*Guidelines for a great motor combination*

Street engine design can intimidate even veteran mechanics, using this information will ensure a positive result. Many times staying close to factory specs will be right for your application. Always choose the best quality parts your budget will allow.

1. COMPRESSION: Obtaining a cranking pressure between 150-180 p.s.i. will allow use of unleaded fuel, without needing octane booster. Cranking pressure is a combination of static ratio and camshaft profile. For street use we recommend between 9.0 - 10to1 static compression ratios. Power adders like Superchargers/Turbochargers increase cylinder pressure by boosting atmospheric pressure.
2. PISTONS: Quality of materials used in pistons & rings, dictate the cost of these parts. High silicone hypereucthic pistons are adequate for 450 hp. This type of piston operates with tight clearances and provides superior ring seal. Forged pistons should be your choice when building NOS or supercharged / turbocharged engines.
3. STROKER MOTORS: Three dimensions determine engine displacement: piston diameter X length of crankshaft stroke X number of cylinders. Stroke is distance down the cylinder a piston is moved by crankshaft. Engines with long stroke cranks have increased low speed torque, perfect for street performance engines. Stroker assemblies will require reliving (grinding) the block, for adequate clearance of rotating parts.
4. CRANKSHAFT & RODS: Materials used in crankshafts & rods can vary from cast iron to machined billet steel. For engines producing less than 450 h.p, most original equipment crankshafts and rods will be adequate. Upgrade to premium alloy rod bolts, this eliminates a potential weak link in the rotating assembly. Forged cranks & rods offer greater strength than factory pieces, providing a greater margin of safety.
5. CYLINDER HEADS: The cylinder head fills & discharges gases for individual cylinders thru intake/exhaust ports and valves. Compression is created as the piston rises and both valves are closed. Reducing combustion chamber volume, or adding a dome to the piston top can increase compression. Factory engines are designed with small ports and valves for economy. Porting the intake & exhaust runners will increase their size, and increases airflow thru the heads.
6. CAMSHAFT: Camshaft choice is vital to achieving the level of performance you want! Select a profile between 200`-218` duration @ .050" lift & 116`-112` lobe centers for everyday driving. This selection will provide good idle quality, with good fuel economy and torque. Weekend warrior performance will require a cam with 218`-230` duration @ .050" lift & 112`-108` lobe centers. Longer duration cams are only recommended for off-road use. Valve spring pressure must match the camshaft profile, or premature valve float will limit your engines rpm capability.
7. INDUCTION SYSTEM: Intake manifolds utilize passages to distribute air & fuel to the individual cylinders. Single plane manifolds with large volume runners; work best on high horsepower and large displacement engines. Larger airflow carburetors/throttle bodies will provide more peak power, but reduce fuel economy and throttle response. Selecting the proper airflow for your engine combination is important as any internal modifications!