Hx motor conversion?

[dsolie]

Re: Hx motor conversion?

Swift... $40 and I might be able to deliver it. We have a job in Camano Isl that we are bidding on!

[Bill O'Neal2]

Re: Hx motor conversion?

I have built several HX's with 787 engines in them.

I had several tubular stainless steel bedplate adapters made so I could install 787's into HX's and did not need to cut away any of the hull liner. The adapter bolted to all 4 motor mounts and to the engine.

The dent in the chamber is no big deal at all. I have done it using a mallet and also I have used a press. I have assembled about 6 or 7 HX's with 787 engines in them using the Spec2.

One of the weak points to this conversion is the inner bedliners. They tend to crack across from one side of the hull to the other a few inches in front of the two front motor mounts. I really do not think cutting that liner to clear a pipe is a good idea, although it may be in an area where it would not make any difference in liner strength, I don't really know. Seems cutting it would weaken it further.

You also might run into a problem with the rear driveshaft carrier bearing holder and mount tearing loose from the bottom where it bolts to the hull due to the added strees created by the 787 power. We fabricated bracing to attach to the deck and to the carrier bearing mounting box and that solved the problem. This can be a very serious problem if you allow that mount to pull out of the hull. It is very difficult to repair once it pulls out.

As good an idea as it seems, to put a 787 into an HX is really not that great of an idea for several reasons. Over time, these things will be a problem:
The inner hull tends to crack from the stress of the heavy motor.
The rear carrier pulls out the aluminum plates that are imbedded into the fiberglass.
The driveshaft components wear out rapidly.

A highly modified 718 engine is just as fast and as quick as the 787 modified HX, as with the 800cc rules, they can both be built to the same size motors, but it is lighter and a more well balanced watercraft with the 718 engine, and it does not cause the inner liner to crack or pull the aluminum mounting plates out of the hull liner.
Both are capable of speeds over 60 mph, and the modified 718 engine may even out accellerate the 787, because it is a lighter setup. The 787 will have more torque and pull through the corners, but a really talented rider on the modified 718 will learn not to overload the engine in the turns and will be able to keep pace with or even beat the 787 HX. The modified sport class rules package will allow for some extra engine mods and 800 cc engines.

I hate to be the party pooper here, but with the current rules package, the 787 HX just does not make nearly as much sense as it did in 1995 when we first started building 787 HX's.

[swiftman]

Re: Hx motor conversion?

Taking what Bill has said into consideration...im probly going to go with the boring option for two reason's. One being I allready have a pretty fair amount of money invested into the current 718 and now that I think about it boring the 718 and having a bottom end put in seems like it will be more economicle in the long run. The second being my buddy's Xp blew up yesterday while we were riding, Lost the Pto end rod thru the block... So I might be a nice guy and and give him the motor I have so that I will have someone to ride with still...Hes helped me out in the past. Besides who wants to lose bearings and have stress cracks anyways? Hopefully the 718 wont do it any way...Bill, in your opinion would the carrier bearing brace be a good idea?
Dsolie...When are u visiting Camano...If you win the bid, On a weekend by any chance, i still dont know what you do for a living, that is besides for PWC.

[Bill O'Neal2]

Re: Hx motor conversion?

The carrier bearing mounting seems to be ok with the 718 engine if you keep the bolts tight.
Keep in mind, the type of riding plays a big role in cracking and breaking things. Our HX's were used in alot of surf races on the national tours.

[swiftman]

Re: Hx motor conversion?

I will probly be having a problem then :)

[dsolie]

Re: Hx motor conversion?

Swift,
I own an architectural design business. We have abid for some home remodels up there. It would probably be a weekend... hell, maybe I'll drag some ski's up when I come.

[swiftman]

Re: Hx motor conversion?

The ski dragging was what I was getting at... Are u a general contractor or a sub?

[dsolie]

Re: Hx motor conversion?

Neither... I design em... Somebody else has to build em....

[swiftman]

Re: Hx motor conversion?

Lol thats sweet, I had a 3 semester class on architecture. Do you just do residential stuff? U should meet my dad and Uncle sometime My father is a Electrical contractor and my uncle is a General Contractor in this area.

[dsolie]

Re: Hx motor conversion?

Sweet! My business is mainly residential, but I have years of commercial too. All the commercial stuff we do now is small T.I (tenant improvement) work etc..... I don't feel like holding a multi-million $$$ policy for this large commercial stuff.

One of my employees, Nick is 17 and doing CAD in school.. You have talked to him over on JetSkiNews.com... Member KgBsUkA

[swiftman]

Re: Hx motor conversion?

What kind of CAD is he learning? 3d modeling or stuff like building plans? What app does he use in school? I know Autocad and Rhino 3d and some other program I cant remember the name to for building plans:emotredf . I myself mainly do stuff with the c&c at school and not so much plans.

[dsolie]

Re: Hx motor conversion?

We use strictly AutoCAD. Nick has school experience using all the AutoDesk product, LDD, AD, AC, R3D etc. I have ACAD 2000 on my computer now. I have this 06 disk sitting next to me, but I really like 2k..

Nick did a lot of civil design work. I am training him on home design. He's getting pretty good at the basic layouts. Once he masters that, I will teach him about engineering (Truss design, beams, headers and foundations)

[swiftman]

Re: Hx motor conversion?

That's pretty sweet, sounds Like your setting him up pretty good...Ive never even ran 2000 lol....My how this thread took a turn, from pwc to meetings to software and everything in between.