aquacraft .18

[scootertrash]

has anyone done any mods to the aquaceaft .18, porting ect.or can you guide me to the right location to find stuff about the mods.i went on another web site and asked about porting and mods. they acted like its all top secret.

 

[Bill Gibson]

has anyone done any mods to the aquaceaft .18, porting ect.or can you guide me to the right location to find stuff about the mods.i went on another web site and asked about porting and mods. they acted like its all top secret.

You need to contact Alden Cost...he is modding a coupla of my aqui .18 engines....it appears that he is finding some speed out of these cheap little motors with a little work....he is on this forum and is one HECK of a real nice guy!

 

[Ron Olson]

Yeah, I replied over there. One guy responding was an idiot and the other gave some good advice (JD). One thing that I didn't think of at the time would be to get an OS .18 carb as it has a larger bore which will let it breathe.

 

[camaroboy383]

lots can be done to these little puppies... think i can help you here...

the port timing in the sleeve can be raised by cutting them higher,,,you must retain the stock angles and shape of the ports when doing so... the cuts need to be cleaned very well with fine paper 1500-2000,, if you dont clean them very well you will for sure be scoring a piston on its first venture through the port section of the sleeve..

transfer ports in the case can be cleaned and ramped.... most rear one needs to be finished out into the crank bore,,the factory machine stopped just short... the front port can be ramped to the crank bore...

head space in insane,, way large... needs to be brought down to .007-.008,,, the bubble volume can be brought down also depending on nitro...

you can machine the pto pin off of the crank and install a cvr back plate which frees up some power as well..the back plate needs the .018 lip machined off to fit in the case...

the carb barrel can be matched to the body venturi,,and the exit of the throat can be finished out to a bell shape..

the carb ron is speaking of i beleive is the o.s 11j,,, that carb has a different mounting system than the aqua but can be made to work....

last but not least,,, k&b1L plugs

hope this helps,,, if you need more info feel free to ask..

alden

 

[Rick Sowell]

Alden: how much do you cut on the ports, if you raise the port, how much do you cut and what ports do you modify. I have done the case mods before, so that is not new, on the head do you cut the top of the sleeve? or machine the button? for the head clearence. Rick

 

[camaroboy383]

oops,,sorry,, forgot to add that info... .030 off of every port,,,,UP.... ive run different variations and this works just fine...as far as correcting head space,,, i machine the buttons,,, ive only once cut the top of the sleeve to drop the head,,,and that was on a marred up sleeve... i currently have only two tanks through that engine so have no feedback yet on that type of cut...suppose its no different?????..... if cutting the button take the .012 lip off the outer edge,,,then pull .017 off of the whole sleeve land.... this will give you .000..... slap a .008 shim in there and your in... bubble volume and squish band shape can be played with if using higher nitro i.e 60%....a bubble volume of .17cc has worked very well with 60.. squish shape,,,ive tried flat,,stock angle,and increased angle... flat will tend to run rough on land and straighten out when loaded up...the angle just runs slightly better on land,,perdy much yields the same results in power that ive seen...

alden

 

[scootertrash]

hey thanks for the info.what is the bubble volume and what % nitro should i run and oil content.if i machine off the pto pin off of the crank and add the crv back plate can i still use a pull starter.do you machine off the hole pin or just the nub.i have a crv car motor with pull start,can i copy the cylinder sleeve to the aquacraft one.in the front and back of the ports in the crank do they need to be ramped.can i use the sleeve out off my .18 cvr and crank in the aqua .18.would there be any advantage using the cvr head button.Do you also raise the transfer ports. finally what bit do you use for porting.

Thanks Darren

 

[camaroboy383]

some slight confusion here,,, the pto pin only,, has to be machined off... the back plate is a standard one,,, no pull start.. you have to use a belt to start it...

bubble volume stated in my last post .17cc with 60% nitro,,, i use technology hobbies fuel by john otto here on the board..beleive his mix has 18% oil,,dont hold me to that number though,,could be slightly higher or lower..regardless,, it is great fuel...

cvr sleeve will not work,,different port configuration.. cvr pull start will not work,,larger in o.d,,plus if your stayin pull start then leave the aqua one..

pull the sleeve,,, wipe it with alky to clean it... take a permenent black marker and color all around the tops and sides of the ports..let it dry up for about 5 mins. then take your dial caliper and set it at .030" gently while riding on the upper side of the port with the lower arm,, scribe a line through the marker with the point on the upper arm of the caliper.. this will give you your .030" that you need to cut... remember to keep the natural shape and angles of the port.. when it comes to the sides of the port you just want to come straight up,,,DO NOT cut the sides out to the scribed lines,,,width of every port stays the same,,you just want to up them,,nothing more...

in the crank case.. look down through the sleeve bore... the rear port (one nearest the pull start) you will see the ledge of aluminum that was just short of being popped out,, you will see the machine just chipped a small piece out.. you need to clean that right out,,again keeping the natural shape.. the front one i just put a nice ramp down into the crank bore..

for the case ports,, i use a small carbide ball mill..for cutting the sleeve i use a small (like 1/16") straight carbide mill...

another thing you can do to used piston and sleeves is take a sharp pipe cutter and just lightly ring the top of the piston just over the hole in the skirt,,, but VERY lightly or its junk, just like that.. that will give you a little tightness in the sleeve..

alden

 

[scootertrash]

so all ports in the sleeve get raised ?

 

[camaroboy383]

yes sir

alden

 

[Grimracer]

What does this set the timing to?..

Exhaust and Trasfer right..as we know there is no boost port.

Grim

 

[camaroboy383]

grim,,, off the top of my head i forget,its been a while,, i will degree it tonight..to be honest when i started this venture i just started cutting sleeves at random thou. numbers.. the .030 is what i ended up liking.. i did degree these ,,,hmmmm possibly the beginning of the summer.. but the numbers didnt mean much to me since i already knew what to cut.....

to add to the cvr standard back plate... once you get the plate to fit the aqua case,,, install it and look throught the sleeve bore again,, the rear port you cleaned just got half way blocked off again by the plate... you can take that black marker and color the plate where it sticks in the port... pull it and ramp that section nice nice, where you marked it... forgot to add this earlier in the thread..

been workin on two things lately,,, better rods,,and better mods to the carb... if you look at the carbs on the new novarossi .12's that glenn sells you will have an idea... ... thats to be posted at a later date,, to cold to test anything right now...

 

[Sean Bowf]

What does this set the timing to?..

Exhaust and Trasfer right..as we know there is no boost port.

Grim

EDIT: Redid all my measurements

About 171 and 129 duration from what I can figure...stock is 158 and 112.

Sean