In the last installment of our NASCAR Late Model Stock engine build, brothers Charlie and Robert Long of Charlie's Automotive completed filling out the Ford 351 Boss block with a Crower crank and rods along with a set of Wiseco pistons. And in case your dog ate the last issue of Circle Track before you got a chance to read it, we courted a little heresy with the build by using Chevrolet-spec LS rods and pistons. Charlie Long has found this works because he likes Wiseco's excellent LS piston forging with its boxed design, and the rods are the maximum 6.250 length and have shown excellent durabil-ity. This works, however, but does require a bit of machine work on the underside of the pistons because Chevrolets use an offset on the rods while Fords do not. This means when you bolt Chevy-spec rods to a Ford-style crankshaft, there may be contact between the small end of the rod and the side of the piston pin boss.
This month, Charlie and Robert finish the motor and prepare to go racing. Next month, for the final installment, we'll be done turning wrenches and will take our Boss-based motor racing in a NASCAR Late Model Stock big money race. So check out the rest of this build and stay tuned to see if it all pays off.
Before installing the heads,...
Before installing the heads, Robert Long double checks piston clearance to the top of the block. He wants each piston to be between 0.008 and 0.010 below the deck at TDC to maximize squish, which promotes good fuel burn. Also, since most Late Model Stock rulebooks only have a minimum cc rule for the combustion chambers and no compression rule, you can sometimes gain a bit with Fords because the 10-degree valve angle means valve pockets aren't required in the top of the pistons like Chevrolets.
After checking, Charlie Long...
After checking, Charlie Long found the valve guides to be dead on. The expense of adding bushed guides with Ford's new N351 heads are not necessary, and all that needed to be done was to hit each of the guide bores with a hone to open up the clearance slightly and add a crosshatch pattern which helps keep oil around the valve stems.
Charlie's uses a Drake water...
Charlie's uses a Drake water pump from Van Dyne Engineering on practically all of its Ford engines because it is efficient and engineered with an integral backing plate. One odd feature, though, is this pump only comes with a 2-inch diameter hose inlet when almost all racing radiators are made for 1.75-inch hoses. To fix this Charlie's has to cut down the o.d. on a mill.
Here's a shot of the water...
Here's a shot of the water pump mounted up on the block with the modified housing.
After extensive testing, the...
After extensive testing, the Long brothers have settled on PSI valvesprings distributed through CV Products. These springs are chamfered on the i.d. to keep them from rubbing on the steps of the retainers, which significantly helps with longevity.
The valvesprings will be on...
The valvesprings will be on the cylinder heads at a 1.810-inch installed height. That will give them 180 pounds of pressure on the seat and 425 open.