SoCal Jet Boats
Discussion => The No Wake Zone => Topic started by: TooSober on November 13, 2015, 06:40:34 PM
-
Ok so I removed both to put new gaskets on (had a small leak). I know this is probably a dumb question as I am learning as I go but should I clean out the insides and if so how should I do it? Motor is a bbc 454. Thanks for your help
Sent from my iPhone using SoCal Jet Boats
-
Well....anything that eats that soot and oil deposits, carb cleaner,oven cleaner(careful it eats aluminum if you leave it)on inside only,small wire brush etc. Ware mask,read and follow label directions. While you got um off,match gaskets to logs,then same treatment to the heads,you'll be amazed what you find! After all that,polished those baby's. Then have a cold one,you deserve it,have fun with it.
-
A little Parsons will clean some of the corrosion up.
-
While I am working on the boat this winter what add on can i do that can add some more power? I saw these headers (looks like China) but i couldn't find any first hand reviews. being so cheap i know i cant expect much but could they give some more power? link below
http://xs-power.com/other-specialty-marine-6.htm (http://xs-power.com/other-specialty-marine-6.htm)
-
Back drag a razor blade. I'd cut off the step on the snail an go larger on the hose. If your ss or aluminum tips aren't larger then add a small piece of hose on them an run the larger over it all.
-
While I am working on the boat this winter what add on can i do that can add some more power? I saw these headers (looks like China) but i couldn't find any first hand reviews. being so cheap i know i cant expect much but could they give some more power? link below
http://xs-power.com/other-specialty-marine-6.htm (http://xs-power.com/other-specialty-marine-6.htm)
The most proven method of gaining performance on a log style exhaust is a crossover.
It also makes them sleeper quiet.
GT
-
The most proven method of gaining performance on s log style exhaust is a crossover.
It also makes them sleeper quiet.
GT
how would you do a crossover on this type of exhaust?
-
how would you do a crossover on this type of exhaust?
If you have more than 8" of exhaust hose between the rusts ant the tips, you use 3" aluminum tubing. You need to make two tees the size of the hose and an inverted elbow to connect the two over the pump.
GT
-
how would you do a crossover on this type of exhaust?
If you have more than 8" of exhaust hose between the rusts ant the tips, you use 3" aluminum tubing. You need to make two tees the size of the hose and an inverted elbow to connect the two over the pump.
GT
-
So something like running a X pipe on a car
-
So something like running a X pipe on a car
No, exactly like an X pipe. Hee hee.
GT
-
Got any pics of this set up? I think i have enough room to pull it off, but since i havent done it before (or seen it) it would help me plan it out in my head.
Sent from my iPhone using SoCal Jet Boats
-
Hahaha like this!? No not really I found it but just had to post this craziness
Sent from my iPhone using SoCal Jet Boats
-
Ok another issue is I keep snapping the bolts on the alternator (3 so far). I am using grade 8 bolts. Do I have it mounted incorrect? Should I have a longer belt. The adjusting arm never seems to line up correctly and the alternator seem to be slightly slanted when bolted on. Pics below.
Sent from my iPhone using SoCal Jet Boats
-
Use a grade 5 bolt and flat washer to make up that offset. The bushing looks too thick to me.
Use a lock washer and a hardened flat washer where the bolt goes through the bracket.
A grade 8 bolt is too hard.
-
At second glance, flip that bracket over.
The alternator bolt should go through the front. Not the back.
Jmo
GT
-
Like this? The belt seems to small as I can't get the bolt thru the adjusting arm.
Sent from my iPhone using SoCal Jet Boats
-
Ok another issue is I keep snapping the bolts on the alternator (3 so far). I am using grade 8 bolts. Do I have it mounted incorrect? Should I have a longer belt. The adjusting arm never seems to line up correctly and the alternator seem to be slightly slanted when bolted on. Pics below.
Sent from my iPhone using SoCal Jet Boats
Also, I use turnbuckles. Not a slide bracket.
Might work great in this case.
GT
-
Like this? The belt seems to small as I can't get the bolt thru the adjusting arm.
Sent from my iPhone using SoCal Jet Boats
Really?
The bracket should be at the front of the alternator. You may need to use a grinder on the bracket so it fits the block flatter. And yes, the belt is a couple inches short imo.
The turn buckle.
http://www.amazon.com/Tensioner-Turnbuckle-Adjustable-Alternator-Steering/dp/B00MI7Q1TC
-
From the pic on cp website it looks like it should go behind. When it is in front it is very close to touching. Thanks for all the help
Sent from my iPhone using SoCal Jet Boats
-
You are going to likely need to notch the floor and buy a longer belt, nearly touching is better than touching. Lol
Good luck
GT
-
No, exactly like an X pipe. Hee hee.
GT
The mod makes sense on paper. Is is popular? If so, people have done a good job keeping it a secret. I cant find pics anywhere. Haha
Sent from my iPhone using SoCal Jet Boats
-
We did about ten back in the day.
Most popular on aluminum fishing river jets.
-
Toyota uses it in their tow boats. I think Master Craft did it for a short time.
-
The theory of the cross over pipe is to equalize back pressure which helps equalize compression ratio's so the motor runs smoother. It also helps the exhaust pulse to even out which is why it makes the motor quieter at idle and off idle.
-
The theory of the cross over pipe is to equalize back pressure which helps equalize compression ratio's so the motor runs smoother. It also helps the exhaust pulse to even out which is why it makes the motor quieter at idle and off idle.
Indeed. It's also called resonance scavenging. It will take quite a bit of thump out of the exhaust, but can increase upper rpm hp. Meaning an increasing wot rpm.
GT
-
Is this the crossover you are talking about? What about the water lines to the logs? Would those lines run from the two on the top?
Sent from my iPhone using SoCal Jet Boats
-
No. That's just water. All of my pictures are film. It would probably be faster if I searched the Internet. I never had the money for digital cameras. My videos are even VHS-C.lol
-
You could also build a crossover with CPVC (different from PVC). It would be fairly inexpensive. You could buy all the materials from McMaster Carr.
-
To Sober: this my Olds alt. mount. Been ok for 20 yrs. Enlarge pics if u can. idk.
-
I was only able to get 1 nut off of the riser. I have been putting Penetrating spray since yesterday not luck. used a torch and Penetrating spray, wd 40 and still no luck. The nut is too close to the manifold to use a nut buster. any other tricks i can try?
-
I was only able to get 1 nut off of the riser. I have been putting Penetrating spray since yesterday not luck. used a torch and Penetrating spray, wd 40 and still no luck. The nut is too close to the manifold to use a nut buster. any other tricks i can try?
Use a small drill bit and drill several holes in the side of the nut and simply hit it with a cold chisel, drill two sides if you can.
GT
-
The theory of the cross over pipe is to equalize back pressure which helps equalize compression ratio's so the motor runs smoother. It also helps the exhaust pulse to even out which is why it makes the motor quieter at idle and off idle.
i get t... i just wanted to see one done.
-
drilling it worked. now pulling them apart is an issue. I have been using a putty knife with no luck. and tricks on this part?
-
Rubber mallet and a prybar be careful you don't damage the threads. Might want to leave a nut on the very end so you don't ruin the threads while prying off.
Sent from my iPhone using SoCal Jet Boats
-
It's likely corrosion around the studs causing the problem.
You may need to cut the studs off at the gasket.
Sent from my SCH-I545 using SoCal Jet Boats mobile app
-
The cross-over pipe is for resonance wave tuning. Since this thread is specifically pertaining to logs and snails, I will limit it to just that. You need to look at the exhaust system as a whole. Each little segment of the log manifold, including the snails, the through-transom hose, and even the ports in the heads have a cross-section area. First as the exhaust leaves the combustion chamber where it enters the port as it passes the valve and then makes the transition into the first leg of the log manifold. Second is an area of gaseous expansion where the exhaust gasses transition from the ports into the log portion of the manifold. Another change in cross-sectional area is most likely present in the snails. Then yet again in the exhaust hoses exiting the transom.
As each of the exhaust valves open and the cylinders blow down, a pressure wave enters the exhaust system and begins a chain of wave events. Each cross-sectional area will resonate in its own frequency.
Looking at the first part of the exhaust system, the exhaust port (starting at the valve seat) to where the gasses first expand into the log portion of the manifold. The pressure wave travels to the end of that section. An equal and opposite pressure wave is reflected back and returns to the exhaust valve. These pressure waves are a transfer of kinetic energy between the gas molecules present in the exhaust system. These waves continue to reflect back and forth until all of the energy is dissipated. Each cross-sectional area will resonate in its own frequency. After about five reflections, the wave has lost so much energy that it no longer significantly impacts the system. This is organ pipe theory and is the concert behind tuned headers and exhaust (induction as well).
The timing of these waves, by manipulation of pipe lengths, influences the point at which the negative wave returns to the previous change in cross-section area. By timing this properly, a lower pressure can be generated in the cylinder which pulls harder (scavenging effect) on the intake, boosting volumetric efficiency. Additionally, each cross-sectional area length can be tuned independently.
In a car, the exhaust system is so long that two separate waves can resonate in the same length of pipe. The collision of waves inside this same length of pipe creates a high-pressure point. A cross-over pipe provides a point of expansion, in that length of pipe, from which both waves can resonate. Dynamics of the two banks of cylinders working together can further reduce the pressure at that point, helping to scavenge.
Years ago, we determined the ideal location for the cross-over pipe by painting the exhaust pipes. The point where the paint burned off was the ideal location where the cross-over pipe was installed. Now there are refined equations and software, such as PipeMax to calculate this.
It is important to note that optimizing only occurs at ONE point in the RPM range.
So, how does this relate to us in the world of jet boats? It has been said that manifolds can represent a horsepower loss of 10% vs. headers. This is because of reduced scavenging and pumping losses.
IMHO, if you are already working at a disadvantage, everything to minimize weaknesses and maximum strengths should be done to optimize performance. However, in a boat, packaging and heat needs to be addressed. This may not even be feasible for some.
An alternative to a cross-over would be to install idler branches (pictured) on each side. These idler branches would be capped and therefore would not have exhaust gas flow. They would however resonate at their own frequency. If tuned properly, it will produce a low pressure in the exhaust system and aid scavenging. A shorter pipe will show a benefit at higher RPM and a longer pipe at lower RPM. Of course heat will still be of concern.
I have been thinking about this for quite some time, but I keep coming back to the same conclusion. Any max-effort program will use headers. But, food for thought.
Cheers,
Joe
P.S. If interested in this topic, I suggest the book Scientific Design of Exhaust & Intake Systems by Philip H. Smith and John C. Morrison
-
.
-
Check out turnbuckles at Lowes in hardware dept. Not Home Depot. Lowes has better ones. Tgey worked for my set up which looks similar to yours. (Talking about alternator, not exhaust). And I actuslly read Flushers "exhausting" post. (See what I did there?) Interesting and informative.