Tass 928

Dave,

I agree that the airbox will need some addtional mounting points. The picture was taken during a test fit. It took a lot of trial and error to get a design that would give me the same cross sectional area has the stock inlet yet still go on and off without taking anything else apart.

The (poorly worded) question I was asking was will there be a negative effect on the assembly shown below in red?

Joe Twill

Interesting question. I've never worked on or seen CIS apart, but I'm glad to offer an uninformed opinion. The rectangle at the right end of your red circle is a counterweight to balance the mass of the plate and lever, so up/down accelerations are inertially balanced and skipping along the water won't move the air flow sensor. Porpoising might have an effect, but you'll trim the boat out of that. If the bow rises when running, the mixture might change a little (rich?), like driving up a steep hill. So maybe you're thinking adjust the mixture with the boat on the trailer with the bow up at about the running pitch?

DR

Concerning that...well I think you are going to be the one to find the threshold of what that will take with lots of "bouncing" and sharp impacts associated with a (fast light) boat on the ever changing water conditions.

But, roads are not smooth and jar free and have lots of sharp impacts etc...so I would would put that worry on the "B" list for now....or at least until you get some water time to see if you have running issues under harsh conditions.

Tass 928

I'll try to post pictures of the various components that are going into this project. These pictures show the parts that will take me from the 928 crankshaft to the splined jet pump shaft. The original Porsche marine kit was set up for use with an inboard/outboard drive so I put some of those parts on the shelf and created some new parts to suit my application.

sharknoob

Tass,
I am a member at OffshoreOnly.com you should post over there too. You will get any answers you need, and they love build threads

Tass 928

Thanks for the tip, I'll check it out.

I have been monitoring Performance Boat , Scream & Fly and Boat Freaks.
There is a lot of usefull stuff on the forums.

Tass 928

The project moves forward....
While I am waiting for my fiberglass guy to visit and give me an opinion on restoring the exterior finish, I cleared a spot in the garage and brought the boat indoors.
The trailer is a project in itself and since it's basically a big lump of welded steel structurals, I can refurb that without much trouble.

The first step was to get the boat off of the trailer so I made simple cart that has heavy duty swivel casters, brakes and proper support for the hull.

Tass 928

I tied the boat to a solid anchor ( car lift posts) and pulled the trailer out from under it. As the trailer came out, I slid the cart under the boat.

Here is the boat resting on it's new cart. It moves around very easily and will probably stay on the cart for the duration of the project.

fredfox

Not to hijack the thread but...
I was on this boat in the bay off of Seaside NJ and I swear I will never go on it again.
120 is way too fast, 180 is insane.

Tass 928

Here is the trailer....pretty basic. It will get sandblasted and then epoxy coated in black. I'll probably just buy a set of chrome fenders for it. The hubs and brakes will be rebuilt and the axles will be widened so I can run the deep offset 928 wheels.

Tass 928

Before I tear the trailer apart, I did some trial fitting of the 928 wheels so I could measure for fender and boat clearance.

Working with what I have "in stock", I'm looking at phone dials and 10x18 turbo-twists. The turbos have 285's mounted and might present some clearance problems. I need to keep this narrow enough to get through the garage door.

I also think the phone dials are more in keeping with my intended 928 theme.

Cosmo Kramer

I like the twists! Get some fronts in 8" they will fit much better.

Love your project btw!

Mike Frye

OLD SCHOOL BABY! Gotta be the phone dials!


Love this thread!


BTW- Will the cart still be OK when you put the engine in and the center of gravity shifts or will it be back on the trailer by then?

James Bailey

It might be nice to run 15 inch phone dials....there is a much better trailer tire selection and less expensive than 16 tires. I tend to prefer running real trailer tires for a number of reasons......including that the higher sidewalls smooth out the ride and beat up the boat less and they track better than auto tires due to their construction.

Tass 928

Hey Jim

I agree with all of the above but...I'm giving up a little practicality for the sake of design. My gross weight should be well under 1,500lbs and I'm spreading that over 4 wheels.

The reason I selected 16" is that I have a 10 of them here already and I would have to buy 15" if I wanted to switch. Same story with the tires. I have a few sets of tires here that are dying of old age rather than wear.