OHV Porting Help Wanted

korndog

korndog

New Member
#1
#1
So, I have this head and a Foredom flex tool with lots of different abrasives i use for restoring old blades. I can get down to mirror finish if needed. Where do I start? I have referenced some protrusions and sharp edges in these photographs and I was hoping some of the guys here could me with a few tips as to what is the best possible outcome for each area. this is a stock head from a Champion Clone. I don'thave the exhaust port shown, so please advise. thanks, KD



 
Oldschool

Oldschool

New Member
#3
#3
Personaly I would find a 14cc head and work that over changing nothing else on the engine ( including governer ). A mildly ported 14cc head and some timing advance makes for a big improvement.

Resuse the Champion rockers, they're good.
 
minidragbike

minidragbike

Supporting Speed Nut!
#4
#4
I agree with Oldschool
A smaller chamber head is best to begin with. And it's hard to do it right on the first few heads no matter what you do. But the good thing is that your gonna increase the flow no matter what over stock.
 
korndog

korndog

New Member
#5
#5
Yeah, this is my first one, so I figured I would use what I have. I suppose if it comes out good, I can mill it down; right? Oh, and as far as the governor Oldschool; well that ship has sailed. The low oil sensor is now part of my 4 year old's engine shop along with that really cool plastic gear. :) I guess I am looking for some specifics as to smoothing and what finish to put on what surface. Do I round out the red and yellow area? What about the lip at the seat (white arrow)? What about the seat itself? Where should I shoot for mirror and where would it be scratch surface.

Since you mentioned those shaft mounted rockers; Are they good??? I have read conflicting posts on that. I was wondering if they are truly the cat's meow and if it's worth building them up for ratio. I know it's been done, cause I read it somewhere.
 
korndog

korndog

New Member
#7
#7
Oldschool said:
Look here does this help?
clone stuff pictures by Dougwp - Photobucket

and here.

4 Cycle Karting Forums - Porting tools
( much better combustion chamber work than I did )

Don;t get crazy keep it simple.

Get as many 14cc heads as you can find and for that matter het as many heads as you can find and practice tinker away. Each head teaches you something
Click to expand...
Good stuff Old. Thanks, very helpful. I have some ideas about polishing that I haven't seen yet. Going to try some special press-on sanding discs I use on straight razors see what happens. Very controllable.
 
Oldschool

Oldschool

New Member
#8
#8
Don't get creative how many heads you have to work with?

I have two 14cc heads I do something to one and try it out then modify the secodn head based on what I learn from the first. I have some 22cc heads I mock up and tinker on but they are not for running

small steps.
 
novaracer

novaracer

New Member
#9
#9
there are some things that i noticed. the exhaust ports i move the short side rad into the bottom of the seatblending up into the floor of the port. the combustion chamber i like to blend the roof of the combustion chamber around the valve seats into the seats and opening up the chamber around the valves as much as bore allows all in the name of flow. airflow is everything. then i have the head milled to get the compression i need. but i could be wrong :doah:
 
gpxsrxracer

gpxsrxracer

New Member
#11
#11
As far as polishing, only polish the exhaust side, dont smooth out the intake side after you port it, leave it a little rough. Exhaust side definately polish that after porting, smooth port helps stop carbon buildup...
 
TT

TT

#13
#13
Korndog,

I heard a lot of good things about you from EE.

If it were me>? I would have Russell from NR- Racing send the head out and use a flow bench to port and polish the 14cc head. He is a master. MDB would also be able to help you get it right. If you want to tinker with a head, you can, personally I would spend the $250.00 + $60.00 and have a work of art.

BTW, Thank you very much for hiring my good stand by buddy EE. He is a great painter and an all around good guy.....:laugh: :no:

TT
 
korndog

korndog

New Member
#14
#14
TT said:
Korndog,
I heard a lot of good things about you from EE.
If it were me>? I would have Russell from NR- Racing send the head out and use a flow bench to port and polish the 14cc head. He is a master. MDB would also be able to help you get it right. If you want to tinker with a head, you can, personally I would spend the $250.00 + $60.00 and have a work of art.
BTW, Thank you very much for hiring my good stand by buddy EE. He is a great painter and an all around good guy.....:laugh: :no:
TT
Click to expand...
Thanks for the tip on NR; I am playing around with it right now and will see where it takes me. But you did give me another idea. Guess it's time to build a flow bench. lol.
 
isaacson06

isaacson06

New Member
#15
#15
i have a 14cc head coming and looking at your pics and other peoples pics why doesnt anyone port out the valve guides like we do in cars?? this is what i plan on doing to mine http://www.cccylinderheads.com/pics/8p.jpg this is what we run in are sfwd 4cly. the only thing i can think of why people dont do it to these heads is cuz the guides are not long enough but i havent got my head to look at yet.
 
korndog

korndog

New Member
#16
#16
isaacson06 said:
i have a 14cc head coming and looking at your pics and other peoples pics why doesnt anyone port out the valve guides like we do in cars?? this is what i plan on doing to mine http://www.cccylinderheads.com/pics/8p.jpg this is what we run in are sfwd 4cly. the only thing i can think of why people dont do it to these heads is cuz the guides are not long enough but i havent got my head to look at yet.
Click to expand...
I've seen the guides on the intake taken down flat and others leave them in photos. That's why I asked about what a splitter is. Seen a post on Bob's discussing leaving the guide protruding slightly with splitter. What does that mean?? I assume is helps combustion in some way.
 
isaacson06

isaacson06

New Member
#17
#17
i assume they mean splitter is makeing the guide split the air ? Why not get that guide out of the way and make more air flow instead of having the guide and the alum around it blocking air flow you would have just a valve stem in the way of flow. does that make since??
 
Oldschool

Oldschool

New Member
#19
#19
You don't know how the head flows stock and your not sure how splitters and what not will effect flow after ( nor do I ).....

Unless someone is going to give you a very specific step by step its all kind of pointless. Concentrate on the knowns. The short radius needs to be fixed the extra metal around the bowls can be cleaned up and the valves have to be unshrouded. No that alone with a timing advance and the improvement is significant.
Experiment later, get a good straight forward improved head working now because you can never put that aluminum back if you screw up ( Expoxy yes but do you want to go that route to fix mistakes now? )
 
minidragbike

minidragbike

Supporting Speed Nut!
#20
#20
Your gonna just have to go for it, or either spend the money and have a pro it. Or try and do it yourself.

This is the way I look at it, what's your HP goal? 10-15hp then do it yourself. Any more than that have a pro do it.
 
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