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nzjetboating.com Forums => Projects => Topic started by: sje on May 02, 2009, 18:54:43 PM

Title: 17 ft Aitchison copy
Post by: sje on May 02, 2009, 18:54:43 PM
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.
Title: Re: 17 ft Aitchison copy
Post by: Matthewf/Norbert/TuiDog on May 02, 2009, 19:05:37 PM
nothing wrong with cv joints  b>
Title: Re: 17 ft Aitchison copy
Post by: sje on May 02, 2009, 19:31:36 PM
Whats normally used for the end flanges? OR are there cv's with a flange at each end?
Title: Re: 17 ft Aitchison copy
Post by: Midjet on May 02, 2009, 19:39:40 PM
   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.   b>
   Any pics of your set up?  Some pics of the CV joint set up would be good. b>

Cheers Dan
Title: Re: 17 ft Aitchison copy
Post by: sje on May 02, 2009, 20:10:23 PM
Went and took some pics.....
Title: Re: 17 ft Aitchison copy
Post by: Dak on May 02, 2009, 21:08:19 PM
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  O))))
Title: Re: 17 ft Aitchison copy
Post by: sje on May 02, 2009, 21:39:27 PM
Theres gotta be a weak spot in everything ;D
Ill check what repcos got
Title: Re: 17 ft Aitchison copy
Post by: tpft on May 04, 2009, 19:47:30 PM
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
Title: Re: 17 ft Aitchison copy
Post by: Karl on May 05, 2009, 10:47:45 AM
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  O))))
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.
Title: Re: 17 ft Aitchison copy
Post by: sje on May 05, 2009, 18:16:45 PM
Quote
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?
Title: Re: 17 ft Aitchison copy
Post by: steelo on May 05, 2009, 20:14:04 PM
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
Title: Re: 17 ft Aitchison copy
Post by: sje on May 05, 2009, 22:23:58 PM
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.
Title: Re: 17 ft Aitchison copy
Post by: steelo on May 05, 2009, 22:49:36 PM
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
Title: Re: 17 ft Aitchison copy
Post by: sje on May 10, 2009, 08:56:41 AM
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.
Title: Re: 17 ft Aitchison copy
Post by: xplorn on May 10, 2009, 11:02:07 AM
good work and pics keepem coming ;D *-)
Title: Re: 17 ft Aitchison copy
Post by: sje on May 10, 2009, 12:46:58 PM
Cant do much today mothers day and all that. I have always wanted to be able to start and run the motor with the unit connected and out of the water. I am going to fit sealed bearings in the stator(s) but the carbon shaft seals shouldnt be run dry either. I had a special seal made and then made a plastic seal carrier and a sleave for the shaft. I fitted an oring where the slinger used to be. The idea was to run it with an oil bearing housing but I dont have one so will just stuff it with grease for now.
Title: Re: 17 ft Aitchison copy
Post by: Rickety Rocket on July 31, 2009, 21:17:17 PM
Hows the rebuild coming along steve  -00)  ch>v  ::)
Title: Re: 17 ft Aitchison copy
Post by: sje on August 01, 2009, 09:20:41 AM
IF the boss wouldnt give sooo much work to do I might have more time!
Have dummy fitted it all up but dont like how the unit fits so gunna change it after work today...
Title: Re: 17 ft Aitchison copy
Post by: matt on August 01, 2009, 11:01:29 AM
believe it or not steve ther series 1-3 landrover have the correct bolt pattern to match the colorado drive flange on the ends of the d-shafts if you get the front shaft you cut the slined section down in length which gives you the slip joint needed and drill the adaptor for your flywheel to suit and presto,this how many people put chev and falc infront of colorados wth the low intakes,hope it helps,a few j52s etc used this set up too check a few motor shots of trade me and see what i mean.DONT drve the unit off gilmer pulleys you aint seen a bearing collapse till you seen a thrust bearing get side loaded.hope it helps 
Title: Re: 17 ft Aitchison copy
Post by: sje on August 01, 2009, 15:43:37 PM
Thanks Matt got the driveshaft bit sorted the problem is the jet block or the holes in it are crooked resulting in the front of the unit being off center by 5mm. I mounted the motor to suit and it looked ok until I fitted the driveshaft then it looked like shite. I also discovered the crank/driveshaft flang was machined wrong giving me a half mill wobble in the driveshaft so I'm making a new one right now and willl have a crack at a refit tomorrow.
Title: Re: 17 ft Aitchison copy
Post by: cae on December 07, 2009, 09:09:34 AM
Come on steve I,ll be there on friday night. Pull ya finger out. ;)
Title: Re: 17 ft Aitchison copy
Post by: Rickety Rocket on March 19, 2010, 22:03:54 PM
Any more progress on this project or is the boss still  -00) ya?  pop
Title: Re: 17 ft Aitchison copy
Post by: sje on March 21, 2010, 09:10:24 AM
If we didnt have to help you put a real engine in ya sprint boat there may have been some progress!
 p> ch>v p> ch>v
Title: Re: 17 ft Aitchison copy
Post by: Rickety Rocket on March 23, 2010, 05:02:58 AM
 :P :P :P :P :P :P
Title: Re: 17 ft Aitchison copy
Post by: sje on January 11, 2011, 22:57:12 PM
Ok finally I got it wet today its been a long time.... about 9 years with most of the effort in the last 6 months and having just looked, there is a distinct lack of pics. Will fix that later.
 I ended up lifting the unit 25 mm and setting it back at the same time so I could still use the existing hole for the grill and keep to the same intake angle. I made a hydraulic reverse from clutch cylinders which worked ok untill today when the lever broke. Have made an electric one instead. Pics to follow. The engine runs rich as but since the carbs been sitting for a few years I am confident that I will get it sorted. Its a holly with vac secs and elect choke. Its as if the choke is on even tho its not hooked up. The only other issue is the elect fuel pump cant keep up which worrys me considering the price of the stuff. Will check out filters breathers etc.
Anyhow for a fist time out real happy. Running a 2 stage for now with a Hamish Pryde sprint blade in front and a cast steel 19 rear. Got 5000 rpm, on the plane nice and quick and handled rough stuff well. The kids liked it and the missus thought not too bad either so a bonus all round.
P.S. Thats not the missus in the pics.

Title: Re: 17 ft Aitchison copy
Post by: cae on January 12, 2011, 09:42:25 AM
Looks great Steve, nine years is a long tome but a good job all the same
Title: Re: 17 ft Aitchison copy
Post by: iceman on January 12, 2011, 10:51:18 AM
That looks awesome mate,
Im just a tad nervous about the effect your crank/drive shaft flange having the 1mil wobble had.
As I reckon mine has about 5mils at the unit end. ;D