What are your shift points set at?

Everything about my combo is setup to flow(maybe not so much on the KB.......) But, what is everyone using as shift points when you have big cams and a built motor that will take the RPM's

 

I'm at 5400 rpms...

 

Casey
If You're running those 278's I wouldn't be afraid to try 6000+....if you got enought spring to go there.
Dale

 

Well; they are suppose to be the new Nextec springs, but how my motor has went who know

Dale; were your 278's fairly noisy? They make a lot more noise than my Crower Stg2's did. I get that typewritter type noise; I've heard it before in big cam LS1 cars. And we here it in the other local truck running them.

 

HI!... Built 5.4 with everything. Still N/A. Was running the CROWER STAGE II cams and was shifting at 6800RPM. Was still pulling hard! I'm currently switching over to a custom crind from COMP cams, 0.550/0.550 lift, 234 duration. We'll see what this one does after my engines back together.

 

Might you mean 5800 rpm?

Jody

 

Hi Casey
Actually my 278's were nice and quiet but at the time I was running solid lifters with an aluminum rocker arm and the lash was farily tight (.004/.005) so there wasn't any noise to speak of but I do know the noise your talking about quite well.

The first new engine I built for the truck had a shimmed up ModMax breakable valve spring in it with a set of stock cams...seat pressure was right at 100/105 I think and this engine had a typewriter sound to it coupled with the rattling clutch plates in the PI torque converter and it sounded like an old muscle car.

I played around with oil weight at the time thinking that the hydraulic adjusters were pumping down but that didn't seem to be the case....I even poured 15w50 mobil 1 in it and it didn't do a thing for it.
So then when I pulled it apart for whatever reason...I started measuring things and found out that the rocker as it sits over the valve stem has boat load of side clearance somewhere in the neighbor hood of .013 to .015 and add to that the cam lobe wasn't ground perfectly flat and you have your noise problem.....I think that with the heavier spring pressure the rockers are kicking sideways on the valve stem and making a little clicky noise that does absolutely nothing except annoy the hell out of you.

Anyway that's this weeks theory

Dale

PS....the roller tip on the aluminum rocker arms fit over the valve stems much tighter than the stock rocker arms did ....as a matter of fact getting the proper edge chamfer on the valve stem was a really big deal....other wise it would interfere with the corner radius in the roller and bind like hell. I believe this tight fit was one of the reasons the aftermarket rockers were so quiet.

 

Got to play with it more tonight and run it at the track. She pulls good now! DA was about 2k feet and there was a pure dew falling on the track. Managed a 1.64 7.28@95 Pig rich and not a lot of timing in it. Can't wait to get it dialed in now!

Yeah; that type writter sounds is annoying! At first I thought I had a bad/damaged lifter. My LS1 buddy's beleive the noise is the sharp ramps "slapping" the valves closed. I have to admit looking at the Crower Stg2's and the Comp Stg3's it's insaine how much fatter the lobes are and the ramps.

 

hmm sounds familiar


Will

 

HI!... NOPE! 6800RPM was correct sir.........

 

You're a nutball! I have the parts to run that rpm no problem, but it seems to be a waste of time as with the small bore these heads don't really flow enough to need that rpm. It may turn 6800 rpms but it can't be making any power up there, at least I've never seen a dyno that didn't nose over before that rpm. However, it does sound cool!

Jody

 

I have Crower stage 3's shifting at 5400 Rpms.

Peace,

Suavy

 

HI!... Well in 1st and 2nd gear it will bury the factory tach (6000 RPM) with ease and it keeps pulling. JMC can contest to that. Even bumped my 7000 RPM rev limiter a few times. My built 5.4 was built to with stand 1400H.P , that's why the high price tag, but it was specifically built for a large single turbo set-up that will be going on in the spring. It does run good in N/A trim though. Trapping at about 106MPH in the 1/4. It will hit 205KPH though in 3RD gear and I have 4.10 gears and 28" tall tires.

 

Shift pints set at 5850 and limiter at 7000. Hit the limiter often when tires break loose. Hit 6000 -6200 on dyno pulls.

 

Hummm; well I had the shift point set to 5700 and the rev limiter set to 6100 and it was hitting the rev limiter

Guess I'll try to log where it's actually shifting at, and move the limiter up some more.