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Big Valve Head

For Smart 700cc petrol 450 or 452 (Roadster)

It is recognised in the tuning community that standard heads from German car manufacturers are some of the best in the world, So any amount of porting will give minimal improvements (Typically less than 6% additional power).

The advantage this head has is it has larger valves. Both valves are 3.5mm bigger diameter. They also come fitted with springs that can take up to a 12mm lift cam. (although fitting a 12mm lift cam may need additional machining on the heads of the pistons). Expected Power gain 14.2%+ (head alone).

Availability: 5 in stock

The graph above shows the Big Valve Head with other upgrades (This graph is from simulation software. See disclaimer)

There are 4 versions of the head and all come with valves, springs, collets and (Titanium) retainers. (All heads have 33.5mm Inlet Valves and 28.5mm Exhaust Valves)

*flowed/ported heads have a 1 in 4 failure rate and this is reflected in the price.

**Nimonic 80A was developed in 1945 and was a key part of the UK jet engine project and classified as one of the original superalloys. It has massive strength at elevated temperatures, where other valve materials have already started distorting and melting. I highly recommend it's use with the MC120 CAM where the combustion temperatures are at extremes and the cam closing times area reduced with the longer valve opening durations..

Contact

Company:
223D Developmental
41 St Georges Road
Torquay
Devon
TQ1 3QY

Email: mike@223.com

Phone: 44(0)7970108386

Disclaimer

On this website i use outputs graphs from a simulation software. These graphs are for comparison only and should be used in that way. They all assume a standard engine in good mechanical condition and a Turbo that can generate 1.5bar of boost at whatever RPM is shown and at whatever engine load.