I do understand the cam SHOULD be spun to 6500 but the power drops off at just over 6k. Like 6,100 the power falls off and I shift because the engine feels like the pull is gone. The heads definitely are coming off this winter to have them checked. I have a feeling that maybe the porting wasn't as great as it seemed. If they don't check out then I'll know I was just given some BS flow numbers. They do look like they have been ported at least a little bit. I took a picture of 2 ports on one of the heads when I had my intake off like a week ago. Of course I didn't have a micrometer otherwise I would have taken a few measurements.

 

Here are the best pics I took. Pretty annoying that it's hard to get light down the port. I'm sure these don't help but it does show someone was in there doing something.






Actually the more I look at the pictures the more I'm thinking I shouldn't be seeing "pitting" on ported heads. I see pitting from the cast surface merely being smoothed out. Around the pushrod bump I see it. Also these heads do have some welding done to them where they created a hole when they ported the heads. (Top of the port where it opens up after the pushrod bump)

 

Was the cam degree'd in, or just timed to marks, there can be a lot of power left on the table if the cam is off even a degree or two... Especially at the upper end.

Just a thought...
Dave

 

I just lined it up with the marks. I should have degreed it but I didn't have the means to when I put this engine together. Can it really leave that much power on the table? I did ask LE about it and he said maybe it's an issue but more than likely not. But I guess you never know.

 

Put it on a dyno you'll know instantly whether or not you have valve float. You can also get a spring pressure tester and test a few springs (the ones you can reach) and see if they are too light. Even after this is all fixed you're still going to want at least a 4.10 gear.

 

On my 2.5 liter jeep motor, with a bal and blueprint, some mild head work and a .512 lift cam,,, it makes 15 HP.. changing 5 degrees. On a engine that makes about 160 HP thats HUGE. (Was < 130 stock)

On a 406 sprint I fiddle with for a buddy, its almost 10 HP per degree, we are constantly adjusting the cam to suit certain tracks. But thats a 850 HP allky motor... But the bigger effect is the way it pushes the power band up and down. On a short track we want it to spin up quick, on a long track we want it flatter so we can make it down the straight without running out of RPM's//

I'm don't consider myself the motor ninja at all lots of guys know WAYY more than me,,,, the guy that built the motors comes to the track with us a lot and adjusts it there, then I keep a log book of the hot adjustments for each track.
So this is all based on observation and tuning the car to the track.

One other thing, Ive seen a LOT of timing sets with the marks WAY off, or the locator pin/keyways on the cam and crank way off,, even on $40K rotating race assemblies, don't assume ANYTHING is correct. I also use a cam doctor on any new cam on all the lobes to see if the bozos at the factory did their part.. Also always use break in oil on a new cam, the new oil doesn't allow high lift cams ,, especially flat tappet to break in right, I've seen a cam go flat in 1,, 20 minute track session... If you don't have a cam doctor to play with once the cam is degreed in on jug 1, use a dial indicator on the rockers and check each cam lobe for lift and duration with the degree wheel.

 

Well the dyno near me won't be available until after I put the car away so there's no chance of getting her on the dyno before winter. This winter I plan on tearing down the motor and taking a look at the bottom end. The oil analysis I had done before showed metal in the oil so I'm going to take a look and see if I can find the source. Regardless I plan on doing a 383 so long as I actually do have a decent set of heads on the car like I think I have. Plus it gives me a chance to degree the cam also. I planned on having the block cleaned up/checked at a shop anyways so it all works out.