Looking After (Engine) No 1
Last Updated on Wednesday, 23 June 2010 07:50 Written by RustyW Tuesday, 22 June 2010 15:00
Having been doing this sport for a few years now, and having to find the money to buy and maintain my own engines, I thought I'd share my experiences- so this article is a culmination of several years of racing gas cars and the process I currently go through after each and every race meeting. The following is a guide only, and I do not pretend to be the fountain of all knowledge, indeed, I would be glad to hear from anyone who felt they could add to or modify my regime.
Firstly I must say that having the right tools makes the whole process easier, but also helps keep the screws and other parts of your engine in good order, since you are going to be taking it completely apart after every meeting. I would advise that you select screwdrivers that fit snugly to screws and will not cause the screws to burr etc. You will also need a flywheel puller. Yes I know that you can remove a flywheel by levering it off- but in doing so you are putting a large sideways load on the bearings in your engine which they are not designed to take, and since you will be doing it often then I suggest you get hold of a puller. On the plus side, you will not be buying after run oil. Using my method, I only ever use common all garden 3 in 1 oil which is cheap and easy to get hold of.
The first thing about engine care is golden rule No.1- Only start your engine if you are prepared to strip it and clean it afterward. I know that people often fire their engine up to see if it still runs ok from the last time they used it and then cut it before putting it and their car on a shelf somewhere till race day. If you do this then firstly your engine will not get up to temperature and so will tend to hold condensation inside. It will also have unburnt fuel, which will combine with the moisture and begin attacking the internals, and before you can say…. Well anything its too late. This is especially important after running a new engine in at low temperatures. Also do not switch brand of fuel if at all possible- stay with one fuel and your engine will wear well- switch it and you can accelerate wear since different fuels have different oil types and characteristics.
Well lets begin… here is a picture of my sirio evo4 just pulled out of my car after a weekend at Mendip. First thing is to clean the outside before opening it up. I use Brake cleaner for this- not the aerosol type, but just the liquid. You can get hold of a 5litre can for around £8 from a friendly motor factor or garage. Remember to take precautions with your eyes when using this stuff. I also use disposable rubber gloves at this point. I dispense the cleaner from a pressurised pump bottle , but you could use an old trigger bottle from the house. I also use a compressed airline to blow it off the engine whilst it is still wet. Whilst doing this I keep a cap or one finger over the exhaust outlet to prevent debris or solvent from going into the engine.
You should end up with something like this- 
Take off the back plate and as you can see below, because I go through this procedure every meeting, your internals just look clean and in good condition… 
Next, loosen the glow plug, strip off the clutch, and take off the cooling head and underhead. Slide out the liner, carefully unhook the piston and conrod from the crank and remove it before taking out the crank. Remove the carb, and place it to one side for later. The internals should look a bit like this- 
You should see that this particular crank has putty in it DO NOT allow any solvent to come into contact with the putty- simply wipe the crank off with kitchen roll, add a few drops of 3 in 1 oil and wipe it over. Do not immerse it in oil, but just a light coating. Finish by blowing it with compressed air if you have it.
Next I take an old crank and put it in the engine, push on the backplate and fill the engine with brake cleaner. With the engine full, I then spin the crank to wash the engine bearings of any nitro fuel left on them. Take the crank out and blow out the engine from the small bearing end. Repeat this process until you feel happy that the inside the bearings have been flushed and that there are no contaminants left. When dry drop a few drops of oil into the bearings, replace the crank and spin it in to check for grit/wear. You can tell this by feeling the grit with your fingers as you turn the crank in the bearings.
Next up - the piston. As you see below there is a nice brown coating from the combustion. Most of this simply wipes off. For the bit that doesn’t, use some more kitchen roll with brake cleaner. 
After the piston gets cleaned, take a small piece of Brasso wadding and very lightly clean up the last deposits on the piston- regular engine cleaning means that this should be a doddle. Make sure that you clean off all the Brasso with kitchen roll and rinse with more brake cleaner. Next flush the little end bearing with more brake cleaner by holding the piston assembly upside down and waggling the piston on the little end. Blow it out to dry.
Next examine the liner for damage and cleanliness. I only polish the outside of the liner with wadding, although I do know racers who also do the inside. Complete the cleaning by also polishing the button and making sure you have cleaned off all the Brasso compound. 
We are now ready for re assembly. First add 1 or 2 drops of 3 in 1 oil to the little end joint to the piston and rock back and forth to work it into the bearing. Also place a drop of oil into the ends of the wrist pin. The key to the oil is not to use too much- it is only there to prevent corrosion and lubricate the joint when you first fire your engine up.
Next place 4-5 drops of oil into the engine and onto both bearings, Insert the clean crank and spin it to ensure that all balls in the race are covered. Insert the piston and just as you hook it over the crank pin, again add a drop of oil to this joint as below ...
Moving onto the liner, align it in the engine with the piston just located. Add 3 or so drops of oil to the top of the piston and allow it to run around the edge so that all the piston/liner contact area is lubricated. 
Push down the liner making sure the piston moves away from top dead centre as you do so. Replace the button and cooling head making sure it is tight. Rinse the glow plug in brake cleaner, dry and insert it into the engine. If you allow oil to contaminate the plug, then the engine will not start easily and the filament becomes dirty with deposits when heated. As you replace the backplate, smear a drop of oil around the rubber seal to stop it drying out.
The carb is very simple to clean- just blow it out with the airline and brake cleaner before adding a drop of oil onto the slider and pushing it back and forth to ensure full coating of the moving parts- again smear any rubber gaskets before re assembly onto the engine. Having built your engine back up, you can store it in an airtight container before you next use it in the knowledge that it is ready to go and in perfect order.
When you do come to start it, the first moments of life will be smoky as the oil burns off, but this only lasts a few seconds.
This process is a little involved and you may not want to do this at 10pm on a Sunday night after a long drive from a National, but you don’t have to do it all. I get home and clean off the engine, take it apart and wipe the crank and flush the engine bearings and piston/liner. I then wrap each part in a sheet of kitchen roll and place it all inside a plastic box- ready to clean at another time -It takes 10-15 mins tops. The engine you have been looking at has completed 9 UK National meetings with the original parts having been run on both Saturday and Sunday. It has not missed a beat, nor has it given me any trouble whatsoever.
If you have any comments or questions then PM me (Rustyw) or see me at a meeting and I will be happy to go through it with you.
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written by RustyW, June 24, 2010
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written by Daxcossie, June 24, 2010
I used to inspect / rebuild after every 3rd meet when i was racing. Would always let the engine idle after the final and empty what fuel was left in the tank and lines etc. Would just then use after run oil.
Never had any issues on inspections with pitting or corrosion etc.
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written by S. Steady, June 24, 2010
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written by julius kolff, June 23, 2010
Good article. Good tips for us all!
I personally do not clean the carbon deposits of the piston as I feel they provide a better seal between piston and liner. If there is excessive particle buildup I'll remove that, but the nice golden brown coating as is seen in your engine I do not remove.
Just a matter of personal preference I think.
Ciao
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