munro1656

I have just spent the last hour searching for a thread on a illustrated step by step on how to mod a zen can any one help with that at all? I would like to mod my own motor

OLD_SLOW and in the WAY

some good links and info here... http://www.rcuniverse.com/forum/m_7962719/tm.htm

sikk and zen mods are pretty much the same

munro1656

OLD...SLOW
AND IN THE WAY
Thanks for the reply that is just the kind of thread I'm after if only i could read dutch! [:@]
cheers craig

martno1fan

Here you go mate best how to there is.
Mart
[link]http://www.modelgasboats.com/Magazine_Content/Tech_Articles/Engine_Porting.html[/link]

munro1656

Thanks mart

I have just pulled motor from our fun run at redcliffe this afternoon so I guess i'll start with die grinder tomorrow

cheers craig

GRANT ED

Make sure you post your results.

cyclops1970

My Feedback: (5)

http://www.jrcbd.com/showthread.php?...zenoah+porting

munro1656

After completly stripping and inspectig motor in my view the weakest link in the internal driveline would be the rod does anyone have any input on the strength of a stock rod or is there something i can do to improve it ie. machine a lighter but stonger alloy rod, or would that be a waste of time ?

sonicracing

The rods are fine Craig, you gonna have that thing put back together for this Sunday ?

Cheers, Danny.

munro1656

This sunday will be out for me my wife due for third kid so boats on dry dock for a while

martno1fan

Third she'll be fine get the boat wet .
Mart

Ron Olson

My Feedback: (1)

One of the cheapest hop-ups is adding zero-drag seals. They're around $15.00 and will add 200-500 more RPM.

ryan_t888

Ron, drag seals for what?

Ryan

Ron Olson

My Feedback: (1)

They go in by the crankshaft bearings to reduce the drag of the rubber seals.
Here's some from Zac's site about 2/3's of the way down to give you an idea of what they look like: http://www.americanrcboats.com/produ...gineacczen.htm
Most engine modders carry these, I just had his site handy.

ryan_t888

Thanks Ron, I was thinking of something else.

Ryan

munro1656

I thought about it but she might get upset when I tell her to catch a cab in because I'm busy running boats
That would be castration with a blunt kitchen knife
Thanks ron I was thinking of adding them but wasn't sure if they made a huge difference

MrMikeG

Like Danny said, Rods are fine. Reduce piston weight and smooth the airflow. Get a degree-wheel to do your intake and exhaust timing and your all set. 260's have rather small transfers, open them up smoothly and you will notice the most gain.

Scott Schneider

Follow what you can of this "How Too" ...... Your power. RPM will be substantially improved

pedro2-5

craig i will let you drive the WHITE DEATH on sunday if your too slack to finish the mod ,can i book in for the kitchen snip too lol

pedro2-5

hey im packed and ready to run

munro1656

Well I have finally found the time to do some work to my zen after the kids, the wife and the car oh and a little bit of work
I read the links that everyone had posted and there was some very helpfull info in them so I put them to practice ( keep in mind I am a amateur at this, a virgin so to speak so go easy on me)
Here is a few pics of my first attemp at mods
it's only rough cut and nothing has been cleaned up yet

glennb2006

It looks like you have everything you need there to proceed, what exhaust and intake timings are you going to aim for? Also, don't forget, as someone touched on, when your engine is done, it will produce power at much higher revs, so, unless you can reduce the inertial loading on the con rod and crankpin you are risking failure, your piston will need to be lightened for reliability.

I will be interested to see how this works out for you.

Glenn

munro1656

Thanks glenn the next step after match porting crankcase to jug was to machine internals of piston to lighten, I had read somewhere that you machine top of piston?? in my thought that wouldn'd that reduce compression?
cheers craig

OLD_SLOW and in the WAY

glennb2006

Larry has posted a picture of a piston done the way he used to mod them, as you can see, far from stock.

The turning down you refer to is done by some on the diameter of the piston to give some relief in the cylinder when running, so will not affect compression.

What timing are you going to aim for on your completed motor Craig?

Glenn