Hello and Welcome to Hammer Down Dyno Service, home of affordable dyno testing for the Briggs V-twin. Please take some time to read our information. Feel free to e-mail us with any questions or concerns. If you have never visited our facility or are unfamiliar with Dyno Testing. Please read the Frequently Asked Questions below.
How does it work? Hammer Down uses a custom made dynamometer that utilizes your current engine mounting plate and clutch setup. Your engine is connected to a drive axle using the typical clutch/sprocket setup found on the race car. Upon engagement, the chain drives a heavy wheel to act as a load resistance similar to how the car would be on the racetrack. Because the engine has a load on it there is no additional stress placed on the engine versus what it would experience on just one straightaway of a track. In this wheel are sensors which provide data in the form of acceleration vs. time measurements. These ultimately tell us the horsepower of the engine during a run. This form of dynamometer is widely known as one of the most accurate and repeatable ever produced which is very valuable when comparing tests and configurations. Also attached to your engine are two cylinder head temperature sensors and an rpm sensor to monitor everything you could see if you were in a race and also to keep test conditions similar.
What do I need? In order to make serving you easier and to save you in additional set-up costs your engine should be configured as follows: -The engine mounting plate should be attached (we may need to adjust the bolts for chain alignment on the dyno). -The L shaped throttle mechanism must be attached to the engine along with the carburetor linkage and throttle return spring you normally use. -Your engine must be complete as it came from the racecar (starter, carburetor, flywheel covers, full exhaust system etc…) -A reliable and working clutch (with or without crank saver) that can withstand the warm-up procedure and repeated tests. A spare clutch is highly recommended to bring along as we have encountered limited clutch problems in the past. -Your own preferred fuel. The system uses its own fuel pump that will draw fuel from any reasonably sized container (Gallon jug-5 gallon can). BE SURE to bring enough with you so you can use the same brand and grade of fuel throughout all of your tests. KEEP IN MIND that average fuel consumption is about 1 gallon for five pulls. -Tools you would use to adjust, work on, or repair your engine. We do not guarantee to have all tools necessary to fully adjust your engine and would prefer to protect our assets. You should have the tools you would need to build a carburetor, remove manifolds, shrouding, spark plugs, flywheels, clutch repair, tape for flywheel cover, change jets, and other operations.
The dyno is equipped with the following: -Breather lines to attach to your valve covers -Its own battery with cables to connect to your “hi-tech” starter (no solenoid is present so the “old style” starter can not be used. -Its own fuel system with a line to connect directly to your carburetor. YOU MUST SUPPLY YOUR OWN FUEL
Does it really work? In a spec class it is common knowledge that any advantage is critical. Everyone preaches about set-up and handling being the key to speed. While this is true, having a horsepower advantage will certainly help. Like most things, experience is the key. Understanding how engines work is important to gaining anything from your experience. If you don’t know how to do anything to an engine besides change the oil and gap the spark plugs, dyno testing is not for you. However, dealing with a sealed engine still leaves a lot of variables to adjust and configure. Without going into the list of adjustments that are available one should also remember that you can bring several sets of parts with you to see which ones work best. Changing carburetors, manifolds, carburetor spacers, spark plugs, exhausts, and air filters will certainly affect power ratings. Isn’t this information you’d like to know before hitting the track?
Will it damage my engine? After reading the disclaimer you may be apprehensive about trying this. Many people visualize dyno testing as an engine with open headers sitting at redline in a room being put through every torture test you can imagine. This is not the case. A typical dyno pull lasts about 10 seconds. Max rpm can be set wherever the customer wants. Theoretically, an engine running a dyno test is under no more stress than one accelerating from pace speed to the first turn of a racetrack. Ensuring that the engine’s oil does not become milky and monitoring head temperatures make test conditions the same as a normal race.
Is it legal? Certainly. No illegal parts or machine work are offered by Hammer Down. We are simply a provider of a very expensive and sophisticated tool for you to rent to measure your engine’ s performance. We are not affiliated with Speedway Entertainment or any dealers, tracks, or manufacturers. We will test any engine under 50 horsepower legal or not.