ah ha, we are slack, we just get our builder to whack them on the dyno and run them in (nationals) they seem to pull hard but dont rev as much as some of the others on the track

Imo hamg off off the good oil for 3000 klrs then Synthetic....They don't hone the bores like they used to and these days low tension rings are used....

It's not really a question of what revvs to hold or use cheap oil or any of the 'generic' responses that have been given here... in my experience.

The whole point of running an engine is is to 'bed' the rings and cam in.

The only thing that will bed rings in is cylinder pressure. Too much cylinder pressre early on will cause damage to the engine, too little will result in the cylinder walls galzing.

Now, two things affect cylinder pressure.

1. Cam shaft
2. Throttle

More throttle = more air into engine = more cylinder pressure. Simple.

As for camshaft, max cylinder pressure is attained @ max torque. So, if you've got a cam that delivers max torque @ 2500 RPM, you want to be keeping the engine around those speeds. No point taking the engine up to 6000 RPM if you don't get any torque there.

If you've got a cam that is designed to produce torque up @ 4000 RPM, you don't want to be piddling around down @ 1500 RPM because you'll have very low cylinder pressures and the engine won't bed in properly.

This is why a race engine will bed in nicely if you take is for a few hot laps, but if you did that to your Falcon, you'd be rebuilding your engine again after those few hot laps.

The other thing to consider is oil. Modern engine oils are multi grade with EP additives, anti-friction agents and friction modifiers. They do this to prevent wear. Only problem is, the process of running in an engine can be described as nothing but wear. You're wearing off metal from the rings, so you don't want an oil that prevents this wear.

When I had my last engine rebuilt, it was a 3.5L Rover V8 in a Triumph TR7. The car weighed 1000kg with fuel and occupant and had a 3.9 diff ratio, so loading up the engine was extremely difficult. Rover will tell you that these engines redline @ 5500 RPM. When I ran my engine in, I regularly gave it plenty of stick after about 100km and revved it out to 6800 RPM. Something I was able to do as the car was so light since the lifters pump-up @ 6500 RPM. I never had any problems with rings not sealing properly.

what is a good oil to use when running an engine in. are there special oils designed especially to break an engine in??