"Smoked" crate motor

[Blewbyu]

Went to the hydro/flatbottom Nationals on Lake Washington a week ago-and noticed my beloved ZZ1 crate motor sounding like someone poured a box of rocks down the carb.Pulled it Saturday-and to the machinist yesterday.1/2 thumbnail sized piece broken off edge of #5 piston,rust in #6,both head gaskets blown between 3/5 and 4/6.Machinist said bad gas.I have always run Chevron Supreme until this year when our village built speed bumps on the launch ramp hill that annihilate boat and the truck trans-now I have to buy gas on the lake,and it's all regular at $2.50 gal.The engine was 10.5:1 compression-and we are going to 9.0:1 so she will run on "crap" gas.Anyone know how much performance loss I can expect? Will hole shot suffer significantly?(she tailwalked easily before).Have also bought 6 gal tanks to get Supreme at the station,but it's a pain!Your thoughts?? :mad:

[Forrest]

That sucks about the ZZ! Don't give in and let those rip-off, speed-bump installin', pompus putzs (that was for all you old timers around here), dictate what kind of performance you will get out of your Donzi. :mad: Fight back! :mad: Get a few nice plastic fuel jugs like those made by VP, or even a fuel caddy with wheels, and put 93 back in the tank! BTW, that engine was probably designed at an optimal compression ratio for that cam and the fast burn-heads. I think that you will notice the lower performance and the engine may have weaker idle than with ten point something to one compression. Best of luck.

[GEOO]

WOW, Bummer!! I know the feeling all Too well. Doulbe check your valves for rust. Make sure you didn't have any reversion. I'm with Forrest, Buy some jerry jugs. Keep the CR. GEOO

[Jamesbon]

Oh, I feel your pain. I hope all is well from here on out.

I had the same thing happen on one side of my old 355. I don't think it was bad gas, I think it was a bad seal between the head, gasket and block. Hence the rust.

Personally I wouldn't even THINK of going from 10.5:1 to 9.0:1, but that's only a matter of personal preference.

I would GUESS the drop would be in the 50-100 HP range?? Anyone??