matt rem Posted January 1, 2006 Report Share Posted January 1, 2006 I haven't posted in awhile, but I have been doing alot of mods. I added a set of WCCH stage 2 heads in Nov. Went to the dyno and found that the Harland Sharp Rockers where causing some valve float at 5200 rpms.Then the power just dropped off dramatically. So I picked another cam, a Comp 220/224 581/581 on a 115LSA. This is a XER lobe cam so I could use the stock rocker and get the lift to match the heads. I plan on a Radix sometime in the next year or so thats why I went with the 115LSA. I swapped them on Friday and I am hoping to get back to the dyno this week. The old cam was a 216/220 525/532 on a 114LSA. I hope to make almost 400 hp at the wheels with this, Bryan said it is really possible. I will post the results this week after I get back from the dyno. Link to comment Share on other sites More sharing options...
Krambo Posted January 2, 2006 Report Share Posted January 2, 2006 Keep us posted. I have been considering a different cam as well. 400 HP to the wheels NA on a 6L is awesome. Link to comment Share on other sites More sharing options...
zippy Posted January 2, 2006 Report Share Posted January 2, 2006 what converter are you running? Link to comment Share on other sites More sharing options...
matt rem Posted January 2, 2006 Author Report Share Posted January 2, 2006 Still on the stock converter, I think I am going to go with a 2600 10.5 PI. Not sure yet. Link to comment Share on other sites More sharing options...
zippy Posted January 2, 2006 Report Share Posted January 2, 2006 how high are you running it to? Link to comment Share on other sites More sharing options...
matt rem Posted January 2, 2006 Author Report Share Posted January 2, 2006 I think around 6200, I think thats where Allen had it shifting, Bryan lowered it cause of the valve float. I hope to be able to put it back up there. Link to comment Share on other sites More sharing options...
zippy Posted January 2, 2006 Report Share Posted January 2, 2006 with that cam and those heads you should be able to turn 6200 without breaking a sweat. you may find your shifting too early at 6200 if you get rid of the valve float. Link to comment Share on other sites More sharing options...
misterp Posted January 2, 2006 Report Share Posted January 2, 2006 I dunno, I would think that if there was a rocker arm problem it would be deflection; a rocker arm would have to be really weighty on the nose-end to contribute to valve float. What springs are you using? Mr. P. Link to comment Share on other sites More sharing options...
matt rem Posted January 2, 2006 Author Report Share Posted January 2, 2006 I am using the Patriot spring, I was thinking the roller tip on the Harland Sharp was causing the valve float. I just talked with another guy with almost the identical combonation,just with a bigger cam. A FMS 228/230 576/595 on a 114lsa.He is using the stock rockers. He made 370 ftlbs of torque and 350 hp. I made 355 ftlbs and 350hp, with the 216/220 cam. Both of us are on 42lb injectors cause we ran out of injector. I am starting to wonder if the intake manifold is the problem? A fbody will make more power and the only difference is the manifold. Both of the dyno graphs start to fall off around 5000-5200. What do you guys think? All the truck guys are making good power pushing the air thought the manifold with FI, Does anyone have a dyno graph from a N/A 408 or heads and cam truck? Link to comment Share on other sites More sharing options...
BenKey Posted January 3, 2006 Report Share Posted January 3, 2006 Are these HS rockers adjustable? If they are I can see the possibility of valve float. If they're not I just don't see how it is possible, unless they were installed improperly or an improper design for the application being used. Link to comment Share on other sites More sharing options...
matt rem Posted January 3, 2006 Author Report Share Posted January 3, 2006 No they are not adjustable, you have to shim the base or use a shorter pushrod, which then screws up the geometry. That was some of the problem, I should have tossed them in the garbage from the get go. Thats why I have the new cam. I just don't understand these 2 trucks are almost identical except the cams, same heads ( WCCH stage 2). Richard at WCCH says that he has seen the truck manifold fall off at 5000 rpm before. The seat pressure and open pressure are right on also. 165 and 390. Link to comment Share on other sites More sharing options...
zippy Posted January 3, 2006 Report Share Posted January 3, 2006 are you going to look into the car intake swap? Link to comment Share on other sites More sharing options...
matt rem Posted January 3, 2006 Author Report Share Posted January 3, 2006 I was thinking of trying the LS2 truck manifold, I think the truck manifold is restricted by the volume of the plenum, the car is 5.19 liters and the truck is only 4.0 liters. I think it could be running out of air on the top. The plenum on the LS2 truck manifold is supposed to be the same as the LS6. Someone makes adapter to go from a 3 bolt TB to a 4bolt manifold. Link to comment Share on other sites More sharing options...
deezel Posted January 5, 2006 Report Share Posted January 5, 2006 Considering the truck intake... Maybe the "tube-with-a-hole-in-it" core of the intake is part of the restriction in the truck intakes. I thought someone was considering enlarging one of those at one point... but I don't recall ever seeing any results. If one could figure out how to enlarge that hole without screwing up the air distribution to the cylinders, one could possibly improve the high-rpm performance of the truck manifold. Link to comment Share on other sites More sharing options...
matt rem Posted January 6, 2006 Author Report Share Posted January 6, 2006 I cut one in half last nite, its a poor casting. It started to neck down then opened up before the hole in the plenum. I really don't know what to do, I just feel like the manifold is holding me back Link to comment Share on other sites More sharing options...
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