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Title: K800 valve spring pressure Post by: Jonny Grigg on September 01, 2010, 23:31:14 pm Just some more advice please...! ;)
I have set the valve spring installed height to 1.850", and at full lift (Webcam 251 on a 1.4 rocker) it appears I have a pressure of 447lbs. This appears to be rather high, but I have nothing to measure this against..... So, my first question is whether this spring pressure is too high. the second question is actually whether I need to use K800 springs at all and whether I switch back to the chevy springs that came with the Comp Elim heads I am using? The valves are titanium, so there is quite a low oscillating mass. Stupidly when i had the valve seats installed and the heights set I didn't consider the need for steel shims in the head. I'll now need to get the head machined to take a steel shim so the spring does not chew the aluminium out. Where can I get I get some shims (in the UK) that suit the chevy or K800 spring? Thanks Jonny Title: Re: K800 valve spring pressure Post by: TexasTom on September 02, 2010, 01:56:19 am What is the max lift you are experiencing?
The spec on a Web251, if my notes are correct, are .420 total lift at cam. That should be a minimum of .588 at the valve. The spec for a K7800 spring is: 165 lbs @ 1.850 and 471 lbs @ 1.200, or ~47 lbs/.100". The numbers you're seeing sound good to me. What size valve are you running, stem & diameter? Title: Re: K800 valve spring pressure Post by: Jonny Grigg on September 02, 2010, 06:39:25 am Hi Tom
The lift you stated is correct for the cam. I don't have my notes to hand, but it measured out fractionally more at the valve. I am using CB titanium valves and Ti retainers in CE heads, 46mm inlet and 40mm exhaust. Thanks for your help. Jonny. |