Engine start-up info - general - revised 29 Jul 06

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Guy Croft
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Engine start-up info - general - revised 29 Jul 06

Post by Guy Croft » June 28th, 2006, 12:13 pm

This is a set of general instructions only, written for background info. No one set of instructions can appy to every engine. Especially dry-sumped, supercharged units. For your specific engine advice is available from me direct at croftengines@aol.com or via this forum.


1. Ensure sump plug is secure. All oil lines and accessories must be thoroughly cleaned out and new filter fitted. Check all oil and water hose connections and oil filter for security. Fill cooling system with 50% Fiat Paraflu mix. Fill engine oil to level on dipstick or if dry-sump to tank level just below top baffle. If engine is new use non-synthetic 10W/40 oil for break-in eg Castrol GTX. Engines with accumulator: The feed to the oil pressure accumulator should be blanked off using the gate valve - thus preventing the unit from drawing oil from the sump. The unit can be connected up later.
2. New competition cams should be liberally coated with a good brand of cam lube or smeared with molybdenum disulphide grease. Use engine oil to fill the camboxes, the oil filter, cooler, remote filter and as many of the oil lines as practicable.
3. The engine must not be started until all lines and accessories are fully primed and the crankcase and head fully lubricated at high pressure by the oil pump.
4. Oil system priming:
Dry sump: use remote drive to spin dry-sump pump to prime the whole oil circuit & engine. It may be necessary to disconnect hose lines to the pump and prime it to generate pressure.
Wet sump: An excellent method of priming is to spin the aux driveshaft clockwise with a high-torque electric drill, although this does mean removing the cambelt.
If bring-up oil pressure by cranking the engine: Disconnect the electric fuel pump and the ignition coil live feed. A dry pump will NOT self-prime. You must ensure the oil pump is primed by removing the oil filter housing accessing the feed gallery (in the block) from the oil pump and squirting oil down this gallery to the pump. Once you are sure the pump is primed and functioning correctly crank up main engine oil pressure on the starter motor with the plugs out and the throttle wide open. Do not crank the engine for more than 7-8 secs continuously and for more than 20 seconds altogether, the oil pressure should easily come up by this time. Both: You must ensure the oil is reaching the camboxes (highest point) With wet or dry sump do not attempt to start the engine until the unit until oil pressure registers on the oil pressure gauge. There will be a marked change in load and cranking speed at the pump as the oil pressure comes up.
5. Connect the fuel pump, allow the system to fill and check for fuel leaks.
6. Adjust the distributor or ignition system to give the required level of static advance (usually around 10 deg). Connect the ignition system and check that it generates sparks when the engine is cranked, by holding the main feed from the coil to the distributor 0.5cm from an earth point.
7. Fit start-up plugs.
8. Prime the carbs - if used - by several applications of full throttle to actuate the pump jets or apply cold start mechanism.
9. Start engine with minimum application of the throttle. (Especially important on supercharged engines ¢‚¬Å“ too much throttle at cold start can damage the crankshaft bearings) If new cams have been fitted it is vital to then run the engine up to 2000 -2500 rpm and maintain that speed for 15 minutes to allow cams to bed in. If engine will not run comfortably at this speed without overheating turn off and investigate the cause.
10. Adjust idle speed to 800 rpm and strobe/set ignition timing (usually 10 deg +/- 2 deg at 800 rpm is about right).
11. Switch off and check that everything from the silencer to the alternator belt is secure.


1. Check cooling system for leaks. Don¢ž¢t ignore drips ¢‚¬Å“ they usually get worse. Early pattern head gaskets are however prone to leak in the first few hours, visible by a dribble of coolant down the side of the block, but this will stop.
2. Check oil level.
3. Start engine, check oil pressure and when the engine reaches 75 deg C, throttle back and adjust idle speed screw to give 800-850 rpm, then adjust idle mixture to give mixture setting on data sheet, balance carbs if used. Switch off.
4. Accumulator equipped models: This should ideally have been wired so as to be activated by the ignition switch. Remove the gate valve and connect the hose line to the solenoid. Fill engine with additional oil. Restart engine and run at idle for 2-3 mins to allow unit to fill. The unit should register the same pressure as the engine oil pressure gauge at any given speed.
5. Run engine at range of speeds to max 3000 rpm to warm it up and check cooling system integrity and temperature. The engine should respond well when the throttle is blipped ¢‚¬Å“ if it does not, do not drive the vehicle and contact GCRE for advice.
6. Drive the vehicle but about ‚½ hr only at low load and speed, and keep a careful watch on temperatures and make sure the cooling fan cuts in by 90 deg C max.
7. On models where the head gasket is required to be retightened it should now be retightened but you must first leave the engine to cool overnight. Get the torque setting direct from GC ¢‚¬Å“ settings depend on bolt and gasket type.
8. Fit the race plugs if specified.


Don¢ž¢t be in a rush with this. The ideal break-in period is 500 miles road use, or 1.5-2 hrs dyno.
To achieve successful bedding-in of rings, the engine must be run under load, under no account left idling. To bed-in an engine with unproven mixture settings (carbs or injection) a rolling road session is recommended. Break-in with the wrong fuelling or ignition settings will damage the engine.

1. For the 200 miles do just local driving and do not exceed ‚½ throttle and 4500rpm. Use the gears very freely and at all costs avoid heavy load: ‹Å“high-gear ¢‚¬Å“ low engine speed¢ž¢. This will lead to heavy bearing load with low oil pump output. Stop from time to time and check the underbonnet region for leaks and problems. Make sure oil pressure and engine temp is OK and stop immediately at any sign of overheating. Test the engine response on a quiet local circular route void of traffic lights and congestion and don¢ž¢t venture too far, as the engine jetting may be wildly wrong. Do periodic spark plug checks; the plugs should be pale brown to grey around the outer body of the plug with insulator nose pale brown to yellow-white. If the mixture is too lean the engine will overheat and if the mixture is very over-rich, severe piston ring and bearing damage may result. If the engine shows any sign of labouring switch off and recover the car by towing or trailer.
2. For the next 300 miles use throttle to 3/4 and speeds leading up to light load 5000 rpm. Avoid heavy load with high speed.
3. Do not attempt full-throttle runs until you have put post-break-in oil in the engine and changed the filter. (see engine data sheet)


For all GC engines race grade oil should be used, eg: Selenia Racing or similar.
GC strong recommendation is use oil with not less than 50 high temperature viscosity rating, with certification API SH or SJ, CCMG G4 or higher. Buy the best petrol. Texaco, Shell, Esso, Gulf are my recommendations. If you use cheap petrol ¢‚¬Å“ expect a lot of combustion chamber, ring and valve fouling. Oil filter: Motaquip, Cross, Fram, OE and K&N are all good. After any break-in period and major overhaul - change oil and filter. Recommended oil & filter, plugs change interval 6000 miles or annually.

Rolling road: The engine should have a confirmatory power run to check jetting. Contact GC for info on settings as these vary according to engine type. If you allow 3rd parties - however well-intentioned to tamper with GC settings without checking with GC this is totally at your risk. If you use a rolling road, make sure your coolant and oil temps do not exceed:
Coolant: 75-80 deg C
Oil: 80-90 deg C
Joeri Int dyno_01.JPG
After I prepped his head and he made many other mods, Joeri Pronk, restaurant owner from Holland wisely took his 16v Integrale to a very competent rolling road to be set up.
Joeri Int dyno_01.JPG (75.66 KiB) Viewed 16338 times


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