Selecting the correct camshaft
This section is designed to help in selecting the correct camshaft for your engine. There are many different programs available on camshaft selection, Ivan Tighe Engineering Pty Ltd (I.T.E) have invested in three (3) of the latest technologies available to ensure the best options in both camshaft and engine design are explored.
The most important thing to remember is that there are 2 or 3 different profile combinations that will have identical results in an engine, particularly in a road driven vechile. The engine may have different characteristics but produce the same horse power (H.P)
This range is designed for bottom end, better economy and better
throttle response designed for a standard engine. If an engine
has been modified this range of camshaft will still perform well but
wider lobe centers may be required to achieve best results.
This range is designed more for the midrange, smooth cruise and slightly lopy idle. This is still suitable for automatic transmission using standard stall converter. Modified Distributor and exhaust systems are recommended. This is good for towing in larger capacity engines. Higher compression ratio is not required, larger valves are not recommended. A typical lobe separation is 108* - 112*.
This range is for modified street, limited modification race or speedway.
Used for single carburetor (350 Holley) and 6 cylinder engines. Twin
carburetors are recommended for 4 cylinder engines.
Note: Valve spring retainers must be checked for suitability, depending on piston choice. Valve to piston clearance will also require attention.
This range of camshaft are more for an engine designed rather than
for camshaft replacement. The engine must be designed and built with
the design of the camshaft in perspective.
Points to keep in mind when selecting your camshaft
The following are remarks intended to help you to select the correct camshaft. If you have a camshaft that works well in one type of engine this will allow you to adapt it from one engine to another.
" If the cylinder head is flowing more (has been ported) the lobe centerline can be closed. This will give the best benefit of the improved airflow.
" If the capacity of the engine is smaller the lobe centerline will be opened to achieve the same results.
" The exhaust profile is much less critical on low compression
engines. I.T.E recommends a smaller exhaust profile on low compression
" The closer the lobe centerline the harder the engine will "come on the cam". I.T.E use wider lobe centerlines on speedway applications for this reason.
" If a hydraulic camshaft is being replaced with a solid camshaft the .050" duration needs to increase by 8* or 10* to obtain the same effective duration.
" The exhaust profile can dictate to the inlet, the exhaust can help the cylinder fill and clean the combustion chamber on overlap. This allows more mid range, but with a loss of fuel efficiency.