David Lin
Inline Four - Director of Operations
IL4 Racing - Team Manager

What is WPC?
WPC is a proven process that has been utilized for many years in the racing and automotive industry. WPC is not a coating, it is a treatment that enhances the surface to reduce friction and strengthen engine parts. WPC achieves this process by firing ultra fine particles towards the surface of a product at very high speeds. The resulting thermal discharge permanently changes the surface, strengthening structure and creating a harder more durable final product.

Why is WPC Superior?
The WPC process is unrivaled in treating engine parts and other surfaces that have contact points of friction. WPC is superior because it is not a coating; it is a permanent surface treatment that reduces friction while strengthening the part. It's unique micro-dimple formation pattern greatly reduces friction and is unmatched by conventional methods of surface treatment. WPC has the capacity to treat carburized, nitrided and plated parts without noticeable dimensional changes, and, upon completion of treatment, no further modifications are required of the parts. The strength and durability improvement on the surface after the WPC treatment is unsurpassed by any current methods. Treatable products include steel, aluminum, titanium, copper and brass and soft surfaced bearings. WPC can treat any metallic item in a disassembled state.

Reduced Friction
The fine grooves, that are intrinsically engraved into the product surface at the time of machining, are transformed into micro-dimple indentations by the impact of the ultra-fine media during WPC treatment. These dimples then act as oil reservoirs. Thus, oil that would normally drain away, through the grooves in an untreated product, when pressure is applied, is instead retained in the dimples of a WPC treated product. This helps to keep the surface lubricated. Furthermore, solid lubricants such as Tin (Sn) and Molybdenum Disulfide (MoS2) can be utilized as media in the WPC process to embed them into the product surface. This reduces friction and improves the life and efficiency of the product to an even greater level.

Greater Durability
The ultra-fine media of the WPC process, when projected at high velocity towards the product surface, creates compressive stress at the impact points. At the same time, a micro thermal reaction takes place. It effectively seals minor surface fractures. It also allows a condensed surface to form that has improved density due to compaction. This altered and highly compact surface condition overcomes the problem of brittleness, that is usually encountered when metals are hardened. The numerous impacts during the WPC process not only increase the residual compressive stress but also cause it to reside a lot closer to the surface. The cumulative result is a product that has a durability unrivalled by conventional peening methods.

Will WPC Treatment change the dimensions of the parts I have treated?
No. The treatment doesnt add or remove material which would alter important clearances and tolerances for your parts. Strictly speaking there is a dimension change however the dimension change is almost undetectable. For example on a hardened surface such as on a crank shaft journal the dimension change will be +/- 0.00004 inches. On softer materials such as Piston Skirts and Bearings the maximum size of the dimples are less than 0.00008 inches.

Does WPC Treatment improve the strength of parts as well, or is it just for friction?
Yes. WPC acts in two ways to strengthen parts. First it adds an extremely high level of compressive stress at and near the surface. The second point is that WPC Treatment creates a Nano - Crystalline structure at the surface of the metal. Both of these mean that metal fatigue and crack initiation are both noticeably reduced.

Click Here to view some photos of WPC treated engine parts.

Click Here to watch a short "Introductory WPC Video" showing the effects of WPC on IL4 Pro Cast Pistons.

Click Here to watch a quick video showing how effortless a crankshaft spins, by hand, when the main bearings have been WPC treated.

How do I order or send in my parts to get WPC treated?
After reviewing the WPC Price List, you will have an idea on how much you will be spending for all the items you wish to get WPC treated. First, you will download the "WPC Order Form"(coming soon). Once you download the form, print it out and fill it out completely. You will then send in the order form along with a "Money Order" or "Certified Cashiers Check" for the total amount of all the items to be treated. Along with the order form and payment, you will send in your parts to be WPC treated. Be sure to take care in packaging your parts. We will inspect them upon arrival as well. On each package that you send, be sure to write "WPC DEPT" on the outside of each package. On the order form, there is a section where it asks you to fill in how many boxes you are shipping to us. Once we receive your parts, inspect them and have them WPC treated, we will then contact you for "return shipping" payment. This payment can be done via credit card, debit card or PayPal(PayPal has a 4% service charge). Like all orders, we only ship to the billing address of the cardholder, so please make sure your bank and credit card information is correct and up to date.

What is the average turn-around time for parts to be WPC treated?
On the average, it takes 3-4 days to complete the WPC process. We visit WPC once a week, therefore, your parts will be dropped off and should be completed by the time we make our next visit.

I own a race team or speed shop. Can I receive a discount for sending in parts in bulk quantities to get treated?
Yes, we can offer you a discount for the parts being sent in bulk quantities. Call us at 714-903-1898 or email accounting@inlinefour.com for inquiries on bulk pricing. Before you call or email, please be sure to know the quantity of parts you plan to send in. This will allow us to assist you with the correct pricing and will also expedite the inquiry.