- Jul 8, 2005
- on the A684
On behalf of everyone, we would like to know your opinion on which oil we should use in our various Fiats please Or if you have a general opinion on oil.
well guy, ive been using castrol products for yrs and yrs, and ive never had a problem with it. always changed it every 3-5000 miles.Guy Croft said:What oil? Experience (usually harsh) counts here.
I build up with ordinary Castrol GTX (10W/40, non synthetic multigrade). This is just for corrosion protection and initial lubrication only.
For running-in up to 3/4 power, almost any big name brand oil will do, Castrol, Texaco, Esso, Valvoline, Gulf, Fina, Total, Shell, get a multigrade semi-synthetic oils pref min 50 upper temp viscosity rating (ie 5W/40, 10W/40, 15W/40) - but 40 will do - with minimum API SH or CCMC G4 or higher ratings (Look at the back of the tin higher rated would be API SJ, or CCMC G5, the ratings go up in numerical or alphabetical order). I place more stock by CCMC than API, the US API rating system places greater emphasis on detergent and dispersant content than film strength and lubricity. Don't run-in (bed-in) on pure synthetics.
After break in I recommend 10W/60 Selenia Racing these days, but that said my engines get driven to the limit. In my opinion as a race engine builder, this is the finest oil available to the clubman racer that money can buy. The only other one I sometimes suggest is Valvoline VR1 (20W/50). I steer clear of anything less than 50 upper temp viscosity rating.
I shall now sit back and wait for the 'what do you think of this ....' questions, bring them on guys, I'll do my best.
only one thing guy to ask;-Guy Croft said:Andy, greetings indeed, dear friend, I'll come back to the question of synthetics.
break-in and change interval - may be useful -
GUY CROFT RACING ENGINES SEP 2005
GENERAL ENGINE START-UP INFO – READ ALL THE WAY THRU - BEFORE STARTING ENGINE!
1. Ensure sump plug is secure. 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. If engine is new use non-synthetic 10W/40 OR BETTER 10W/50 oil for break-in eg Castrol GTX. It is recommended for initial start-up that the feed to the oil pressure accumulator (if fitted) is disconnected - thus closing the solenoid valve and preventing it from drawing oil from the engine. The additional oil for the accumulator can be added later].
2. 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. Remove spark plugs. Disconnect the electric fuel pump and the ignition coil live feed. You must ensure the oil pump is wetted and primed by removing the oil filter housing - or - accessing the feed from the oil pump and squirting oil down the gallery to the pump. You must NOT hook up oil lines until oil backs up from this gallery or hose line from the pump when the engine is cranked or aux d/s spun.
4. Once you are sure the pump is primed and functioning correctly crank up main engine oil pressure 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 20sec altogether, the oil pressure should easily come up by this time. Do not start the unit until oil pressure registers on the oil pressure gauge. An excellent method of priming is to spin the aux driveshaft with a high-torque electric drill, although this does mean removing the cambelt.
5. Connect the fuel pump, allow the system to fill and check for fuel leaks.
6. 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 standard road plugs for the initial start-up.
8. Prime the carbs - if used - by several applications of full throttle to actuate the pump jets.
9. Start engine with minimum application of the throttle.
10. Adjust idle speed to 800 rpm and strobe/set ignition timing (usually 10 deg +/- 2 deg at 800 rpm is about right). Do this immediately and as quickly as possible.
11. If new cams have been fitted it is vital to keep the engine running at about 2000 rpm for 5 minutes to allow cams to bed in. If engine will not run comfortably at this speed without overheating turn off and investigate the cause.
12. You have just run the engine for the first time - so take time go round and double check that everything from the silencer to the alternator belt is secure!
Note: If an accumulator is fitted, the sump needs to be overfilled depending on its capacity. The unit will automatically draw off this extra oil after the engine starts.
1. Check cooling system for leaks. Don’t ignore drips – they usually get worse.
2. Check oil level and top-up if required.
3. Start engine, check oil pressure and run at 2000 rpm to allow cams to bed in if not already done., 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: Hook up unit feed (it should ideally be wired so as to be activated by the ignition switch) and 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 up and check cooling system integrity and temperature. The engine should respond normally when the throttle is blipped lightly – if it does not, do not drive the vehicle and contact engine builder for advice.
6. You can now drive the vehicle but for no more than 1/2hr and only at low load and speed, or leave it idling for 1/2hr, but do 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 – settings depend on bolt and gasket type.
8. Fit the race plugs if specified.
1. For the 1st hour do just local driving and do not exceed ½ throttle and 4500rpm. Use the gears very freely and at all costs avoid ‘high-gear – low engine speed’ as this will lead to heavy bearing load with low oil pump output. Stop frequently 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’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, terminal 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. After the first hour of light running you should carry out a compression test. Typically the low compression engine (7.2/1) will give 180 psi or over and high compression units 210 or more. There should be no more than 5% variance between cylinders.
3. Continue the break-in phase and extend throttle to 3/4 and 5000rpm. The engine requires to be driven at a range of speeds within these limits for a further 200 miles to fully bed in, but make sure that increased speed and load is accompanied by periodic plug checks to confirm mixture or damage may occur.
4. Do not attempt full-throttle runs until you have put race oil in the engine and changed the filter.
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.
You get what you pay for – buy the best oil you can afford and the best petrol too. Some fuels are bought on the spot market and Texaco, Shell, Gulf are my firm recommendations. If you use cheap petrol – expect a lot of combustion chamber, ring and valve fouling. Same is true of 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 change interval:
Road – 6000 miles
Clubman rally – 3 times per season
Clubman Race – mid season
Remember that a remote filter set-up requires a filter with an anti-drainback valve.
If you can find a rolling-road you trust, the engine should have a confirmatory power run to check jetting. I only recommend Northampton Motorsport 01604 766624.
Contact GC for info on settings as these vary according to engine type. Do not allow 3rd parties – however well-intentioned - to tamper with GC settings without checking with GC or you will invalidate any warranty immediately.
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
problem with a lot of commercial cam lube, is they are not too clever. who's do you use? [i dont change eh guy]Guy Croft said:5 minutes is plenty at that rpm.
according to legend, sierra cosworth engines would p**s synthectics out and tend to go bang. tolerances must have been pretty large.oilman said:Indeed I do.
The most common reason for this is seal compatability because pao tends to shrink seals whereas esters swell seals. It is pretty outdated now as I'm not aware of any OEM's not using compatible seals, even Mazda.
Many OEM's today specify synthetic oils only due to variable servicing routines.
sumplug said:according to legend, sierra cosworth engines would p**s synthectics out and tend to go bang. tolerances must have been pretty large.
oilman said:I would say that is closer to myth!
The correct grade synthetic is the same thickness as any other oil.
A 15w-50 synthetic is the same thickness as a 15w-50 mineral oil, that is why they are rated as 15w-50.
The fastest street legal sierra cosworth in the world uses synthetic oil, I know that because I supply it!