SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: radracer1 on July 02, 2008, 05:33:24 AM

Title: engine swap questions
Post by: radracer1 on July 02, 2008, 05:33:24 AM
Just ran across a 1972 17' regatta jet boat with 402 and Berkeley jet for $125.00. The owner told me that the motor was blown and needed to be rebuilt. I have notice that all the boats i have looked at on this site has the big blocks powering the jet. Will a small block work behind a jet drive?
Title: Re: engine swap questions
Post by: crewchief22 on July 02, 2008, 06:14:07 AM
Welcome to the site  ;D

A small block will work in a jet application, but better in a smaller hull.

I have a friends Hawaiian with a 383sbc with aluminum heads that runs 60's with a Jacuzzi YJ pump.

http://www.socaljetboats.com/index.php?topic=1784.msg22736#msg22736  Check this one out also, very cool with a sbf.
Title: Re: engine swap questions
Post by: AA/Paul on July 02, 2008, 07:45:55 AM
The 402ci was also a BBC.
Title: Re: engine swap questions
Post by: Jetaholic on July 02, 2008, 08:20:36 AM
Yes  it will...it just all depends on how its built. The pump could care less what type of motor is turning it. All it knows is how much power is needed to spin vertain RPMs given a certain impeller size and volume of water its trying to push. If you can make a small block that makes enough power to spin the pump to the desired max RPM (and yes it is possible to build a small block with enough power to spin an A impeller to 5500 RPM for example) then yes it will work.
Title: Re: engine swap questions
Post by: gregb on July 02, 2008, 01:02:51 PM
I have a 383 small block and it turns a new A impeller 5K.  The hardest thing you will encounter is finding the exhaust for it, especially if you are looking for OT headers.  New they are pricey and available, used very hard to find since they are uncommon in jet boats.  The bellhousing will be the same, you'll need a small block front mount if it's a 4 point mount system, if it's a 3 point in the boat now it might work with a small block.  I'd line up the parts before you commit to that, it might be just as cheap to slap another big block in there, that stuff I see all the time. 
Title: Re: engine swap questions
Post by: beerjet on July 02, 2008, 01:28:56 PM
I think the key to the sbc is the cubic inches . Thats probably why it already has a 400 + inch motor . Easy to make enough power beyond 400 inch . .02

-beerjet-
Title: Re: engine swap questions
Post by: beerjet on July 02, 2008, 01:30:45 PM
Generally the smaller (16'er's) had the small blocks . It'll be alot cheaper to work with what you already have also .

-beerjet-
Title: Re: engine swap questions
Post by: radracer1 on July 02, 2008, 05:13:05 PM
Thinks guys, I think the hards thing to find will be the bell housing to fit a sbc. I have a sweet 350 that came out of a race car on hand, but finding the right parts might be a task. any good places to find part would help..
Radracer1..
Title: Re: engine swap questions
Post by: GT Jets on July 02, 2008, 05:34:01 PM
BBC and SBC use the same bell housing. ;)
Title: Re: engine swap questions
Post by: radracer1 on July 02, 2008, 06:09:59 PM
I was pulling the motor apart this afternoon and noticed it is not a 402, it is a 403 buick motor.
Title: Re: engine swap questions
Post by: crewchief22 on July 02, 2008, 06:20:11 PM
That could be a problem.

Very little, if anything will be usable for a BBC or SBC swap.
Title: Re: engine swap questions
Post by: GT Jets on July 02, 2008, 06:21:57 PM
Can you say Cadillac?

500" stocker 8)
Title: Re: engine swap questions
Post by: Oldsquirt on July 02, 2008, 06:39:59 PM
I was pulling the motor apart this afternoon and noticed it is not a 402, it is a 403 buick motor.

Far more likely that it is an Olds 403. Olds has distributor behind the intake. Buick had distributor in the timing cover.

Posting pics would be helpful to identification.
Title: Re: engine swap questions
Post by: radracer1 on July 04, 2008, 06:52:19 PM
Does anyone out there know were i can find a bell housing for a Berkeley Drive for a chevy 350?
Radracer
Title: Re: engine swap questions
Post by: GT Jets on July 04, 2008, 07:19:05 PM
I've got a rear motor plate that gets used with a stock "Velvet Drive" transmission bell housing if needed, but dont have a housing. If you need it, I don't. Its bead blasted and in pretty good shape (aluminum).

$20 (see you don't even have to make the standard So Cal offer ;D)

Camera blew up, here's a drawing.


[attachimg=#]
Title: Re: engine swap questions
Post by: jet boat performance on July 05, 2008, 09:46:14 AM
Radracer we've buit several "small block" powered small jets 16's an even 18's They make good economical power If your boat had a 402 (and you still have the parts) the rear mount and Driveline etc will be the same You'll really only need exausts and water inlets Call me if I can help you Tom
Title: Re: engine swap questions
Post by: radracer1 on July 05, 2008, 02:51:29 PM
Thanks Tom,
This is the first jet boat i have played with and i just would like to take my time and get all of the right parts together. I have all of the parts to the boat, at lest i think. I paid $125.00 for the boat and all of the parts that was in it. The guy i got it from, took it apart so i hope i have all of the parts. I was mistaken about the motor that came with the boat it is not a 402 bb it seems to be a 403 olds. SO the bellhousing is not the same, as for the exhaust. I having a hard time find headed for a 350sb without paying a left nut for. By the way this might sound like a stupit question but does this motors have to spin the same as a normal engine? I heard that a marine motor rotates backwards?
I will try to post same picture when i learn how to do it
Radracer
Title: Re: engine swap questions
Post by: GT Jets on July 05, 2008, 03:03:17 PM
Older engines, in some aplications rotated reverse (50's and 60's), but it is a practice no longer followed, the standard now is based on automotive engines, (your good to go). ;)

Here is a picture of a true 85MPH small block powered jet (sorry, its a "Rock Dodger").

[attachimg=#]
Title: Re: engine swap questions
Post by: radracer1 on July 05, 2008, 03:14:32 PM
Man That is so SWEET.... Is that a white water boat?
Title: Re: engine swap questions
Post by: GT Jets on July 05, 2008, 03:38:24 PM
Yeah, this is one of the coolest guys you will ever meet, this boat runs whitewater marathon races and they run in the Small Block FX class, that engine is a ZZ4 crate from GM Performance parts div.

 No internal mods allowed, they run pretty hard.

 I have not yet gotten all of my video downloaded to Youtube, but there is one of mine on there with 2 boats running side by side (bbgmjet is my site name), these are bigblock powered but you'll get the Idea how hard these things run.
Title: Re: engine swap questions
Post by: GT Jets on July 05, 2008, 03:49:47 PM
I forgot to add that that engine was in the process of being installed (during the boatshow) when these shots were taken, I believe due to a spun bearing. That is why there are no wires or anything on the motor, the boat show was two days before the race...
Title: Re: engine swap questions
Post by: jet boat performance on July 05, 2008, 06:27:53 PM
Rad you can still do this fairly inexpensively using a mix of new and used pieces, yes SBC headers are scarce but recently I ended up with two sets the same week Tom
heres a few JBP Small block jet boats from recent past !
(https://www.socaljetboats.com/proxy.php?request=http%3A%2F%2Fi147.photobucket.com%2Falbums%2Fr319%2Fjetboatperformance%2Fjosh%2FMVC-022S.jpg&hash=04a4a40eccedbb30a8751c7b43941b7042a3e5d0)
(https://www.socaljetboats.com/proxy.php?request=http%3A%2F%2Fi147.photobucket.com%2Falbums%2Fr319%2Fjetboatperformance%2FV%2520tahiti%2FVTahiti-03.jpg&hash=9a60f4fbb3fa6efa59c29764343c976af23ff48c)
(https://www.socaljetboats.com/proxy.php?request=http%3A%2F%2Fi147.photobucket.com%2Falbums%2Fr319%2Fjetboatperformance%2FGood%2520Enuf%2Fimg8.gif&hash=396c83645787fe405e054284406bdb4f9cd508ec)
(https://www.socaljetboats.com/proxy.php?request=http%3A%2F%2Fi147.photobucket.com%2Falbums%2Fr319%2Fjetboatperformance%2FGood%2520Enuf%2FMVC-004S.jpg&hash=d730544a9a948e864c42b3801225afb87eaf7636)
Title: Re: engine swap questions
Post by: GT Jets on July 05, 2008, 09:25:21 PM
Here's Merv's boat in action, this is the 2008 Worlds in Ore. 8 miles upriver from the Pacific (between 75 and 85 mph) keep in mind the water is moving 5-7 mph.


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Title: Re: engine swap questions
Post by: radracer1 on July 06, 2008, 08:05:22 AM
Ya i watched some videos on Youtube, this guys are SICK..IN THE HEAD....LOL  Just wondering how deep is the water on some of this rivers?
Title: Re: engine swap questions
Post by: GT Jets on July 06, 2008, 09:38:43 AM
These guys typically see water thats about 6" or so, the engine often pics up rpm due to the cavitation from the rocks :screwy:
Title: Re: engine swap questions
Post by: GT Jets on July 06, 2008, 10:18:21 AM
2007 Rogue River Marathon at 2-mile rapid. Just to give some idea of what shallow water is. Every white area is a rock, sometimes the size of a VW bug!

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Title: Re: engine swap questions
Post by: Sanger Pete on July 07, 2008, 11:57:31 PM
GT
If no one has taken your motor plate, I'm interested. Give me a call, or email me your phone number and I'll call you.
Mark--"Sanger Pete"
(559) 917-1785
markpete559@yahoo.com
Title: Re: engine swap questions
Post by: GT Jets on July 08, 2008, 08:55:52 PM
Hey Mark, here's a pic of that plate, I'll save it for you. Thanks again and nice talking to you. BTW hope you have fun at the lake.

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