Project RiverRat II

[1550]

what impeller you put in that pump?
Do you have pics of pump with impeller but without wear ring. Im interested how that tbm pump cone will fit.... Do you use 144 skat magnum impellers?

By the way yours ski gonna rock, nice too see very shiny and fine parts that will go at a kick ass flatwater ski (here in Finland there no other than booring flatwater...)

Ossi

 

[RiverRat]

For the impeller I am going to run (at least start out with) a -3mm cutback 12/15 Solas concord. The TBM will work with either a Concord or C-75 magnum impeller. I have heard the mag impeller works a little better but I got teh concord at a pretty good price and I have had good luck with them in the past. I was slightly spinning my 13/17 last season but adding the TBM changes several parameters and I don't think I will have that much of a problem. I would like to retain as much low end snap as possible so I would rather start low and slowly work my way up until I do not have slippage issues.

I did not want to run a mag pump for several reasons: 1) They are allot more expensive 2) I don't think the power quite warrents that type of pump and 3) This set up will be significanty lighter than a mag pump and lightweight was something that I want to keep a close eye on. If anything this boat will be a little back heavy but I will minimize that as much as I can. A light nose is a charcteristic that I also wanted to retain............the lighter the nose the faster it can rotate........a quality I think will be benificial when trying a flatwater backflip, throws or around the worlds.

 

[Proformance1]

It just occured to me that no one has achually seen me ride :haha: Lanier I was still building and Daytona I was just hanging out The only people that have seen me ride are: Superjett, Squid, Sjweber, RamboRosie, Typhoon Tommy and Duster8. to everyone else I am just a post junkie :cool2: I have been riding for several years I assure you :haha:

I saw you ride, but I don't have any proof. I have picts of us standing by our skis, but none of you riding.

 

[RiverRat]

This is a very rough idea of how I am keeping track of weights and the boat will obviouly be different b/c I can't factor in weight distribution across the hull yet as i don't have it. Foam will add about 8lbs to the rear and the ride plae will add anouther 2lbs. Some weights are spot on, some are over estimates b/c I was missing some parts to get an accurate weight. Taking the motor as a dividing line and canceling out its weight he is the spread the main components (no cables or bilge pumps or anything like that factored in yet)

This is just how I am looking at the boat from front to back. I need to get more individual weights to get a side to side idea of the weight distribution.

 

[1550]

Thanks for a good pictures and info...

 

[rebelwalker]

I have been pretty straight forward with him. I told him that I would like to put it in the build off but that is only if I get the hull by March. I am not rushing the project like I did last year. He has been really busy lately but when he says that he will crank it out by late Feb I am going to hold him to that. If I get it in April or May thats great but it won't go in the build off. The bottom deck was completed in early December and I asked him for some pics but have yet to get any............I am not jumping to any conclussions. I know he can make a nice ski and that is why I chose him to build my hull. I am 100% confident that he will complete this hull on time and it will be bitchin :headbang:

its early march did you get it yet? lets see some pics

 

[RiverRat]

its early march did you get it yet? lets see some pics

Still waiting on Jeff to send me some pics. He is working on the hood this week. Once that is done he can start painting the prepreg topdeck.....bottom is black gel and already done. Ski is plumbed as well......we will see.........

Waiting on intake manifold to arrive so I can ship one more batch of parts to Jet-hot to be coated..........that will take a few weeks.

John at JSS finished my TL system and that will be here soon.

I am waiting on a new o-ring kit for the ADA head and some Hylomar.....then I can reassemble the motor. Need to order turf and foam for the boat soon.......that always seems to take about 3 weeks to get from Hydroturf.

Got reeds in :haha: Here's a pic and some the cases after paint pic :biggthumpup:

 

[D-Roc]

nice reeds and stickers, for your ada head are the seals re usable? mine are only a year old and they seemed good with minor flat melting on them, does one replace them everytime or will they seal back up with a little hylomar grease?

 

[RiverRat]

nice reeds and stickers, for your ada head are the seals re usable? mine are only a year old and they seemed good with minor flat melting on them, does one replace them everytime or will they seal back up with a little hylomar grease?

one o-ring was questionable (outer head shell) and I needed a replacement so I bought a kit for like 9.00. Tacked it onto the JSS order

 

[D-Roc]

i see, i got a new kit here but don't want to use it if my seals are still good. I was under the impression that the seals were reusable. The total loss is going to be kick ass when you get it back from jss, his installs are so clean.

 

[RiverRat]

i see, i got a new kit here but don't want to use it if my seals are still good. I was under the impression that the seals were reusable. The total loss is going to be kick ass when you get it back from jss, his installs are so clean.

The seals are great b/c you can use them over and over unless it gets kinked or stretched. Coating them with a little hylomar keeps them from sticking to the cylinder and stretching or riping when disassembled.

 

[RiverRat]

Intake mods are done :cheer: Thanks blaster800!!! :hail: You did a smokin job :bigeyes: If anyone is interested in doing this mod shoot him a PM. The man has it down to a science now and I could not be happier with how it turned out.

Not only do the mods get the carb and reeds closer together, decreasing the length of the intake track and eliminating a reed spacer, but the mod significantly lightened the manifold. I will get some numbers but it is very noticable difference.

EDIT: Weighted the manifolds and the machining removed .63lbs. Not to shabby.

 

[RiverRat]

more.....

 

[blaster800]

Intake mods are done :cheer: Thanks blaster800!!! :hail: You did a smokin job :bigeyes: If anyone is interested in doing this mod shoot him a PM. The man has it down to a science now and I could not be happier with how it turned out.

Not only do the mods get the carb and reeds closer together, decreasing the length of the intake track and eliminating a reed spacer, but the mod significantly lightened the manifold. I will get some numbers but it is very noticable difference.

Glad i could help and be part of an awsome project like this one ! ! Now if i could only build one like this, then that would be really nice !

 

[RiverRat]

New waterbox arrived today as well. I did not think it was possible to get any lighter than the x-metal unit :bigeyes: Figured I would give this set up a shot. No internal baffles, straight through resonating chamber w/ a water injection fitting installed. Top notch construction as well. The welds on this thing are impeckable. It is a old PJS resonator. No idea how it performs but we will see. Using all silicone hoses w/ smooth bends so it should ahve nice flow and a clean sound. I am not running a front exhaust, just rear so this system should not be that loud.

It also allows me to keep some back pressure in the system. Rather than going form a 2.0 outlet to a 2.5 I can have a stepwise transition. The mod chamber has a 2in outlet. The resonator has a 2in inlet/outlet. I plan to do a 2in 90 degree hose up. Then to a 90 degree reducer hose back going from 2in inlet to a 2.25 outlet to meet the 2.25in diameter aluminum exhaust tube from the water box to the bulkhead. It will then go from 2.25 to about 2.5 into and about 3/4 the length of the exhaust tube through the hull. Then go from 2.5 to 3in outlet on the last 1/4 of the exhaust and exhaust tip of the x-jet. Nice smooth transitions should produce a clean exhaust note :biggthumpup:

 

[RiverRat]

Since the exhaust will be pretty much be all metal it will all be coated inside and out with Jet-Hot's ceramic coating. It will keep the gases warmer, allowing them to flow a little faster plus keep the metal from heating up and radiating that heat into the engine bay. All high temp silicone reinforced hose will be used (ebay :headbang. I used that stuff last year and it held up very well. I keep my system pretty dry also.

 

[Idok]

very nice RR....going back a couple of posts, you mention moving the carbs and reeds closer together to shorten the track..


I always thought it was beneficial to LENGTHEN the track...ie reed spacers, velocity stax etc etc......

 

[SuperJETT]

Remind me to wear earplugs when I ride with you, that's going to be the loudest ski on the river this year.

 

[Idok]

Remind me to wear earplugs when I ride with you, that's going to be the loudest ski on the river this year.

with rear only it shuoldnt be TOO bad....:cat40:

 

[RiverRat]

very nice RR....going back a couple of posts, you mention moving the carbs and reeds closer together to shorten the track..


I always thought it was beneficial to LENGTHEN the track...ie reed spacers, velocity stax etc etc......

Referencing my previous experience w/ cars, a lobger runner will have a different power band than a shorter intake track. Typically the short track will allow for better throttle response and low end perofrmance. A velocity stack is typically before the throttle butterflies. They starighten out the flow and operate better as RPM's increase. Look at the set ups on crotch rockets. They typically have carbs mounted right onto of the cylinder head. The manifold is nothing more than a rubber coupler between the carb and head. They also have velocity stacks before the butterflies to increase that upper RPM power. Some manifolds produce the low end torque, others opt to increase power in the upper RPM's by smoothing out that flow and increasing runner length. There are allot of variables concering this and my experience tells me short intake track for low end power. Look at the sidedraft carbs on a gp800, crotch rockets, Chevy LT1/LT4 manifolds, edlebrock manifold designs vs their rated performance RPM's.

On this set up I want fast, smooth flow through the reed cages. I am not worried about fuel atomization and don't want to rough up the track too much. If the fuel can't stay atomized between the bomb site and the reed cages my carbs suck :haha: The fuel charge is being drawn/sucked the through the reeds anyway. Cases will be rough but the intake will go over with a 120 grit sanding wheel.

Reed spacers are designed to move the reeds back to increase petal life. Allot of builders find it benificial to epoxy the fingers of the cases when adding a reed spacer. Boyesen and Full Spec designed a manifold that does exactly what this mod does, move the reed cages back while not adding additional case volume.