GPR-SHO conversion

[Bruce]

Hi there

Since there has been such a lot of hype and speculation on this subject of the GPR and the SHO engine, let me introduce “Shotime”, the first GPR-SHO conversion build. Wait and wonder no longer, it can be done and relatively easily too. I will document every step of the process here and try to answer any questions. Getting the boss DaveB on board with this project was no problem after explaining the possibilities and benefits to our SHO engine program. Besides, its just plain cool and a whole lot of fun, so he gave me a budget and said have at it. This is something I have been working on after hours and weekends, kind of a stress reliever, but something that brings me great joy and satisfaction. So, I am posting this here on Greenhulk as an enthusiast passing on something cool to other enthusiasts so please lets keep it positive and on topic. Conversion builds are extremely popular now, so I hope this will be of help to others out there thinking about doing it. I will try to get it posted up over the next week or so depending on how my days go, but , I’m a forum rookie so bear with me.

Getting the engine, driveline and pump into this hull was no problem and a sleeper GPR, looking totally stock from the outside can be easily achieved. Aside from the hull work, there is some modification to the exhaust system and some other minor tweaks, but I have photos for everything, so it will be easy to follow.
“Shotime”, will not however run a stock engine package. We have ditched the supercharger in favor of a turbo and various other engine components will be upgraded and modified, details and photos to follow. Since my build is not exactly the same as one with a stock supercharged motor, I have not done some things that will be necessary with that, but will document what needs to be done for those of you who will be doing a stock conversion down the road. Also, with the turbo installation, there are a lot of extra things needed, which are not in the regular swap. I have gone a little overboard on this, but making one off custom stuff is something I really enjoy, so this is going to be one cool ski. The majority of the one off stuff is well under way or complete, water jacketed turbo adapters and exhaust system, intercooler, manifold, fuel system, ignition, pump setup, etc. etc. etc. I was hoping to bring it out to Mudbug, but with my late start to the project and all that’s going on at work, there is just not enough time in the day or night to make that happen.

The plan is to assemble the whole ski, get it running and dialed in and then to strip it down again for final finishing, paint, fluff and buff and all that cool “bling” stuff. A very cool paint scheme has already been picked out so it should be a showstopper. Because of the turbo installation and all the other one off parts the motor has been in and out of this hull so many times, it almost does it automatically now. The guys in the shop keep on coming up with cool ideas to tweak it or make it just a little better, but that’s half the fun I guess. Even though this is a fun project, it’s definitely a good tool for us for engine development, and we are able to test engine components and packages in a less restricted environment.

It was actually pretty cool going up into the our loft in the shop and pulling out some of the cool old GPR race parts to see if we could utilize them on this build. It’s been so long I barely recognize some of the stuff. I even brought the race hood mold out of retirement and popped out a new carbon hood.

It’s definitely been a while since I was in two stroke development land on a GPR and it seems that a lot of progress has been made on hull and handling issues lately, so I would like to thank those forum members who have been very supportive with my venture and I appreciate the advice and tips as well as the parts donated to me for this ski. Thank you also to those people who helped me source out some hard to find items.

For us enthusiasts, this is a dream ski, unfortunately something that will never see the production line, but I am sure there will be plenty more to follow, but unless you have deep pockets or you are just a little twisted, keep those SHO’s together, there are cool things coming and besides there is no cup holder on a GPR…….

Bruce

Fortunately we have the necessary basics





so here goes...........

[SUCKMYWAKE]

sweet build. keep up the informative assembly process. and hats off to dave b. for the green light for an eagerly awaited finished product.

[addicted]

Why not stick with the SC first. see what the stock engine package can do, then go turbo?

[Bruce]

I won’t bore you all with the basics of the tear down of the stock GPR or SHO. I have already glassed up all the bolt holes that will not be used, oil fill , exhaust, rivit holes, etc. etc. so that the finished product will be flawless. fficeffice" />>>

[Bruce]

Got all the right parts and ready to go...

[MPower]

Oh boy, this is going to be cool. Any idea how much boost you will run? What are you thinking in terms of top speed, ballbark?

Jerry and Dan now have some competition for the fastest conversion ski!!

[Bruce]

Now for the important stuff, the conversion mods needed to shoehorn this beast into the GPR hull. Once the hull is stripped, two cutouts will need to be made in the inner liner as shown for clearance for the oil pan and the oil pump in the front. The center one is obviously very similar to the 4-tec conversions. The first three photos show the first two cutouts prior to sealing up.

[Bruce]

[Green Hulk]

Welcome to the forum Bruce. I'm really glad you decided to share you buildup with us all

[Bruce]