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PRP USA
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PLATINUM RACING NISSAN RB26 WET AND DRY SUMP ENGINE CRADLE (PREC26P)

Platinum Racing Products
www.platinumracingproducts.com
PRECINST02C Revision 12092019

Congratulations on the purchase of your RB26 Platinum Racing Engine Cradle (PREC)! This PREC will assist in preventing block twist, block cracking as well as prolong engine bearing life whilst allowing 4WD Sump compatibility. Below will outline the necessary steps to ensure the correct installation of the PREC. All machine work mentioned below is to be performed by a qualified or experienced machine shop/operator. Platinum Racing Products does not take responsibility for any damage caused from incorrect preparation and/or installation of this product. This is for off road use only.

Prerequisites: Prior to the installation, your block’s standard main bearing cradle will need to be machined. This is the same process used to deck a block or machine a cylinder head. The below steps will outline this process in detail. It is strongly recommended that you tunnel bore your engine if the clamp force is modified or changed from factory. Please ensure a bore/hone is performed to ensure the life of your build. Although not a requirement for a PREC installation, if your engine block is to be tunnel bored, or mains closed and honed etc. Please arrange that your machine shop does this prior to commencing the below steps.

1) Bolt down main cradle without crankshaft and tension main bolts to specification. Important Notes: You should use the actual bolts that will be used in your build. They must be torqued to their correct specifications. Please ensure your OEM Main cap girdle is centered, this is usually done with a rubber mallet on the 4 pointy corners of the girdles reinforcement. If installing aftermarket main studs, there may be 3 studs that require shortening as they will protrude into the machined surface. We recommend machine down the seats of these nut seats to ensure all the studs are equal 4.4 inch lengths. 

2) Prepare RB25 / 26 engine block on mill and set level along sump pan reference to ensure main bearing cradle is machined parallel to sump mounting surface. Mill material off the installed cradle to precisely 22.5 mm above block deck height (i.e. sump pan face)(Please measure this with your own equipment to ensure uniformed result) allow 1 thou clearance on block pan surface to allow for sealant if possible. This will provide a machined face on each of the seven main bearing caps. Important Note: Please ensure you check your installation height and zero your own measuring equipment before machining.






Note: If you are retaining 2WD and not converting the block to 4WD, the following steps are not necessary, please skip to – Oil pick up.

4WD Sump Preparation (please skip the step below if 2WD application)

4WD Sump Preparation (please skip the step below if 2WD application)