JimMueller

iTrader: (9)

There is a dashed line on both ends of the checker to help you measure revolutions.

I didn't turn anything over that day. Yesterday the #1 intake was slightly compressed and the rocker arm wouldn't move anywhere. I turned the crank clockwise until the #1 intake opened and then closed, and then turned it a bit more to make sure the spring had fully risen. There was just a little horizontal slack in the rocker arm at that time. I did not do anything to insure the position of the #1 exhaust.

I wrapped a rubber band a couple of times around the bottom of the checker and inserted it. I then tightened the rocker arm down by hand just until the rocker arm wouldn't move side-to-side on the valve. Then I extended the checker until it stopped. Taking the rocker arm off I was suprised to see the lines were exactly lined up. It was exactly 8 turns.

When I put my 7.4 pushrod back in and tightened it down to 22ft-lbs, I noticed that the spring was slightly compressed in that process.

Patrick G

iTrader: (14)

Jim, looking at the curves, they look just as they are supposed to. The design of your cam was to allow you to make the most area under the curve for autocrossing, while still being able to kiss 7200 if need be. Realistically, the constraints of the intake manifold runner length are going to dictate a power peak in the mid 6000 range which will always make it difficult to pull past 7000 with any hydraulic cam.

Some autocrossing experts were critical of this cam design saying it would have no low or mid range torque (critical for tight corners). I think the dyno curves prove those negative comments as being totally without merit as you make outstanding power down low and up high. As Tony Mamo mentioned, there is no cam out there that can give you super strong low end and the ability to make strong power above 7000 rpm. The cam you have is an all-arounder. I would think that you have achieved your goals. And as far as pushrod length goes, I think the 7.400s are right on the money for that cam and the amount of milling you have (based on previous experience with nearly identical combos).

JimMueller

iTrader: (9)

The reason I questioned the pushrod length was because it fell really hard on the street above 6000, like it dropped anchor. A friend with his 408 made the same comment on his and he thought it may be his valvetrain. So I was wondering if the pushrod length was right so I started playing with the numbers.

Once I went to the dyno and saw the curves, I was happy with the flatness of the torque curve, but was hoping for the curves to be a bit higher. This dyno has a reputation for being stingy, so I scheduled an hour tomorrow to work on the tune a bit.

On a tangent, I'm getting a P0332, even after having replaced the front sensor and the harness. The front sensor wasn't generating voltage when tapping on the block, but the rear one was, so I left the rear sensor alone. I'd like to eliminate the code to insure the knock hardware is operating correctly before desensitizing the sensors or putting in race gas. And ideally like to have it all resolved before tuning.

Edit: Is there any concern for the 'roughness' in the curves at the upper end? It only shows up with smoothing set to zero. Does it indicate the tune needs something?

Patrick G

iTrader: (14)

Keep in mind, the factory tach only goes to 6500 (then it stops). It may look like your rpm is dying above 6000 rpm, but it may actually be dying closer to 7000 rpm judging by your dyno curves. I used to think my motor was falling flat at 6500 until I got a 7000 rpm shift light. The light would come on when my tach was reading 6100-6200 rpm in 1st and 2nd gear. I'd trust the dyno curves more than your factory tach. You're probably twisting it a lot harder than you thought. Where's the rev limiter set? How hard is it to hit?

The codes you're getting may be related to the added noise coming from the rev kit. That rev kit is installed right next to the knock sensors and there's a good chance they're picking up some noise.

JimMueller

iTrader: (9)

Rev limiter is still set at 7200. I haven't been taking it above 6000 much until I was confident there wasn't an issue I needed to resolve. But once the stoch tach indicates it's past 6000, it happened quickly on the street... but not on the dyno.

Here's a street log after replacing the knock hardware. On pull 3 above we zeroed the max KR table as a test. I guess I need to figure out how much to desensitize the sensors.

Patrick G

iTrader: (14)

Word to the wise. Do not trust the factory tach. Set the rev limiter to 6800 then see how fast you hit it.

jegten

iTrader: (22)

are you sure the preload for those lifters is .060?
i think it is, but thought i post the question. geometry is very important in our engines. i just went through something similar.

vettenuts

iTrader: (4)

You also can't add/subtract the shim under the rocker directly, you need to go through parallel triangles as 0.010" of shim equals approximately 0.016" of preload.

JimMueller

iTrader: (9)

Geometry!? I threw in 5gal of 104 unleaded over lunch and will log tonight to see how my KR is affected. My octane blend should be right around 96. Hopefully that'll be high enough to determine if it's false knock. I cancelled my dyno appt tomorrow pending resolution of the KR issue.

The preload of .060 is what was published by SDPC in their original advertisement. That is where I obtained the figure.

DMONEY06

iTrader: (2)

i was told to use 7.4

vettenuts

iTrader: (4)

jegten

iTrader: (22)

+1

am with vette on this one.

JimMueller

iTrader: (9)

The knock is still all over the place with the 5gal of 104 mixed with the ~8gal I'm guessing was in there. So I'm going with it's false.

So do I desensitize the global gain table using the current octane blend, or wait until it's back to the normal octane? And both the P0327 and P0332 codes are back... are the codes the symptom or the cause?