Berkeley 12Ja Install?

[crowsridge]

Hello,


Does anyone have pictures of how the 12ja gets installed? It fits different than other models.

Thanks, Chris

[jetboat77]

The Berkeley 12JA was the original design;same mounting as jb,jc,jg

The je and jf were transom mount

CP Performance is the Berkeley manufacturer now (the original Berkeley closed in 93)

American Turbine and Dominator also use the same intake

You have an intake that is bolted or welded into the bottom of the hull and the pump mounts on that.

[crowsridge]

Thats the problem then I guess. This one must be missing the part that is part of the boat bottom. It has the intake grate, and adjustable ride plate, but thats it. Guess I will hunt for a different pump.

I found a different donor boat with a Hamilton pump, but it has a bad gasket (not a big deal?) and they have a rebuilt straight 6 in it and it takes up almost 4' of boat.

Id like to find out how the Berkeley mount was layed out. Maybe fabricate something? What a speedbump to my build.

Thanks, Chris

[CDK]

Here you find the installation instructions for various jet pumps:
http://www.americanturbine.com/downloads

[speedboats]

go see the guys at American Turbine, they are on the border between WA and OR. They both have the same intake mount plates. Else, like you say, fabricate your own...

[crowsridge]

I picked up a 20' aluminum sled yesterday. It has the same exact pump as the pump I have. So now I see how it mounts at least.

The next deilima. I had seen several jet boats running 4 and 6 cyl engines. So when this ones 455 was bad, I thought I would just put a smaller motor back in its place. I am not running the Snake getting out of a hole.

I called Berkely and the tech said I have to have a big block or I wont be happy. Darn! Is that true or is that the company verse to gain maximum performance? He said a small block doesnt have enough torque. A diesel has torqe, but he says not enough RPM's. So is it hp, torque, rpms or a combination of all three?

Weld a plate over the hole and hang an outboard? Options and input?

Thanks, Chris

[CDK]

Chris, welding a plate over the hole will surely solve your problem!

[speedboats]

I've used small and large motors. It will depend on your impellor cut, although you can re-cut if you need.

How much power did the 455 make? Personally I'd bin the Big Block and go LS. You'll probably have a power increase and save heaps on weight, else go to a 4.3 V6 and save a rediculous amount of space, and they still make okay power.

To get more hole shot and low end grunt you want to leave the impellor as large as possible and open up the nozzle orifice, so you may find even if you down-grade to a V6 you might just need a bigger nozzle insert rather than to machine your impellor.

Toyota 4.0L V8 (1UZFE)(260hp)


Chev LS364/440 (Carb'ed LS2, 440hp)


Chev 350cid ZZ4 (355hp)


Nissan 2.0L Turbo inline 4 (SR20DET)(220hp)

[speedboats]

Found a pic of a Berkeley intake housing bolted to the intake mount...

[crowsridge]

CDK thanks, the plate was only half the solution. I would love to salvage the jet system if possible. And if I can do it with less fuel consumption, that would be awesome! Speedboat has some great looking options. I dont know what the LS is yet though.

[BMcF]

You can have your current impeller cut down on a lathe to be equivalent to the original 'C' trim..or you could have it cut down even more than that. The mod is simple and CP Performance has a diagram that shows where and how much the differences are between A and C trim impellers. But figure out which trim you are starting with and take it in small steps..because you cannot put the metal back.

I just read all of Speedboats comments ..and the nozzle diameter mods. Again..some machining of the original nozzle is required to allow the use of the nozzle inserts, but CP still sells those too.

[crowsridge]

I finall get a day off this weekend. Been spending about 70-75 hrs a week at work since first of year. Cant wait to get going on the boat. I pulled the Mercruiser 165 out of the donor boat. Put a new starter on it and can get it to turn over. But I dont have any spark. Im getting it to turn over by jumping from one side of the starter to the other. I have the wiring harness for it, but the guage/key end is cut off.

How can I make a simple system to make it run? I dont want to go any further with my jet plans until I know it runs. I was told it does, but want to confirm it.

Suggetstion? I see videos of engines running on blocks, I need to make mine do that.

[CDK]

On the std Mercruiser plug connect 5 to 6 to power the ignition, then shortly bridge that to pin 7 to run the starter motor.

[powerabout]

dont forget the shift interrupt switch

[crowsridge]

Ah! Closer to sucess......... Thanks CDK. I did as you decribed plus put a ground jumper from the block to the solenoid and it performed. But, still no spark. I cant help but think there should be something else simple disconnected? I know there is a neutral cutout for example.

????????????????????? Now what? Powerabout, I just saw your note about the Neutral.. Will look for those two to jumper.