I'm starting to piece together a Nailhead in the Engine Analyzer Pro engine/dyno simulator. The more accurate I get the specs the better it will be for testing out combinations like Cams intakes and carbs etc. as well as things like port lengths and intake runner lengths to look at how Dirty Honda's head mod (cutting off some of the intake port) will change the power band. I'll make the Engine file available, and plan to post some dyno plots of various mods once I get the engine specs into the program. EApro is available in a trial version from www.performancetrends.com it is a popular simulator among race engine builders (its not Desktop Dyno). I'm wondering if anyone wants to help me out, I don't have a Nailhead short block or heads or intake to take measurements from, and haven't been able to google up the kind of minutia that this program wants. I need stock port cross sections, width across each type of bearing, to give you an idea. I've got most of the common specs like bore stroke, rod length etc. For starters I need the width and diameter for each type of bearing, Rod, Main and Cam. that's the measurement across the bearing (diameter) and the width from one side to the other, of the bearing (not the journal). Intake and exhaust Port Width x height x length (length can be approximate centerline). Stock intake manifold Plenum volume without runners. Intake runner width x height x length and CFM flows if anyone's out there's ever flowed stock or aftermarket nailhead intakes. I've found some head flows here. Wont take long if someone who has some parts wants to help out, I took the same measurements for a Jeep engine in the dark with a flashlight in 15 minutes. Excepting the intake plenum volume of course.
sorry i dont have a engine apart to measure but i am interested in the reslts. hope some one responds with the #'s you need
Bearing Dia (ID) Width Rod 2.30" 0.82" Main 2.50" 0.935"/1.200"(Rear) Cam 1.665" 0.780' (Cam shaft surfaces NOT a bearing) Port Width Height Length Intake 1.65" 1.55" ~4.5" Exhaust 1.05" 1.50" 5-5.25" 17 in3 (passenger) + 9 in3 (driver) - this is for a 66 spreadbore intake. Estimated volume with 4 cylinders (d = 1.35" - primary; d = 2.25" secondary; depth 1.67" driver, and 3.10" - passenger). Width and height are the same as head ports. Length ~7"
Wow. I was still thinking about doing it, while you DID do it!:TU: It's cold out in the shop how did you measure intake volume?? The intake port height is smaller than what you can measure at the intake/head flange. At that particular spot, you are looking at a diagonal slice of the port, and not a true cross section. It's closer to 1.25" than it is 1.55". But I'm sure it varies along the length. I've been wanting to make a casting of the ports with urethane or something. It would show exactly what the ports look like. I'll probably be thinking about doing it for a few more years.ou:
HOPE THIS WORKS BUT THIS POST HAS THE FLOW #'S YOU NEED I THINK http://www.v8buick.com/archive/index.php/t-19122.html
"Measure" is a bit of a stretch. I estimated the vol. based on the easy to measure primary and secondary holes in the intake xdepth to the plenum floor. The values i listed will be slightly lower than reality, perhaps 1-2 in3 more in there that i did not count in the method used. thought about trying to use liquid volume measure, but this is hard to separate from the runner volume. Walt makes a good point here. the calculator probably wants to know the height and width of the area the air sees when it flows through the runner; a cross section area that is oriented perpendicular to the direction of the flow. it would also be ideal if the cross sectional area were representative flow anywhere in the runner. The 1.55" intake port height i measured at the flange is larger than a true cross section height due to the head design, so 1.25" may be more representative of the height of a flowing stream of air at this point. However, the intake height is ~1.48" at this same flange intersection point and this area cross section looks like it is more representative because it appears to be perpendicular to the direction of flow. The intake/head flange is located in the middle of a mild "S" curve for the air flow. It is also true that the heightxwidth varies significantly through the length of the runners in the head and intake.
I was thinking of measuring ports with liquid as well....convert the volume into area, Then measure the port length with tubing (to follow port contours better than a piece of thin wire). If you know area and length, you can calculate average port cross section size. Here's a cross-section pic that shows how the intake manifold/head opening is a diagonal slice, making the port appear larger than it is:
Funkyriv and all you guys thanks! Man what a great response thanks for hooking those measurments up for me. I will make the engine file available for download if anyone wants to play around with EApro. Assuming of course I can get the engine to output authentic torque curves and peak numbers. Wkillgs; man if you're willing to cc the volume of the runners that will help a ton! EApro can use width x height at the port and runner enterences. but it is more accurate with actual volumes. With W x H it's pretty much making an educated guess at the runner/port efficiency, based on flows, and the cross section shape (which is also inputed) The Nails ports are so oddball that it might not have an easy time coming up with accurate numbers and curves due to all the S curves. I'm patiently waiting on ebay for a set of head cores and intake or an entire core engine near me in Virginia to pop up for local pickup cheap but until then I'm glad there's other nailhead fanatics out there. :laugh:
There's a farily complete 401 & trans on eBay right now. It's in MD and is only $127.50. And please, for the love of god, don't bid on the only 4bbl intake ray: . It's the only one on eBay, I'm a poor kid, and I need it bad!
It's on my 'to do' list! I don't know when I will get to it tho. It would be cool to make molds of the ports. I just found this site, take a look: http://www.diyporting.com/molds.html I gotta do this!!:grin:
Yeah I'm watching that too, its the first Nail that's popped up in my area in over a year... and now it's advertised here on a forum filled with nailhead nuts... :rant: great. (goes off the look for that intake... just kidding :laugh
Yeah, the mold jelly is cool stuff. I'm curious as to why you need bearing measurements for airflow calculations. I would assume that could be figured into frictional losses but it's a little perplexing. I know a STOCK port is as previously posted 4 1/2 long. and 5 1/4 for the exhaust. Intake runner volume will be tricky with a dual plane since the area is all shared. I think the long runner is about 12 inches long though. Curious to see the results. Mike (dynomation user)
The bearing measurments are to calculate friction, EApro wants every possible engine metric including number of bearings and their surface area, CFM flow at as many valve lifts as you care to input AND port/runner sizes, among a hundred other inputs. Valve angles, chamber types, carb/TB sizing, Exact header specs, etc. etc. I am going to start working on the Virtual Nail tonight. Does anyone care to measure the width and hieght inside of the stock Exhaust manifold at the face where it meets the head? I've already got a Jeep 4.0 (one of my other interests) that sims within 3 foot pounds and 2 horse power, at the correct RPM's with very realistic looking curves. It also responds to virtual "mods" with results that seem to mimic real ones..
which reminds me I forgot to ask how many cam bearings, and mains I recall 5 mains but I could be off
Anyone got a stock iron exhaust in there garage care to measure the stock exhaust primary length and cross section (from where the port ends to where the manifold opens up significanty)? On a nail this looks like it would be just before the meeting of the collector pipe and the manifold.
Hey Simon, are you still out there? Someone resurrected your old thread on the JeepStrokers forum, and I recognized your username from here on V8 Buick! Wondering if you made more progress with the Nailhead and Jeep Dyno sims.
