WHAT motor for my Berkeley?

I thought teak might be the answer,not alot of trim but i can do it myself,ripped out the the poorly built frame for the motor today,and did some interior stripping
Im getting all the smaller things like handrails,light holders etc chromed

 

Barry how will i know what impeller ive got? Is it stamped onto it?

 

Hi
In your first post, you mentioned that you had a 12JC A
Have not installed a Berkley since about 1985, so not sure if it is on the impellor.

 

The name plate says 12 J C A H,whats the H for?
Will it say AAA on the plate then rather then AH?

 

Not sure what the H says and on some other forums this has come up an no one
really appeared with a conclusive answer.

The A or AA or AAA (9.25), (sometimes called A, A2, A3) are different machining configurations of the impellor.

Would need to know the year of the 302 as they produced 210hp (4400rpm) up to 1971, then dropped to 135hp (3400rpm) to 1984, then 185hp (3800rpm) to 1993, then 200hp (3800rpm) to 1996.

Note though that your boat will require a certain thrust to move it through the water at a given speed. Perhaps that might be the neighborhood of 1800 pounds for your 24 foot cabin cruiser at 28 mph

Just for an example
Say your 302 produces max 200 horsepower at 4000 RPM and is mated to an A impellor and gives you the 1800 pounds of thrust and 28 mph
But you are at Wide Open Throttle, and is burning an obscene amount of fuel, say 20 US gallons per hour,1.4 miles per gallon

Instead you install a 330 hp big block with an A3 impeller which can produce the same thrust at 2900, not even close to wide open throttle, and burns 7 gallons per hour or 4 miles per gallon.
( but you have a lot of unused horsepower to run the boat faster, accelerate quicker)

Barring costs to get the impellor and bigger motor, which would you take.

And there is also the chance that the 302 cannot produce enough thrust to move your heavy boat properly

Berkleys installation manual, an old one had this statement
"If the RPM is reduced to 70% of maximum, the fuel burn is 1/3 of max fuel consumption at wide open throttle"

 

Morning Barry
Thanks for all your input,i think i must rather go for a 350 chevy or 351 ford,just to be safe,like i said it had a 454 installed previously but was realy overpowered according to the previous owner
So i think 350 will be on the safe side!

 

I agree, a 454 with an A impellor is overpowered, ie too much horsepower for the A impellor
When we started building 21 foot jets, 6 foot chine, 12 degree deadrise, the first pumps we used had 460's, 320 hp, turning an A, which gave us high rpm 3600 to 3800and high fuel usage for say 30 mph

Then we went to the A3's with 454 at 330 hp, and dropped the rpm to about 3000, depending on loading of the boat for the same 30 mph

It takes a certain amount of horsepower and I am speaking about the generated thrust, over a given distance with respect to time. ( to move the boat at 30mph)

Ie if you hooked a rope up to the boat, I am only guessing that it would take 1800 pounds of force and you pull it at 30 mph ( 2640 feet per minute), the boat requires in the neighborhood of 150 horsepower to move it along. But adding in jet losses through the pump you will need more. Again, an assumption, say 200 hp

So matching an engine with an impellor, you want to find the match that gives you the optimum thermal efficiency, (other parameters could come into play here, maybe you want longevity of the motor which you get with lower than max rpm)
Optimum thermal efficiency in this context will be taken as the least amount of fuel burned to create 200 hp.

So a few choices are
1) the 302, (if it is an older one) only able to produce 200 hp running at max hp burning a lot of fuel and requiring the A impellor (4000 rpm)
2) your 350, maybe producing 270 horsepower running an AA impellor but running at lower rpm and a better fuel savings (3500rpm)
3) a 454 matched to the A3 impellor (3200rpm)

My opinion only, is that if you have the 454, it would be cheaper to put in a AAA impellor for the size of your boat. This is what we found with 21's

That being said all of the examples that I have given you relate to carbureted engines.

With the higher horsepower ratings of the new EFI engines and consequent fuel efficiencies, we found that the A3 worked very well with 350 EFI engines.

I would check out the American Turbine website as there is a wealth of information contained in it.

Good luck

 

Was thinking..how is the 350 Buick V8? 1978 model!
Just came across an ad where one is available

 

Be careful what you wish for. There are three basic versions of the small block, each with sufficient enough differences to make parts procurement a pain in the butt. The first run of small blocks had a large journal crank with circular flange, was only a 2 bolt main cap and generally fairly weak. The next version had a smaller journal crack with counter weighted flange and can't be used in the first gen block (nor the first used in the second). Most of the other parts will interchange though. The next major change was the 1 piece rear main block, and is typically is a heftier casting, usually 4 bolt mains too. The last version it commonly known as the Vortec and it has it's fuel pump boss removed, much better (different) heads, roller valve train is common, etc. Many of the parts interchange, but some don't. So, you need to be careful what you wish, particularly with the "other" GM division "350's", like Buick. Generally, the other divisions, where left to develop their own small block, which can lead to parts availability issues. If you stick with the "corporate" blocks or a Chevy, you'll not have difficultly finding parts, but 35 year old other division blocks, like the Buick or Pontiac (for example) might have some availability problems.

 

one site suggested 155 horsepower, this is pretty light

 

As I previously mentioned the 12JCA can handle more than a usually well warmed up small block can toss at it (400+ HP).

 

Par
True but then you need to go to bronze or stainless impellors
At least according to the impellor selection charts

 

Yeah, so . . . what do you expect shoving this amount of HP into an impeller. What about "yachting" or "marine" has ever been cheap? This is a discretionary funds activity. You either have it or have to steal it . . .

 

Removed the jet drive today,what a mission!
Will start stripping it,looks like a brass impeller,a little pitted...but will see if i remove it if its still useable