Vortec Head Modifications / 1hdt Cylinder Head Performance Modifications Ih8mud Forum - Discussion starter · #1 · jun 15, 2005.. Replaced stock cylinder heads with world products 305 s/r torquer heads. A 28 hp increase over the stock heads, and the 305 engine now has close to 300 hp. Two years ago we undertook an exhaustive (no pun intended) study of the vortec head in numerous modified states with different valve sizes, throat cuts, valve jobs, port mods, guide mods, etc. I will need to cut (reduce the height) of the valve guide boss.this is the curse (or part of the curse) of the vortec heads. Featuring the comp cams xm270h ca.
Camshafts with more than 0.475 lift require machining valve guide bosses and checking valve seal to valve spring retainer clearance. Im trying to make them suitable for my selected camshaft. 298 hp @ 5,500 rpm. The real weakness of the vortec head is the exhaust port, a fact that is readily apparent when you get into porting these heads. 5.7 vortec heads and regular 350 heads.
Tbi To Vortec Head Conversion Gmc Truck Forum from www.jegs.com Discussion starter · #1 · sep 24. Featuring the comp cams xm270h ca. As illustrated in the pics in post #60; Valve spring seat diameter is 1.280. Increased valve lifts require stronger springs. Considering summit advertises 450 hp and 420 torque we would. Two years ago we undertook an exhaustive (no pun intended) study of the vortec head in numerous modified states with different valve sizes, throat cuts, valve jobs, port mods, guide mods, etc. A 28 hp increase over the stock heads, and the 305 engine now has close to 300 hp.
By changing the springs, the distance between the retainers and the valve seals hasn't changed.
Discussion starter · #1 · sep 24. I have a set of 1998 5.7 vortec heads # 10239906 and replaced the stock cam with marine cam about.470 lift. Vortec head modification for.480 lift. Considering summit advertises 450 hp and 420 torque we would. Modifying the heads to accept early intake manifolds is not recommended. Increased valve lifts require stronger springs. 5.7 vortec heads and regular 350 heads. The intake port of the vortec head is different and measures 160cc with a modified port that increases the flow velocity. I will need to cut (reduce the height) of the valve guide boss.this is the curse (or part of the curse) of the vortec heads. The cam is based on the maximum lift for stock vortec heads and is a single pattern 215d/470l on a 112 center. My cams gross lift is.559. Joined jun 15, 2005 · 2 posts. I ported mine and fully worked the exhaust port (bowl work and contouring the runner).
They also feature gm logo cast into bottom of intake ports. The heads are easy to spot because of their intake manifold retention bolt configuration. 1 of 2 go to page. Joined jun 15, 2005 · 2 posts. Comp cams recommends that its pn.
Bbc Vortec Heads Don Terrill S Speed Talk from www.chevelles.com They also feature gm logo cast into bottom of intake ports. Considering summit advertises 450 hp and 420 torque we would. This quick tech video from comp cams® demonstrates how easy it is to use valve spring seat cutters and valve guide cutters to quickly and easily machine near. 308 ft/lb torque @ 3,900 rpm. The heads are easy to spot because of their intake manifold retention bolt configuration. By changing the springs, the distance between the retainers and the valve seals hasn't changed. For stock cam, heads and cr that's very good. 290 hp (216 kw) at 4000 rpm and 410 lbâ·ft (556 nâ·m) at 3200 rpm.
Comp cams recommends that its pn.
Just be careful with used vortec heads as they are prone to cracks after 100k+ miles of heat and cooling cycles, iron cracks. Heads, vortec 4.3l heads are cheap and easy to come by but it does take a little modifcation to make them work with tbi but its worth the effort. I am not going to install lash caps. 298 hp @ 5,500 rpm. Are you looking to get almost 100 more horsepower from your gm 350 crate engine? The cam is based on the maximum lift for stock vortec heads and is a single pattern 215d/470l on a 112 center. Vortec head modification for.480 lift. The end result is a head that will produce a measurable improvement and. Rocker arm studs can be pinned or drilled and tapped to 3/8. My cams gross lift is.559. I have a set of 1998 5.7 vortec heads # 10239906 and replaced the stock cam with marine cam about.470 lift. There are other, smaller points that are important to know because they affect cam selection. For stock cam, heads and cr that's very good.
The study generated 100+ pages of flow and swirl data, which i have at my. Even with the valves removed, it resembles a stock head. My cams gross lift is.559. These heads are good for a minimum 50hp gain. This is the speed secrets episode for you!
Super Chevy Tech Article On Vortec Cylinder Heads Crate Motors Chevy Motors Automotive Repair from i.pinimg.com As illustrated in the pics in post #60; Vortec head modification for.480 lift. Rocker arm studs can be pinned or drilled and tapped to 3/8. The real weakness of the vortec head is the exhaust port, a fact that is readily apparent when you get into porting these heads. 308 ft/lb torque @ 3,900 rpm. My cams gross lift is.559. We used up about 10 heads, numerous valves, and about $50,000 worth of labor. The end result is a head that will produce a measurable improvement and.
298 hp @ 5,500 rpm.
So the best bang for the buck is gm vortec head but does require a special intake and lots of egr work if you need egr to remain emission legal. The end result is a head that will produce a measurable improvement and. Joined jun 15, 2005 · 2 posts. Discussion starter · #1 · jun 15, 2005. The heads are easy to spot because of their intake manifold retention bolt configuration. Camshafts with more than 0.475 lift require machining valve guide bosses and checking valve seal to valve spring retainer clearance. I will need to cut (reduce the height) of the valve guide boss.this is the curse (or part of the curse) of the vortec heads. They also feature gm logo cast into bottom of intake ports. Increased valve lifts require stronger springs. This modification does typically require changing to the 350 5235206 truck injectors 4. I ported mine and fully worked the exhaust port (bowl work and contouring the runner). A 28 hp increase over the stock heads, and the 305 engine now has close to 300 hp. 308 ft/lb torque @ 3,900 rpm.
