Went to the track again.
Thread Starter
Launching!
Joined: Feb 2010
Posts: 296
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From: Capital region, NY
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.
Thread Starter
Launching!
Joined: Feb 2010
Posts: 296
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From: Capital region, NY
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)
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)
Thread Starter
Launching!
Joined: Feb 2010
Posts: 296
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From: Capital region, NY
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.
TECH Addict
Joined: Oct 2016
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From: PDX-OR-USA
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.
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.
Last edited by pdxmotorhead; Oct 21, 2016 at 01:12 PM. Reason: add a bit
Thread Starter
Launching!
Joined: Feb 2010
Posts: 296
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From: Capital region, NY
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.
