JampJ Posted October 21, 2005 Share Posted October 21, 2005 Can anyone tell me what size valves are used in the 1700 Supersprint head? Cheers J&J JFDI (Just F*****g Do It) Link to comment Share on other sites More sharing options...
DaveMorris Posted October 21, 2005 Share Posted October 21, 2005 Toppical Question ☹️ From measure ments taken from one today - Inlet 39.8mm outlet 34.1mm (note these are "as measured" and include carbon etc.) If you use teh "search" facility in tech talk the approx 18 months ago someone listed a compelte Supersprint spec. It says :- 1700 Supersprint Engine Specification Base unit Ford ohv 2265E Kent crossflow Bore Stroke 83.27mm 77.62mm Capacity Compression Ratio 1690cc 9.75:1 Cylinder Head Gas flowed and enlarged ports Valves Oversize, gas flowed design manufactured in 21-4N steel. Valve springs Heavy duty, Duplex with retainers to suit. Camshaft Caterham BCD with high lift short duration profile Pistons Cast aluminium modified to give valve to piston clearance. Crankshaft bearings Uprated competition type main and big end shell bearings. Flywheel Lightened and balanced Clutch Uprated competition cover assembly and drive plate. Ignition Caterham distributor with special side entry cap with optional Lucas electronic ignition. NGK B8ECS spark plugs. Valve cover Caterham cast alloy with "1700 Supersprint" script. Lubrication High-pressure oil pump with standard wet sump. Inlet manifold Caterham cast alloy. Carburation Two Weber 40 DCOE 151 Air filtration Two K&N high performance air filters. Performance Data. Maximum power 135 BHP (99KW) @ 6000 rpm Maximum torque 122/lb/ft @ 4500 rpm Servicing Data * Static ignition timing 10 degrees at BTDC Valve clearances (cold) inlet 0.22" Exhaust 0.24" Spark plugs NGK B8ECS Spark plug gap 0.25" Firing order 1-2-4-3 *Fuel 97 octane (4 star) leaded Oil pressure (normal temp) 3-4 BAR Contact breaker points gap 0.025" Engines numbered with the suffix "UL" can be run on unleaded 95-octane fuel with static ignition timing of 14 degrees BTDC. Plagiarised from earlier post with NO RESPECT (though not a lot of help on the valve size). I'm sure someone will be along soon with actual, real sizes, Dave. Link to comment Share on other sites More sharing options...
Tyrone Posted October 22, 2005 Share Posted October 22, 2005 I scrolled all the way down that, reading as I did so, got to the end and thought "it doesn't mention the only piece of information J&J had asked for." Refers to everything else though but. What you done this time Dave. It must be sabotage, these crossflows are 'bombproof' as you well know. Link to comment Share on other sites More sharing options...
Tyrone Posted October 22, 2005 Share Posted October 22, 2005 Lifted from Puma Racing Website: The port design is actually pretty good - round and fairly straight and with a reasonable downdraft angle so the flow per square inch of valve area can be brought up to pretty high levels. Being a Heron type head there's no chamber shrouding to worry about either. For the engine size though (in 1600 trim at least) the valves are small. The 1300 and standard 1600 had 38.2mm inlet valves and 31.5mm exhausts. The 1600GT engine had 39.2mm inlets and 33.7mm exhausts. As a very minimum go straight to these sizes for a modified head because the increase in valve area is well worth it in power terms. Most modern engines have much bigger valves to start with. The 40mm inlets of the VW Golf , 41.6mm in the Peugeot 205 and the 42mm ones of the CVH engine for example. The first common oversize for the crossflow is a 41.3mm inlet valve which is available off the shelf in OE material with a chromed stem for very little money. It fits nicely with the 33.7mm exhaust in any head and makes the most cost effective solution for any decently modified engine. The problem with going much bigger than this is the spacing between the inlet and exhaust valve. The specification figure here is 1.54" (39.1mm) with a few thou variation depending on how well the tooling at the factory was set up when the head was drilled. This measurement limits how big the valves can be before they touch. Copyright David Baker and Puma Race Engines I think it is safest to measure the valves that you have in the engine! Link to comment Share on other sites More sharing options...
J A T Richardson Posted October 22, 2005 Share Posted October 22, 2005 Burton list a range of valve sizes - go to https://www.burtonpower.com/default.aspx and look under valves/Xflow Stinky toy driver - and proud of it! Link to comment Share on other sites More sharing options...
andy couchman Posted October 22, 2005 Share Posted October 22, 2005 We had problems recently getting replacement valves, which apparently are a one off and not produced anymore. We could get exhauts but not inlets IIRC. However, Vulcan Engineering were very good at advice annd providing a suitable replacement. Andy Link to comment Share on other sites More sharing options...
Westfield Posted October 23, 2005 Share Posted October 23, 2005 Try ringing this number and asking for Paul Ivy 01902 373770 he only works part time though so keep trying He has helped me out no end of times with Valves and guides. He is part of a company (Rimflow?) that manufacactures valves for al sorts of competition engines including all the big teams… he sold me some Crossflow valves last year at a very reasonable price. He also does K series and VX valves as well. back to work - no time to update the web site!! Link to comment Share on other sites More sharing options...
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