Probably the most important part of any car is the engine. If you have ever wounded why your car can’t clime like those other sand rails it’s probably because they have a better engine. The first question you have to ask your self is how far do I want to go? How much money do I have to put into it? The basic engine is the 1600cc. If your budget stops here make sure it’s a DP (dual port). The next size up is a 1776. This is the biggest engine out there that’s reliable. Don’t get me wrong you might have lots of luck with bigger engines but all my buddies I’ve talked to that have had a 1835 or bigger have had a lot of problems with it and again don’t get me wrong when I say it’s not reliable. A popular choice of bajas is the 1835 DP. The list goes on beyond 3000cc so I am going to stop here but if you really want hp with something like 2000+cc get a type 4 or Porsche engine. They are if you hale an unlimited budget. They can be bored out to 3000cc easily with little or no problems. I hope this will help you to pick out what size you want but it doesn’t stop with a good long block. There are many other things to consider.
Air Filter
A good air filter is very important when out on long off-road trips or in the sand. The stock filter is really no good for off-road driving. There are many after market styles to choose from. Probably your best bet would be a dual stage filter. This meant there are two elements in one housing. There are also single stage elements. One of the only good single stage filters would be a KnN cotton-gauge element. Another thing you can do with a KnN is to combine it with a dual stage filter. One of the most important things you need besides a good filter is the location of the filter. Since most of us only have one filter we don’t have to worry about this but, when some racers put on more than one filter they have to make an air box. An air box is simply a box where you can mount more than one filter. If you have one of these or have a large filter that won’t mount on top of the carb and need to mount it some where else you need to make one small change. You will have to mount it some where as close to the carb as possible, with a straight path with no restrictions. The bast thing to use here is a large green stripe radiator hose. Another thing to consider with a filter is a good breather.
Cooling
The most important to protect your engine from is heat. While a stock 1600cc engine will be fine with the stock oil cooler, a 1776 or bigger engine will need an external oil cooler. When mounting a cooler remember the reason you put one on in the first place, because of heat. Don’t mount one in the engine compartment or behind the fan shroud. This will do nothing for your engine, and will be nothing more than a waist of money. Also when selecting a location to mount a cooler remember to protect it from rocks. Don’t put it somewhere where rocks might fly up and damage it resulting in an oil leek. If your car doesn’t have windows a good place would be inside the car. Here the cooler would be protected and have high airflow. Another good location is below the back window. Airflow is ok and it’s protected. The roof is another possible location. Airflow is good and it’s protected but will be crushed in a rollover.
Ignition
Distributer-A stock distributer works well with a stock stock carb. If you change your carb, changing your distributer would be a good idea. I recomend a Bosch 009. I have heard they can burn up a stock engine,but so far I have not had any trouble with mine.
Alternator-If you plan on running extra lights for night driving you will need an alternator. Get a 54 amp or larger. A 54 amp would be good for about an extra 400W worth of lights.
Dust and water proofing-Two things you dont wan't in your ignition are dust and water. Dust is not a bug problem, but water can make your car stall out quickly. There are kits you can buy for this. It's like a glove that couvers the distributer and coil, but if you want to save the $6.00 use silicone sealer.
