As with the other pages, all figures are in 50thou increments of lift, in 'Cubic feet of air per minute- Cfm', with some having been tested on the Janspeed flowbench and the others on my own new 110 superflow machine- this I will indicate by 'mine' or Js.

There are many European manufacturers heads I have modified, that I have not flow tested due to time/cost retraints, so if you don't see it on this page it does not mean I have not done one, this page as with others is UNDER CONSTRUCTION so I may not have put up the tests as yet, such as various Fords, Vauxhall, Alfa Romeo, Renault etc

FERRARI 355 V8 5valve. Inlet- 26.5mm valves, interestingly, the two outer inlet valves of each set of three are in a compound angle layout. Still operated by direct action of the cam lobe onto the follower but the cam lobe is ground on a complex angle to achieve the correct action, very ingenious- F1 knowledge? Ports are modified by factory as one might expect, good flow, tested on an 86mm bore. My new machine.

26.33 52.1 76.17 97.94 114.77 121.92 127.45 130.91 133.68 135.75 137.13

As above, reworked and fitted with larger valves- restricted by use of existing insert- also considerable combustion chamber reworking was required on one head due to a large volume difference to it's other casting, some 2cc of volume.

28.56 56.64 83.16 106.67 121.52 130.55 136.1 138.56 140.39 142.23

As above, std Exhaust flow. 28.45mm valves. All std parts. As with the inlets the ports are factory modified BUT these have been done incorrectly, thus flow poorly to other heads using the same valve sizes- considering how much you pay for a ferrari, you think they might get it right! The ports themselves are a good design. One other poor feature is that it appears 2 different people worked the heads as they are not alike in the work as they should be! EDIT NOTE Having now seen, flowtested & modified a pair of 360 heads & how the exh ports/porting were perfect I believe the 355 heads may have been NON factory ported destroying the flow.

16.78 34.64 53.32 68.35 76.73 82.7 88.1 90.7 93.11 93.65 96.85

As above, reworked and fitted with larger valves, this to reintroduce desirable features removed by the factory? poor porting, the inserts were left unchanged/unaltered but the ports reworked. New valve size 30mm. An excellant result.

21.55 45.43 67.14 83.95 96.84 103.7 109.37 112.9 114.76 116.89

BMW MINI, Sohc. Inlet 30.2mm valves. All std parts. 77mm bore. JS flowbench. Very well executed Chrysler design. A point of interest, these castings are not the first made, the first had overly small exhaust ports which caused the valves to overheat and pop their heads off!! Chrysler had the heads recast with larger exh ports- I know because I saw/worked on these heads nearly 5yrs before a car went on sale!! the first and later castings.

20.2 42.1 63.9 83.85 99.25 107.47 108.17 110.97 112.33 112.52

As above, modded. All std parts.

20.6 42.1 62.6 83.15 101.5 113.7 119.5 122.8 125.6 126.98

As above, std exhaust flow. 23.3mm valves. All std parts.

15.24 33.27 47.25 58.28 62.85 64.38 64.8 64.8 65.1 65.1

As above, modded. All std parts.

16.34 39.16 63.45 75.25 77.28 78.15 78.6 79.1 79.3 80

MERCEDES C36 AMG twin turbo, 6cyl 4valve. engine type 104. Inlet- 35mm valves, all sts parts.

24.22 49.1 72.79 95.3 111.1 120.8 127.95 131.4 134.17 136.25

As above, modded. All std parts.

24.5 49.27 72.37 96.2 113.88 128.46 138.88 142.25 144.98 146.8

As above, std Exhaust flow. 31mm valves. All std parts.

21.55 48.38 80.64 99.65 107.53 112.2 113.6 115.7 116.45 117.13

As above, modded. All std parts.

22.27 48.68 79.8 111.48 121.36 126.3 130.35 131.76 133.89 136.72

MERCEDES SMART Car. 600cc turbo 3 cyl, much as it's name, these little heads are very smartly made!! Inlet- 30mm valve. All std parts.

7.9 15.47 23.2 31 36.9 40.1 40.85 42 42.5

As above, modded. All std parts. 7.8 15.6 23.5 32.4 40.3 44.3 44.7 45.3 46.5

As above. Exhaust flow, 25mm valve. All std parts.

6.65 13.45 20.5 25.9 30.3 33.1 35.3 36.7 37.7

As above, modded. All std parts. 6.8 13.7 20.8 28.2 34.6 38.4 41 41.7 42.3

MERCEDES SMART Car. 700cc version. Inlet- 30mm valve. All std parts.

8.1 15.98 25.2 34 37.6 39.2 40.9 41.8 42.7

As above, modded. all std parts. 8.45 16.5 25.3 34.7 42.5 42.5 43.2 44.4 45.6

As above, modded exhaust, 25mm valve. All std parts.

6.6 13.3 21.3 30.7 38 40.6 41.1 41.1 40.6

FORD ZETEC, 1800 'silvertop', Inlet- 32mm valves. All std parts. Janspeed flowbench.

21.3 44 61.97 78.5 93.3 96.57 106.1 110.6 111.3

As modified & fitted with larger performance Inlets of 33.5mm

23.2 45.7 66 85.9 102.3 116.2 125.97 132.26 137.16

FORD ZETEC, 1800 later 'blacktop', Inlet- 33mm valves. All std parts. My flowbench.

21.1 43.2 62.9 79.99 93.88 101.66 105.8 107.2 107.2

As modified to be fitted to a 2Litre, larger performance valves 33.5mm, 84.8mm bore. Note, the std heads 'seat inserts' are NOT large enough to fit the 33.5mm valves, so the std Inserts MUST be changed

23.4 48.48 69.99 91.66 111.35 125.9 134.9 136.94 138 139.8

Retested with heavily worked Inlet manifold to be fitted with Jenvey throttlebodies just to see what losses might occur.

00 00 00 00 00 125.7 132.8 134.86 135.5 137.3

A Note on Zetec Inlet valves, they are a fairly chunky item with a wide 45 degree seat area, do NOT be fooled into trying to alter the shape. By reducing the 45 degree width, it is a disaster for flow- the following is one well known british performance valve suppliers altered product, note the high losses against the set of figures 2 rows above in the Mid/high lift figures

23.4 45.54 69.16 90.77 109.27 121.7 126.56 130.7 134.86 137.3

FORD ZETEC, 1800 'Silvertop', std Exhaust flow. 28mm valves. All std parts. Janspeed bench

17.15 36.17 52.45 67.7 74.1 75.85 77.85 79.6 80

As above, modded. All std parts

20 42.42 61.5 78.7 88.5 93.9 98.3 100.8 102.4

FORD ZETEC 1800, 'Blacktop', std exh flow but on a 2 litre bore unusually- the 1800 head was chosen for a High power 2 litre engine so I could customise the chambers as 'I' wanted. All std parts. 28mm valves. My flowbench.

17.35 37.6 56.35 71.7 77.2 80.86 82.55 83.83 84.25

As above, modded. Fitted with larger 30mm performance valves on new seat inserts- the std seat Inserts are not big enough. Note the outstanding flow, compare to the Ford Duratec flow below with the same sized valves.

21.85 48.68 75.6 91.7 99.6 107.25 110.78 113.6 115.7

A Note on the above, the later heads have been cast differently with increased waterway areas in the exh port area, this caused MAJOR headaches getting the required port area for that great flow- The earlier heads are a better starting point- wether there is advantage in cooling with the later heads I do not know.

FORD DURATEC 2- 2.3 Litre(06 casting) Inlet- 35mm valves. All std parts. My flowbench.

23.93 50.74 74.46 97.39 115.27 126.38 131.94 134.05 134.17 134.86

As above, modded. All std parts.

24.08 50.15 73.92 97.65 119.22 135.95 142.57 146.82 148.65 151.4

As above, std exhaust flow. 30mm valves. All std parts.

19.65 39.6 59 76.32 86.26 89.96 92.61 94.57 95.63 96.17

As above, modded. All std parts.

20.3 49.56 72.53 86.26 93.67 96.84 100.55 101.61 104.67 105.2

FORD 16v, RS2000 95'. Inlet-33.5mm valves. All std parts. 86mm bore. My flowbench.

22.76 51.62 73.5 94.12 106.94 112.49 115.96 119.44 120.34 121.72

As above, modded, all std parts. Owner-Mr Ricky Marks/southampton.

23.34 47.5 71.4 97.26 117.35 129.85 135.41 137.49 138.88 139.48

As above, std exhaust flow. 30mm valves. All std parts.

18.99 39.8 60.72 78.74 92.65 98.43 105.2 109.1 110.5 112.64

As above, modded, all std parts.

21.25 44.9 66.47 86.1 98.29 109.8 114.76 118.8 120.43 123.26

VAUX/OPEL XE 16v. Inlet- 33mm valves. All std parts. 86mm bore. Janspeed flowbench.

23.4 47.7 72.3 94.8 104.97 111.97 114.77 116.87 118.97

As above, modded, all std parts. My flowbench.

23.35 47.2 71.5 92.7 109.72 118.05 122.9 127.95 132.15 134.17

As above, modded, performance 34mm valves, 86mm bore. Js flowbench.

24.1 49.35 74.6 97.15 113.77 125.67 133.66 138.14 138.35

As above, modded, performance 34mm valves, 88mm bore. Js flowbench.

23.9 49.6 75.2 99.5 118.5 130.7 139.8 143.9 147.6 150.42

As above. Exhaust flow-29mm valves. All std parts. 86mm bore. Js flowbench.

20.4 45.9 73.4 89.4 91.9 97.3 98.4 99.3 99.8

As above. Restricted modded. All std parts. My flowbench.

20.96 43.37 66.63 86.97 97.37 101.1 103.2 104.13 105.2 106.26

As above, modded, performance 31mm valves, 88mm bore. Js flowbench.

22.9 47.9 75.95 95.3 109.7 113.98 117.3 118.1 118.1

VAUX/OPEL 1.8E, 8 valve. Inlet- 41mm. All std parts. 85mm bore. Js flowbench.

14.66 28.6 44 56.8 66.6 75.35 83 88.7 91.3

As above, modded, all std parts. Js flowbench.

14.1 30 44.3 57.7 71.25 82.7 95 100.8 102.4

As above. Exhaust flow. 35mm valve. All std parts. Js flowbench.

10.5 20.3 28.55 36.8 43.45 49.3 53.9 57.4 59.5

As above, modded. Performance 36mm valve. Js flowbench.

12.2 26 38.8 48.3 56.95 65.1 69.25 71.85 74.7

VAUX/OPEL ECOTEC 2 Litre. Inlet- 32mm. All std parts. 86mm bore. Js flowbench.

22.45 46.57 72.8 93.28 107.17 114.17 119.67 122.10 124.85

As above, modded, all std parts. Js flowbench.

22.35 47.57 73.23 96.57 111.27 120.37 126.66 129.47 131.56

As above. EXHAUST flow. 29mm valves. All std parts. Js flowbench.

19.67 43.45 72.11 83.97 87.64 88.18 89.25 90.68

As above, modded, all std parts. Js flowbench.

20.78 48.14 77.54 93.88 100.14 103.23 105.92 107.96 110.12 110.84

RENAULT 16V 1800- F7P-720/722 engine. Inlet 30.7mm. 83mm bore. Js bench.

20.24 43.41 68.15 91.33 105.35 110.93 110.23 113.1 114.4

As above, modded, all std parts. Js flowbench.

21.56 44.1 67.35 90.12 110.35 123.17 131.57 136.46 137.16

Same head then fitted with 'Williams' model 33mm valves on new larger seat inserts. Js bench. The difference between the std head and the early 'Williams' version is the larger Inlet valves only, these are fitted on the std head seat insert- massively limiting full flow potential, this can be improved by fitting correct size inserts at a sensible price- as you can see here.

22.88 46.1 69.42 91.17 110.57 127.37 139.64 147.96 154.43

As above, EXHAUST flow. 28.4mm valves. All std parts. Js flowbench.

19.6 41.2 59.6 75.1 83.2 88.4 90.95 90.7 93.6

As above, fully modded, all std parts. Js flowbench.

20.7 44.65 72.5 93.3 106.1 112.5 114.7 114.7 115.9

CLIO WILLIAMS, later model, same engine type- unlike earlier models this has a larger seat insert from the factory, early models just whack a big valve on a small insert and do not gain the full advantage of the larger valve. Saying that, gains are still posssible. Flow of head as factory produced. Js flowbench. Inlet 33mm.

22.3 46.57 71.82 95.24 113.13 122.97 128.4 129.99 131.4

As above, fully modded, all std parts. Js flowbench.

22.9 47.16 71.11 95.24 115.94 130.75 139.83 144.85 147.95

As above, EXHAUST flow, FULLY modded, 28.4mm valves. All std parts. Js flowbench.

20.7 43.9 70.8 93.72 106.6 112.55 114.7 114.7 115.9

RENAULT 16v 1800- F4P760 late engine, same head as Clio 172, uses 5.5mm dia valve stems instead of early engines 7mm. All std parts, 83mm bore. Js flowbench. Inlet 33.5mm.

21.77 45.2 66.2 84.5 97.6 108.8 115.8 119.3 120.7

As above, fully modded, all std parts. The results here are missing one last test, due to time constraints the combustion chamber relief was untested, But on the '172' version tested at a later date (same casting), the relief was tested and found to give 4-6cfm. See lower down the listing to see how well the hand fettled work compares to the factory Cnc'd item.

22.5 44.6 66.2 87.15 105.67 119.3 128.4 130.5 132.56

EXHAUST flow was not tested.

CLIO '172', same engine range as the 1800, uses the same head casting. The port runners are Cnc machined through the ports, otherwise no difference to the std casting. The machining is poorly executed leaving room for improvement, basically the port runners are just enlarged but with an extremely poor finish in critical areas. See how the hand modded version above with a far smaller port dia flows very favourably. Js flowbench.

21.4 45.5 65.2 83.5 98.7 111.97 123.9 130.17 134.35

As above, fully modded, all std parts. Js flowbench.

22.5 45.2 68.15 89.6 108.5 125.1 137.7 144.26 147.96

As above, EXHAUST flow, all std parts. Js flowbench. 28.5mm valves.

17.5 36.87 55.97 76.38 92.1 97.85 102.7 107.1 110.4

As above, fully modded, all std parts.

20.2 44.35 68.97 89.79 102.1 112.3 116.3 119.9 122.85