I just got my 4 month PV544 project on the road and what fun it is. I took it on the expressway to let the engine open up a little, as it hasn't been driven at speed in over 10 years. Anyways, I installed a tach and the tach indicates that at 75 mph, the engine is working at 45000 rpms, is this about correct. At 75 mph the engine sounds as if it could run at this speed for hours, but not much more, is 75 mph about top end for distance driving. Any suggestions would be appreciated.

To calculate speed from RPM, you will need to know the tire radius and gear ratios (transmission/rearend).

There are a few calculators on the internet like this one:

http://www.nightrider.com/biketech/calc_speed_rpm.htm

Paul

Thanks for the replies. It's nice to know that after all these years of this car sitting without being started, that the engine and trans seem to be working fine.
Thanks

If you have a 4.56 rear end and stock size tires (sounds like you do), the motor should be spinning at about 4600-ish RPM at 75 mph. Top end will depend on condition of motor and how well it's tuned. Both the b16 and b18 are robust little motors and seem to thrive on running them hard. Still I'm going to be putting an overdrive in mine soon.

Yeah, the motors might be able to handle it, but it just seems abusive to have it screaming away at such high rpms for long periods of time. I put an M41 OD in mine a long time ago. It involves quite a bit of major sheet metal surgery on the car, but the result is well worth it.
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'63 PV544 rat rod, '93 Classic #1141 245 +t