Clutches with a lot of pressure plate pressure are tough on thrust bearings (and throw-out bearings). When the clutch is depressed, the crank is being pushed forward into the thrust bearing with the force of the clutch springs. Most CM plates are in the 1900 lb range, which is easy, but a double diaphragm unit can exert as much as 2800 lbs and that’s a load. I’m coating the thrust bearings wear sides with the same ceramics we used on the pistons, and spring seats to help the situation a bit. The dual diaphragm clutch I’m having built has 2,200 lbs of plate pressure, so if it’s the unit I decide to go with, the ceramic coating and a clearance of .005” will insure that the bottom end will be in good shape.

This should give as few of you something to think about on your next clutch purchase…..and when you’re sitting at that traffic light with the clutch pushed in, rather putting the trans in neutral….

The crank is installed in the block using a generous coating of assembly lube on the bearings. We’re only torquing the main caps to 12 ft lbs and we’re not installing the girdle and doing final torquing until the pistons and rods are installed, as it’d just be in the way when we’re guiding the rods home and tightening the rod bolts.

The girdle is a Z10 piece that we’ve doweled to fit precisely with the main caps. I’ve also noted that engines we’ve built in the past with these girdles seem to oil the cylinders more than engines without girdles, so we’ve machined a couple _” holes in the girdle as additional drains for the oil. We’ve also carved some troughs to direct oil to these holes on the crankshaft-side of the girdle. Excessive oil on the cylinder walls can make life difficult for the pistons’ oil rings and that’s something we want to avoid.

The rods are assembled to the pistons, making sure that the bearing “tangs” on the big ends are facing the exhaust side of the pistons, just like Honda does it. Retaining clips are used to keep the pins in place.


I’m using some moly-type assembly lube in the pin bores and in the rods’ bushings for good start-up lubrication and protection. It’s very important that the moly be used sparingly and not on the exterior surfaces of the pistons. If the moly gets on the cylinder walls, it can cause the rings not to seat properly. This is also the reason we never use moly when assembling the valves to the valve guides, as it could be washed into the cylinders during start-up and contaminate the rings/cylinder walls.

The piston rings are gapped at .012” for this engine application and we’re installing them with their gaps “clocked” just as Honda recommends. The pre-fitted rod bearings are inserted in the rods next and lubed with the same moly-type paste we used on the piston pins.

We use WD-40 liberally on the pistons rings and the cylinder walls. This will be the only lubricant we’re using for their assembly. We don’t use motor oil, as we’re trying to create enough initial friction between the rings and cylinders to hasten their seating process. WD-40 also lights-off quite well, which makes engine start-up faster.
’m using new rod bolts (which weren’t used in the bearing fitting process) for final assembly and we’re lubricating them (and their bolt seats) with the supplied ARP moly paste. I measure and record the length of the rod bolts using a stretch gauge for reference and torque the rod bolts to 28 ftlbs in two steps (1st at 12 ftlbs.). Next we come back and measure the stretched bolt length to confirm that it’s in the optimal +.0051” range.

With the pistons and rods installed in the short block, it’s time to put the modified girdle on and torque the mains. We’re using the factory (GSR) torque settings (and new , well lubed bolts) to button up the lower end.

Rear main seal is standard-issue Honda, and the oil pump is a new ITR unit that we’ve modified to increase efficiency. The windage tray is a new GSR part that’s been trimmed in several places to make it a perfect fit with the Moroso oil pan.

It’s a good idea during earlier “fitting” sessions to fit the oil pan, as well as the pickup, as these things always need some minor massaging before they’ll fit correctly. We also removed about .175” from the flywheel-side of the rear oil pan rail, as experience has shown that a non-modded rail will hit the small bolts protruding through the flywheel. You don’t want to encounter this sort of problem with the engine and transmission installed in the car.

The lower-end is now complete.

As with all the engines we build, this one receives a new water pump. Since it’s going to be a high rpm combination, it’s best to use the ITR/GSR water pump with its larger diameter pulley. This will reduce the pump’s rpm compared to an engine built with the CRV, or LS pump with its smaller pulley diameter. Maintaining good coolant flow is essential on a high output engine, and the CRV/LS pump would spin so fast that cavitation would be a certainty at anything over 7500 rpm.