I am thinking about sending out a set of heads to have them ported, polished and the works. I was wondering who else does nailhead heads besides Gessler? Anyone have experience with or opinions of other companies? I would appreciate all thoughts from my fellow nailhead enthusiasts. I am looking for my best bang for my buck.
Try this archive link for lots of information regarding this subject. A Few years old, so there is question about availability of some of these people (Ed Mosler). However, some of the people listed are still actively porting NH's in addition to Gessler. http://www.v8buick.com/archive/index.php/t-19122.html People on this board (56familycar) post results of flowing NH heads and intakes after performing mods, too. But this points in general direction rather than stepwise DIY info.
I did my own .... I only blended, and smoothed and matched to the intake and exhaust gaskets.... dont try to ''hog out''.... this is the best bang for the buck... works good for a street driver....if you are going to race all out that is a different story.... if you are looking for the absolute last bit of power , then you need to get some pro to do the job with the probes and flow bench and other stuff... but most guys drive on the street and actually dont need the exotic stuff.... Back in the day , porting jobs were done in the back yard garage by some guys that wanted to go faster and so just began experimenting with smoothing up the passage ways and making them bigger.... but with with a nailhead the small relative size of the ports helps the torque and the performance....bigger is not allways better.... but.... any guy with a brain and the guts and the tools, can do a pretty good job of porting for a little money and effort.... the hardest part of doing nailheads is the long runners... you need 6'' long shanked carbide burrs and some small stones... and a good die grinder and yes the dremel tool can be used but when you do a complete set of heads the dremel will be pretty well ragged out.... If you just blend and smooth, then if you decide to, the job can be taken further by a pro.
Mike Lewis, in Fresno, has just finished up a couple of set of heads. He is excellent and reasonably priced. Contact him at 559 285-1185. This no. is his cell phone. Mike
Closest is Mike Lewis in Ca. Next is Mike Atwood @Mondello Tech Center in Tn. Next is Greg in N.J. Farthest away is Steve Magnotti in N. They are all excellent. It takes a lot of time to prepare these heads properly. The faster you want to go the more $$$$$ it costs. The most bang for the $$$$ is bowl work, floor radius & contouring, then port matching. Mostly making sure your intake manifold opening is not larger than the head port or the head port for the exhaust is not larger than the exhaust manifold. They have all gotten much feed back from myself. I can't get all the credit as I just gave them the ideas & they were the ones that rolled with it because they have the equipment nec.
Thanks for the input TT! :TU: When you mention port matching the intake so it is not larger than the head, does this assume the head intake port is opened up for gasket match? Open up the exhaust manifold ports to gasket match? There can be a lot of metal removed in that process.
I looked at a set of heads, manifolds, and gaskets (felpro), and decided i'm wrong. Not much material that could come off heads or manifolds to match the ports to the felpro gaskets. lots of places to smooth casting flaws and blend sharp radii. strange notch cut in the side of each intake valve bowl on wall that separates exhaust bowl. Valve guides hanging down into the intake bowl. looks like a lot of work.
Attached a photo illustrating the amount of material between head intake ports and the felpro gaskets. Not much there. These heads came off of a 425NH engine. The other photo shows the intake bowl area and notch cut in the side of the valve bowl on wall that separates exhaust bowl. Valve guides hanging down into the intake bowl. Does the notch serve an important purpose or can it be blended with the bowl? Can shorter guides be used to free up flow?
You got it..... What i did was to just make the opening on the intake gasket match the gasket,,,,,, but you have to be carefull here because the intake gaskets are directional..... if you swap sides or ends ,either one,there is a possibility of botching it up.... make sure that the little humpy ridge is facing up and the word ''front'' is to the front..... Buick doesnt use gaskets on the exhaust manifolds and that is the best idea, but the exhaust manifold gaskets make a good pattern for port matching the heads and the exhaust manifolds.... but again you have to use your noodle,,,, if you match the heads to a gasket, then use the same gasket facing the same direction for the exhaust manifold, on the same side, so that there is no ''shift''. exhaust manifolds can be improved quite a bit by this tech.... in fact on a street driven car, one can almost match a set of headers by doing this and installing a set of bigger pipes and mufflers....
The head flow data that Eric linked to above is shown on this page: http://www.teambuick.com/reference/head_flow.php There are some comparisons to 455 heads which puts the NH numbers into perspective. I believe the notch below the intake seat is just a result of the machining operation, and not necessarily done to improve flow. As the valve pocket is cut, it just happens to remove part of that bump, leaving a notch. Again, that's my guess. But there is a distinctive bump in the ports between the valves. It looks like it would impede flow, but I don't know if it is safe to remove it. I did a set of heads this summer. My goal was 'near stock', but I couldn't resist doing some work! I just blended the machined valve pockets into the port, trying to leave the bowl relatively stock. I'd call this 'step one'. Next step would be to attack the valve guides....lots of material sticking up to impede flow! Next would be opening up the bowl and raduising the short turn on the intake port. It gets tricky at this stage, as some areas are thin (water passages). And if contours aren't done properly, you could hurt flow. I'm just an amateur without a flow bench, so I can't say what helps and what hurts.... I use my finger and my eyes as a flow test to judge whether there is a smooth transition from port to valve opening. Exhaust ports confuse me.... A small valve dumps into a larger diameter bowl. It looks to me like some of the bowl should be filled to direct the gas toward the port exit? Not to be confused with filling those exhaust heat passages that lead to the intake manifold. Those can be filled with aluminum to make the exhaust port function strictly as an exhaust port. There is a description of the different levels of porting on www.gesslerheadporting.com Wish I had a flow bench.....
You could talk to Shawn Willis of Britco Machine in Centralia (I think he is still there). While he isn't a nailhead expert he is a very experienced porter and pulled some good numbers out of my Stage 2 TA's way back when they were still a fairly new commodity. Unless you are looking for a max-effort all-out porting job, I think he could deliver you an improvement with a good bang for the buck; take your heads there and ask what he thinks he can do. He likes wierd stuff and I think will be very honest in answering any questions you have.
Walt, you have described to a T what I have done to my nail head heads.... like I said ,porting can be taken to a certain stage and if one wants to take them further for that last little bit, it can be done..... and then there are those like myself who are doing this on a budget and has to cut cost any where they can.... so I do my own and,,,,, so far the results have been good.....
Thanks Tom. I'll be watching this thread for mucho pics. Post em up boys!!! I will be doing my own head work on my 401 heads. Bowls seem to be very important and alot of smoothing in general. Port matching goes without even saying.:TU:
That is me too! Thanks for taking the time to describe what you have done, techniques that seem to work, and other areas that are still confusing. i've wanted to port my heads for a long time, but hindered by the lack of knowledge. The guys who know the secrets deserve to be paid for the effort they have put in to figuring out how to flow NH's. Plus the fact that NH's are a small, specialized market. Unfortunately, my budget does not allow for shipping heads half way across the country and $$$$ involved in the work. I realize expectations need to come down on DIY vs. Pro porting, but that is ok with me. looks like a fun project!
I for one would be ever grateful if some one would post a picture by picture tutorial (even a youtube video) on what to hit with the dremel and what to leave alone. Of course on NH heads. :TU:
I did my own set with a little advice from some guy who knows a bit more than I:laugh: . I would say they are more like a stage II version. I don't have a flowbench either, but can say that they made a big difference in how the car runs. No actual times, but pulls much better through the higher rpm range, then I installed a set of Telesco rockers and gained a bit more. I would guess the two changes are good for an honest 35-40hp.:3gears: Not bad for a set of rockers and a couple days work.:Brow: I had posted some pics under the "nailhead project pics" thread a couple years ago. I can't figure out how to link it though, check #12.
Here is a picture as I start a home porting project. Lots left to do. Hope we get more pictures. More to come later<a href="http://s166.photobucket.com/albums/u91/66gsconv/?action=view¤t=newintake003.jpg" target="_blank"><img src="http://i166.photobucket.com/albums/u91/66gsconv/newintake003.jpg" border="0" alt="Photobucket"></a>
On any head, the short-turn radius is the key to making or ruining a port. I learned not to screw with the short-turn during a home port unless you are advised by someone who knows what to do. Messing with the short turn without a flow-bench is a bit like shooting in the dark. You have just as much chance of doing harm as doing good. Just blend the bowls, valve guides, match the ports, and clean up any casting flash. Some generous porters will port one and let you do the work on the other 7 cylinders if you are ambitious and good at copying the 3-D work. It can be difficult to understand the subtle diffences in the work unless the porter explains it, or if you just have a good eye.
