550sx to 750 "All or Nothing" build

[Myself]

I don't know how much Tigershark stuff you still have laying around but the models with the stainless steel exhaust the cone is a bit longer and a bit larger in diameter , it will still fit in the 650SX rubber coupler though, it's a quick cheap fix for adding length to the stock pipe that it is not well known, I found it just like you are doing , by swapping parts and seeing what fits.

I actually remember you posting that in the past. I have some nice Shark projects around (Ts1100R), but the only 640 stuff left is the larger Daytona style cast aluminum pipe. If I can hone in my TIG skills, I have a trick up my sleeve for this exhaust.

 

[WFO Speedracer]

I actually remember you posting that in the past. I have some nice Shark projects around (Ts1100R), but the only 640 stuff left is the larger Daytona style cast aluminum pipe. If I can hone in my TIG skills, I have a trick up my sleeve for this exhaust.

I have some still laying around if you want to try one but it will be a minute before I head back up to the lake to get it . ATM they don't want me driving over an hour at a time and its about an hour and a half to two hour trip.

LMK

 

[Myself]

Thanks bro but I'm good. If I don't get my skills up, my buddy can do it for me.

 

[WFO Speedracer]

Thanks bro but I'm good. If I don't get my skills up, my buddy can do it for me.

Aight

 

[WFO Speedracer]

I also got the e-box relocation bracket from RCJS. Looks like it will work just fine. The starter terminal JUST touches the rubber pipe coupler but when everything is bolted during final assembly I'm sure there's at least that much play I can find in the motor plate positioning. And it seems there is still ample room to access the battery.

Is that electrical box getting moved over, it looks like really close quarters to the exhaust in that pic, I am just asking because it has piqued my interest on the 750 manifold -head pipe combo.

 

[Myself]

Everything was just mocked up.....nothing really bolted solid. The terminal really was just touching, not digging into the rubber. I could find an easy 1/8" of clearance sliding the motor plate forward on the mounts. I've ordered a piece of .010" stainless shim stock to make a headpipe gasket with no water holes. Obviously I need to drill a water hole in the 750 headpipe. The "adapter" as you probably already know is the center gutted out of the stock 750 rubber coupler. And 2" rubber slides right over it and the 650sx chamber. I'm really scratching my head here trying to figure out why everybody pays good money for an aftermarket exhaust manifold when these will fit and they're a dime a dozen. Maybe it's just bragging rights on throwing around name brands?....Or maybe I'm the first thrifty, problem solving, type of guy to actually try it?!. If that's the case we'll name it "PWCr's 750 conversion manifold".

 

[WFO Speedracer]

Everything was just mocked up.....nothing really bolted solid. The terminal really was just touching, not digging into the rubber. I could find an easy 1/8" of clearance sliding the motor plate forward on the mounts. I've ordered a piece of .010" stainless shim stock to make a headpipe gasket with no water holes. Obviously I need to drill a water hole in the 750 headpipe. The "adapter" as you probably already know is the center gutted out of the stock 750 rubber coupler. And 2" rubber slides right over it and the 650sx chamber. I'm really scratching my head here trying to figure out why everybody pays good money for an aftermarket exhaust manifold when these will fit and they're a dime a dozen. Maybe it's just bragging rights on throwing around name brands?....Or maybe I'm the first thrifty, problem solving, type of guy to actually try it?!. If that's the case we'll name it "PWCr's 750 conversion manifold".

I wouldn't know this Superjet I am building is the only ski I have ever put an aftermarket manifold on, of course on those there isn't much of a choice, the 300SX is running a ported and polished stock diverter manifold opened up slightly.

I can see where the extra volume in those 750 manifolds and head pipe could be a huge benefit.

The only drawback I see here is that the long exhaust studs on the 750 manifolds means the manifold cannot be removed or installed with the engine still in the ski.

 

[Myself]

The only drawback I see here is that the long exhaust studs on the 750 manifolds means the manifold cannot be removed or installed with the engine still in the ski.

I already have the easy solution to that, replace top 2 long studs with bolts. It slips right off.

 

[Myself]

I got some more time in today. All the sticky goo is gone off the hull, and I got almost all the glue residue out of the tray. Tomorrow..........hood and pole.

 

[Myself]

Video I made of how to remove the decal sticky residue WITHOUT screwing up your hull.

 

[Myself]

I got the hood and pole de-stickered today. I took a chance on these gimicky fabric sanding discs at Home Depot.......they're great! Buy u some! I did a rough sand of the whole topside, and even started some of the bilge.

 

[Myself]

Found a few stressed areas but nothing real bad. Easy fixes since I'm doing glasswork anyway.

 

[Myself]

New waterbox came yesterday. Anybody recognize it? Super lightweight, unbaffled, no markings of any kind. Oem fiberglass only has 1-5/16" inlet and 1-1/2" outlet ID. This one has 1-5/8 ID on both. I know that doesn't sound like much difference, but that's a 17% increase in sectional area.......which equates to OVER a 30% increase in flow!

 

[Myself]

I took advantage of the warm(er) weather and washed a bunch of parts today. I don't know what that whitish residue was on the hoses but I had to scotchbrite that crap off.

 

[Myself]

I also put the flap disc in the angle grinder and cleaned up the "PWCr" conversion exhaust manifold. This kind of stuff bothers me on a custom build. It looks much nicer with the casting smoothed out.
And I also added some 'adjustment' for the exhaust chamber mounting.

 

[Myself]

I decided to get the grinding out of the way today. Most jet pumps can benefit from casting cleanup, the rough water hookup is noticeably improved. I knocked this pump out in about 45 minutes. I do a full 'blueprint' on my personal machines which can take 4-5 times that long. Check out that pile of shavings just from smoothing the casting marks.

 

[Myself]

Next up was chamfering the port edges of the freshly bored cylinder. I also gasket matched the exhaust ports, and widened the bottom half of the exhaust ports a tiny bit. That'll bring in a tad more bottom oomph.

 

[Myself]

And finally, before cleaning my carbide burr and putting the grinder away, I made some minor adjustments to the intake area of the case. These things have some really hard edges for the incoming mixture to ram into. I just rounded things out a bit so the mixture can flow in a bit easier. No porting here, just 'cleanup'.

 

[WFO Speedracer]

Looking good keep it up !

 

[Myself]

High temp was about 10* today with 4" snow on the ground. So I worked in the shop all day. Half the day I was moving stuff around organizing. Then I did some real work. I got some aluminum mesh to stuff in the waterbox. I did this on my wife's as well. It really takes that annoying loud bark/buzz out without hindering the flow. First cut a piece, then stretch it out some, then roll it up. I got about 6 shoved in there.