These push rods are 240mm long and are unfinished so that customers can cut them to the desired length. The lower ball pin is fitted whilst the upper cup is not. Once the desired length of push rod has been identified the tube can be cut to length and the upper cup is then inserted into the push rod tube.

This push rod will suit all 6-cylinder engines both standard and modified. Many gains in power and reliability in an engine can be achieved by careful building. When the rocker gear is installed, the rocker motion should result in the rocker being at 90° to the pedestal at half lift. To achieve this, the pedestal is either raised with shims, or the under face machined off. This exercise will invariably result in the push rod ball pins being out of adjustment, requiring different length push rods.

NOTE: Only two lengths of push rod were used in TR 6 cylinder engines although longer ones were used in saloon cars with lower compression.

Part number 149513 is used in TR5 and CP TR6; it is 207mm long (overall length).
Part number 148916 is used in TR250, CR and all carburettor TR6; it is 211mm long (overall length).

When a cylinder head is skimmed, a different cam is used or the rocker pedestal length is altered to adjust rocker geometry, a push rod of a different length may be required and these can be supplied under the following part numbers.

RTR1191 is 198mm long (overall length)
RTR1192 is 204mm long (overall length)
RTR1193 is 214mm long (overall length)
RTR1194 is 240mm long (overall length) but can be cut to length to suit individual engine requirements.

TECH.TALK
Above I have specified the overall length of these push rods. I realise that measuring the overall length is not ideal and we should be measuring from the centre of the lower ball end to the centre of the cup at the top but this is usually impractical.

As the overall length does not have to be any specific figure (as there is about 10mm available in the adjuster) we are usually looking to find a rod that is longer or shorter then the ones we already have. With this in mind the figures above should be used as a guide but do bear in mind that RTR1191, 2 and 3 have a flat end to the ball at the base of the rod, so for a true comparison with the standard rods, about 2mm extra should be added.

To make a true comparison between one rod and another hold a rod in a tappet with an adjuster pin in the top of the rod and with a height gauge measure to the top of the adjuster pin. Use this method with the same tappet and adjuster pin to measure another rod and any difference in effective length will be immediately apparent.

If there seems not to be a push rod available in the range you are looking for, use Part number RTR1194 which can be cut to the exact length you require.

J. N. Revington