Port matching is a waste of time and or $$ and more than likely will hurt flow rather than help it because it creates a large pocket in the intake track. Going from the relatively choked runners of a factory intake from the carb opening and have them larger at the end of that run matched to the heads being opened up where the intake meets then back to the factory untouched choked off port will be an interruption in velocity and slow the air flow down as a result of "port matching" so IMO you're better off not doing it. If you have the grinder out anyway if you're doing this yourself why not do the entire port on the heads? Not as much work as you would think to do some moderate port work. Just make sure you don't take much material off of the bottom of the port, just to remove any casting flash or irregularities off of the bottom, don't even worry about matching the floor to the gasket because the higher the floor is the better.(some head porter will fill the bottom of the port with epoxy to get a more line of sight to the valve to increase flow) As for the sides of the ports, get a set of inside dividers so you can find the narrowest area of the port because that will be the choke point where it will only flow as much air as the smallest point in the port. So now that you have found and recorded the smallest point in the port, measure the largest point in the port and subtract the difference. If the difference is greater than .125" then good thing you didn't port match the heads because that metal once removed would be VERY difficult to replace. The .125" is what you can safely take out of the pinch point of the port, that would be approximately .062" per side of material to be removed in the pinch point to safely not hit any water jackets. Now that the smallest point is opened up check to see if there is another area of the port that is now smaller than the opened up pinch point and take that area to the same size as you did with the smallest point. Keep doing this until the entire port is opened to what the smallest point in the port was opened up to. Don't worry about the areas that are larger than what the pinch point was opened up to, just make the irregularities more uniform out of the area removing minimal material there. That's it for the sides of the ports, they should help flow more air now without hurting the velocity. Now for the roof, I would say that most of the material should be removed as high as the gasket opening is tapering down guessing around .125" per inch of the port so about an inch in you would probably be done blending, after that just make the irregularities more uniform after that and you're done with the roof. Under the valve is called the bowl, the bowl is probably the biggest pinch point there is in a factory cast iron cylinder head. In this area you should start with the throat of the bowl, that is the area just under the valve that should be opened up so that there is still enough material to support the valve so don't grind away the area where the valve job is and leave a bit more beyond the valve job(where the angle is cut). Now going into the bowl further the guide can be shaped narrower where the air flow would be on each side of it coming from the port. That should be more than enough for a novice porter to do and stay out of trouble in the bowl and port areas. With the head on the block with a bolt or 2 in so it stays on, reach your hand up the bore and scribe a line on the head" deck mating surface on the intake valve side and the exhaust valve side or a complete circle if you want it won't hurt anything. After that you will be able to see where the cylinder wall is so you can grind on an angle starting from INSIDE the scribed line at least .010" away from it to the intake and ex. valves. This will help unshroud the valve in the chamber to get more air in and out. IMO porting the factory intake is not worth the time it would take to do because of how long the runners are you can't get inside far enough to make a difference or to the beginning of the runner would be a bitch to get to try and open there up as well. If you wanted to put the effort in though then look at how the head intake ports ended up and make the intake manifold ports slightly smaller as far as you can possibly reach inside to grind those. Under the carb, the Doc dual plane mod is suppose to work well with a factory 4 hole intake, probably the most worth while mod on one of them. The mod is posted as a sticky in the Nailhead section. Goodluck and happy grinding. Derek
Id like to go roller but im a college kid that only has enough to do a complete top end rebuild. I wish I could find a timeslip of someone running a 212 because im after 13.00-12.50's or faster(also spraying a 125 shot). I think Ill end up going with either a level 4, 294(if I can figure out that it has enough torque for the car), or a lunati if it doesnt have ptv problems, and lobe problems. And I would never go thumper because all sound and no bite isnt fun at all. Also whats the part # for the Crower lifters?
Id like to go roller but im a college kid that only has enough to do a complete top end rebuild. I wish I could find a timeslip of someone running a 212 because im after 13.00-12.50's or faster(also spraying a 125 shot). I think Ill end up going with either a level 4, 294(if I can figure out that it has enough torque for the car), or a lunati if it doesnt have ptv problems, and lobe problems. And I would never go thumper because all sound and no bite isnt fun at all. Also does anyone know the part number for the Crower lifters?
Be careful with that docs mod. A 350 is NOT a nailhead. The nailhead intake is about 1/2 the runner volume of a 350 intake. 350 does not need any more volume with those long runners. What ever you do, do NOT remove or cut down the center divider. You will lose lots of torque and gain nothing anywhere else.
The 212 with right compression and the rest of combo setup right and a 125 shot of nos will make it to the times your looking for but other combos will come much closer without the nos. . do more research here for other combos and posted times. But I would think the 310 ,413 or the level 4 will come closest. More convertor will be required and porting with bigger valves will be needed. But you will have less risk of nos damage to engine . not saying nos is bad but if your not tuning for it and tempature,fuel quality, or just timing is off can cause you to lose engine.
http://www.v8buick.com/showthread.php?302437-Custom-cam-from-Scott-Brown&highlight=Scott+brown+cam Read this tread ,specs on scott brown custom can from another member.
I think ive settled on the Crower level 4 I think it sounds like what I wanted and seems to have the RPM range I was looking for. I think it would be a really good street cam. just one more question on cam comparisons, would this make more torque than the 290-94h like what I first had picked? Also hoping the Crower will get me by buddy in his judge spec 455(that I built) in his TA and around some of the mustang guys at the college my girlfriend goes to and the one im going to next year. :3gears:
Yes, it does. I'll likely be starting a thread of my own soon regarding this topic(cams) and input in general on the Custom Convertible I have right now. Having spent more of my time around Pontiacs, I'm used to varying levels of camshafts along with some other items(exhaust manifolds, cylinder head design, compression ratio) for increased horsepower models. These are generally what they used from the mid to late '60s to the mid '70s. I'm just surprised that Buick didn't really do something similar. These would get used on engines from 350 to 455 CID. [TABLE="width: 1000"] <tbody>[TR] [TD="width: 64"]Brand[/TD] [TD="width: 64"]Model[/TD] [TD="width: 64"]AID[/TD] [TD="width: 64"]AED[/TD] [TD="width: 64"]ID050[/TD] [TD="width: 64"]ED050[/TD] [TD="width: 64"]IL1.5[/TD] [TD="width: 64"]EL1.5[/TD] [TD="width: 64"]LSA[/TD] [TD="width: 64"]OL[/TD] [TD="width: 64"]Notes[/TD] [/TR] [TR] [TD]Pontiac[/TD] [TD="align: right"]9779066[/TD] [TD]273[/TD] [TD]282[/TD] [TD]200[/TD] [TD]210[/TD] [TD]0.41[/TD] [TD]0.41[/TD] [TD]111[/TD] [TD][/TD] [TD]2 bbl and 4bbl applications.[/TD] [/TR] [TR] [TD]Pontiac[/TD] [TD="align: right"]9779067[/TD] [TD]273[/TD] [TD]289[/TD] [TD]200[/TD] [TD]213[/TD] [TD]0.41[/TD] [TD]0.41[/TD] [TD]114[/TD] [TD]54[/TD] [TD]4bbl MT applications[/TD] [/TR] [TR] [TD]Pontiac[/TD] [TD="align: right"]9779068[/TD] [TD]288[/TD] [TD]302[/TD] [TD]212[/TD] [TD]225[/TD] [TD]0.41[/TD] [TD]0.41[/TD] [TD]116[/TD] [TD]63[/TD] [TD]HO, Ram Air, Great mild performance street cam[/TD] [/TR] [TR] [TD]Pontiac[/TD] [TD="align: right"]9785744[/TD] [TD]301[/TD] [TD]313[/TD] [TD]224[/TD] [TD]236[/TD] [TD]0.41[/TD] [TD]0.41[/TD] [TD]119[/TD] [TD]76[/TD] [TD="width: 64"]RA III[/TD] [/TR] [TR] [TD]Pontiac[/TD] [TD="align: right"]9794041[/TD] [TD]308[/TD] [TD]320[/TD] [TD]231[/TD] [TD]240[/TD] [TD]0.47[/TD] [TD]0.47[/TD] [TD]114[/TD] [TD]87[/TD] [TD="width: 64"]RA IV[/TD] [/TR] </tbody>[/TABLE] PS Sorry for the brief thread hi-jack.
I understand that, just make sure you use the proper break in oil and change afterwards. I like the Crower level 4 cam and should work well for you. If the heads are ported a 80 shot will make the car run a 12.20, I know I did it. A 120 shot put me in the 11's. I used a 1 inch open spacer along with the nitrous plate. As Steve said DO NOT cut down the center divider in the TA intake. Spacer takes care of any of that business. Set the nitrous up right and you will be fine I am about the only one around here now that has done it on a regular basis, With a 350. I have a thread running around here somewhere on it.
I guess I'm just not being clear. The Level 4 will work on a street car just fine. You will make more torque at lower RPM with the level 3. Your higher stall converter will mask the missing torque so should be a wash. Cutting, eliminating, OR defeating the divider by any means including by using an open spacer will reduce your low end power. With a stock or TA stage 1 intake you will NOT make more power at upper RPMs by doing so. Disclaimer: talking NA engines and can not speak for nitrous because I've never used it.
Mainly the Doc mod is making the carb opening like an aftermarket Q-Jet opening by making the front and rear holes on one side opened up to each other so there is only two opening one on each side. Yes I would have to agree to NOT grind the center divider out on the factory intake at all. Opening the front to the back will help extend the RPM band and help equalize the front and back cylinders out when at WOT though is how I understand that mod. Derek
What are our options in a roller cam, if a person was looking to go with a Crower stage 3 or 4? I keep hearing stories of wiping out a regular hydraulic cam after limited use.
Roller cam blanks available from ta performance. Custom grind. Wiping out a lobe is possible but many things can contribute, as proper breakin, proper oil ,spring pressure,engine temp and type of driving. Any of these can wipe out any flat tappet cam regardless of design.I have heard more lunati cams going flat then others .but for a vehicle that's going to sit for weeks at a time without being started , this can cause a cam to wear also. Roller is the way to go but costly. And you will need valve springs to match cam.
As a general rule, the more intense a flat tappet cam is, the greater the odds of it wiping. Not only upon break-in, but shortly after. Even so, don't expect too many miles out of one. One of the reasons why I stress the Federal Mogul cam if going flat tappet, as your odds of success are dramatically increased, if not guaranteed, unless you fail to follow proper break-in procedures. There are those of us who can break in just about any flat tappet cam (within reason) and have it live a fairly long life (relatively), but even with the best of us it's still a gamble. Take into consideration that many readers here are not professional engine builders, and your odds of success decrease significantly. Roller is the safest bet obviously, providing your checkbook doesn't object. Some reasons not to go roller: 1) can't afford it 2) can afford it, but would rather spend money elsewhere 3) not going to own car for long 4) building a 'test' engine or 5) building a strictly race engine for your dragqueen that you plan on pushing to the limit and may blow up or otherwise any reason you may have that results in your planning to not own/run the engine for long. Then there are the diehards who believe their Buick is invincible (which it is, practically, in stock form--and could be the leading reason why such a fallacy is believed) who want to run a flat tappet solid cam with less than 50* lobe intensities. These are the ones who tend to be bitter when camshafts are discussed and reasons are offered up as to why their valvetrain miraculously functions on borrowed time, with the usual 'how many engines have you built' snide comments ensuing, as if it took 101 engines to figure out what you were doing wrong after repeated mistakes. Why not do some research and/or simple reading of others' opinions before investing any more money into it? Seems only logical to me. What we know so far is that the Federal Mogul (or a similar 'OEM' type grind) is your best bet as far as break-in success and longevity, with other cams following in progressive order up to around .450 lift and 55* duration intensity between .006 and .050 being about the upper limit on flat tappet cams. After that, your risk dramatically increases of flat tappet failure upon break-in or shortly thereafter. Said cams up to .450 lift and 55* duration can increase power beyond stock cams by up to 25 or so HP, but typically only see around 10-15 more than stock. To me, it's just not worth it. If you want lope and increased power, save up and go roller. Remember that the Buick 350 stock head will only flow good up to .400 lift, with the sweet spot ranging between .300-.400, and anything more is peanuts (about 2 CFM gained on exhaust from .400 to .500 and zero gains on intake), even with moderate port work. You have to reshape and essentially redesign the head characteristics in order to gain any measurable results beyond .400 lift. The reason I say .450 lift max is because that's about the sweet spot for symmetric design which must 'overshoot' its goal of .400 in order to stay within the .300-.400 sweet spot long enough to maximize flow potential within this range. This is in contrast to the Asymmetric lobe design which opens the valve faster and closes it slower (which is by the way easier on the valvetrain and head seats), requiring less valve spring pressures (which aid in lobe/lifter and overall valvetrain longevity) to retain valvetrain stability, and incidentally causes the valve to stay open for longer periods of time within its opening window, extending the time in which it stays within the sweet spot of .300-.400 lift. This method is not quite as effective as the .450 overshoot symmetric method in terms of maximizing power, but it only falls a few percent short, and does much better than the 'on paper' specs would indicate until further investigation of the numbers is made and a better understanding is achieved. These 'OEM' style camshafts take many things into consideration within the engineering behind them, not just power. Longevity, emissions, ease of installation, production costs (which is achieved through mass production--which also incidentally ensures proper camshaft geometric accuracy, as one small mistake would affect entire production runs), as well as power. Gary
What all else are you planning to do with your engine? Match the compression as best you can to this camshaft and you'll be pleased with the results. :TU: Gary
Reasons for exhaust lobe emphasis are typically to aid in exhaust evacuation due to stock exhaust system restrictions, which include the head itself all the way back to the tailpipes, depending on design. This is why you see so much emphasis on stock big block engines than you do small blocks on exhaust lobes. Adversely, if you were to open the exhaust up and still use these cam designs, you'll see greatly improved scavenging effect which will make the smaller intake lobe seem larger than it is, since at higher RPMs the exhaust valve and subsequent improved exhaust flow will dramatically increase drawing in more air than it would otherwise be able to do with a stock exhaust system. At lower RPMs, the camshaft behaves as if it were smaller due to the smaller intake lobe. This results in an increased power band, making it wider using street friendly parts. Buick did have different cams for their engines, though for the 350, it's very vague on exactly what was used. Even ordering OEM cams back then resulted in getting the same part number, suggesting there was only one cam used for all engines, until around 1975 or '76, when catalytic converters were introduced and camshafts became much smaller to aid in emissions with the newly-introduced (and primitive compared to today's) catalyst systems. The design of Buick's 350 cam makes it sensitive to its environment, working well with low flow and permitting better airflow when things are opened up (as mentioned earlier). As long as airflow is restricted, such as with single exhausts, catalytic converters, 2 barrel intake/carbs, etc. The CS647 cam will behave like a small cam, with power peaking within the 4200-4400 range and torque peaking below 3000 RPM. Put on a 4 barrel, improve head/manifold flow, and add dual exhaust with no catalytic converter but instead an "X" pipe, and it extends the power band up to 4600-4800 RPM with torque peaking around 3200 RPM. Add on headers instead of manifolds, and you can boost that power band up another 300-500 RPM or so. All using the same camshaft. The ultimate reason is scavenging and the way the lobes control airflow in a dynamic way based on the camshaft's environment (intake, heads, exhaust), or the lack thereof. All cams do this to a degree, but the OEM cams do it better because of superior engineering. Gary
Also keep in mind that there is no direct copy of a camshaft into a roller version, we cannot just ask for say a TA212 cam in a roller version it will be a totally different profile based on the design differences between the flat tappet and rollers. TA has a few cam profiles designed already for the roller cams, and can design more as people order them.
