Motoriding

Archive for August, 2009

Motorcycle And Atv Cylinder Rebuilding Options

Recent History of Cylinder Types
The oldest and most common method of cylinder design is a cast iron block that is machined with a cylindrical bore directly from a solid casting. There is also a cast iron block that incorporates a sleeve that is pressed into the iron block. Generally iron block motors werent very successful in small engines. Most small engines were used in vehicles and equipment that needed to be light and mobile. This made cast iron blocks undesirable for this purpose. There were a lot of single cylinder motors used in lawn mowers construction equipment scooters small tractors and small motorcycles that used cast iron block motors in the early years. These began to disappear in the 60s and they were replaced by aluminum block motors with castin iron liners. This opened the door for new lightweight motors that could be used in many more applications and in bigger displacements than ever before. This was accomplished by placing a cast iron sleeve into the mold before the molten aluminum was poured into the mold. This made the sleeve an integral part of the cylinder block. The sleeve usually had locking rings or flanges around the outside to prevent it from slipping in the casting as the engine expanded from the heat generated by the combustion process. A major problem occurred often when air pockets would develop during the casting operation around the sleeve. This caused hot spots and often caused premature engine cylinder failure.
There is another type of aluminum block with a cast iron sleeve that wasnt castin; it is installed in the block after casting. The cylinder bore of the aluminum block is machined to 35 thousands of an inch less than the sleeve diameter block is then heated to around 600 degrees Fahrenheit and the sleeve is dropped in. When the block cools the sleeve is held in place by the interference fit and the flange at the top or bottom of the cylinder. This cylinder can be rebuilt by simply reheating the block to 600 degrees and removing the old sleeve and replacing it with a new one. Of course the finish bore will have to be machined to size and honed.

Near the end of the last century it was discovered that you could make a mold pattern using a computer aided molding system out of Styrofoam. This made it possible to have precise duplicate patterns of a particular cylinder that you wanted to mold of aluminum.
These are placed in a mold made of sand molten aluminum is then poured slowly into the mold melting and replacing the Styrofoam pattern. This process is called total loss mold casting. Now all they have to do is a little milling and drilling plate the bore and hone to size. For the two stroke market the best part of this is the finished product is an identical copy of the original. The factories love this because it just eliminated a whole lot of assembly line workers. No more absenteeism no health insurance or pensions and no coffee breaks. As far as the consumer goes they get a cylinder that doesnt need a lot porting before they can be competitive.

There are a lot of four stroke motors that use aluminum blocks and aluminum sleeves that are plated a variety of hard finishes. These sleeves can be removed and replaced. The replacement sleeve can be either iron or aluminum. If you want an aluminum sleeve it will have to be plated after installing otherwise it wont be true and round.

There are several types of plating that has been used over the years and the companies doing plating guard their formulas carefully. The finish in the early years was a simple chrome or hard chrome electroplating. The plating was generally only a few thousands of an inch thick. If it was more than about ten thousands of an inch thick it was prone to chipping or flaking because of heat expansion and contraction. In the early seventies Electrofusion became popular. Electrofusion was different from electroplating in as much as it was a fusion process instead of electroplating. Next there was ceramic composites and Boron. All of these perform in about the same way as far as wear and durability. Then there was Nikasil. Nikasil was a new plating formula of nickelsiliconcarbide. It was harder than the others that came before it. For years you couldnt get a cylinder replated when you damaged one the only way to get going again was to buy a new one. Now you can choose from many companies doing their own version of Nikasil.

Now lets look at a persons choice of repair or rebuilding methods for their Motorcycle ATV Snowmobile Personal Watercraft or Outboard. You can have your Nikasil or other plated cylinder replated or some called it recoated. This includes the composite types.

Or you can have it sleeved with a hardened alloy steel or cast iron when you add alloys to iron its considered steel. If your cylinder has an iron sleeve already whether its castin or not youre only real choice is replacing it with another sleeve or a sleeve liner.

Lets assume youre an avid racer and race 25 weekends a year youre going to need a rebuild of your cylinder by the end of the year no matter what type cylinder you have. If it is a plated type cylinder you have three choices. 1 buy a new cylinder for 500600 for the top end and expect to do the same next year. 2 replate it for about 300400 with piston kit and gaskets and figure on doing it again next year. 3 have it sleeved for about 250350 with piston kit and gaskets and next year have it bored most models to the next size for about 55 plus piston kit and gaskets.

A properly sleeved cylinder will perform as well as any plated cylinder. A properly sleeved cylinder is one that has the proper interference fit proper presleeve bore finish accurate flange machining and sleeve made from the proper alloys. The most popular sleeve is the Moly 2000 chromemoly iron. The proper boring and honing to match the piston clearance requirements goes without saying.

Pros and Cons

RePlated Cylinder Bore
Pros
Small advantage in heat transfer
Slightly better wear factor
Somewhat lower coefficient of friction
Weighs a few ounces less
Cons
Costs slightly more
Cant be bored when damage occurs
More fragile
Can flake and peel

Iron Sleeved Cylinder Bore
Pros
Costs less
Boreable for future over sizes
Honeable to keep bore true and proper ring seal
Can be worked with common tools
Can be replaced when needed
Cons
Slightly slower heat transfer

The Bottom Line

Both systems perform equally well when professionally done so it really comes down to economics. You can expect a sleeved cylinder to give more life for the money. Replated cylinders are as close to original as you can get. So if youre happy with your OEM plated cylinder you should have it replated. If not have it sleeved by a company that has the reputation experience and warrantees to protect your investment. http://kustomkraft.com

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Motorbike Restoration: Classics

Many accessory shops make a business out of it by knowing something about motorbike restoration. Very few have mastered this art and crave for perfection in the field of motorbike restoration.

Motorbike Restoration Art of Recreating a Baby

The three basic things for any motorbike restoration project are:
lt;olgt;
lt;ligt;The enginelt;/ligt;
lt;ligt;The framelt;/ligt;
lt;ligt;Manufacturer’s parts booklt;/ligt;
lt;/olgt;

Consider your bike like a baby. Imagine you had a chance at recreating a baby motorbike restoration is a bit like having the opportunity to recreate a perfect baby.

Consider the engine and frame to be the heart of the baby. The parts book which has the exploded diagrams is the baby’s heart. This is where the craftsmanship of a motorbike restorer adds value. With strong expertise in the field of restoration you will find that a restorer will understand the internal dynamics of a bike. Then with good quality craftsmanship you can ensure that all the parts of the bike are mechanically polished and replaced. With an end to end quality check your bike will be superior to showroom quality.

Top 10 Motorbike Restoration Tips from the experts:
lt;olgt;
lt;ligt;Get your motor cleaned and if it is older enough get it rebuiltlt;/ligt;
lt;ligt;The bright metal parts have to be mechanically polishedlt;/ligt;
lt;ligt;Examine your frame for cracks twists acid damage. Get the welding proper if neededlt;/ligt;
lt;ligt;Get your frame dry assembled along with the cleaned or newly rebuilt enginelt;/ligt;
lt;ligt;Go for stainless steel bolts since cadmium bolts will rust under dampen conditionslt;/ligt;
lt;ligt;Replace every nut and bolt for every section of the bike except the engine and framelt;/ligt;
lt;ligt;Check your forks for wear and tear. Your forks should also be straightlt;/ligt;
lt;ligt;Replace your shock absorbers if needed. This must be easy as shocks for all brands are easily available in the marketlt;/ligt;
lt;ligt;Replace your tyres if needed preferably with a modern one which is made in the same countrylt;/ligt;
lt;ligt;After restoration make sure that you ride your bike. Without riding your bike and checking the quality of the restoration you will have to restore the bike again sooner rather than laterlt;/ligt;
lt;/olgt;

These are the basic things which need to be considered when a motorbike is restored. Anyone can restore a bike with these tips. But restoring the motorbike with an art of perfection needs an expert.

If the motorbike restoration is done perfect you will be flashed backed into the past where you and your bike were young. After all you can see the value of your motorbike increasing faster than your stocks!

About the writer:  Classic and Motorbike Repairs and Restoration

Motorbike Insurance Money Saving

Ok little tips here to help you lower the insurance premium for your motorbike a few simple rules to follow when considering your insurance options.

Where do you park?

The answer to this question has a massive impact on the cost of your motorbike insurance. The best option according to the insurance industry is locked your own garage. If you don’t have one is it possible to use neighbours. This does not give the same benefit as having your bike parked in your own garage but it will still bring your premium down. You can also buy specialist bike sheds for around 700. These are a worthwhile option if your budget allows as it will give you the same discount as having your bike in a garage.

If you park on your driveway you will get some discount but not quite as much as if it was in a garage/shed. If you have any space on your property use it to park you motorcycle overnight. Insurance companies do not like bikes to be parked on the road as it is more likely to be stolen or damaged out in the open.

What security do you have?

There is a comprehensive range of chains ground anchors and other security devices. Some companies build in security into new bikes. Honda has their HISS system an advanced immobilizer. You can purchase alarms for under 100 and quality chains and locks can be bought for around 40 upwards.

Whichever security device you buy be sure they are Insurance approved. This means that the insurance company has tested the security item and that it meets their requirements.

Alarms and immobilizers give you the biggest discount but chains and a lock make your bike harder to steal. If possible get both.

How old are you and do you have any No Claims?

Age you can do nothing about. The younger you are the more Insurance you pay simple as that. No Claims Discount/Bonus or NCD/B is basically a discount the insurance companies give you for every year of riding without claiming. So the safer you are the less you claim on your insurance the more NCD you can get. This can save you a massive amount up to 40!

In summary insurance is an expensive but necessary cost of biking. By following the items above you can save a decent amount on your premium leaving you some spare cash to spend on goodies for you and your bike.

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