonation it would have pulled to 6,800 with out issue. We started talking and I forgot about it. Next time will put 2* more timing back in it and run it again. Maybe a straight Av gas pull, but I always blend the av gas at 2:1 or 3:1 so I wanted to run it as I use it.

I'm sure with a 10hp loss, as you see the 10 hp was because the timing was turned back, I'm thinking the av gas was about a 5 hp loss as it was the last time I did this in 2000 when the engine made 855hp on Trick 104( 10.8:1 comp) I switched to av gas blend at 3:1 and with the same jetting and timing the engine was down 5 hp, it made 850 at the same rpm.

I wouldn't recommend running av gas with 13:1 compression at 2:1 blend for most engines, but with this engines chamber and piston design I thought it would be fine. Turned out it was. The engines dynamic compression ratio works out to 8.75:1 for what that's worth. but I'm sure it helped.

If things go as I hope over the next couple of months I'll go back this Winter and play with a few things.....maybe even a few nitrous pulls.

G-

Jon

Nice Results.

I finally figured out why I couldn't do my own graphs from the disk I got of the dyno runs........Superflow has some old software..........

I plotted a few things just to play around but things didn't change much after the first full power pull # 4 ...the most change on any two passes was 10 hp. Most kind of look like this when overlayed:

This was max power pull with the 1,050 and the best pull with the 1,200. The fuel curve change is huge...... the 1,050 made more power and used less fuel. The max power pull had Mobil 1 15-50 if the 1,200 would have been put back on it would be worth 5hp more than the 1,050 made.



Nothing dramatic. maybe next time I'll capture some interesting changes.

If I wasn't running the wet exhaust I'd sure like to cam the engine to keep that hp ramp-up like from 5,400- 6,100 and carry that to 6,600 or so. It sure flattens out at 6,200.

G-

the 1250 needs different boosters and some tuning. the signal is better with the 1050.

dfree383 wrote:the 1250 needs different boosters and some tuning. the signal is better with the 1050.

I need to seen Patrick at Pro Systems the dyno sheets. I'k kicking my self that I didn't modify a intake spacer to hook the vac port up to so we could read the vac. I'm sure with some air-bleeds we can make so porgress....the boosters might need tweeking too.

G-