Drat, that's the 2nd time I've missed it by just a few horsepower. Maybe the 3rd times the charm.
It's also the 2nd time that Shady has won.....I promise this isn't rigged. But the last time he won, I sent him some decals, etc., and he turned around and ordered a short block from me. I'm waiting to see what he orders this time.
I would consider yesterday a pretty big success. All-in-all, I wasn't out to make big horsepower, as I mentioned quite often. It was a rather mismatched combination and it simply reinforced that the cylinder head plays a huge role in how the engine makes power. If you compare this engine to the TFS headed 390 that I built a few months ago, there was a large difference in the components used, but only a small difference in corrected horsepower....actually only about 4 hp. However, we have one head that flowed 330 cfm at lift and the other head that flowed mid 280's at lift. Big difference.
After we got heat in the dyno room, we were seeing corrected numbers of 542 hp/460 torque. Peak torque was at 5500, which was pretty much where I thought it would be on an engine that's higher strung.
With a pan full of 5W-20 oil, we didn't have any issues with the lifter function. It was very hard to get the oil temp up, but with 150° temps, we were seeing 70 psi at 4000 rpm and 80 psi at 7000 with a Melling HV pump and a Milodon oil pan with 9 quarts in the system. I was oiling through the pushrods on this one with the head feeds blocked off in the block deck, so that gave me a good indicator of how the engine oiled with my rocker arms. Running with a valve cover off, there was a nice little trickle at the roller tip. Now, obviously, at 190-200° oil temp, the oil pressure would drop, probably by about 10 psi, but it would still be plenty enough to feed the system. I was running .003"/.0025" bearing clearances.
At 7500 rpm, we were not hearing any audible sounds of the lifters giving up, or the valve springs being in distress. I think if it would have had enough cylinder head, it would have pulled to 8000, but it was simply starting to run out of camshaft/head flow at around the 7250 mark.
Oil filter was clean and the plugs/exhaust ports looked real nice afterwards.
FWIW, it made the most horsepower with 41° of timing, but only dropped 6 hp at 36.
Next plan of action is to try another camshaft. It won't happen for awhile but there's a couple of things that I want to try. I will keep .050" duration the same and lift the same, but my plan is to tighten up the advertised durations considerably (more aggressive lobe) which will let me tighten up the lobe separation as well. I wanted to start out with a "lazy" cam just to make sure that it wouldn't be a hindrance on pulling the rpms. I can now start to creep up on the lobe aggression.
If anyone wants to hear a 7500 rpm hydraulic roller FE, here you go:
https://www.youtube.com/watch?v=C_JY47anClA (Cool to watch the vacuum secondaries open)
