lzvagias

damn fine work! i'm envious of your tooling you have access too. there's no substitute for have the right tool for the right job, that might take me a while to build with a jig saw and a dremel! have you dropped in to the stringers yet? just wondering if the heads of those bolts will clear the stringers, if so you have plenty of material to allow you to counter sink them. me thinks it might look pretty trick if you put some oval shaped holes with and beveled the edges of them a little. looks great though.

Delinport

Thanks Izvagias....I thought about counter sinking the bolts...I still may. I still have to install vibration mounts and rails. The pictures of my engine in the hull show 5 inch rails...They won't work. I have to send this hull back to expresscraft anyway. I will have them send me one without rails so I can put them in myself.

Del

lzvagias

that sux about your hull, but once its done and your on the water with it you'll forget all about it. still, i hope tom returns to expresscraft and starts kicking a@# and taking names. regarding your bolts, whether you counter sink or not some ss hex head bolts inplace of your exhisting ones would really look nice! not trying to be critical just trying to throw some ideas out there for you.

Delinport

Thanks, Izvagias......I am open to any ideas to make my boat better. This will be my third gas boat, but the first one I built myself.

Del

FROGMAN524

My Feedback: (5)

Delinport, those look like very short stringers, what are they, about 17"? Mine were just past that step in the hull that your motor is currently sitting over. Have them send you long stringers, I forgot to ask for those when I ordered my hull from Roger. Ken.

ps, looks like good work on those motor mounts. Keep up the good work, KEn.

Delinport

Ken...they seem short to me too. The next hull I'm going to have them send it without stringers installed. I might use a little thicker wood.....Just for more support. I don't really know if it needs it but I would rather add just a bit more weight and be safe. I don't want to rip the stringers out when I got to pull start my motor. I was also thinking of drilling some holes in the mount I made to lighten it. I don't really know if it's worth the time...and it might look like crap. I will have to think about it.

Del

lzvagias

Matt could shed more light on thicker stringers than me but i don't think thats really going to be anything to worry bout. if you where to do anything regarding strength i would maybe just reinforce the glass or if you glass them in yourself i'd use wider strips of cloth and use epoxy. but again, i don't know that you'll even need to worry bout it. i'd try not to over build it if its not needed as this will only add weight and ultimately effect performance. just my two pennies and some pocket fuzz.

Delinport

Thanks for the two cents and the pocket fuzz Izvagias. I will stick with the standard thickness rails. I ordered the drive from Loo at MHZ today. I also broke down and ordered a $235 water cooled tuned pipe. I was happy with the one I made. But after doing more research...It seems the exhaust can really play a key role in a 2 stroke engines performance. I am not an engineer and I really don't have the skills to calculate proper angles and dimensions for an expantion chamber. Sometimes it's best to let people do what they do best and not try to patch things together if you really don't know what your doing. Just because you can cut and weld some metal...it doesn't mean you can make a pipe that will benifit the performance of your engine.

Del

Justaddwata

My Feedback: (3)

Hey Del,

You will be happy with the stainless pipe from MHZ. See if loo can supply you with the correct pipe length for the Polini. Will save you some trial and error.

It would not be a bad idea to spread some of the load of the motor over a bigger area in the hull. Either longer rails or a layer or two of glass below the rails you install would help. Remember that this motor is going to give that hull a pounding and it is always better to build it a little stronger from day 1 than try to rebuild it after damage is done.

Looks like your heading the right direction there !!!

Delinport

Thanks justaddwata...I will ask loo if he can give me a good header length to go off of.

I got an email from Laura at expresscraft today. She said she is very sorry and they will resolve the issue by sending me another hull. She also said they would send the hardware and parts that came up missing. She seemed concerned about me as a customer...It was nice to see for a change.

Del

Justaddwata

My Feedback: (3)

I have had nothing but good experiences with Expresscraft. Glad to hear they are coming through for you.

Delinport

I fabricated a carb intake manifold over the past couple days. I used a metal band saw, drill press, belt sander, and dremal tool. Here are some photos.

Delinport

I got my S6 drive and tuned pipe from MHZ today. It looks great....but I still have no hull to start doing much. I hope expresscraft sends one out soon.

Aslo...I'm trying to figure out what I should do for carb throttle control. I picked up a cable setup I was thinking about using but it seems like there is a lot of friction. I hooked the throttle cable up to the servo on my Monster GT truck and it didn't seem to move real fast. I could build a linkage setup that might be better. Does anyone have any great ideas? I would be hooking up to a walbro carb if that helps....thanks..

Del

Delinport

Over the past few days I got a few important things done. I fabricated a bracket and linkage for my throttle. Thanks to some other posts I was able to come up with something that I feel will work very well.

I also fabricated an adaptor plate for the exhaust and welded it to a braided steel flex line I plan on using. Due to the length of the pipe I got I think it will have to bend forward and come back kind of like I'm showing in the photos. I will have to wait to see how everything lines up with the exhaust before I weld the pipe on.

I hope I get my hull back soon....

The throttle lever I made feels smooth. Does anyone see any reason it shouldn't work?

Del

lzvagias

Del, does that exhaust have a rubber hose core?

Delinport

No, it's metal inside. I have used them on the discharge of Recip air compressors that see 300 Degrees F. and not had any issues with leaks or melting so I don't think it will be an issue on my engine....I hope!!

lzvagias

where can you buy them?

Delinport

Well....I will have to find out who our vendor is for that air line. We sell them...but I'm sure they are not cheap. The company I work for is named Rogers Machinery. We Sell, Service, and Repair industrial air compressors. We are also a manufacture. We have Two different Types of compressors we build and a multitude of other air type products we distribute. The line I used is off a two stage oil free compressor.....We use the same flex lines for oil lines on bigger machines and a larger size hose as shown in photo for discharge air lines. I did not have to purchase the hose I used because it was used and came off a machine we scraped out.

Justaddwata

My Feedback: (3)

Have to hand it to you Del - you do some very nice fabricating !!!

Only observations of the throttle linkage is that it is pulling from a harder angle than possibly ideal. I would try to move the pivot a little lower so the rod is pulling at a little better angle (though I could be wrong as this may not give you full throttle). Also trim off excess rod.

The pipe looks very good but I have questions about it being air tight. Firstly your exhaust temperature will be well over 300f I would imagine. How is the braided wire air tight (is it air tight ??). If it is not air tight you will get leaks that will make a mess inside the hull with oil and soot. You will also be loosing a lot of tuned pipe benifit with the braided wire. The braid will flex with the pulse of the pipe. This pulse needs to be contained (within pipe) in order blast back into the exhaust port to function correctly with both correct timing and maximum pressure. While ugly - I was able to make up a manifold for my blata with copper fittings from the home depot that worked beautifully and fit the MHZ pipe with ease. I do like the look (and work) you have done with the braided hose. I am just not sure it is the best product for the application.

I did buy some flexible stainless pipe from Mcmaster carr which will work ok for the application. It is the same pipe Quickdraw are now using for their new 25 pipes. Only problem is that it is not very flexible and certainly would not like the curves you are after for your installation.

Let me know what you think

lzvagias

del, given Matts comments and your obvious abilities with metal fab, how bout using the copper elbows to achieve your desired shape then transfer that to s-steel pipe. i would think you'd have no trouble bending, cutting, and welding it to shape. it would probably look super trick too.

Delinport

The throttle linkage pivot arm is 90 degrees from half throttle. I tried a bunch of different angles but this on seemed to be the best. You can't really see it, but I used a small brass bushing on the arm I made so it would turn freely and perhaps not wear out as soon. I'm hoping I won't have to have to much of a bend to get back to the proper place on the radio box. I won't really know until I get my hull again.

Speaking of my hull. I called today and they are hoping to ship it again on Tuesday. They had one ready to ship today but I guess they put stringers in it. Small communication error. I guess I should have been more clear. I wanted it without stringers.

The steel braiding is more meant for safety in the hoses original application with compressed air. There is another flexible metal pipe under the braided steel that you see on the outside. Like I was saying.....We use them on our air compressors at 100 to 150 psi range with no leaks. The compressor shown above has been known to have discharge temps of over 400 degrees F. It may not work and I may have to eat my words....but I'm going to give it a try. I know the exhaust temps are going to be hot on this engine...but it's a low pressure application and I feel the steel braided hoses are well suited for it. Thanks for all the compliments. I will continue to keep you guys posted on here. I like getting feedback...both good and bad. Sometimes ideas look good on paper...but in the real world they just plain suck. I like trying to do things a little less main stream, but no so far off that I look completely nuts.

I will keep the copper idea in mind.....it's always a good idea to have a backup plan if thinks don't work out. Thanks Izvagias and Justaddwata


Anyone ever use aluminum stringers??...I thought I saw a photo of a boat that has alumintum brackets glassed right to the bottom of the boat like stringers. He was still using rubber isolation mounts for the engine.

Del

Justaddwata

My Feedback: (3)

Hey Del,

If it is air tight then it should be a good option (provided it can take the heat) and you may have found something for me to use (if I can afford it ).

The aluminum stringer idea is good. You have plenty of options. Personally I dont like adding wood to a boat that has no wood anywhere on or in it. Only trick will be to match the profile of the stringers base to the hull to ensure good support. I used aluminum in my Jolly motor cat and it worked great.

The best way to work with stringers I have found is to mount them after you get everything bolted to them. That way you dont have all the challenges of drilling them in the boat (and less drill shavings floating around inside the hull too!!). Once everything bolts cleanly to the rails I add a little reinforcement to the hull where the rails will be running (you have a heavy motor) and then glass them in place.

lzvagias

i've only seen pictures of al stringers but you can mix up some resin with west marine micro fibers until it forms a paste (aka cavisil) and use it to fill any voids between stringer and hull. it is also a very good bonding agent so its a win/win situation. exhaust temp- i think a zens exhaust is around 500-600 degrees and i would think yours is comparable. i hope it works cause that hose looks great.

"I like trying to do things a little less main stream" most people call this being inovative and sometimes inovators can become trend setters.

Delinport

We have a west marine close to my work...I will have to check out the stuff your talking about Izvagias....Might be kind off cool to have aluminum stringers.

This morning I went down to the shop to bench test my engine.

I hooked up fuel and water and clamped the engine down to the bench. Primed the carb and it started on the 4th pull. I was pretty happy. I ran about of tank of gas through it but didn't rev it too high. I thought I had heard it was bas to rev a small engine with no load on it. I didn't really get into tuning the walbro carb much because I don't have the pipe on it....just the header. Plus without a load I don't think you could really tune the carb that well. I did get it to ide well and seems to respond well to moving the throttle lever. You want to talk about loud. I hope the pipe I got quiets it down. Here are some photos. Hope they are not too dark.

Justaddwata

My Feedback: (3)

I am sure it was loud !! The pipe you have will surprise you how quiet it will make it. Tuning the carb will be a little trial and error and as you said - should be under load. She is coming together (just needs a boat !!)