Valve lifters…solid/hydraulic/roller tappet/flat tappet?

[xb-60]

Originally Posted by RICK LAKE

xb-60 Glen I know of 2 guys running them in street car. The clearance is important, good oil pressure and IMO warm up the motor before driving any where. Up side quicker spinning motor, down side less bottom end to start car from stop. It's a trade off. Flywheel weight is also important on which way you want to go. The lighter the flywheel the less stored power to move the car. heavy flywheel you can release the clutch pedal at idle and the car will move and not stall. I started with a 40 pound and the car had bottom end torque and can blow the tires off the rims. Now I have a bigger motor and lighter flywheel, still have the same problem of too much bottom end torque. I will advance the cam to kill some of the bottom end. Aluminum rods in a street motor will go 20-30K miles if everything is done correctly. This is a street motor making 250-400 flywheel hp not a top fuel or funny car making 9,000 hp on nitro. Another thought is Honda 1.88 rods. Prostock run them to 9,400 rpms. If money is no issue titanium is the final answer. You are looking for an rpm range, these are some ways to get there. Depend on weight of rods, pistons, bearings, rings, piston pins and oil you can lighten the crank shaft weight to. I will say that a 4 bolt main caps or a gridle for all the caps is needed period. As for 8 carbs or throttle bodies, with the right camshaft, 114 LSA, you will pick up 10-30 hp and about 15-20 ft of torque. With a small motor you shouldn't run out of air in the 7,000 rpm range unlike a 427 BB on 48mm webers where 6,800 is about the limit. Big tricket is getting air to bend into the throats of the carbs and not having a lean condition in the back ones. The air will get dirty the farther back it goes from passing over the other bodies. Pressurize air box helps stop this. Later Rick L.

Rick, sounds like something (for me) to avoid in a street car. Makes you wonder how much the rods grow as they heat up! I think as Brent has already said a well balanced forged steel rotating assembly is a good starting point.
I have experience with Webers on another car, and set up correctly (this is a factory setup) they have almost no downside. I believe that the Dynatek FI is even better.
Cheers,
Glen