Discussion in ''Da Nailhead' started by Bigpig455, Feb 9, 2019.
Very interesting .
Is there much difference ( HP gains )
in the " D " port heads
What converter are you running? I would suggest something completely different for a cam. Camcraft is ok, but their grinds are from the dark ages. I have my owns cams cut to my specs. Results have been a good so far. What rings size are on the pistons cut for? Also, headers or manifolds?
it's a very mild cam to mimic somewhat stock specs 218/222/110 - They may be old grinds, but they did offer a better "hydraulic intensity" than the TA-25, if you buy into that as a measure of success. I'm not married to it, but on the deslktop dyno it looks like a step in the right direction compared to a bunch of others. We can debate this till the cows come home but there will be full disclosure! PM me with how you'd spec a pure stock cam!
I'm running a stock 12" SP converter, reworked by some diesel place in the midwest. It's a great converter but somewhat tight at maybe 2800 high stall? It's well matched to the chassis anyway, or at least it was with the old motor.
The bore is 4.23, so I'm running standard Ford 427 rings- 1/16, 1/16. 1/8. Also running manifolds, although I do have a set of brand new GSCA headers up in the attic for down the road...No stroke work, standard rods and a pin height of 1.954. I screwed that up a little, I should have gone 1.958 (like Tommy originally had it) and committed to the composite head gaskets. We're measuring deck clearance today, but it should be at .010.
Bill - These power in these heads will come from the valve job, although they flow well there was (what I'm gonna call) minimum port work - I'm trying to be transparent for the Pure Stock tech guys..
More to come...
Got it, that paints a clearer picture. DM me your phone #, will call you to discuss camming. I could type it, but my fingers will be bleeding after, lol.
I spent LOTS of time on Decktop Dyno! Had great results with the Comp cams, but using the next larger exhaust lobe. For example, taking their 218/224-110 cam and increasing the exhaust for a 218/230-110. It increases the power without hurting the low end. Joe used a cam like this in one of his builds. Been wanting to swap out the Isky 244/244-108 that's been in my blue 66 for a few decades for something more streetable.
Rhett, what are you using for Main bearings? There isn't much new out there except for Rebulders Choice and the occasionally in stock Sealed Powers.
Carmen isn't selling cams anymore. I have the cam card and cam doctor info from one of his grinds that I want to use. Is that all I need to get a camshaft ground?
The cam card gives info at certain points. The profile between those points will vary depending on whether it's a fast-ramp design or stock slower-ramp. The cam doctor info may have more data points to get you closer to his actual cam. Is this the W-30 cam? Comp has those lobe designs avail. They can grind them on a Buick core.
Hoping to hear what Dual Quad has available for cam designs.....
I'll post more soon, but the short version is a substantial amount of exhaust duration is needed to make these motors run, as Wkill mentioned. The cam designs for the last 50 years don't even come close to addressing the problems. It's just same rehashed bs with no thought put behind it.
the only thing dark ages about camcraft cams is charlie the owner lol. this guy has great knowledge and spent thousands of dollars on his CNC machine. he has profiles with faster ramps then comp cams. but for the nailhead using hydraulic cams he tones them down a might. there is a lot going on with the nailhead valve train. if you want real fast ramp go with solid lifter cam. i had no less then 8 different cams. 6 were hydraulic and 2 solids. soilds is all i would run now. even had a ta-cam that schinder grinds for them [talk about dark ages] that russ martin ordered for the guy, it came with a car i bought.
your right with modern cam designs, but not with old school thinking [just like i was thinking on my first nailheads] about wide spreads on intake and exhaust. the only thing the extra exhaust duration dos is keep peak HP up a few extra 100 rpms past peak HP. it also makes the engine run hotter, less bottom end, less vacuum and contamination of the air fuel mixture. like the owner of isky racing cams said if you need more top end with more exhaust duration your intake duration is too small. lol
The Packard 352 has little to no support. Alot of parts are used from ford.
Joe, I do not agree with a lot of that, but camming is more about testing, opinion and results. I am in the "exhaust flow does not matter" camp and that I do believe that naturally, an IC engine wants to have a straight pattern cam to achieve peak power, but that is in a theoretical world with ideal intake/exhaust ratio, etc. Reality is way different with a lot of factors that go into the mix. I try to look at the overall picture and build my combo from there. As far as what Isky said, that applies to the theoretical world I mentioned. Real world example, I run a 215/231 118lsa .630/.645 cam in my daily driver SS. Doesn't run hot, makes ridiculous torque throughout the powerband, and idles at 650rpm.
Edit: To make this more confusing, the last 383 SBC I built which made 495fhp in the car w/ low rise Brodix HVH dual plane and Brodix RR200 heads I ran a Comp HR 224/224 110lsa .525/.525 straight pattern cam. Why? Intake/exhaust radio's were near perfect and the car had a beautiful long tube side exit exhaust. I even think running a reverse split with touch more intake lift-dur would have been even better. It's all about the combo.
I love you guys!
i was talking nailhead cams here, only know nailheads, 340 buicks and 440 mopars from experience. you make me up a cam for my 401 and i will try it. or make one for Rhett and i will buy his camcraft for my car and try that one. am open mined for testing stuff out. your right thats why headers are so important for the nailhead to get the exhaust out.
valentines day is over but
we love you too. lmao
Joe, I think your car/combo is very unique and I think that your camming is close to ideal for what it is. I would probably add 2-4 degrees on the exhaust to what you have and call it perfect. If you still had the iron manifolds, I would have added a lot more. Think about this, when you leave in your car, it's making an off idle to peak power pull w/ very little assistance from trans(2spd) or converter(stock, if I remember right), or gear(3.23, correct?). With that, you need torque over a very wide band(wider than I would call normal), which a narrower spread favors usually. I'm still experimenting where the outer limit of spread is on Nailhead, but I am guessing somewhere in the 22-25degree area. Yes, I think the exhaust port is that bad. I am doing a 18 degree split now for a 401 I am building for a 4spd Skylark, street car.
About time we all started talking again!
yes that 218-230 cam was great in my 425 .030 over so 430 cid,that motor ran great. i think looking back now that the 218 intake was on the small side for that 430 built and it needed the extra exhaust duration to make up for it. the 2 cams on your desktop the 218-224 has less overlap. to make it fair. need to compare the 218-230 against a 222-226 now both with the same overlap. then see what happens at the upper end. you have that great video of you at the drag strip. i was watching the tach that 244-244 Isky was making power in the upper end. i like to see the video again, am sure the guys would love it.
Walt - I know the rod bearings are Clevite but I think the mains are too? and yes, the video please!
I spent a lot of time on the desktop dyno too, and while it is all theoretical, there were three cams that stood out on my combo: Joes's 218/230 cam, Camcraft's 222/226 and and my 218/222. The first two made slightly more power than mine, but mine was less peaky. All cams were spec'd on a 110 LSA and installed straight up. The Camcraft 226/230 also made more peak power, but it was a dog up until 4000 rpm.
Just for kicks I modeled the Camcraft lobes with a 218/230 tonight, the average gain over the 218/222 was 3 HP and 4 lbs average between 3000 and 5000 rpm.
Hey Rhett, do you have flow numbers for your heads?
With the flow numbers a cam could be designed a whole lot closer for your combo.