Cylinder Head U20
Datsun Roadster U20 Thicker Lash Pad Sets - (SET OF 8)
"Using thicker lash pads for the U20 do NOT create any problem in terms of losing a rocker arm lash pad as most of the forces are downward" - From Dave Rebello master engine builder"
Heat treated, correct width for stock U20 retainer, lash pad sets. Works great with re-ground cams with reduced base circles, to correct the geometry between the rocker arm and the camshaft lobe. Selecting the correct thickness allows one to match the theoretical lift on paper with the actual dial indicated lift during mock up and assembly. Since there are no L-series lash pads under .150 thick available these lash pads will work with camshafts that require thicknesses less than .150 in order to obtain the correct wipe area, lift etc. of the cam you are using. Camshafts requiring lash pad thicknesses above .150? You can choose our Chromoly retainer set Click here
PHOTO: The 1st lash pad on the left is a stock U20 lash 2.0mm / .078
LASH PAD SELECTION NOTE: Camshafts are listed at part # 1499 & 1517. To figure out which lash pad to select based on a camshaft you have purchased from someone else please use the following formula. (Be aware that valve length, seat depth - installed height and individual ground or new rocker arms can affect geometry thus rendering a different lift value "at the valve" other than the theoretical lift values based on the cam card lobe lift multiplied by the 1.396 rocker arm ratio)
Mocking up the assembly, is of course, the last course in obtaining the wipe area you are looking for. Please keep this in mind when using the following formula.
FORMULA: Use the following example and plug in your own numbers. Base circle diameter of your camshaft .___ subtracted from the constant 1.310 = .___ divided by 2 = .___ + original lash pad thickness of .078 = .___ new lash pad thickness required. Select a lash pad thickness from our stock as close to this thickness as possible.
Choose your lash pads with care as they are NOT returnable.
The following parts numbers are for each lash pad from left to right starting with the second lash pad:
2.5mm / .099" Order by PART# 2551A
2.7mm / .107" Order by PART# 2551B
3.0mm / .118" Order by PART# 25511BC
3.2mm / .126" Order by PART# 2551C
3.4mm / .134" Order by PART# 2551D
3.5mm / .138" Order by PART# 2551E
4.2mm / .165" Order by PART# 2551G