SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: doug olah on May 17, 2016, 07:56:44 AM

Title: engine choice
Post by: doug olah on May 17, 2016, 07:56:44 AM
Hi , I'm new to current jet boats. I had a couple in the 70"S but need your imput on current engine choices. We bought a 1985 taylor  with a 454 CI with a dominator pump. Took it out but sucked a valve. Need new short block. Do I need a marine short block? not looking to race but want decent power, running msd, air gap oval intake and 800cfm.Any suggestions?

thanks
Doug
Title: Re: engine choice
Post by: FordLover on May 17, 2016, 08:01:12 AM
No way!!! A chevy blew up?!! I am suuuuper surprised. Lol

Lots of options. Someone on here could have something that could help out. Or you can go the short block route but you need to make sure it is set up for marine specs. The pros will chime in.
Title: Re: engine choice
Post by: doug olah on May 17, 2016, 08:07:53 AM
thanks need to know more about marine applications.
Title: Re: engine choice
Post by: doug olah on May 17, 2016, 09:51:52 AM
Anybody recommend a supplier for a short block with large oval intake ports? thanks
Title: Re: engine choice
Post by: mash on it on May 17, 2016, 10:04:56 AM
Anybody recommend a supplier for a short block with large oval intake ports? thanks

So... a long block?
GM crate motor is an option.
A used/take out motor?
How bad is your motor? salvageable?

Whats your goals?- stock? performance? race?

Oh, and budget?

Its really easy to spend other peoples' money...

Dan'l
Title: Re: engine choice
Post by: doug olah on May 17, 2016, 10:17:27 AM
HI Dan'l
motor is shot need long block. Performance goal, large oval ports. I run a 468 in a 68 vette with aluminum heads which works great. Whats your opinion of aluminum heads for the boat engine? thanks and by the way thanks again for your imput on removing the engine came right out.
Title: Re: engine choice
Post by: mash on it on May 17, 2016, 10:23:28 AM
HI Dan'l
motor is shot need long block. Performance goal, large oval ports. I run a 468 in a 68 vette with aluminum heads which works great. Whats your opinion of aluminum heads for the boat engine? thanks and by the way thanks again for your imput on removing the engine came right out.

Aluminum heads- I run 'em on 2 diff boats.
ZZ454, 440 hp. GM crate motor
or collect parts to build ya one.
454 HO was the model/build sheet for mine.

Dan'l
Title: Re: engine choice
Post by: crewchief22 on May 17, 2016, 06:49:59 PM
I don't recommend a "reman" or even a "new" crate engine for a marine application with an open cooling system, unless it was built specifically for that purpose.
 
You would probably be money ahead by going to a competent machine shop and having it built for what you want to achieve.

Title: Re: engine choice
Post by: doug olah on May 18, 2016, 06:38:26 AM
thank you crewchief22
Title: Re: engine choice
Post by: GT Jets on May 18, 2016, 07:26:07 AM
The single largest differences between a marine engine and the car are machining clearances, cam grind depending on what exhaust and materials used in head gaskets and freeze plugs.

Brass plugs and Marine head gaskets are a pretty big deal if the boat spends lot of time on the water, to control electrolysis.

A machine shop familiar with the added clearances needed on a marine engine should be able to get you going on the right direction.

Depending on what you intend to do to the engine,  the clearances will be somewhat of a moving target.

RPM, HP, how long it will run hard,  exhaust system,  fuel used,  compression ratio all pretty much come into play in a small part.

I like forged internals for an all out performance engine. I would not turn cast pistons past 4,800rpm. Forged crank is optional to an extent, I use 500 horse as a guidline. Four bolt block after you touch 600 plus.

JMO based on my experience and the stories of others.

The reason for the added clearances is the extreme temperature differences seen with open cooling,  these engines rarely run warmer than 140°F with very cold entering water.

Good luck,  sorry for your troubles.

GT
Title: Re: engine choice
Post by: GT Jets on May 18, 2016, 07:31:17 AM
No way!!! A chevy blew up?!! I am suuuuper surprised. Lol

Me too..........

Normally we hear about a Ford crapping itself.

Weird.

Must have been a 30 year old build.

GT
Title: Re: engine choice
Post by: FordLover on May 18, 2016, 07:45:15 AM
Me too..........

Normally we hear about a Ford crapping itself

GT

No kidding!! My last one looked like a grenade went off inside it. But dont you worry, my blue oval is waiting for you. For as long as it can last. Lol
Title: Re: engine choice
Post by: mash on it on May 18, 2016, 08:53:44 AM
No kidding!! My last one looked like a grenade went off inside it. But dont you worry, my blue oval is waiting for you. For as long as it can last. Lol

On a ford, they call that an oil change.....



Anything that got touched by oil...needs to be changed...

Dan'l
Title: Re: engine choice
Post by: FordLover on May 18, 2016, 08:56:43 AM
On a ford, they call that an oil change.....



Anything that got touched by oil...needs to be changed...

Dan'l

Lol. Ironically I am doin an oil change before memorial weekend festivities.
Title: Re: engine choice
Post by: ron.h on May 18, 2016, 02:38:00 PM
Some people are really hard on Ford's around here
Title: Re: engine choice
Post by: FordLover on May 18, 2016, 02:44:33 PM
Some people are really hard on Ford's around here

Bunch of jerks!!! So insensitive!
Title: Re: engine choice
Post by: ron.h on May 18, 2016, 02:47:09 PM
I like my Ford
Title: Re: engine choice
Post by: Outlawmayhem on May 18, 2016, 11:43:05 PM
I like my fords too
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