Re: Porting Your Own Heads(comments Only)

[crazypj22]

Ratledge,
you may need to get the small carbide cutters,1/8th shank quarter inch head, ' rounded tree' shape' about $7.00 each. Dremel doesnt have a lot of torque. you can knock off the bigger bumps and then get the sanding rolls to smooth everything out. Harbour Freight had a Makita electric die grinder on offer a couple of weeks ago, about $40.00 I think, dont know the quality but should be ok for a head or two
This may not be the best or 'correct' place to put this information but it sort of ties in
The major expense seems to be in the cutters, cheapest place I've found is ENCO. (www.use-enco.com , at least I think thats right) Both companies list a flexi shaft/remote motor set up with foot speed controller. With a larger machine you get a quarter inch collet so you can make your own polishing/flap wheels out of a 5" or 6"piece of quarter inch rod, just put a slit lengthways with a hacksaw and wrap some emery strip around bar. (you can buy them ready made for about $30.00, but they are hardened and precision made)
I'd just like to say I have no afilliation with Harbour Freight or ENCO, I have found them cheap and cheerful though, gets the job done, and while I'm at it I may as well recommend Victor Machinery Exchange in New York, they have taps and dies in all sorts of 'odd' sizes, (largest selection of metric I've seen outside of Britain) plus a bunch of other difficult to find stuff .
PJ

[cswamp1]

Hello to all;The porting section is well done and shows a lot of thought-you should be proud of it.Some extras I'd like to share might add to it.This is stuff I've been doing on heads since about 1971 with success.DON"T drive out the guides(I know thats what it taught)Tap the guide with any thread that suits you,install a scrap bolt in the guide.Use a long punch or steel bolt to drive from the combustion chamber side on the bolt.This draws the guide out - no mushrooming,galling,or loss of alum supporting the guide.If possible heat head(not a must do)it makes it easier.I've always had good results with bronze guides,but these next steps seem to do it best.Heat the head to 350 in the oven 1 hr.;Lube the guides and freeze(check sizes first-.003+)Use a guide tool that fits in guide 1.5 in.or so and is larger faced than guide.Quickly and smoothly drive in guide,let it find it's way,even strokes should not stop or distort.Most times 1 or 2 turns of a tapered reamer cleans the top burr out and your done.Most times this doesn't shift valve seats & alignment hardly at all.If your wife hates dead dinosaur smell (all do,don't they);You can find a counter top 110v oven with burners at any mobile home salvage-runs on a wall socket or extension cord.Mine cost me $ 15.00 Hope this helps some of you

[cswamp1]

To Jack;Could you share your method of superflow cipherin'-my 110 max flow rate is 185CFM(all it can flow) wide open-My stock head maxed out at 92.2CFM on the intake at .486 lift-a"street" port-job(4 hrs;6-7 beers on a sunday afternoon) yeilded 99.5CFM at same lift.My old pro Kawasaki head only pulled 112CFM(don't even want to remember how long it was worked on).I'm not unhappy with the apx.10% gain,(bout same as yours)I just can't figure your figures compared to mine.I used factory test data sheet/procedures in superflow handbook ;looks like same unit-Superflow 110-highest scale-185CFM tested at 10in.per valve size directions.Any thoughts??

[50gary]

This post is from <Jack>, but posted by me <50gary>

Tell Tom,I guess that's is name that that our modified was pulled on a 4 inch fixture cuz there's was'nt a 3 inch available at the time and this incease area of volumn always increases the cfms due to drastically unshrouding the valve in relation to the cylinder wall. Sounds to me like your bench racing flow benches here and you of all people should know that when working on heads, the objective is your looking for a comparitive gain or loss from the base stock head. For me to speculate as to why my head out flowed yours is like wanting to see a big fly but I assure you that the exhaust valve was in place during the flow testing(Smile) and my port work was nothing out of the ordinary compaired
to your port work. All I did was work the roof,turned down the guide it's self to reduce the overall diameter,opened pocket to within 85% of the
intake valve size , worked the shortside but most important opened the spigot area to within 36mm and last but least,the valve seat prep work. The seat work is Bobby's speacialty which picked up the CFMs, look at the 100 lift, very impressive(Smile)

Bobby has been doing porting and designing cylinder heads for some 25 plus years and is a true magician when it comes to unleshing
the CFMs on any head and he uses the 110 for all of them and the heads go from stock right up to pro stock heads so you might wanna start looking at your pressure drops and use the conversions for the amount inches of water that was pulled to calulate the correct CFMs. Again
I'm not a flow bench expert and you know the old saying A flow bench is a measuring instrument and is only as good as the operator using
it and I don't mean this in a disrespectful way either. You may not of have the machined calibrated correctly,there might of been some air
leakage around the fixture, air quality and temperture might of been a facture in your low readings,I just don't know................Jack

Gary if you would please post this and let him know why I've asked you to relay this message.......A Friend Always..........Jack

[cswamp1]

No harm to you or Bobby intended;not trying to race(no point-no gain)You're #s are consistent,stk to mod, in so far as changes in %s of increase,etc. with mine.I just have no idea what method you use to get calculated flow rates in excess of the machines physical limits-it only pumps 185 CFM max air even with nothing on it;and all stoppers out-my 110 manuel has no method for it-they adjust the test pressures to stay with-in machine's scales-thought you could teach me something I'd not seen done-Thanks for the reply.

[cswamp1]

Jack-there's always more than one(right) way-do what feels good to you-mine works for me every time.The heat is no threat to the head/seats I've used higher ones with oversizes-no problem.The hotter they get the easier it slides in,been doing it this way for a living off & on since about 1972-never lost a head or a seat.I do the same for over size sleeve installs but I support the cly block and place a weigth flat across the top while they cool-no warp-minimum surfacing.Enjoy

[cswamp1]

.To those interested;If you wish to try porting,but not commit big bucks consider this approach.You need an air compressor anyway-get one.It should support air tool use-one of them should be a die grinder/cut-off wheel type(H.F.-$ 20-30)-Has endless uses wether you port much or not.Invest in 1 6-8 inch carbide cutter in the shape of a candle's flame w/diamond cut pattern(this gives you a flat,curve & pointed cutter all in one depends how you hold it)and 1 6-8 '' sanding roll mandrel ;a handful of 1/2 " sanding rolls 36,80,120,& 600.This combo used carefully does all you need;if you hate porting and quit-you'll use these regularly in other ways & haven't lost anything.A pair off screwdrivers with equal length handles inserted in stud passages can serve as a head stand easily.When cutting aluminum at high speed this way-lube is your freind.I dip the cutter in a can of cooking grease(Crisco) constantly;if cutting edges load with metal-wire brush off and dip more frequently-cool tools work best.I have cutters used this way that are still sharp after 20-25 years.Hope this helps some of you-Enjoy-Tom

[crazypj22]

Hi Tom, ;D
Jack, this is not to detract from anything you or Bobby has done, its an awsome job, great pictures and excellent write up, I wish I could do half as much.
Tom,I had some thoughts about your question on how a Superflow 110 could be flowing over 200 cfm when its max flow is only 185cfm
All the car sites I looked at, and the build your own flowbench sites use 20" plus of water pressure ( some up to 48"+ )
Could the readings be extrapolated from the 110 flowbench?
i.e. the actual reading is about half of the given reading. That would put things in line with Tom's experiments (Bobby's 209cfm, if halved is still about 105cfm@10" water. Thats pretty damn awesome, I only got 98cfm@8" on a new YZF250, and that has 3 intake valves ) This doesnt take into account any correction factors, but, is it a reasonable assumption?
People are used to seeing high flow numbers on automotive heads and it may be an automatic function.
For example,
I was a precision machinist, ( 6micron tolerance) and automatically halved any cut on bars or bores as the diameter will be reduced (or increased) by double the amount of cut. When I started using Boremaster boring bar I was only cutting half of what I thought would happen. The Boremaster micrometer is direct reading, it measures the bore size not cut size. Took a couple of bores to get it right. (wasnt a big deal as everything is undersize, just takes a bit longer)
Hope this makes some sense?
All for now,
PJ

[cswamp1]

So,you skipped the the L/D ratios & correction factors,ran them at straight intervals-used 10 inches for both intake/exhaust and multiplied all readings by 1.67 for some reason to simulate 28 in. water, if I read you correctly.Yes/no

[cswamp1]

I've got the info,just couldn't tell if y'all did since you pick/chose what you use of it.The conversions help judge carb sizes on cars since they are "flowed" at such rates(2bbl & 4 bbl use different standards for instance)Sorry to aggravate you,was just first I heard motorcycle data reported that way when straight input is what is usually given(or bragged about) in this industry.It's hard enough to compare gains when on the same scales so we don't factor them-I'll assume you used 10 in. play with the # s and make myself happy.This wasn't meant as a problem only a curiosity;I'll hush.

[JeffB]

I just wanted to say thanks to Jack for the great info in his porting posts. I just finished mine and I am very pleased with the results. I did not embark on this with any specific goal in mind except to clean things up a bit and remove the casting flaws where I could. Your inpiration was exactly what I needed to just get on with it.
All in all it wasn't all that difficult, spent more time trying to figure out a tool to get into all those tight places. I concentrated on the exhaust for the most part where most of the flaws were. I think getting rid of those nasty "shoulders" just at the entrance should make a big difference. It's hard to image the factory not taking care of those right off the bat, they did do some grinding in there (pretty crude) but left these towers. Anyway I ended up using a formed wooden mandrel with a narrow slot at the end attached to a rotary tool with a flex shaft. I wrapped progressivly finer emery cloth ending up at 600 grit. Changed the cloth often and took my time. 600 really brings up the shine so I hope the carbon will have more trouble clinging to it in future. On the intake I did my best to smooth out the exit area under the valve (more crude factory grinding) and enlarged the entrance just inside the flange to remove the second "venturi" (not the actual flange hole diameter since it's a perfect fit to my carb boots already). This narrowed spot is clearly not intentional since it was irregular and different from one side to the other. So now the intake bore is more or less uniform from the carb all the way to where the port begins to expand under the valve. I used 30 grid on a sanding drum at the intake.
I managed to avoid nicking the valve seats on all the ports .

[JeffB]

Hey Jack thanks for the detailed reply. I am still running stock head pipes so I won't be attempting an insert yet. I tried to take some pics tonight but they all came out blurry, I'll need some practice with the wife's camera or maybe I should consult the manual on how to take macro photographs . When you said the port in your photo flowed like crap I thought to myself shioot, mine don't look any better shape wise, so now I'm thinking oops what have I done. When you said the shape of that port flowed terrible, did you mean worse that untouched stock?

[Hammerin]

;D When porting or cutting Aluminium I use the proper oil for the job. I also use a Fordum and at times I use a dremel. Ocational dripping the oil onto the surface being cut or reshapped is messy but really works.

Guess I'm gonna try Crisco though. ;D

[71XS1B]

Hey Jack,

Your posts on “Porting for XStreme Power” are terrific. It is so well documented and described that it gave me the confidence to give it a shot. I picked up a spare head on Ebay and spent yesterday afternoon dismantling, cleaning and inspecting. There are casting flaws everywhere on this head, inside and out! I found that the cast iron cap protrudes above the short side radius on both intakes. One side is worse than the other. Do I grind the cap down to meet the aluminum surface?

[71XS1B]

Not a problem Jack and thanks for the very kind offer, its certainly not too late. To be honest, I haven't gone any further with this. This is a long term project, and just something I tinker with to keep me out of trouble. I've got other things going on with this project and right now I'm modifying a Suzuki GS1100 swingarm for fitment. I still need to pick up some of the tools you recommended in your posts. McMaster Carr has them.

The right intake port is the worst, with the skull cap protrusion starting at the outboard side of the SS radius and continuing around the inboard side to the top of the port. The worst part is in the middle of the turn. I haven't actually measured the protrusion but it feels as though it could be sticking out there in the flow as much as 3/32" to 1/8" at the very bottom center of the port.

I'm sitting out here in the middle of the Pacific, and postage back and forth can be hellish! In fact the postage to get the head here the first time was more than the head itself. Any chance you may want to post the techniques for welding up the port?

Cheers,
Dan