64'' fountain by bonzi

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Seems like to much to one side port.... unless I need to trim the header a tad? :unsure: ... bottom line is its too tight and I have to force the header down to the manifold
 
Yeah definitely don't wanna put too much stress against your nice hull or the exhaust flanges and gaskets. The header needs to be 13 inches minimal from the bend in your header. I found this out with mine. Check this article:
https://www.modelgasboats.com/magazine/tech-articles-mainmenu-608/358-tuning-a-tuned-pipe
Need to tune your exhaust. 1" makes a big difference in how your engine rpm acts. There's a little bit more to these boats brother than our cars, So just saying don't just cut your header to fit. Use a copper pipe cut off tool grinder or dremel or it makes for ugly work😂
 
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I took the exhaust tip off and I feel I need to make the hole a tad bigger coming through the hull.. the pipe is resting on it and the tip isn't letting it lay where it wants to
 
PortCityRC said:
Yeah definitely don't wanna put too much stress against your nice hull or the exhaust flanges and gaskets. The header needs to be 13 inches minimal from the bend in your header. I found this out with mine. Check this article:
https://www.modelgasboats.com/magazine/tech-articles-mainmenu-608/358-tuning-a-tuned-pipe
Need to tune your exhaust. 1" makes a big difference in how your engine rpm acts. There's a little bit more to these boats brother than our cars, So just saying don't just cut your header to fit. Use a copper pipe cut off tool grinder or dremel or it makes for ugly work😂
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Ideally you would do this for all types pipes, but in our vehicles it's kinda hard to move the expansion chamber around due to fitment constraints. You've got a bit more room in a boat to play with in these cases, stinger length and diameter can cause about the same reaction as header length. You just using the header to get max rpm out of the engine wile under a load using your specific set up. Sure wish we had an easy way to do this with our cars.
 
Pull the velocity stack setup off of the carb side. You will hurt performance with it.
 
This is true but minimal, and he's not using that bs garbage mini alloy China stack that the port doesn't match. And be careful you will need shorter carb bolts bro if you choose to ditch it. I'm not running a stack. I only threw mine on to bag and tag to store temporarily
 
I appreciate it guys...am I going to see an rpm based disadvantage? Ive built the boat with the goals of it hitting atleast 60 so im all ears and the stack is a bartolone v2 he includes 2 different length carb bolts and intook notice thanks for that port (y)
 
I don't believe you'd really be able to see the difference without a dyno comparison. It is one less obstacle though to get air to the carb as these boats don't have tons of air flow. Definitely won't hurt not being there. All the boat racers don't run them, so I say your choice and test and seen if there's a difference when your tuning.
 
Problem is it screws up the flow coming into the carb. On a car you need a filter to protect it from the dirt and what not. It makes the engine rich and not run well at high rpm. I had this happen on a 35cc engines of ours when we first built them. I rebuilt the engine and on the test stand it was so dog rich and would not run. I left it on because the customer had sent it in when it came in to rebuild the engine. Took off the velocity stack and now engines was too lean to even run. So had to open all the needles back up on it. There is a loss in power on flow bench and the dyno both.
 
I don't think it'd be bad for it, just wouldn't peak out in the rpms. Not 100% on this one. Sean knows a bit more than I on carbs. I bought mine as the full package and 1048 mod was supplied and everything came assembled. The venturi I believe is bored to 13.8mm and they installed bearings on throttle shaft not sure what else was done exactly other than using a matching billet isolator block as well, I see your using the zen delrin/plastic which I assume will restrict, make sure the ports match. I'll have to find my receipts though to see what else Was done. I went for every option they offered.
 
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