Head porting...

[kliff]

How many of you guys have ever used a ported head, or even better a ported head with a port matched intake?
The results on a GY6 are astounding, add an A-9 cam, and you'll think you strapped on an extra 100cc. It isn't really hard, but it can be time consuming, and having all the right bits and burs for getting inside tose tiny ports can be a real bear, but if you haven't tried it...you should!

Bolting on parts, BBK, cams, exhaust, ignition...all work, we know that, but what is really missing is the smooth delivery of that fuel/air mixture to the combustion chamber, and the unrestricted removal of the exhaust...

[Lyonsperf]

That was the first thing I did when I got my Gy6. Port matching and porting the head are free ways to increase power. I also swirl polished the valves as well as back cut them for better flow. All hot rod tricks we use when building race engines.
Its important to remember to have a free flowing exhaust to take the advantage of the extra flow. Having a larger exhaust pipe vs the exhaust port opening helps to prevent reversion of the exhaust gases.

[kliff]

Yup, there are a lot of tricks, I've even made press in steel sleeves, to reomve that terrible "step" in the exhaust port...

then fab up header stubs of the internal size I want, and port match them, before continuing with the complete header...



I also do my own head milling...


And sometimes you come across a project where a certain tool would be most helpful, an electric hack saw, fow exaple...clamp everything down, turn it on, and walk away....slow, but it can cut quite a lot of steel all at once, without an attendant, like a band saw....so when in need...build it...


LOL...I love to tinker, and if I ain't modifying engines or parts of engines, sometimes I have to build the tools to do the job I invisualize...

[metalstudman1]

SWEET!!!! How much time and $'s is invloved? Man you've got skills & some tools!!!!
Glad to see you're up and running in the buggy world again- you always have such informative tid-bits for us to improve our toys with.

[kliff]

Thanks Metal! It ain't something I'll ever get rich at, but a basic P&P job on someone's head is 40.00 labor + parts and shipping. That includes polishing the valve faces, and tulip grinding, with a swirl polish on the back face of the valves while reducing the stem diameter slightly. Also, if they send me an intake manifold, I'll port match it too.(same price) Actual time involved to do all this, is about 12 hours....so you can see, I'll NEVER get rich, it just gives me something to do, and the labor helps pay for the expendables I use. polishing burs, and pads, that sort of thing.

Or the Big Tamale, with new titanium valve springs, a new exhaust valve, new intake manifold (all supplied by me), and all the P&P, valve mods, and return shipping for $100.00. Turn around time is usually 2-3 days on my end, and I return ship USPS Priority flat rate. So, if you're in the lower 48, about 1 week to 10 days, depending on where you are.

I really recommend a new exhaust valve, as a bare minimum, as these things take on heck of a beating, and every "dropped" valve I've ever seen has been an exhaust valve. So why play with dynamite, the engine is down, we're gonna do some high performance work to the head, why not go the distance with a few bucks more, and try to prevent that catastrophic failure that can ruin an entire engine. That's the same reason I like to replace the valve springs. A broken spring at best can ruin your day out, but may not cost you an entire engine, but worst case scenario....it can lead to a dropped or bent valve, destroyed piston, and even a bent connecting rod.
If you're gonna do it, budget for the Big Tamale, and do it right. Let your engine breathe, and give it a chance to live at some high RPMs too.

PS....this is a BuggyMaster exclusive too. I don't make this offer on any other sites, nor do I discuss it on any other sites. This is for BM people.

[Superman]

Flat out amazing Kliff! Oh I will definitely be talking to you about having this done either later this year or early next year. Our wedding is in September so that has priority on funding

[kliff]

No problem Super, I ain't going anywhere...I'll be here when you're ready.

[Superman]

Originally Posted by kliff

No problem Super, I ain't going anywhere...I'll be here when you're ready.

Sweet man! I'll PM you my contact info and if I could get your I'll keep it on file for then!

I'm trying to get my fiancee' into the mini buggy scene. I just found a friend of a friend up here in CT who has a 250cc Roketa and 8 acres and a neighbor with 300 acres who lets him ride on that as well. I also intend to ship 1 for sure and most likely 2 (if my Dad will sell one) up here early next year for us to start riding together if she's into it. Shipping both would only cost me $432.00

My other buddy up here lives on 1 1/2 acres but his homeowners association has 75 acres for trail riding that they are allowed to use. Pumped! Too bad my schedule is going to be busy as hell next year.

[metalstudman1]

Is this type work limited to the GY6 engines? As funding allows I'll want to rebuild my 200's and treat them to P&P. Wish I had a mill or a lathe!! I end up making stuff without the right machinery- I'll definitely get you to do the work- Thanx for the resource.

[kliff]

The 200's won't be a problem labor wise, I may need help locating some of the smaller stuff like valve stem seals, & valves, but with all the info, make model, etc, we should be able to find everything we need. Time may be a little longer on the first of any head, as, if I need to mill the surface, I may have to fabricate the appropriate fixtures to hold it down etc. No charge for any of that, I just add any fixture or tool I fab up, to my collection for future jobs.

Like I said, it's just something to stay busy with...

[metalstudman1]

I'd be buying a re-manufactured head- I'd just want the P&P really or if you see something that needs attention.Another issue- I've had one intake manifold made solid and I'm going to have 2 more made as the factory ones are rubber coated aluminum(2-pieces not connected except by the rubber) and the bouncing from the lack of a factory airbox causes them to crack pretty fast- those I'd like to get P&P'd & properly matched bore as well- Is that a possibilty?

[kliff]

Originally Posted by metalstudman1

I'd be buying a re-manufactured head- I'd just want the P&P really or if you see something that needs attention.Another issue- I've had one intake manifold made solid and I'm going to have 2 more made as the factory ones are rubber coated aluminum(2-pieces not connected except by the rubber) and the bouncing from the lack of a factory airbox causes them to crack pretty fast- those I'd like to get P&P'd & properly matched bore as well- Is that a possibilty?

No problemo.

[roysheepdog]

klif I p and p the head and intake,and mached the gasket got it all the same size and when I drove it the thing was so rich it smoked black.Went from a 135 jet witch was fine before to a 125.Now its runs better and smoother and faster.
The gasket was about half the size of the hole?!
Have you seen that before?I would have thought it would need a bigger jet not smaller.

[kliff]

Originally Posted by roysheepdog

klif I p and p the head and intake,and mached the gasket got it all the same size and when I drove it the thing was so rich it smoked black.Went from a 135 jet witch was fine before to a 125.Now its runs better and smoother and faster.
The gasket was about half the size of the hole?!
Have you seen that before?I would have thought it would need a bigger jet not smaller.

It happens, not always, but the port work can make everything else so much more efficient, the smaller jet works better. It's usually about 1 outta 5 that happens with though, and a simple change in the pipe, air filter, or anything else on the intake or exhaust tract, could throw you right back up to a larger jet. usually we have to run sorta fat, because the head is so inefficient, as is, that is the only way to make power. A P&P job just brings it all together.

[chuckorlando]

P&P aint as easy as Kliff makes it sound. hahahahaha. To a guy who can port, it's simple as can be. I read an artical from one of the top head porters in nascar and he said for the first 5yrs he actualy made some engines slower. Now any one can clean up a head and make it flow better. But dyno numbers dont lie. I can send any one on this site one of my cylinders from my stroked 400 and you wont pull 70hp out of it like ritter or hpd can. They have hours and hours and hours on the same tyoe cylinder, to flow bench, and back to the lab. Then add a stroker or a bb kit, the squesh needs readjusted so back to the lab back to the bench back to the lab. There are machine shops and engine builders and then there are race winning builders

So before you undertake porting on your own, you might do a little research on how to flow a head. To much os just as bad or worse than to little. So a guy who's done a few engines should always out flow a guy with some long shank bits.

Most gains are found in places you cant reach, so have the right tools

[chuckorlando]

I mixed heads and ports far as squesh goes. But same on the ports. A stroked, piped 400 has a unique powerband and a unique porting to match. A race port aint a trail port aint a drag port

[roysheepdog]

Chuck how much hp are you getting out of that 400,and how much $$$$$ did it cost?If you dont mind me asking.

[chuckorlando]

I should be right at 70hp and right at 2k. But for 2k every single part is brand new. New 5mm stroker crank, new counterbalance, all new bearings, all new seals, trail ports adjusted for the crank, HPD billet head milled for the stroker(unfortunatly I have to run 50/50 108 race fuel), Girdle for the cylinder, case saver, machine carb to make it as big as god will allow(2+hp in a 40-42mm carb still on the table over the 2hp from a bored stocker35.5mm), v force 2 reeds, and trail pipe. And I had ritter put the bottom end together and send a new piston, rings, and gaskets and included a fresh bore.

Now I leave cheap power on the table as well. I can have my flywheel machined which will allow the engine to spool faster an is said to be as much gain as ports. Thats 60 bucks. Then the bigger carb as well. If a guy wanted a basic trail mod engine, basicly my engine minus a stroker, and is willing to split the case, clean it, and rebuild it, you can get 55-65hp for 1000-1500

Ports+250-300, head machined= 60, girdle = 150, rebuilt crank = 150, rebuilt counter=60, bored carb = 60, pipe = 300, case save = 60, bearings for the bottom with gaskets bout 200.

Basicly the 400 power levels are as follows... Stock engine 35hp. Trail mod is 55-65hp. Race engine is 75-85hp, drag engine is 85-95hp and a powermax or aaen with the sled reed cage welded on is in the 125hp range.

WELCOME TO THE WORLD OF THE 2 STROKE

[kliff]

2 stroke and 4 stroke porting are like apples and oranges, 2 entirely different animals. My 2 stroke porting experience is so limitted, and never resulted in any earth shatterring performance increase, that I wouldn't even consider doing it for myself. If I do a polaris swap, sometime in the future, and decide to have some performance porting done, it will definitely be done by an established shop, with a known Polaris background. The actual tear down and rebuild, would present no problem, but the porting....well like I said.

4 stroke porting, on the other hand, possibly I do make it sound too simple, started doing it, 40 odd years back, and never have been too far away from it for any great amount of time. When picking up a new head, that I've never done before, there are certain things I know to look for, several variables that have proven themselves to work, time and again. And while I no longer have my flow bench, to measure results, and show print outs, I've not yet had a head in the last 10 years or so, that the ole "seat of the pants, dyno, couldn't feel an improvement in. I wish I could have said that when I first started off, cause I, like many before me, paid my dues with some heads that were worse than they started off...all part of learning. Glad that is 40 years behind me now...LOL

[roysheepdog]

Wow chuck thats work and cash for a 400,but 70 hp is not bad.

For p&p I dident find it very hard at all.That being said I dident do as much as kliff is talking about,but it was still worth the time.If you know all the tricks it will be another motor when done.

[chuckorlando]

Yea I'm that dude. hahahaha. If I dont think the engine is worth the money I just scrap it. Like the 250's. Simply not enough gain for my cash.

I dont think portings hard to do. It's the optomizing thats hard to do. My point is that if a random guy grabs a head and tries to port it, I would bet money that Kliff's will out perform it.

Theres alot of guys who build polaris 400 engines. Or 2 strokes period. But a guy who specializes in that engine, will always be better. He knows right where to grind and just what to remove for every situation

[kliff]

Valve springs, Ex valves, stem seals, intake manifolds(stock) are all here now, in stock, so there won't be waiting for parts on the GY6 150cc heads. Who's gonna be first? Hmmmmmmmm....

[chuckorlando]

Ya'll better jump on it.

[trailsntails]

Would like to get this done. What kind of speed increase would I get?

[jmansracerocket]

Where has kliff been ?

[chuckorlando]

I been wondering the same thing. Hope all is well

[bear]

Hey kliff u still offering ur big tamale p&p? on heads

[mb1134]

I have a stock head i am sorta interested in having a port and polishing done too. I bought Toms big valve head, but was wanting a ported head. Let me know. Maybe i can squeeze more power out of this stock head than i can the big valve?