Engine Modifications, Carbies, Exhaust, Heads etc.
Okay folks, straight into it. Have you ever wanted to do some mods to your six cylinder (those of you with V8 motors, please proceed to the last line) to get a bit of performance without outlaying a whole lot of bills?
Here is some more info at this site
www.oldholden.com/possible/index.php/Improving_performance_on_6cyl_motors
Well first of all if your motor is in sound condition, we will start from there. If not, then you will have a multitude of six’s to choose from. Starting with the original 149 red motor all the way to a 3.3 (202) fuel injected black motor from a VK Commodore. The politics of each motor and its attributes or failings will not be mentioned here.
You’d be surprised what you can pick up for around 500 bucks. A good start is a good top end package. For example Holley 350 carbie, inlet manifold, accelerator cable and air cleaner. The difference will be remarkable. Throw another couple of hundred bucks on the counter and you’ll get a set of extractors. A set of HR X2 headers or Torana XU-1 headers is another budget option to consider, especially if you can get the front engine pipes as well, they can set you back as much as $150, but hard to find.
Now if you’re game, we can regrind your camshaft at around $70 and okay for a budget. Or fit a new cam and a set of lifters for around $180. Alloy timing gear is a must and good insurance at around $50. Or a straight cut timing set if you must have a noise. With a few more dollars you get yourself a Hmmm lets see a stage III head for around $400 that is ported, bigger valves, heavier springs. That’s the basic bolt ons for the six. Other options that l can suggest are, regraphing the distributor at around $45 and replacing the points. With this outlay or a similar amount you can go from having about 50-65hp at the rear wheels to maybe 10-20% more, depending on which on which motor you started with, so its a substantial increase in horsepower without to much outlay.
The things to remember are that the blue motor has a 12 port head that flows really well, but you must have twelve port manifolds to suit, and the black motors have computer ignition that can be fitted to your red motor, and fuel injection on some models, but it is virtually impossible to do anything with yourself. Once fitted with fuel injection set up well, some real good economy and horsepower gains are possible. There are quite a few guys getting around now with very well set up injected sixes running on aftermarket Wolf 2D computers that really get things happening.
However, getting back to the mods outlined, they’re budget-costed and effective . Sure, some guys have spent eight grand on a Holden six, but why bother? For that you can change over to a V8 and get more power…..