Valve lengths

[sudboy1490]

Does anyone know the valve lengths between different motors? I measured some today and got 92mm with 38mm diameter which i think are from a 95hp twin lobe motor.

The 2nd set are 94mm with 40mm diameter and supposedly from a 1.7 mechanical lifted head.

Am thinking that maybe these 94mm valves are from hydraulic heads and not mechanical ones. iv heard the hyraulic ones are longer and am supposing all mechanical valves will be the same at 92mm.

Can anyone clarify this?

[PETROLHEAD]

That assumption sounds about right to me colin, the shimming arrangement is clearly quite different on mechanicals to the always on hydraulics.

[sudboy1490]

Done some digging this morning shrew, 1.7 IE valves are 93mm long. So am thinking these 94mm valves are maybe correct as they came with a pair of stripped down 1.7 mechanical heads. Taking into account the compression chamber in the 1.7 mechanical heads theyr defiantely going to be a different length to the earlier 1.2-1.5 flat head engines. I was shocked to see that 1.5 IE engines have 98mm valves.

Col

[88liam]

Colin, could the 40mm valves not be remachined to the correct length? Liam

[sudboy1490]

It looks like 1.7 mech head valves are longer than the hydraulic ones liam. I'll know for sure when I get these hydraulic heads stripped this week.

I bought some mech heads years ago and I just want to make sure they've come with the correct valves before I send all the bits to the builder.

[amichie]

I can confirm that 1.7 Mechanical lifter heads have valves about 1mm longer than the hydraulic lifter heads.

[sudboy1490]

Thanks for the confirmation Amichie; that's what I found once I got the heads stripped. 1.7 Hydraulic valves are 93mm, whereas mechanical are 94mm

Col