Those in the Yahoo Nailhead group will recall 'Rotted Honda's' experimental cylinder heads. He milled off the intake manifold flange to use a custom intake manifold with a straight shot into the valve bowl area. Too bad this idea wasn't pursued. Anyway, the heads are now on eBay: http://cgi.ebay.com/ebaymotors/ws/e...=33617&sspagename=WDVW&item=140263500400&rd=1
The idea was to take the 'S' curve out of the stock setup by cutting off the flange and fabbing a new intake. Like this:
Yeah Walt, too bad he left the group. He had some ideas that I feed him & he went with it. He seemed to have the capabilities to perform some of this work. Too bad he got too heavily involved in other topics. I feel many would have had a thing or two to learn from him & the ideas I was feeding him. I just don't have the time to play like I would like. It's called, family, home, business, etc. I'm not independently wealthy, so I DO have to work to provide just like most of us. I really wish I was able to get a phone number & converse some with him. If I remember correctly he was also from PA. Where I don't know.
He's in the Scranton, Pa area. It would be great to see someone pursue the idea. If it worked, it would shake up the Nailhead world. Makes me wish I had a flow bench. (and unlimited funds so I wouldn't have to work a regular job everyday!!)
This begs the question (and I'm sure I'm, not the first to ask): how much of the nail's ports were by design, and how much was a compromise due to other design choices (like fitting things underhood)? If we consider that Buick engineers were after Low RPM torque above all else, then how much of those S curves are intentional for tuning runner length? How precisely tuned are the lengths of those runners? Without increasing valve size considerably I bet this mod without a very scientific (helmholtz tuned) new manifold design drops 30 foot pounds of torque across the power band. Look at a conventional factory 60's big block most of them breath way better than a Nail with conventional intake ports but some of them aren't even making nail head torque with 50 extra cubic inches!
as our esteemed member Tom Telesco has told me time and time again; "A fully ported set of nailhead heads could barely support a full-blown 322ci nail, much less a 401 or 425 ci setup... You cannot over-port these heads..." through flow bench testing, he has proven that it is actually the intake side that is the biggest bottleneck in these heads.. food for thought:beer
If I am not mistaken, Max Blachowsky ran heads set up this way in his Ol' Yeller race cars. He is the man reponsible for building TV Tommy Ivos, Tony Nancy's and several other Nailhead engines in the late fifties and early sixties. He had gone as far as having his own aluminium heads cast and machined. It is said that he routinely spun his engines to nearly 7,000rpm on the roadcourses. I have a set of AlGon injection for Nailheads which help reduce the first bend where the intake mates to the heads as the ports are coser to the same angle as the ports on the heads. They are far from as direct of a shot as these heads are though.
I am far from the kind of guy who thinks the factory can do no wrong, but look at the power output of the Nail. They clearly designed that thing to pull stumps off idle, those runners are like that for a reason, and its not because Buick Engineers didn't know that a straight short intake port makes more HP than a long curvy one If you want to turn a Nail into a SBC it would be a hell of a lot cheaper to start with a SBC... I'm just sayin'
Well, this was Buicks first V-8 engine designed in the late 40's/early 50's....it's not like anybody had much experience in designing max-performance engines. The designer probably used a slide-rule to calculate port size, length, and flow velocity for the 322 cubic inches. I do wonder why they did put the manifold flange where they did...my guess it was it was just to reduce the amount of machining...machine the valve cover surface and intake flange in one step, instead of two. The new intake could be designed as a dual-plane with longer runners for better low-end response, not necessarily a short-runner design like in the pic. To determine if this idea is worth pursuing, would take someone with the time and resources to test it.
Well then where is Marty's (EELCO) single 4bbl intake????? It was supposedly done. o No: He had the single shot / single plane intake going out to 50 customers 3 months ago. Any word on these. I am sure the design will answer a lot of the questions posed already.
That certainly wouldn't have been my first guess. Since I don't own a flow bench, I'm not going to dispute this--but--I'll say that it doesn't make a lot of "intuitive" sense to me. I saw those heads on eBay yesterday; I figured the guy who did that was a total hack, and once he figured out how restrictive the exhaust valve 'n' port were, he decided to back out. But what do I know?
Yup,,Shurkey, right on, if i was going to do more to my heads than I have already done, [hillbilly porting job] then I would have worked on the exhaust side of it.....not the intake side.....
Well, the exhaust gets pushed out by the piston, so it doesn't have much choice...it's gotta go! Figure 150 lbs force at the peak. The intake charge just gets pushed in by atmospheric pressure....maybe 10 lbs. The seller was a pretty sharp guy that knew theory, not just a hack with a hacksaw!
Guys, This was kicked around on the Yahoo Nailhead group this past summer. Someone on that list said that this intake flange milling had been done back in the 60's, nothing new here! I'm with Shurkey on the exhaust ports being the bottle-neck on the Nailhead. As far as the exhaust being pushed out at 150 PSI, that is not exactly the case as pressure won't build if the exhaust valves are open! I was told to look at a cylinder head port, especially exhaust, as a bath tub drain, the smaller the drain, the longer it will take to empty. Put in a big drain, it drains more volume and drains it faster. There are even some pictures of early Nailhead dragsters running reversed ports, where a GMC blower is plumbed to the exhaust ports and the intake ports are used as exhaust. Got to be something to the theory that the exhaust ports are the weak link to making lots of power. All that being said, I'm very happy with the way my 401's perform! :3gears: My 2 cents! Tim
well, i lost the auction.. some sumb!tch got them anyway, As far as the exhaust vs. intake restriction; I was only repeating what Tom Telesco had told me. He had said that in the flow bench work he did, he found that the intakes were more restrictive and less responsive to portingo No:
