The SVO injectors are flow rated at 2.7bar (39.15psi). The multiplier for flow when running them at 3bar (43.5psi) is 1.054. So he's running a 31.6 #/HR capacity. 380rwHP through an M6 is about 440HP at the flywheel. I'd guess he's approaching 90% DC, which is not a good idea. But it's probably not the problem.

And on a different topic, with a 2.05" intake valve, I'd be very concerned about shrouding of the valve.

 

I'm currently useing a 280XFI HR with the same 0.050 duration numbers. I made 401 at the tires at 5980rpm and it dropped off fast after 6000rpm. Now I'm looking to go bigger on the cam (Adv./Ind. or LE). My original plan was street and now I'm going racing.

 

I wonder if solid mounts have you in heavy knock retard.
10.5:1 compression is a bad bad thing, stock was 10.4 a built NA LT1 should be over 11:1 many are even over 12:1.

bubba4 if power drops off fast I would look at springs before another cam unless you want another cam for some other reason.

 

I will look into the springs, thanks Dwayne.

 

Numbers look fine to me, give the mod list. Mild compression, small cam, and LT4 heads...

Run it at the track and see what it does.

Curious, the second curve on the graph showing 380whp, doesnt look like it peaked yet at 6200. Try running it out to over 6500 to see what the top end is doing. That motor could use more compression but really needs alot more cam. Something in the higher 240's if sticking with solid roller.

 

Probably dont have the springs for those lobes. They need a good bit of pressure. If using a double spring, I'd run something like the 1.26-1.30" diameter doubles with 150-160lbs on the seat and closer to 400 lbs open pressure at the valve lift. That will get it done. Or maybe the Pac-1219/1519 beehives. XFI stuff needs a stiff spring to turn rpm

Also when looking for bigger cam, may want to tighten that lobe separation abit... 280xfi is a good cam but would improve abit with tighter LSA...109-110 would be nice to try.

 

So whats a good cam for this motor? Its mostly street, goes to the track maybe once or twice a year for fun. Something that sounds mean would be nice. The cam thats in it has no chop to it at all. Especially with true duals with bullets. Its a stick so Im sure it can be somewhat aggressive.

 

Before you cam shop you need to tighten the plug gap and probably go ahead and have the knock sensors turned off in the programming because I doubt that knock sensors and solid roller valvetrain work well together. Make sure what you have is working as well as it can before trying to change things.

Who led you this far astray on this build? If you tear back into things you need a new source of guidance. Aside from personal opinions about parts the hard facts are that is a really small cam for a solid roller stroker, so small there was little if any point in going solid and the compression is very low for a built NA motor. Even an LT4 was 10.8 from the factory.

 

Several things, first being issue being that the build sheets just sucks, it's missing a lot of pertinent information.

Why the heck were the oil clearances set so damn loose?

Who chose that dinky doo little street solid roller?

No quench, little low on compression.

Stock LT1 rocker studs with 250# seat pressure and what should be 550# + over the nose - SCARY!

...again more information left off the build sheet, open pressure, coil bind, retainer to seal, a freaking spring part number???

rings are gapped loose.

Motor looks like it's choked on the intake or exhaust side - when horsepower plateaus and carries a number like a flat table it indicates a volumetric efficiency problem.

 

If this is mostly street, by all means change cams to a hydraulic roller. Solids wont last as long as a hyd roller and you really arent pushing the limits of valvetrain stability to require a solid roller anyway. Just order a custom grind from one of the good cam grinders out there....Lloyd Elliott could work with Bullet for a cam, or AI may beable to spec a cam for it. Would be nice to know information about the heads tho and see abit more compression...may just need a head gasket change if its thick and pistons are in the hole abit.

With rings gapped that loose and fairly low compression, a smal turbo would work really well here Or a good bit of nitrous. You have options which is nice

 

When I saw the ring gaps, I wondered if they did that on purpose?

 

I think this cam is for a 350 not a 383. I use to have a 94 camaro stock 350 lt1 and we put a gm 847 cam in and that car pulled Wayy the F harder than this motor ever has. I think the cam is choking the chicken BIGTIME. Obviously if Im going to do the cam. Im goin with AFR 220's or bigger. I think they put comp 947 springs in it.

 

As cast AFRs would not be my first choice by a long shot. Do some research in newer LT1 head design. Stuff like the new AI TFS heads are kicking some serious ***.

 

I have emailed Adv ind with all the specs. They have not responded to my email yet.

 

AFR does not make an as-cast cylinder head for the general public. The only as-cast heads that they sell are to head porters. Those heads have a rough cut and the porters are free to run whatever cnc program on them that they want to. Every AFR head that is available to a customer is cnc'd. There are 3 levels of cnc'ing that they offer. The levels are street, race, and comp. Each level goes into finer detail. I'm curious why you would say they wouldn't be your first choice "by a long shot"? The AI TFS 215cc head is an awesome piece, and I'd bet it would be very similar to the AFR 210cc Comp ported piece power for power. Both have similar sized runners, accept the same valvetrain and flow similar, 304.4cfm at .700" for the AI with a 4.030" bore and 322cfm for the AFR at .650" on a 4.060" bore. Both are to your door for around $24xx. The AFR eliminator stuff is "newer LT1 head design". You talk like the AFR's are outdated or something, just want to clarify a bit. Both heads can make some serious power.

This is what you get on the "street" cylinder head from AFR;

100% CNC Ported Combustion Chambers
100% CNC Ported Exhaust Ports
100% CNC Ported Intake Ports
Competition 5-Angle Valve Job