17 ft Aitchison copy

[sje]

About 7 or 8 years ago a mate made this boat modeled on a sprint boat and added a meter. Its steel with a light weight glass top as we had access to the sprint boat top mould. I had a 351 windsor/cleveland but it got stolen so now have a standard '95 302 windsor. Today finally its been dragged back into a shed so work can really start. Dropped the motor in, and as suspected, with a colorado and a bronco sump the driveshaft angles gunna be a bit big. Am wondering if anyones used cv joints before? Am going to strip one tomorrow and see what can be done.
Thought I had some pics but cant find will post tomorrow.

[Matthewf/Norbert/TuiDog]

nothing wrong with cv joints 

[sje]

Whats normally used for the end flanges? OR are there cv's with a flange at each end?

[Midjet]

   Yep can get them with flange at each end.  just go to your local stockest and have a look through their listings.  You should beable to get a re-cond one for around $70.   
   Any pics of your set up?  Some pics of the CV joint set up would be good.

Cheers Dan

[sje]

Went and took some pics.....

[Dak]

Late-ish models Commodores with IRS have cv joints with flanges on them for the rear half shafts. But then you'd have unreliable Holden bits in ya boat Steve 

[sje]

Theres gotta be a weak spot in everything
Ill check what repcos got

[tpft]

my 4x4 trial buggy has a chain driven transfer box that feeds all 4 wheels.
drops down lower then gearbox output
do any jetboats use a v drive etc to get the driveshaft angle straight?

p.s i,m always blowin cv,s

[Karl]

Late-ish models Commodores with IRS have cv joints with flanges on them for the rear half shafts. But then you'd have unreliable Holden bits in ya boat Steve 

Yep seen a few boats with these, they seem to work ok.  Why not trim the sump down and shorten the oil pickup.  That way you can use a std driveshaft which you get bits for if you have a breakage.

[sje]

Why not trim the sump down and shorten the oil pickup.  That way you can use a std driveshaft which you get bits for if you have a breakage.

Its one way I thought of except was trying not to chop it as its not actually my sump but also chopped and welded pickup tubes have failed in the past. I talked with ken from SSS this morning reguarding belt drives as this was an option but he has talked me out of it...for now.... A mate has a belt driven suby driving a jetski unit at double engine speed. Works well but bit whiney in the pullys.
I think I will unglue the unit and stick in a wedge.
Where do you get wedges from?

[steelo]

Hi there.
I think I've read in this forum that the bearings in most jets are not designed to take sideways pressure (which you may have to apply to get the belt tight enough to drive) and may fail prematurely. Someone else may advise different.
Cheers and good luck

[sje]

Steelo, that was one of the reasons ken was against it. How its been done with the suby was using a bellhousing to mount a sliding plate that had a lay shaft with the driven pully. from that it uses the normal jetski rubber coupling to the unit. For me to do that type of idea I may as well go to a driveshaft for the amount of room it would use.
Have just gone and measured and found I would need to wedge unit 40mm at the coupling or 45 mm at the front of the housing to get a 4 degree driveshaft angle. I think thats a bit much so will probably go the with a cv for now.

[steelo]

I'm glad that you are being very well advised then.
I wonder if you could move the engine backwards and have 2 cogs (like in a gearbox pinion) machined with the correct angles. There wouldn't have to be too much pressure against the jet bearings.
Keep us in the loop with your plancs
Cheers

[sje]

I spent all week working out how the best, economic and engineering wise, way of connecting the motor to the unit. CV's loooked good but to get a flange on would require welding which I will leave for now. I removed the sump and replaced it with a modified lowered one and heated/bent the pickup to suit. The front mount is a plate bolted to where the waterpump used to be. I will drill and tap a water fitting later. The rear ones just the usual plate with a top mount suby starter.

[xplorn]

good work and pics keepem coming