b-pipe, can't get any sizzle...

[aramis]

Hey, just wanted to do a sanity check so I can hit the ground running when I get home from this %$#^@ trip to China... the riding season in Rochester, NY is short enough as it is...

I can't get any sizzle on my limited chamber. It barely gets warm, and I can even hold my hand on the header pipe for several seconds. I'm thinking there's something to be gained by dialing this in better, but not sure how to do it. Here's my setup:

- 61x/62t 701 (stock porting), ADA head 35cc, flame arrestors, MSD Enhancer (before i broke it), C-75 5mm cut back (12/17 I think?), stock dual 38's.
- bpipe header and exhaust manifold dremeled open to 47mm
- top screw opened 3/4 turn, mid/bottom closed (mid screw is busted, but checked for no flow with a hose)
- dual cooling, both lines enter bottom of exhaust manifold
- from ADA head, rear exit goes to bottom of header pipe
- top of header pipe exits to T (straight from T goes to FCV, side of T to unrestricted pisser)
- front exit from ADA head goes straight to restricted pisser (5mm restriction, IIRC).

The pisser temps are warm, but I can hold my hands in the stream as long as I want. Should I just play with additional restrictions until the pisser temp gets to ??? degrees?

Should I also be restricting the "side of the T" pisser as well?

It's also entirely possible that my ski is running a bit rich, although it runs well and smooth throughout the powerband. I have a tach on the way and will try my hand at using Watcon's carb tuning posting to dial in the screws, but would rather not mess with jetting unless I have to.

What else can I check / try?

Thanks! I searched through 6 pages of stuff, but didn't find what I was looking for...

 

[nokfir]

im interested to hear some answers, i jsut installed a limited pipe to, i have bottom screw open 3/4 and close middle and top, also got no sizzle.

 

[Proformance1]

Over board (pisser) fitting temps should be approx 120*F in normal water conditions, maybe like 55-65 deg water???? Sounds like you are just still flowing too much water to the pipe to get it to sizzle. I never made mine sizzle anyhow, but I can't seem to find the place wehre I marked down what the screw settings were on my pipe. I have a 4mm restrictor on my line from the head to the T before the stinger and over board.

I was just relooking at your post, were you running this lately? That waters about 40 deg there. You'll never get it to sizzle with those conditions, LOL we were out last week and the overboard temps wer about 90 at best and I only have single cooling. If youre in doubt over the temps stick a meat thermometer in the fitting after warming it up and run it on the trialer backed into the water, or have someone hold the ski.

 

[masterblaster]

Keep closing your top screw until it gets hot and then back up from there.the screw settings are pretty sensitive at a certain point when they first open,use a air compressor with one end of the pipe cooling blocked off and you will hear the sweet spot as you open the screw. also I find for freestyle and freeride,you get much better low end with the top screw pissing enough that you pipe will never sizzle anyway.you will lose some mid range but gain alot of low end.depends how you use your ski if its worth it or not

 

[95FX1]

why is a restrictor on the ada head 2nd exit that goes straight to the pisser???

why would someone restrict that one....just before the stinger after the T is the only restrictor i ever heard of.....but im new so was wondering

 

[Dustin Mustangs]

That is the path of least resistance, ie where most the flow will go. Restricting here will have the most effect on system pressure and engine temp. My engine builder is having me restrict this and the stinger fitting under normal conditions and all three outlets in cold conditions.

 

[munki63]

I wouldn't restrict your cooling off your head to the pisser, put restriction before your water enters your exhaust manifold, if you do that you will cool your cylinders equally and reduce the amount of water flowing thru your system, thus running your entire set-up warmer...which is a good thing, But its a little early to be worried about making your pipe sizzle when summer actually gets here then worry about it, if you get your cooling set-up perfect for 40 deg water, you will be running way to hot

 

[aramis]

thanks for the feedback, guys. I can never help but tinker with the ski every spring instead of leaving well enough alone. This ski was setup for dual cooling when i got it from Mississippi, and I always wondered if I was just flowing too much water through it.

Proformance1, I haven't had it out yet this year. Wanted to put on the suit and go out on Easter weekend (it was in the 80's), but family things got in the way...and I've been away on business since May 1st.

masterblaster, thanks for the tip using the air compressor. At least that way I'll know how far closed I can go on the screw. I am looking for low end mostly, so maybe I don't even want it to sizzle from what you said. I just hating not knowing if it's set "'right", and I feel like I can't find out what "right" is until I am able to notice a difference in the adjustments.

So, I should be restricting the pisser that's T'ed off the line to the FCV / stinger, too? ...and checking for 120F water out of each pisser? makes sense now that I think about it more. I realize that I'd have to adjust the FCV as well, since I'd be effectively increasing pressure seen by the FCV by restricting at that line's pisser.

How hot is too hot for the pisser temps?

 

[judd17]

The chambers never get hot enough to sizzle, if its hot to touch for more than a few seconds thats normal

 

[95FX1]

over 120 seems to be to hot as stated.....

remove restrictor after the head before the pisser
if u want to restrict water flow totally...then do it at the water IN....before mani....not after head as it will not flow evenly

restrict flow before stinger after pisser -T- to help dry out ur waterbox.....
after the pisser -T- so all flow is still even and steady in the boat and out the boat....just the stinger going to box is slowed which does not effect total water flow....

all makes good sence to me

glad im setup that way.....

 

[Penken]

if you restrict the front outlet on the head to a pisser. would only make more water go through the pipe.

 

[rollin5150]

I don't quite understand what you are asking. Are you concerned about the pisser temp or are you concerned about your FFP chamber sizzling. If you want your chamber to sizzle, just start closing your water adjustment screws by 1/8 turn and test. Trust me, you will get to a point to where it will sizzle. Never have all three closed at once though. The water injection into the exhaust is what is controlling your chamber temp.

If you are concerned about your pisser temps (engine cooling) then you need to restrict the cooling water at the pissers.

 

[Proformance1]

Very good points rollin5150! He is talking about two separate issues. We'll get him straightened out as soon as he gets back in town and meets some of the local guys in Rochester/Buffalo.

 

[aramis]

Yeah, sorry for the confusion...all in all, I was asking how to increase pressure to make the bleed screws more effective but without also killing flow so much that cylinder temps got dangerous. Or, at least I was confused on how to verify things were ok. Specifically, I wanted to know:

- is 3/4 open on one screw possibly still too much water to make the pipe sizzle, even with header bore opened up to 47mm? (and it sounds like an overwhelming "yes, it can be". Cool, I'll play with that more when I get back. I didn't realize how sensitive that screw was, and will do the air compressor check to know where the lower limit is.)

- what is a healthy pisser temp? I got my head messed up on this, since there's no way that both pisser temps (overboard from head and exit from header) should necessarily be the same. Increasing pressure in the header jacket by using pisser restrictors helps the bleed screw to be more repeatable / adjustable, but at some point you are also restricting the flow out of the head too much and cooling suffers. In addition, the water that flows from the head through the header pipe jacket is seeing more residence time and has more surface area contact with high temps, and so would be expected to automatically have a steady state higher temp out the pisser than the straight overboard line from the head.

So, I'll just measure water temp right near the head for both cylinders, and play with restrictors in both pissers, to get both a) equal cylinder temps and b) make sure they don't go above 120F or so. That's my plan and I'm stickin' to it...Unless someone tells me otherwise.

95FX1, munki63, I'm sorry but I have to disagree with your advice. Putting restrictors before the exhaust manifold has to be a bad idea, since it will cause uneven / nonstable flow through the rest of the system, and make tuning that pipe more difficult. Think of it in an extreme case (lots of restriction): you'd have a lot of pressure from the pump to restrictor, and then just a trickle after the restrictor through manifold / head / pipe. Also, what happens when you suck up some sediment or something? That single restrictor before the manifold would get clogged easier, I would think.

(Proformance1, thanks again...I'll hit you guys up when I get back in town)

 

[95FX1]

in my case i deff. do not restrict before the mani.....But what i was agreeing to was the statement that was said about if someone was going to restrict total water flow to the cooling system then it should be before the mani after the pump brings it into the ski...if restricted there then it would decrease total cooling evenly....
what i dont understand is what u saying it would not be even....its restricting total volume...so it would be the only spot it could be done evenly....
again i see no need to ever do this....
but we (mukini/I) where reading where u have a restrictor before a pisser....that would lead to uneven cooling on that line....and thats what i/we where talking bout

I only restrict before the stinger on my boat...i am currently set up for single cooling from my pump but have the option for dual on my mani and head....but i ride in colder weather most times and dual is not needed for me....not yet anyway....

 

[chriselmore_1]

You can trade me your bpipe for my sizzler pipe. That will give you sizzle

 

[rollin5150]

Yeah, sorry for the confusion...all in all, I was asking how to increase pressure to make the bleed screws more effective but without also killing flow so much that cylinder temps got dangerous. Or, at least I was confused on how to verify things were ok. Specifically, I wanted to know:

- is 3/4 open on one screw possibly still too much water to make the pipe sizzle, even with header bore opened up to 47mm? (and it sounds like an overwhelming "yes, it can be". Cool, I'll play with that more when I get back. I didn't realize how sensitive that screw was, and will do the air compressor check to know where the lower limit is.)

- what is a healthy pisser temp? I got my head messed up on this, since there's no way that both pisser temps (overboard from head and exit from header) should necessarily be the same. Increasing pressure in the header jacket by using pisser restrictors helps the bleed screw to be more repeatable / adjustable, but at some point you are also restricting the flow out of the head too much and cooling suffers. In addition, the water that flows from the head through the header pipe jacket is seeing more residence time and has more surface area contact with high temps, and so would be expected to automatically have a steady state higher temp out the pisser than the straight overboard line from the head.

So, I'll just measure water temp right near the head for both cylinders, and play with restrictors in both pissers, to get both a) equal cylinder temps and b) make sure they don't go above 120F or so. That's my plan and I'm stickin' to it...Unless someone tells me otherwise.

95FX1, munki63, I'm sorry but I have to disagree with your advice. Putting restrictors before the exhaust manifold has to be a bad idea, since it will cause uneven / nonstable flow through the rest of the system, and make tuning that pipe more difficult. Think of it in an extreme case (lots of restriction): you'd have a lot of pressure from the pump to restrictor, and then just a trickle after the restrictor through manifold / head / pipe. Also, what happens when you suck up some sediment or something? That single restrictor before the manifold would get clogged easier, I would think.

(Proformance1, thanks again...I'll hit you guys up when I get back in town)

I am not 100% sure on your B pipe, but on my SXR wetpipe, 3/4 is a whole lot of water. You will not even come close to sizzling the pipe with that much. If I am going to get the pipe hot, I have one screw open about 1/4 turn. I would just play with it since each boat is unique.

 

[Dustin Mustangs]

in my case i deff. do not restrict before the mani.....But what i was agreeing to was the statement that was said about if someone was going to restrict total water flow to the cooling system then it should be before the mani after the pump brings it into the ski...if restricted there then it would decrease total cooling evenly....
what i dont understand is what u saying it would not be even....its restricting total volume...so it would be the only spot it could be done evenly....
again i see no need to ever do this....
but we (mukini/I) where reading where u have a restrictor before a pisser....that would lead to uneven cooling on that line....and thats what i/we where talking bout

I only restrict before the stinger on my boat...i am currently set up for single cooling from my pump but have the option for dual on my mani and head....but i ride in colder weather most times and dual is not needed for me....not yet anyway....

This really isn't true. Restrict before the manifold and yes you can get both lines to put out close to the same flow AT THAT POINT but really they should be very similar with out restriction there. In the manifold and cylinder the cooling water from the two different lines are allowed to mix. Because of this the amount of flow going past each cylinder, and more importantly dome, is controlled by the outlet condition which is controlled by the path the water takes down stream of the two outlets on the head. With this type of dual cooling these paths are inherently unique and the only way to try and minimize differences in flow between them is to restrict at the outlet.

Not to mention the bleed screws in the head pipe need a certain amount of pressure to properly mist the water they inject. The quicker the system builds enough pressure to make these mist the better, esp if you are trying to tune your pipe around low rpm performance which most around here are. Restricting before the manifold will make the pressure lower as compared to no restriction and doing it at the outlet would make it higher. This would be true at all engine speeds.

 

[95FX1]

^^ WOW

i have now learned someting new that makes great sence...

thanx bud

 

[munki63]

Jetworks Adjustable Inline Water Restrictor

http://www.atlanticjetsports.com/water_restrictors___flow_control_valve.htm

Use these