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The dynos have moved to the home page Basics of producing power
	Pontiacs are well known for bruit torque therefore they are a very likely contender for racing. Many people like Pontiacs mainly because they can get decent gas mileage, fry the hides off just about any set of tires and pin your ears to the seat. When you drag race, the only thing that matters is how fast you can get form point a to point b. this is called acceleration, and acceleration is brought on by torque. The more torque you have the faster you will accelerate. How do we get torque? There are several ways to get this white-smoke mojo; here are a few ways to get your hands on some. The longer the stroke the more the torque, the downside to this is that the longer the stroke the less wind. Horsepower comes from torque, but horsepower is the combination of torque and R.P.M. Horsepower is the measure of how fast the torque can be accomplished Having the right combination of bore and stroke is the most effective way to get power. Take the 326 and the 400 for example they both have the same stroke, so the 326 has to have a smaller bore to be a smaller engine. The 400 will make more power over the 326, but not just because it's bigger. The 326 has more stroke than it needs and less bore than it needs, therefore it will run out of breath long before the 400 will. The 326 cant wind fast enough to make horsepower so its pretty much stuck with torque. Cams will also have a large effect on torque. The lower the duration the more low-end torque, but the downside to this is that the more low-end torque you have the faster the motor will run out of breath. The more duration you get the higher in the power band the torque curve will be. So your motor will spin more R.P.Ms, but this comes at the cost of low-end torque. When you are a serious drag racer (400+ hp) low-end torque can hurt you. How? Low-end torque promotes wheel spin. While it makes you feel like superman creating plumes of white smoke, it doesn't do you any good at the dragstrip. While you are burning off worth of tires your opponent will be getting closer to the finish line. Valves have an effect on the production of torque; a smaller valve will make more low-end torque, but here again it will sacrifice R.P.M. If you grind the valve seats out to accommodate for larger valves, you might hurt your performance. The valves take time (rpm) to effect hp. So if you grind out the seats for bigger valves, you might be doing in vain. Lets think about this for a moment. If you put in bigger valves to gain more R.P.Ms you might be flowing air that your motor can't use. Grinding out the seats to stab in bigger valves is usually only necessary when you are spinning more R.P.Ms, so if your 400 is about to be a stick of dynamite at 5000 R.P.M you don't need to be accommodating airflow for a 6000 R.P.M engine. Intake manifolds are another source of torque. There are several different types of manifolds, the most common I will highlight here. Note manifold types two and three are both a dual or divided plenum manifold. Type one: single plane this is mostly a high R.P.M. (2600+) intake manifold, it usually makes more peak power and a very narrow torque curve. So if you have a cam with a powerband of 1000-4500 R.P.M you don't want to use a single plane manifold. Type two: low rise, this is a low-end torque (idle 5000 R.P.M.) Manifold. This manifold would work best with the aforementioned cam. Type three: high-rise, this is a mid R.P.M manifold (1500-5700) it would obviously work best with a cam with a 1500-5700 R.P.M range. Do you see a pattern here? Headers are a way of affecting overall power. Headers will always gain you some power over stock manifolds. But they too have a downside, if you live in Phoenix you can have headers on a daily driver, but if you live anywhere where the temperature gets low and you will have problems. From the factory, exhaust manifolds have a tube (it looks like a toilet paper tube wrapped in tin foil) that goes from the manifold to the air cleaner. When the temp gets low enough a flap changes position so that the warm air around the manifold gets sucked into the air cleaner. This will keep your carburetor from icing up. When you ditch the manifolds for headers, you loose this setup. So when the weather gets cold your carb will ice up. But hey, you will have some more juice. The most common type of header is the four into one type; this has its greatest effect on midrange and upper R.P.M horsepower. Some of them are equal length and some of them are non-equal length. Equal length headers will always be a better performance header, but they are bulkier and harder to fit into tight engine bays. Since exhaust travels in pulses, you don't have a continuous flow of exhaust gasses. This can create low-pressure areas in the header, and in essence can "suck" the exhaust out instead of being pushed out. The other common type of header is the tri-y header; the try-y header will usually boost bottom and midrange power. A stepped hearer is visually similar to a four into one header, the difference with a stepped header is that the tubes on a stepped header get bigger as the tube gets farther from the head. Stepped headers have small improvement gains over other headers. So try to match the header to the powerband. Carbs are another source of power gain. There are several to choose from. A Rochester quadra-jet is a good carb. Sure they are hard to work on and even harder to tune, but they have many advantages also. For one thing when you tune a q-jet they stay tuned for a long time unlike a holly. They have small primary barrels to aid in low-end torque and huge secondary barrels to give you a top-end boost. They have been around for a long time so they are plentiful. Where I used to live junkyard owners practically gave them away. However where I live now, well that's a whole different story. I sold one for , as where before I couldn't have gotten for one. So as you can see, the price of a q-jet can vary from place to place. On the other hand a holly is a carb that can be tuned easily. A monkey with a screwdriver can tune a holly. A holly usually delivers about the same amount of power as a q-jet, but a q-jet will deliver better mileage. Bottom line, simplicity and fair mileage vs. complicated and better mileage, you make the call. Gears, while gears do not directly affect a motor's output, they can give you an edge. If you're motor doesn't make power until 2600 R.P.M. then a set of 2.56:1 gears simply wont work. If your motor runs out of breath at 2500 R.P.M. a set of 4.88:1 gears will be impractical. It is very important to match your gears to the powerband of the engine. An engine with low-end torque can live with a higher (numerically lower, i.e. 2.56:1) gear. But when you give up the low R.P.M. torque in favor of higher R.P.M. torque you will need lower (numerically higher i.e. 3.23:1) gears to get you movin. Some people stuff in a set of 4.10s and just live with the fact that interstate cruising is about 4300 R.P.M., but this too is impractical. There is a solution to this though, overdrive trannys. Most overdrives have super low 1st gears and very pleasant overdrives. So you can still have that wicked racecar lope, and get mileage. The overdrive trans will help in two ways. 1) You will have better acceleration with out using lower axle gears, because of the lower 1st gear. 2) You can reduce cruse R.P.Ms by 30 percent. Since torque means acceleration, you will need to plant that acceleration. How? Traction is the answer my friend. There are several ways to get traction; usually a wider tire comes first. Now some of you might thinking "narrow tires deliver more traction." Well to solve this mystery of physics I will give you an example. Lets say you have a 3800 pound firebird, and you have "borrowed" the wheels off the neighbor kids bicycle and put them on your car, what will happen when you drive it on the sand, and dump the clutch? You will bury it up to the axle in half a second. Now lest say you put on a set of tires that are 16 inches wide, and do the clutch dump, what will happen? You will probably still dig into the sand, but not as bad. Why did the bike tires dig themselves into the sand so bad? That's because they spun more than the wide tires. Why did they spin more? They spun more because all of the weight of the car was concentrated on a patch or rubber that is one inch wide. The same rules of physics apply to "one part asphalt and two parts tire" combo. The wider tire will get you movin better because more of the tire is in contact with the pavement. Still not convinced? Try it yourself. Only don't go to the beach, go to a dragstrip or a parking lot (preferably an abandoned one), and put on a set of six-inch wide tires and see how fast you can get from point A to point B. after you have tried it a few times to get an average, put the wide tires on and try again. See what happens. Softer springs can get you planted to the pavement. But the downside to this is that your handling will become nonexistent. When you accelerate the front of the car will come up a little, and the back of the car will go down a little. When you put soft springs on the back that tilting will plant more of the weight of the car on the back tires. Meaning even more traction. The wide tires, positraction and softer springs work with everything, but there are several other ways to increase traction. The most effective way to gain traction is with a posi or limited slip unit. Stay away from using a spool, on the street anyway. A spool locks both wheels up, so if you go around a corner the outside wheel will be dragged around the corner. The best way to get traction is trial and error, since all cars are different. Some cars benefit from things that other cars do not benefit from. Follow all instructions and bake the tires at 3000 R.P.M. the result an ear-to-ear grin.

	How To Avoid The Seven Deadly Sins Of Engine Building By: Matthew Burns When a person builds an engine they usually have their buddies come along and offer assistance. There is only one problem with this. Engine building theories will vary greatly from person to person, so in turn you have five different people with five different opinions on how to get the job done. So how do you sort through what is the good stuff and what isn't? Well experience is one way, but where does this experience come from? Reading is one way to gain experience. Reading combined with the wisdom that time often brings and a LOT of hands on projects is usually the best way to gain experience. So sit back, relax and take in this knowledge that I am about to impart to you. 1) Build every ford you can get your hands on. You don't really think I would recommend that do you? That's one of the deadliest of all. No, I just did that to get your attention. Now that I have it I might as well say my piece. We'll start from the beginning here. First of all remove the hood, you wouldn't want to try and remove the engine with the hood still on the car. Whether you are simply rebuilding the engine that already exists between the fenders or pulling one from a junkyard, when you take the engine out of the car your going to drive make sure you mark all of the wires (alt, for alternator, dist, for distributor and so on) to make sure you can figure out where they go when you put everything back. It can't hurt to take a few pictures of the brackets either so you can figure out how everything goes back together, believe me it will make you cuss trying to figure out how to get those things back on from memory and trial and error alone. Don't cut any wires or hoses unless absolutely necessary. Most wires and hoses will have provisions for removing the whole thing without cutting anything, but sometimes the installation of a wire or a hose is a one-time deal, so a SAWZALL might come in handy. You should also remove or cover your radiator overflow tank and windshield washer fluid reservoir if the hood will be off the car for a while, as these items can get brittle if left in the sun for too long. 2) Tearing it down Usually you start by removing the intake, heads, water pump and so on. If your cylinders have excessive ridge at the top, you will need to "grind" this ridge out with a ridge reamer in order to remove the pistons. When you tear down an engine inspect every part closely. For instance: a broken ring will often necessitate boring the block, so it pays to look at these parts. If you are going to be re-using any parts of the engine (which is highly ill advised for some parts), break out the ZIPLOK bags, your gonna need 'em. Match each component, of each cylinder. For example: put the rocker arm from the #8 cylinder with the pushrod from the #8 cylinder, and put those with the valve from the #8 cylinder. Put the rocker arm from the #7 cylinder with the pushrod from the #7 cylinder just don't put the pushrod from the #3 cylinder with the rocker arm from the #5 cylinder, and so on. Do you see a pattern here? Check levelness of the heads and block by using a straight edge of some sort. Mark the pistons AND the connecting rods if you plan on re-using them. The reason for this is because each connecting rod has to back on the crank journal that it came from. The reason for marking the rod and the piston is so if you separate the pistons from the rods you wont be able to figure out which piston went on which rod. In order to mark the rods and pistons, you might be able to use a very hard very sharp nail or screw, but this can be unreliable. The best thing to use is a number punch or an engraver; just make sure each component is clean BEFORE you do this. The machining process 3) After you get the engine torn down you will find a plethora of items that may need to be machined. More often than not, the valve seats on the heads will need to be machined (good time for that 3 angle valve job). The crank may also need to be machined, as a crank has the tendency to "loose its round," in other words, the journals on the crank may not be perfectly round. So in turn the crank must take a trip to the local machine shop. Some (NOT all) machine shops will tell you that the crank needs to be ground, when it really doesn't need any machining at all. This is a bit more common than one might think. If you even have the slightest idea that your machinist is giving you the run around, now would be a good time to get a micrometer. You don't have to get anything fancy, just a cheapie. All you need to do is learn how to read a mic, and your set. That way you can go to the machinist and say "this crank needs to be ground" instead of asking "does this crank need to be ground?" if you are going to getting anywhere in the 400 hp mark (with or without nos, blower etc) some additional machining may need to be performed. "Decking" the block and/or heads, align boring the main journals and having the boring performed with a torque plate should be standard procedure for a high performance build. If you spring for some boring, get the pistons first then take the whole shebang to the local machinist, if you have press in wrist pins you may need to talk the machinist into pressing the pins (and no beating the wrist pins in with a big hammer and some lube isn't an option). Building engines isn't like performing carpentry; you can't be in the ballpark and call it good enough to move on. When you break the 1 hp per cubic inch mark you want all your tolerances to be as close to perfect as humanly possible. You don't want anything to be "in the ball park" when your spinning six thousand rpm. Peaceful assembly 4) This is going to be a long one, so be patient. First of all I will start by saying...ALLYAYS USE BREAK IN LUBE, not oil, break in lube! (Note: do not use break in lube on the piston rings) Generally when a person starts a build they start with the block, so that's where I'll start. First of all get the cylinders honed. Most of the time, the boring process will come with a honing, but if the block wasn't bored (or the machinist is a tight wad), it'll need to be honed. If you do it your self, (and it's your first time) try to find a book or magazine that shows you how, make sure you get a 45 degree cross hatch pattern. After your block gets bored and/or align bored (assuming you had either of these operations performed) make sure everything fits the way it's supposed to. Do a "dry run" with the pistons by taking the piston (If you are not re-using the piston, and have different ones inspect them very carefully for cracks, chips or anything else abnormal. Also make sure that the piston is clean, not just kinda clean, clean enough to feel safe licking it) and putting it in the cylinder (without the rings on) just to see how well it fits. If the piston is visually too big, or won't fit you obviously need different pistons. Now that the pistons fit the way that their supposed to, its time to move on. Now it's time to check for crank/bearing clearance by means of "plasti-gauge". Plasti-gauge is something that looks like thick fishing line and comes wrapped up in paper like a candy bar. You simply place a small strip (about one inch long) plasti-gauge one the journal of the crank, then you cinch the main/rod bearing down (just like you are normally putting the bearing on, only without break in lube) then when the bearing is properly torqued, remove it once again. Now the plasti-gauge will be flattened out, save the paper that the stuff is wrapped in, you'll need it. On the paper there are stripes, if the plasti-gauge is now as wide as the stripe, that means you have ideal clearance, if the 'gauge is considerably narrower or wider, you either have too tight or too loose of a bearing or something isn't lined up right. Now, if everything checks out ok, it's time to remove the 'gauge (whatever you do, don't use a die grinder, a pocket knife might work if your really careful. Just don't press too hard, you don't want to scratch your newly ground crank). Now put a very liberal amount of break in lube on each bearing, (also put some sort of lube on the back of the bearing, where it fits in the saddle. Break in lube will work here just don't get carried away) not the whole tube, but don't be stingy either. Now slide the bearing in place, torque everything down to proper specs. When you install the pistons it's a good idea to put some sort of slippery substance on the rings. There are about 80 zillion opinions on what to use here, so I will just say, "use your best judgment." You will need a ring compressor to get the ring/ piston assembly in place. (Note: pistons and connecting rods have a front and back and a left and right side, you can't always use the pistons from the left bank in the right bank, also piston rings will have an up and a down, the up side will usually be marked in some fashion. This is why it's important to keep track of where every component comes from) A tapered ring compressor works best, but only works with one size of cylinder. Unless your running engine assemblies shop, a tapered ring compressor isn't practical or necessary (seeing as how you will probably use that specific size compressor about one time), an adjustable unit will suffice. Find some hose of some kind (under hood vacuum or heater hose works well), and cover the rod bolts with it so that they wont scratch the cylinders when you install the pistons. Now use the plasti-gauge (again) and check for clearance of the rod bearings (the same way you did with the main bearings). This is a good time for a break, eat some lunch, or play cards, do something for about 30 minutes. Then come back to the task at hand. Now with the rotating assembly all put together, spin the crank a time or two by hand. Check all of the nuts again with the torque wrench (sometimes a torqued nut/bolt will "settle" a bit, causing the nut to loosen a few foot pounds) re-torque what needs to be re-torqued and move on. It's time to install the cam. Put a liberal coating of assembly lube on the cam (the lobes, the journals... all of it), and stab it in. Next up is the timing chain; it's not too difficult to figure out how that goes on, when you get the chain on make sure that the cam is degreed right ("straight up," "advanced" or "retarded"). Now come the heads (woohoo!). You will need a spring compressor to assemble the heads if you didn't get that done at the shop. Head studs are recommended but not necessary, bolts will suffice. Be careful to check for any grit or debris on the head surface, the block surface or the head. Even the smallest item will mess things up. Once the heads are assembled its time to drop in the lifters and pushrods and time the valves, then onto the intake and carb. This is one area where silicone is mans best friend, don't use too much of it, or you will be just as bad off as not using enough. (Note: hydraulic lifters will often need to be "soaked" in oil, if not the lifters will collapse when the cam tries to open the valves..... not good) If the heads or block were ever milled you will more often than not need different pushrods, if not the rocker arms might not be centered right on the valve. A pushrod length checker can be made for pennies (see sidebar: Tools, and Tricks) Timing the valves can be tricky, very tricky. To time the valves you will need infinite patience and the memory of a super computer, an experienced builder can do this, but any mere mortal novice can do it with the help of a Chilton's manual. 5) Installing the beast Most of the time you will need to remove the motor mounts, not the parts bolted to the block, the parts you left on the frame. To remove them you will need to do one of two things: 1) get a special wrench. The wrench idea will work well, but it can be pretty tricky, and even trickier getting the nuts back on. Imagine it this way: try tying a knot in a matchbox using only a pair of tweezers. 2) Cut a hole in the frame (not one the size of a baseball, just big enough to fit a socket in) directly in line with the back of the nut. On some cars you can put the motor in without removing the motor mounts, but its tricky. If you opt to cut the holes, drill them out so they are round, thread them, and put a plug in the hole. You also might try to tack weld the nut to the frame for future ease of installation. When you bolt up the transmission make absolute sure that the mating surface is clean, very clean. This is one of the simpler parts of a motor swap; the harder parts are yet to come. If you opt for headers now would be the ideal time to install them, as the motor will be "loose" from the frame, in other words you will be able to rock the motor a bit to gain clearance. One easy way to install the headers is to turn the boltholes in the ends into slots. Now put the header up to place, start the bolts in the end, and drop the gasket in place. Now put the other bolts in place, and cinch 'em all down. Voila, pretty neat huh? 6) Hookin up Well, not that you've got the biggest part of the live toad swallowed, you can start with the little things. What are the little things? Little things are getting it all hooked up after you took it out. This is when marking all those wires and taking pictures of brackets come in handy. Pretty much all you have to do is hook up the starter, alternator, distributor and the rest of it. Be careful not to install the thermostat upside down, they don't work extremely well that way. Once all this is done, you fire it up. 7) Firing it up When you hit the key, you shouldn't have to grind on it for 20 minutes, if you do, something's wrong. If it wont start easily, don't grind on it for long that only wipes the break in lube off, making all your precautionary efforts pointless. If it won't start immediately do the following: check the timing, make sure the distributor is hooked up correctly, make sure the plugs are firing (when they are supposed to), make sure that you have an adequate supply of gas being delivered and make sure you filled the lifters with oil like I told you to. If all this checks out and it still wont start, consult an expert. Once you get it running vary the rpm from idle to about 5000. Stepping it up a little bit at a time and stepping it down a little at a time. Different engines need different break in procedures, so check around for what is best for yours. Now most of all, don't drive like a maniac for at least 500 miles, keep the revs below 4000 for the most part, all in all just go easy on it for a while. Tools and Tricks 1) Keeping the trans supported. While the engine is out of the car, you need some way to keep the transmission supported. If you don't keep it supported you may get the transmissions tail shaft in a bind, this isn't a good thing. To keep this from happening all you need is a stout broom handle or a good piece of pipe. Measure the distance from the outside of one frame rail to the outside of the other. Cut a piece of pipe or the broom handle to that length. Now thread two bolts into the bellhousing to motor (the holes second from the bottom) bolt holes so that they stick out about three inches (it is best to use a 3-31/2 inch long bolt, and place it in the hole, and then thread a nut on the threads. Use a washer on the back of the bolt where it meets the bellhousing). Place one end of the broom handle on one frame rail and the other end of the handle on the other frame rail. Now slide the handle under the bolts, so that the bolts will rest on the handle. 2) Pushrod length If the heads or block were ever milled, you will need shorter pushrods. But how do you know how much shorter they need to be? Simple, all you need is an orphaned pushrod, a good hacksaw, a file, an orphaned rocker arm, a tap and some "allthread" or "ready rod" (whichever you prefer to call it). Cut the pushrod in three pieces. The first cut should be in the middle and the second should be about two-thirds towards one end. The pushrod will be hollow, all you need to do file it smooth where you cut it with a hacksaw (this is a more of a precautionary effort than an effort of necessity). With the old pushrod cleaned up all you have to do is find the right sized allthread to fit in the pushrod and tap both pieces of the pushrod (just tap the "inside" pieces of the pushrod, DO NOT tap the "cup" end where the pushrod meets the lifter or the end where the pushrod meets the rocker arm, these two ends must not be cut, filed or modified in any way) to accept the allthread. Thread the allthread into the pushrod. This way you can make the pushrod longer or shorter just by giving one end of the pushrod a twist. With the head bolted onto the block properly, and cinched down to specs place some of the lifters in the lifter bores. Turn the camshaft until the lobe is pointed down, so that the cam will not lift the lifter. Take a magic marker and mark the top of the valve stem (where the rocker are rests). Cinch the rocker arm down like you normally would with any other pushrod. Turn the motor over a few times by hand, enough to wipe some of the marker ink off of the valve stem. Where the tip of the rocker arm is riding on the valve stem, there should be a stripe across the valve stem where the rocker arm wore some of the ink off. If the stripe is towards the exhaust side of the stem, the pushrod is too long, if the stripe is more towards the intake side, the pushrod is too short, if the stripe is in the middle then its just right. If the stripe is too far one way lengthen or shorten the pushrod until the stripe appears in the middle. Measure the pushrod with a pair of calipers (do not use a tape measure for this measuring, you must measure EXACT length) then call your favorite cam manufacturer and have them custom make a set of pushrods to your specs. Comp cams can make a set of pushrods for about anything, as will most major cam companies. 3) Getting started If your starter has to be shimmed for proper alignment with the flywheel, it can be hell getting the starter and shims limed up with the holes in the block. There is however a solution to all this. All you need is about an inch of electrical tape and some very thin sheet metal (a beer/pop can will work very well here). Most shims will have a "nub" on the end opposite of the "open end" bolthole. Wrap the inch of tape around the nubs (if you need to use more than one shim, if you only need one shim skip this step) so that they are all lined up. Cut two square pieces of sheet metal (pop can) about one inch by one inch. Cut a slot out of the square piece (so the sheet metal looks like a horse shoe or a "U") that is just as big as the threads of the bolt. This sheet metal will be a makeshift nut, a very thin nut. Put the bolts through the starter (like they normally go) then put the shim(s) on. With the bolts in place and the shims on place your sheet metal "nuts" on the threads of the bolt. Voila, now your bolts are held in place by the sheet metal, now your shims will stay put. All you have to do is line up the starter bolts with their appropriate holes. Much easier isn't it?

	Like to compare? Here are a few campisons. (more coming soon) Sometimes people like to compare apples to oranges. Here I plan on highlighting a comparison, only I will be comparing apples to apples, or oranges to oranges, whichever you prefer. While the diehard Pontiac guys will scream "Pontiac forever," the Chevy guys will scream "Chevy forever," and then there are those of us who couldn't care less so long as the engine is healthy enough to make the tires fight for traction. The point here is this; both engines highlighted here can run like a streak, but each has its advantages and disadvantages over the other. What I plan on doing here is to compare the Pontiac 400 to the Chevy 400, either are fine engines, but I will leave it up to you to decide which you prefer. I hate to bring this up, but the Chevy has an obvious advantage here in that due to the part swapping ability and the fact that the small block Chevy is still being produced as we speak, the Chevy has a greater selection of aftermarket parts, at a cheaper price to boot. CHEVY: most Chevy heads flow better than most other Pontiac heads. PONTIAC: "6X" heads come standard with screw in studs, the Chevy studs are pressed. C: aftermarket Chevy heads are cheaper and have a far greater selection. P: Pontiac heads do exist, but they aren't exactly a prime example of affordability, selection isn't as good either. C: Chevy 400s aren't exactly easy to find. P: Pontiac 400s aren't much easier to find, but they are a little easier. C: Chevy 400 can be stroked or destroked due to the many different bore x stroke combinations that Chevy offered through the years. P: not quite as many different stroke combinations. You essentially have two basic strokes, 3.75 & 4.210. C: the Chevy 400 has a pathetically poor stroke: rod ratio. P: Pontiac 400 has far superior stroke: rod ratio. C: Chevy connecting rods are pretty stout as well as affordable. P: Pontiac connecting rods are "soft," the good rods aren't too cheap. C: Chevy intake manifolds are more affordable, and have greater variety. P: Pontiac intakes have longer intake runners for better torque. C: Chevy 400 is lighter, makes for better handling. P: in all reality, the added weight of the Pontiac 400 doesn't make THAT much difference. C: to remove the intake on a Chevy, you need to remove the distributor P: on Pontiacs you don't. C: Chevy 400 can't take more than a .030 overbore. P: Pontiacs 400 can take .060 overbore. C: Chevy 400 requires heads especially made for the 400; non-400 heads can still be modified to fit a 400. P: Pontiac 400 can use heads from any Pontiac engine, with no modification. C: Neoprene rear main seal. P: rope rear main seal C: Chevy 400 has to use special externally balanced flywheel that wont interchange with other small blocks. P: since all "small" Pontiac engines have the same stroke they can use the same balancer and fly wheel. However, Pontiac balancers and flexplates have varied through the years, so they might be different as well. C: Chevy 400 has reputation for developing cracked blocks and heads. P: Pontiac 400 doesn't seem to have this reputation. C: A Chevy 400 with 4 bolt mains is actually weaker than a 2 bolt main block. P: Pontiac 400 uses a pretty stout block; either 2 or 4 bolt blocks are very strong. C: Only other small block cranks will fit in a Chevy 400 block. P: Pontiac 400 can accept any Pontiac crank, assuming it's a V8 of course. 301 excluded, they share no similarities with traditional Pontiac engines. C: Small block Chevy engines have oiling system far superior to just about everything. P: Pontiac oiling system is adequate, nothing more. C: A firebird with a Chevy engine is still pretty cool. P: But a Camaro with a Pontiac engine is cooler. CONCLUTION: Dead heat, Pontiac ties Chevy 5:5, the Chevy however still has the edge of having cheap aftermarket parts. Here we are again comparing engines. In this comparison I will be highlighting the Chevy 454 and the Pontiac 455. The big-block Chevy doesn't enjoy the same parts availability and affordability as the small block does, so this match will be a little more even. The Chevy does have one major advantage that just might spell "victory" in this match, the heads. Big block Chevy heads can flow more than any Pontiac head ever dreamed of and since more airflow = more power, the Chevy has the ability to make monstrous juice without getting really exotic in the shortblock, while the Pontiac will require better and more exotic (read much more expensive) parts to make the same power. C: Chevy 454s are quite expensive due to demand. P: Pontiac 455s are expensive due to demand and the fact that they are so rare. C: Chevy 454 is much more plentiful due to more years of production. P: Pontiac 455 is a super rare piece due to a greatly shorter production run. When you find the goose that laid the golden egg, pull all of its teeth, that would be easier that finding a 455. C: Chevy big block heads have airflow rivaled by nothing accept Chrysler's exotic "Hemi." P: Pontiac heads don't even begin to compare in the airflow department. C: While a core engine may be just as expensive; aftermarket parts are still a bit cheaper. P: In all reality, it doesn't make that much difference in the long run. C: Chevy big blocks are heavier, so they reduce braking and handling and often require replacement of the front springs to keep the suspension from "bottoming out." P: Pontiac has the advantage here, they're just plain lighter. C: Big block Chevys have a tendency to overheat. P: Pontiacs don't usually overheat too badly, unless there is a mechanical failure somewhere. C: Neoprene rear main seal. P: Rope rear main seal. C: Big block Chevys have a horrendous appetite for gas, no matter what you do to them. P: Pontiacs are a bit easier on the dinosaur urine. C: 454 has a shorter stroke, to help make more horsepower. P: 455 has a longer stroke, to make more low-end torque. C: Chevy 454 has superior oiling system. P: Pontiac oiling system can keep up, but requires a lot of work. C: Chevy 454 is one BIG hunk of iron, so it isn't very compact. P: poncho is a bit smaller, so it can fit into engine bays a little better. C: Even though the Chevy has a shorter stroke it can still make gobs of torque (just look at some of the dyno pulls) AND get into some pretty serious rpms. P: Due to the long stroke the Pontiac doesn't have the rpm capability, so it's best to build them to perform below the 5000-5500 rpm range. C: Plainly and simply the 454 has the potential to make more power due to a far greater head design. The heads just plain flow better. P: don't get me wrong, the 455 can run good, but the heads are a stumbling block here. CONCLUTION: Chevy beats the Pontiac 6:5. One must consider that the 454 will use more fuel than practical. A 454 isn't the best contender for a daily driver, due to its horrendous appetite for fuel. Now its time to let the 350s duke it out lets see who wins this slugfest. I will say it right now that the 350 wasn't Pontiacs best idea, it has way too much stroke and not enough bore. Because of this the Pontiac runs out of breath around 5000 rpm, while the Chevy can be built to wind like there is no tomorrow while still having a bit of power on the low end of the powerband. And yet again, the Chevy will enjoy the advantage of a near infinite supply of aftermarket parts at a very affordable price. C: Chevy 350 is cheap due to a near never-ending supply, P: Pontiac 350 is cheap due to lack of demand. C: Chevy 350 is extremely cheap to rebuild. P: Pontiac 350 costs more to build. C: Chevy heads flow better. P: Pontiac 350 heads don't flow too well. C: Chevy has better bore/ stroke relationship, this spells horsepower capability. P: Pontiac has longer stroke to make great torque. C: The Chevy 350 is probably the easiest engine to find parts for; there is a near infinite supply of aftermarket parts that are a direct bolt on. P: Pontiac 350 doesn't enjoy the same cheap, plentiful supply of parts. C: Neoprene rear main seal P: Rope rear main seal. C: Chevy 350 is lighter, translating into better breaking and handling. P: Pontiac 350 is heavier. C: Chevy is smaller, so it can fit into more compact spaces. P: Pontiac is bigger. CONCLUTION: Chevy beats Pontiac 7:1. The Pontiac just can't compare to the Chevy. The Chevy 350 just has way too many advantages here. If the Pontiac guys had used the concept of bigger isn't always better when it came to the stroke department, the Pontiac 350 may have been a better engine. The Pontiac 350 can't wind much more than 5000 rpm and since you have to have rpm to make horsepower the Pontiac is limited to putting all of the eggs into the (below 5000 rpm) torque basket. A Pontiac 350 may be fine for a daily driver, but if you are even thinking of a visit to the track, build something else. Now we will be comparing the small block Chevy 400 to the big block Chevy 402. Lets see how this turns out. If you have ever peeked under the hood of a Classic Hot rod chances are that a small block Chevy will be peeking back at you. Even if you don't have a classic hot rod, the small block Chevy is still a common site to see. The point: The small block Chevy has probably been built more than any other engine in the later half of the 20th century, so there are more aftermarket parts than a person could use on one in TWO lifetimes Big block: Superior head design allows for much more power. Small block: Small block heads are lighter. BB: Big blocks are oh so heavy, this spells "bad handling" in three-inch bold print. SB: Small blocks are lighter, and more compact to fit in many tight places. BB: Big blocks are built with more heavy-duty parts, so if you're racing you wont have to perform as many rebuilds. SB: Small blocks are cheaper to rebuild. BB: Gallons of gas have nightmares about being run through a big block Chevy. SB: Small blocks are a whole lot easier on the gas. BB: Big blocks have a tendency to overheat. SB: Small block 400 isn't much better. BB: Big blocks have fewer stroke lengths, so there are fewer bore/ stroke combos that can be made from a big block. SB: Small block strokes range from 3-3.75 inches, that's 4 stroke choices. BB: Big block has a very good stroke: rod ratio. SB: stroke: rod ratio is pitiful on a small block 400. BB: Big blocks are about 3-4 times the cost of most small blocks. SB: Small block 400 is kind of hard to come by. BB: More horsepower per cubic inch. SB: more horsepower per dollar. BB: Bigger valves only aid in additional airflow. SB: Plainly and simply put, valves aren't as big. BB: Plentiful supply of aftermarket "go-fast" goodies. SB: Small Block has greater selection of parts at a better price. There are still a few points left to compare I'm sure, but I think I'll cut it off now. Basically put; if you want a daily driver with plenty of juice when you want it, use a small block. If you want an engine that can make bruit power and will probably never see daily street use, use a big block. Big blocks just use way more gas than practical to be daily drivers, if you want good mileage for a daily driver, use a small block.