Our roof 101 cyclone four port ohv cylinder head conversion tm is a faithful reproduction of the original robert roof 1928 roof cyclone.
Pent roof cylinder head.
It is similar in concept to the hemi engine both in design and purpose but a hemispherical cylinder head is limited to only two valves without the use of a.
These normally have a central spark plug between the equally spaced valves.
The spark plug is located on the thick side of the wedge and is usually positioned midway between the valves.
The 53 322 heads and pistons are all by themselves nothing can be upgraded it was a bad design best to use the 54 55 56 heads and pistons re balance a must.
Plenty of valve area well shaped ports and a compact pent roof combustion chamber all contribute providing copious top end power whilst still pulling well from low revs the twin cam head conversions fit onto any 1275cc a series cylinder blocks.
Inline valves are normally tilted to accommodate the sloping roof of this design.
The head project was conceived by charlie yapp as a tribute to the original robert roof cyclone valve in head and newly designed with modern engineering by chief engineer jim roof with help.
The efficiency of 4 valves per cylinder cannot be matched in its power potential by older designs.
Among the advantages is a faster burn time of the air fuel mix.
This was the nearest to the current pent roof design incorporating a hemispherical shape cast into the cylinder head and was considered a compromise between manufacturing cost and engine efficiency.
In an internal combustion engine the cylinder head often informally abbreviated to just head sits above the cylinders on top of the cylinder block it closes in the top of the cylinder forming the combustion chamber this joint is sealed by a head gasket in most engines the head also provides space for the passages that feed air and fuel to the cylinder and that allow the exhaust to escape.
Many 53 s were upgraded that way in the 50 s by the dealers.
Pent roof combustion chambers the chamber of choice for four valve per cylinder heads has long been the pent roof design which shares most of the advantages of the hemi chamber and then some.
The combustion chamber is sunken into the cylinder head and commonly contains a single intake valve and a single exhaust valve.
With modern improvements to enhance power and reliability.
In engine design the penta engine or penta head is an arrangement of the upper portion of the cylinder and valves that is common in engines using four valves per cylinder.
The distributors were in the rear and the starters were on.
The relatively steep walls in such chamber design force the air fuel flow path and deflect and force it to move in a downward spiral around the cylinder axis.
In a pent roof configuration the intake and exhaust valve heads face in opposition to one another forming a v shape.
