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iggdog
06-24-2001, 03:44 PM
what kind of rpm can i turn with a bbc, cast crank,hyperutectic pistons,stock rods with 3/8 milodon rod bolts, and roller rockers without grenading the motor? im running an 18' cole jet for fun/family/ski with logs,800 holly, strip dominator intake,and much winter work to make it right.help me keep it together!

mister460
06-24-2001, 09:12 PM
What rpm do you turn it at now? What are you looking for? What kind of oil system do you have set up right now? You can probably turn it higher than you think.

Slow Boat 001
06-24-2001, 10:01 PM
you can go up to 6500 and be ok but it is going to be hard to get it to turn that rpm with the parts you have. Just run GOOD oil and keep it clean.If you dont plan to race it try to keep it around 5500 or so and it will run for ever. Just remember GOOD OIL !!! www.worthingtonmotorsports.nasha.com (http://www.worthingtonmotorsports.nasha.com)

iggdog
06-28-2001, 05:28 PM
Thanks guys. See you at the river.

johnnie jetboat
06-30-2001, 01:28 PM
Will a cast crank hold together at 6500 rpm?
I went off half cocked a popped for a BDS 8-71(7 lbs. boost,twin 750 double pumpers) for my stock 454. I've been told(by a friend who may be a bit bummed that I beat him to the BDS store) that I can expect total destruction of the bottom end. Fearing a season with out a boat,the huffer is still sitting on the bench.
I've also since heard that the cast pistons aren't real happy after 5000 rpm. What's your take on that?
The guy I bought the blower from(Jim @ dragparts.com) assures me that as long as I keep the ping out of it, it should be fine.
I planned to put it together for a season or two, until I can get a big incher with all the trimmings together. I wasn't planning to run it much past 5500 with the stock lower end(yea, until I get whooped by some yuppie in a bass boat!!!). I've read numerous Hot Rod magazine articles where people have done the same thing in auto applications without any problems.
I'd really like to hear some feedback on this, as my bride is pissed at the $3000 bench decoration(it sure looks pretty though!!!).
Any advice is appreciated!

Jetmugg
06-30-2001, 03:11 PM
Don't run the blower with the cast pistons. With a BBC, the cast crank is probably good for 650 HP, but the stock cast pistons should not be used in a boosted or nitrous fed application. The cylinder pressures and temperatures at the top of the pistons will be too great, and failure will occur. After spending 3K on a blower, resist the temptation to save 7 or 8 hundred bucks on the correct forged blower pistons. Buy the right pistons, cam, a steel crank, and good rod bolts. Possibly even aftermarket rods with 7/16 bolts already installed. Then you will have a totallly bulletproof lower end.
I once read a saying by a famous engine builder - "Buy the best, and only cry once".
SteveM.

iggdog
07-01-2001, 08:20 AM
Back to oil. Am I better off running straight 40 wt., or a multi grade? What about Prolong, slick 50, STP etc?

boatnam2
07-01-2001, 09:09 AM
hey iggdog,this is how i run mine,valvoline 60 wt,heavy duty pump thats welded together,14 quart oil pan and a 16" x4" oil cooler with 3/8 oil passages.i change my oil every time out unless its just for the day.oh yea i also run a fram filter with the whole system in 1" hose.

rivercrazy
07-02-2001, 08:11 AM
Don't use the oil additives. Just use a high quality strait grade oil, probably 40W. Or use a 20W-50 synthetic.