Many contemporary MerCruiser engines employ electronic fuel injection, or EFI, that takes the place of carburetors used on older engines. The components consist of a throttle body, intake manifold, ECU module and sensors. Electronic fuel injection delivers a fuel and air mixture to the engine with more efficiency than carburetor fuel systems.
The conversion requires mechanical expertise, experience interpreting wiring diagrams and the EFI components you obtain at marine service centers based on the size of the engine. Remove the engine cover. Disconnect the cables from the battery and the ground on the engine block.
Turn off the fuel supply valve at the fuel tank. Disconnect the throttle linkage and the fuel line from the carburetor. Remove the carburetor from the intake manifold.
Remove and save the intake manifold bolts. Lift the manifold off the top of the engine. Install the new manifold gasket from the kit onto the intake ports at the cylinder head. Attach the new manifold to the cylinder head with the saved bolts that you torque according to procedures in the service manual.
Detach the pair of electrical wires at the fuel pump.
Disconnect the fuel lines from the pump. Remove the fuel pump. Install a high-output fuel pump. Attach the original fuel supply line from the fuel tank. Attach the new fuel line that connects between the pump and the new EFI throttle body.
Reconnect the original wires to the new pump. Mount the EFI throttle body with fuel injector on the intake manifold. Connect the new fuel line from the fuel pump to the fitting on the injector.
Mount the ECU module at one side of the engine compartment in proximity to the intake manifold on the engine.
Install the fuel sensor from the kit into the threaded port on the manifold near the throttle body. Refer to the wiring diagram from the kit and attach the appropriate sensor wire to the push-in connector at the fuel injector. Route the remaining wire to the ECU module and attach it to the appropriate tab on the module. Install the new throttle position sensor at the recommended location on the intake manifold with the provided bolts. Connect the provided jumper wire to the sensor and the appropriate tab on the ECU module.
EFI/Electronic Fuel Injection Systems
Remove the cover. Connect the main leads from the ECU module to the corresponding positive and negative terminals on the block. Replace the cover.Jeep tj magnum swap (FSM ECU pin out binder)
Reconnect the throttle linkage to the throttle body. Reconnect the battery lead and the ground. Turn on the fuel supply valve at the fuel tank. Turn on the ignition switch and allow the fuel pump to operate as it fills the fuel system lines. Start the engine. William Machin began work in construction at the age of 15, while still in high school.Another 11 second run down the quarter mile.
The 5. Used Magnum engines are readily available, and they make great economic replacements for low power, worn out, or displacement-challenged Dodge, Plymouth, and Chrysler LA V8s or Slant 6 engines.
The best part about using a Magnum engine is that the expensive machine shop bill associated with a full rebuild can generally be avoided. Unlike their low compression LA counterparts, the Magnum engines have better, more consistent machining, lighter internal parts, and performance compatible compression ratios straight from the factory. They also carry hydraulic roller camshafts, capable of generating more street-friendly horsepower than flat tappet designs. Hydraulic roller cams are zero maintenance and there are no worries about zinc content in your oil or flattened lifters.
Because the Magnum is a direct descendent of the LA series engines, they are nearly a direct replacement for an LA small block, and many inexpensive and readily available performance components for the LA series engines are direct bolt-ons. Please Note: All of the information presented here is for use at your own risk.
Working on cars, racing cars, etc. We caution you to use good sense and be careful, but accept no responsibility or liability for any outcome. Give them a look when you need parts! Your email address will not be published. Leave a Reply Cancel reply Your email address will not be published.Magnum motors have been in service for seven years, but Dodge has been building V-8 trucks in record numbers, so these engines have yet to become commonplace.
Rodders, always technically curious, have already posed all the possibilities, with parts swaps foremost among them. So, few Magnum parts aside from the crankshaft, connecting rods, oil pump, distributor, distributor driveshaft, timing chain, sprockets, and some nuts, bolts, and gaskets are compatible with non-Magnum versions of the same engines.
Magnum Interchangeability As with most swaps, the practicality of exchanges between early and late A-engines depends on the availability of parts and financial considerations. Mopar Performance's MP Magnum crate motors, for example, offer bolt-in benefits for most Chrysler models, some of which we'll sample for ourselves when we screw a hot into our Plymouth Valiant test-mobile.
The tweaks and techniques MP uses to morph these motors into crate shape are the basis for the conversions covered here. This review of the main mechanical factors will help clarify which early parts work with which late pieces, and vice versa. Pre-Magnum Heads On A Magnum Block The installation of pre-Magnum cylinder heads on a Magnum block-to take advantage of their availability, flow capacity, shaft-mount rocker arm system, and a wide selection of rocker gear and intake manifolds-involves numerous considerations, some of which have yet to be resolved completely.
But earlier production A-series heads even the legendary J and X muscle-motor castings can't beat a Magnum in out-of-the-box low- and mid-lift airflow. Beyond these considerations, mechanical adaptability isn't as straightforward.
In the first installment of our series, we discussed the differences between the lube routes in Magnum and pre-Magnum engines. To review, the oil passages in older A-blocks run from the second and fourth cam journals to each deck face and feed lube to the rocker gear and valvetrain. Many early-run Magnum blocks had oil holes drilled in the conventional fashion, but some Magnums now come through without them.
In order to use early heads on a late block, the top-side oiling routes must either already be open or be opened up. Although the machine-tool-friendly gray iron blocks have sufficient structure through which to cut the holes, the required passage isn't a direct one.
Lube flow follows a multiplane route, which makes drilling for oil a machine shop operation. But even with open oil holes, there are still concerns as to whether the Magnum's pushrod angles are compatible with the provisions of a non-Magnum head. Don't forget, Magnums have roller tappets, which are taller than slider cam tappets. That affects the pushrod paths between the tappets and the rockers, as well as the clearance at the A-head's pushrod tunnels and outer port walls.
The tighter "tubes" in all earlier heads are another matter, however. If you try to work around this clearance problem by using a pre-Magnum-style slider cam and its shorter tappetsyou must also convert the front of the engine to contain the longer camshaft. But it is not known whether using shorter tappets in taller Magnum bores creates any clearance clash when various valve lengths and lobe and rocker combinations are employed.
But the actual costs depend on the parts you already have on hand. Performance-wise, there's little, if any, advantage to using Magnum heads-again, depending on what's already on the motor. Magnums have slightly larger intake valves 1. Preliminary investigations have shown that a Mag casting flows effectively only up to 0. Displacing 65 cc, compared with the nominal 70 cc of the open chambers, the Magnum's smaller chambers raise static compression by fractions of a point.
But installing Magnum heads means using the retro rocker train rather than the A-motor's advantageous pivot shafts. The swap also requires pushrods of the correct length to fit between the Magnum rockers and non-Magnum tappets and still maintain proper geometry throughout the lift range.
In addition, the vertical intake manifold fasteners on the Magnum head make inlet castings especially sensitive to tightening torque and sequence upon assembly. And carbureted intake systems from earlier Chrysler A-engines are attached by bolts nearly perpendicular to their head face, making it difficult to adapt these systems.
The selection of Magnum-compatible intake manifolds is currently limited to a pair of four-barrel M1 alloy castings from Mopar Performance: the P dual plane and the P single plane. A somewhat cruder approach is to redrill and tap the bolt holes in the Magnum head to suit the attaching specifications of the early manifold.
Although there's not much metal for new fasteners to grab, this setup will seal if all the mating face angles are correct. With the Magnum's intake port only 0. And rules-restricted Magnum bullring racers will have 30 years' worth of OE iron inlet castings to pick from. Last month we outlined how an early A-engine hydraulic cam fits into a Magnum block by using a deeper non-Magnum timing case cover P and the appropriate tappets. The deeper cover makes room for the fuel pump eccentric on an old cam's longer snout, and the cover accepts the mechanical pump.
But using a deep cover also means forgoing the OE Magnum serpentine accessory drivebelt setup. The Magnum timing chain and sprockets will work with an A-series cam, but a non-Magnum cam needs a longer key Chrysler PN for its drive sprocket.Installing a Magnum in place of an LA is mostly a direct swap, but there are a couple of areas where the Magnum differs significantly enough from the LA that modification is required.
This is the part of the 5. Be sure to check your headers for fitment before installing the engine in your car. Depending on which headers you use, you may have a significant grinding job to do. We had to remove nearly the entire mid-mount on our engine. This grinding may be possible with the engine in the car, but it would be difficult, messy, and unpleasant.
An angle grinder makes quick work of this, but is messy! Make sure the engine is properly sealed during grinding, and take the correct precautions to protect yourself and your car from the flying iron dust!
Fortunately, the LA style distributor is a direct drop in. We recommend a unit with a performance advance curve built-in. We recommend using a mini starter. Even with the smaller starter, the block may still require some minor grinding for fit.
If possible, test fit the starter before installation to see if grinding is required. While you can do this with the engine in the car, but it is much easier when the block is on the engine stand. Timing Chain Mopar Small Block engines are hard on timing chains because of the unusually long distance between the cam and crank centerlines. The timing chains stretch easily, resulting in poor performance, or worse, breakage. The classic symptom is the rapidly fluctuating mark on the balancer when using a timing light.
The stock timing chain on a Magnum is not a performance piece. A We recommend the best double roller timing chain you can afford. We also highly recommend the use of a Mopar Timing Chain Tensioner.Display Options. Already know the part number you need? Click here to enter them directly into your cart.
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International delivery. United States delivery. Maximize the power, efficiency, and performance of your engine with a new electronic fuel injection system right for your application. Recent Vehicles. Refine results by: Current Vehicle Recent Vehicles. Recently Searched.As we have demonstrated with our shop Dodge Dart, it is possible to turn a junkyard engine into a real screamer. Attention to detail and a little extra money spent in the right places are the keys to success.
Cylinder Heads The key to horsepower is good cylinder heads. Magnum engines have some of the best flowing heads Mopar has ever released. Unfortunately, they are prone to cracking between the seats. This makes spending money to upgrade them dicey, at best.
Considering the affordability of some aftermarket options, and the performance gains realized with them, we think putting a new set of heads on your Magnum is a must. These heads, made by Australian company Engine Quest also called EQwere created as a stock replacement for the Ram truck guys and gals when their factory induction-hardened heads inevitably cracked. Being gearheads themselves, EQ designed heads that flow even better than factory castings.
They even created a version with the LA intake bolt pattern. They carry many of the same improvements as the EQ heads, with a slightly larger combustion chamber 62cc. They are more expensive than the EQ and may not flow as well. Details Here:.
Edelbrock also makes heads for the Magnum. Edelbrock does not sell their Magnum heads with the LA intake bolt pattern. Head Gaskets Magnum engines have more consistent machining than their LA predecessors, but the factory piston is still about. This reduces compression potential, and thus horsepower. Cleanup is a snap as well. They seal well and increase compression significantly over stock. There are some adequate cams from Mopar crate motors, but almost all of the shelf offerings from Comp, Crane, etc.
The best camshaft solution is a custom grind. Additionally, you can have it ground on an LA style cam core to get the proper snout for running a fuel pump eccentric if you want to run a mechanical fuel pump. Watch this space in the future for true performance camshafts available to Magnum swappers!
We will have cams to order without the hassle of having a custom grind. Important note: On custom cams, the base circle is typically a little smaller than the stock Magnum cam, necessitating longer pushrods. Serious racers should seek a more robust solution than stock or cheap replacement pushrods, but those linked to above have served us very will in our shop car. Important note 2: There is a persistent rumor that the Magnum engine will not tolerate camshafts with higher than.
This is not true. While max lift is related to cam duration and other factors, we are using a. Hydraulic Roller Vs. Flat Tappet You could, theoretically, use a flat tappet LA camshaft in your Magnum engine, but we advise against it.
The hydraulic roller system, stock on all Magnum engines, is superior for producing horsepower and requires no maintenance. Even better, there is no cam break in, worry over zinc levels in the oil, or other flat tappet hassles to worry about. Additionally, hydraulic roller lifters are reusable after a cam change.Do you need a custom kit built for your application? Do you need a system installed and tuned?
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