SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: SLKcan on June 28, 2013, 12:08:21 AM

Title: What is max rpm 455 olds rocket 77 challenger 18.5 ft
Post by: SLKcan on June 28, 2013, 12:08:21 AM: Just wondering what is the max rpm and for how long I should run her at that rpm? It is done up good I know buddie spent large on it before I bought it not sure if its roller or not.
Title: Re: What is max rpm 455 olds rocket 77 challenger 18.5 ft
Post by: Chad krieger on June 28, 2013, 12:12:17 AM: Show some Picts.
Title: Re: What is max rpm 455 olds rocket 77 challenger 18.5 ft
Post by: GT Jets on June 28, 2013, 12:20:41 AM: Quote from: SLKcan on June 28, 2013, 12:08:21 AM
Just wondering what is the max rpm and for how long I should run her at that rpm? It is done up good I know buddie spent large on it before I bought it not sure if its roller or not.

IMHO, under 5,000 RPM, I would feel more confident under 4,600.... ;)
Title: Re: What is max rpm 455 olds rocket 77 challenger 18.5 ft
Post by: Xthaspot on June 28, 2013, 01:00:39 AM: Well I just built my 455 olds. I'm going to be taking it out this weekend. Ill let you know what I'm gonna be pushing on the rpm level.
Title: Re: What is max rpm 455 olds rocket 77 challenger 18.5 ft
Post by: SLKcan on June 28, 2013, 11:23:00 AM: Sweet I have been hitting 5500 no probs yet!!!
Title: Re: What is max rpm 455 olds rocket 77 challenger 18.5 ft
Post by: Xthaspot on June 28, 2013, 12:01:29 PM: Yea that's what I'm estimating.
Title: Re: What is max rpm 455 olds rocket 77 challenger 18.5 ft
Post by: mash on it on June 28, 2013, 12:10:52 PM: Quote from: SLKcan on June 28, 2013, 11:23:00 AM
Sweet I have been hitting 5500 no probs yet!!!

Whats the boat/build/pump?
Title: Re: What is max rpm 455 olds rocket 77 challenger 18.5 ft
Post by: SLKcan on June 28, 2013, 12:14:32 PM: It's a 77 challenger 18.5ft 455 olds rocket 500 plus horsepower jacuzzi WJ just rebuilt jet new wear ring hydraulic place diverter brand new.
Title: Re: What is max rpm 455 olds rocket 77 challenger 18.5 ft
Post by: SLKcan on June 28, 2013, 12:29:04 PM: Couple pics I took this spring
Title: Re: What is max rpm 455 olds rocket 77 challenger 18.5 ft
Post by: SLKcan on August 09, 2013, 01:29:52 PM: Quote from: SLKcan on June 28, 2013, 12:14:32 PM
It's a 77 challenger 18.5ft 455 olds rocket 500 plus horsepower jacuzzi WJ just rebuilt jet new wear ring hydraulic place diverter brand new.

I found out my rpm gauge was set for a six cylinder so now I am running 3800 rpm at 70 mph on GPS I have yet to see what the waterhog will top out at!!
Title: Re: What is max rpm 455 olds rocket 77 challenger 18.5 ft
Post by: mobboss on August 09, 2013, 01:41:41 PM: a stock 455 olds in a boat , should be able to run 4500 to 5000 but under 5000 is better. last longer!
Title: Re: What is max rpm 455 olds rocket 77 challenger 18.5 ft
Post by: Havasukona455 on August 09, 2013, 03:48:40 PM: mine is a stocker with a big cam and ive only ever got 4600 rpms and 61. that's with just me in it and fresh pump. might see more rpm down river >:D
Title: Re: What is max rpm 455 olds rocket 77 challenger 18.5 ft
Post by: Xthaspot on August 09, 2013, 03:51:19 PM: I'm pushing 5-5,500 rpms but my 455 isn't stock.
Title: Re: What is max rpm 455 olds rocket 77 challenger 18.5 ft
Post by: Ralph Brunt on August 09, 2013, 04:14:35 PM: Quote from: SLKcan on August 09, 2013, 01:29:52 PM
I found out my rpm gauge was set for a six cylinder so now I am running 3800 rpm at 70 mph on GPS I have yet to see what the waterhog will top out at!!
i say your tach is still wrong or your gps
Title: Re: What is max rpm 455 olds rocket 77 challenger 18.5 ft
Post by: GlassCutter on August 09, 2013, 06:57:55 PM: You really need to calibrate your GPS. One, if not both of those numbeds is still was off.
Title: Re: What is max rpm 455 olds rocket 77 challenger 18.5 ft
Post by: Chad krieger on August 09, 2013, 08:47:51 PM: Under 4500 is the best.
Title: Re: What is max rpm 455 olds rocket 77 challenger 18.5 ft
Post by: Xthaspot on August 09, 2013, 08:59:52 PM: Quote from: Chad krieger on August 09, 2013, 08:47:51 PM
Under 4500 is the best.
I agree on all stock olds. If you do the necessary mods that Mondello performance recommends then you can run way higher RPMs. Restrict the oil going to the top end and you won't. Have an over oiling issue to the top end meaning you won't run out of oil in the bottom end and spin or weld the bearings to the crankshaft. Thats just what I believe.
Title: Re: What is max rpm 455 olds rocket 77 challenger 18.5 ft
Post by: GlassCutter on August 09, 2013, 11:11:52 PM: 2 words for you . . . bearing speed.
Title: Re: What is max rpm 455 olds rocket 77 challenger 18.5 ft
Post by: Xthaspot on August 09, 2013, 11:17:54 PM: Quote from: GlassCutter on August 09, 2013, 11:11:52 PM
2 words for you . . . bearing speed.

Help me understand this "bearing speed".
Title: Re: What is max rpm 455 olds rocket 77 challenger 18.5 ft
Post by: GlassCutter on August 10, 2013, 10:03:15 AM: Olds motors have very large bearing surfaces on both the main and rod journals and shitty oiling systems. I believe Olds rod size is 2.5 inches and the mains are 3.0. Compare that to a 454 with its 2.2 and 2.75 sizings. At high rpm the oil has to run further and cover more surface than in the Chevy. I don't know what original sizing is on a BBF but it is common to cut the cranks down to Chevy dimensions when building a Ford. Makes parts easier to find too. It is like racing a circle track where one car always has to run wide, and so also have to run a lot further than the car who gets to keep to the inside line the whole way.

There is a ton of work that needs to go into improving the oiling on a 455 crank, just limiting the oil to the heads isn't enough. If you are still researching check this out http://aera.org/engine-professional/rocketing-the-455-olds/ (http://aera.org/engine-professional/rocketing-the-455-olds/)