Thread: I think I have a BIG problem

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Jack do you know if the valve locations are offset??? It is common in sbc performance heads to put larger valves in they move the exhaust valve over so that they can also move intake valve away from edge of chamber---------Glad your sure that you don't have a geometry problem----

Whose/what company rockers are on engine and what ratio????
I've seen a few cases of the fast burn heads having valve seat ring get loose because of temp differance in aluminum head and as it moved down it holds valve open some creating an odd clattering noise before it eventauly creating a mess in the cylinder with a dropped valve, pieces then getting into intake and over to other cylinders-------

Originally Posted by jerry clayton

Jack do you know if the valve locations are offset??? It is common in sbc performance heads to put larger valves in they move the exhaust valve over so that they can also move intake valve away from edge of chamber---------Glad your sure that you don't have a geometry problem----

Whose/what company rockers are on engine and what ratio????
I've seen a few cases of the fast burn heads having valve seat ring get loose because of temp differance in aluminum head and as it moved down it holds valve open some creating an odd clattering noise before it eventauly creating a mess in the cylinder with a dropped valve, pieces then getting into intake and over to other cylinders-------

Jerry, It's ALL Chevy parts. The heads are standard Fastburn. The cam is an upgrade cam/kit made by General Motors Performance Products (GMPP) specifically for this engine, as well as the ZZ4. As you probably know, the Fastburn 385 is simply a ZZ4 short block with Fastburn heads. Here's some info from the specs.

THE FAST BURN 385 USES THE ZZ4 SHORT BLOCK AND ADS THE FAST BURN ALUMINUM CYLINDER HEADS FOR 385 HP. IT USES STAMPED STEEL ROCKER ARMS AND THE ZZ4 CAMSHAFT.

430 HORSEPOWER AT 6000 RPM IS ACHIEVABLE BY ADDING THE HOT CAM AND 1.6 RATIO SELF ALIGNING ROCKER ARMS.

The engine and the camshaft upgrade came straight from the GMPP catalog. These are the rockers: Rocker Arms, Stud Mount, Full Roller, Aluminum, 1.6 Ratio, Fits 3/8 in. Stud, Chevy 1987-99, 5.0, 5.7L.

The camshaft specs are: Duration at lash point in degrees (intake/exhaust) is 279/287; duration at .050" tappet lift (intake/exhaust) is 218/228; maximum lift with 1.6 rocker ratio (intake/exhaust) is 525/525. Valve lash is zero/zero and lobe centerline is 112 degrees.

As I have said several times, this was a crate engine that I picked up in Kansas City, and the camshaft/lifters were recommended by many builders at the time as a solid upgrade. Standard stuff for the day .