Mark Smith from across the pond writes. How to install an engine and transmission in a Cobra.
If you have a few basic tools, and can follow instructions, you can install your own engine and transmission.
The following is a step by step guide of the installation of a small block Chevy engine and Tremec transmission in a Cobra kit car, but the process is generic for all engine and car types.
Firstly, we will assume that you have the following parts sitting on your garage floor:-
· Engine, complete with front pulleys, belts, alternator, starter motor and manual transmission flywheel.
· Engine mounts.
· Transmission and transmission mounts
· Bellhousing, clutch, clutch actuating parts.
· Drive shaft with correct universal joint installed to mate transmission to differential.
The engine and transmission is installed as one unit, so firstly we need to bolt all the bits together.
Your Engine Factory engine is a high performance unit, so you need to ensure that your bellhousing is correctly aligned with the engine and transmission. This is a straightforward process, which will ensure that undue stresses are not placed on the crankshaft, and that gear shifting is smooth and efficient. This is known as ‘dialling in’ the bell housing.
· Remove the starter motor from the engine.
· Bolt the bellhousing to the engine block, and torque to the manufacturer’s recommendations. (Do not install clutch at this stage).
· You will need a magnetic base dial indicator, which you can hire or can be purchased from most auto-parts stores for about $25.
· Position the base of the dial indicator on the flywheel, and adjust the indicator so that it is resting on the inside circumference of the bellhousing exit hole.
· Using a suitable socket, get a friend to rotate the crankshaft at the pulley end.
· Note the dial reading during the different positions of rotation. An inspection mirror is useful here to enable readings to be taken through the full 360 degrees of rotation.
· Maximum runout should be no greater than +/- 0.005 inch from the center.
· Off-set dowel pins are utilised to correct any misalignment.
Remove the bellhousing from the engine.
Install the spigot bearing in the end of the crankshaft. This is a tight interference fit. Use a socket spanner of a suitable size with an extension handle, and tap into place. Make sure that you have installed it the right way round. The spigot bearing centers the transmission input shaft on the crankshaft).
Install the clutch following the manufacturer’s instructions. You will need a clutch installation tool to center the clutch.
Fit the clutch actuating parts inside the bellhousing following the manufacturer’s instructions. This will comprise the actuating arm and throw-out bearing.
Bolt the bellhousing to the transmission, ensuring that the transmission input shaft passes through the thow-out bearing. Test the operation of the clutch actuating arm by moving it back and forwards. The thow-out bearing should move freely on the transmission shaft.
Lift up the transmission and bellhousing assembly, and guide the transmission input shaft into the splines on the clutch. The front surface of the bell housing should now be mated to the rear of the engine block. If a gap is evident, then the splines have not meshed. Remove and try again. A small amount of jiggling may be required, but do not force it. If it still will not fit, remove and re center the clutch and try again.
Depending on your method of clutch operation, if you have one, now install the clutch slave cylinder following your supplier’s instructions. If you have a ‘pusher’ type of slave cylinder, mount this to the transmission using a suitable bracket, which should be supplied with your slave cylinder. ‘Puller’ types should obviously be mounted to the engine. Adjust the nut on the slave cylinder rod so that it touches the actuating arm.. ((Note, it is quite normal that the clutch may begin to slip after say 1000 miles as the clutch components have settled in. Simply re-adjust the slave cylinder rod best to have about 1 inch of play in clutch pedal).
Re install the starter motor.
Congratulations! You now have a fully assembled engine and transmission unit.
You will need an engine hoist, and because the engine sits relatively far back in the engine compartment, you will need a ‘long arm’ variety, rated appropriately.
Call in some favours, and get the help of two friends!
· Install the engine mounts on to the engine.
· Remove the hood.
· Remove the transmission shifter tab. (There is no need to jack the car up if this is done).
· Lift up the engine/transmission with the hoist using a chain rated to lift both the weight of engine and transmission, Follow all safety precautions. Support the weight of the transmission at the rear.
· Position the engine/transmission unit over the engine bay, with the transmission angled down as far as possible.
· Slowly and gradually, lower the unit down, and at the same time move it backwards until it is positioned over the chassis engine mounts. Ensure the transmission is supported and guided at the rear.
· Lower the unit on to the chassis engine mounts, and pass through the securing bolts.
· Support the transmission with a trolley jack, and check that it is square with the chassis.
· Center punch and drill the holes in the chassis for the transmission mounting kit, and secure the transmission in position.
· Tighten the engine mount bolts.
· Re install the transmission shifter tab.
· Install the drive-shaft by sliding the splined end into the rear of the transmission, and bolt the other end to the differential, ensuring that it is torqued to the correct setting. Note, if you are using a new transmission, remember to remove the transit oil bung at the rear of the transmission.
Congratulations, you have now finished the installation! All that remains now is to connect the various hoses and electrics.
· Connect the top and bottom hoses to the radiator. Ensure the bottom radiator hose is of the type that is reinforced with spiral wire on the inside. Your engine sucks coolant from the bottom of the radiator, and under heavy load, this can cause a non-reinforced hose to collapse, with resultant coolant starvation.
· Connect the header tank hoses to the coolant system. Ensure that the header tank is positioned higher than the rest of the coolant system.
· If you are using a heater, remove the blanking plugs, and plumb this in to the coolant outlets/inlets on the top of the water pump and the left hand side of the inlet manifold.
· Remove the blanking plug, and connect the water temperature sender unit to the right hand inlet manifold water outlet.
· Remove the plug and connect the oil pressure sender unit at the rear of the block behind the distributor. It is recommended that you use a ‘T’ piece to connect both a gauge and a separate warning light.
· Connect an ignition live wire to the HEI distributor marked ‘BATT’.
· Connect the tachometer wire to the HEI distributor marked ‘TACH’.
· Connect an ignition live wire to the red wire on the automatic choke unit (if fitted). Alternatively, connect up the choke cable linkage if running a manual choke.
· Connect the appropriate wires to the alternator (either three wires, or single wire hook up).
· Connect the three wires to the starter motor.
· Install the throttle cable and linkage together with a throttle cable return spring. It is recommended that you use a double spring type.
· Connect an earth strap between the chassis and the engine. You can use a spare hole on the front or back of the cylinder heads.
· Connect the fuel line to the fuel pump.
· Connect the hydraulic line to the clutch slave cylinder, and bleed the system.
Engine ‘hook up’ is now complete!
First start up
· Disconnect the fuel line and ignition feed to the distributor.
· Ensure engine and transmission are filled with the appropriate oils.
· Fill the engine and coolant system with coolant through the header tank. Turn the engine over so that the coolant moves through the system, and top up as needed. The header tank should be approximately one-third full.
· Reconnect the fuel line and ignition feed to the distributor.
· If you have not yet connected up the exhaust system, ensure that the spark plug leads are clear of the exhaust ports.
· Start the engine! The engine should fire after a few initial cranks. Immediately check that the oil pressure is O.K. Check for any coolant line leaks, or fuel leaks. Turn the engine off after about 20 seconds and check the coolant level.
Post installation checks
· Check the torque setting on the engine and transmission mounts, and the engine/bellhousing/transmission bolts.
· Drain, flush and refill the coolant system. Surface rust may have accumulated on the inside of the engine coolant galleries if it has been left standing for some time before installation. Use a good quality water/antifreeze mix, irrespective of climate, as the antifreeze also acts as a corrosion inhibitor.
· Change the oil and filter after the first 500 miles.
Send Engine Factory a picture of your finished ride!