Vortec Head Modifications - Small Block Engine Cylinder Heads | Chevrolet Performance / 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.. Tbi to vortec head conversion gmc truck forum / vortec heads also use a different intake bolt angle than traditional sbc heads and, as mentioned previously, camshaft lift needs to be kept on the low side, unless other modifications are made. Vortec head modification for.480 lift. Im trying to make them suitable for my selected camshaft. I ported mine and fully worked the exhaust port (bowl work and contouring the runner). Modifying the heads to accept early intake manifolds is not recommended.
A 28 hp increase over the stock heads, and the 305 engine now has close to 300 hp. Increased valve lifts require stronger springs. 1 of 2 go to page. The true vortec 4.3 came out in the mid to late nineties. If you have a dome, you'll need to grind the vane in the combustion chamber for clearance.
Street-Style Vortec Head Test - Tech Article - Chevy High ... from image.superchevy.com The vortec is more heart shaped. The real weakness of the vortec head is the exhaust port, a fact that is readily apparent when you get into porting these heads. 298 hp @ 5,500 rpm. Tbi to vortec head conversion gmc truck forum / vortec heads also use a different intake bolt angle than traditional sbc heads and, as mentioned previously, camshaft lift needs to be kept on the low side, unless other modifications are made. Camshafts with more than 0.475 lift require machining valve guide bosses and checking valve seal to valve spring retainer clearance. Vortec head modification for.480 lift. Discussion starter · #1 · sep 24. A 28 hp increase over the stock heads, and the 305 engine now has close to 300 hp.
Generally for early production the half tons got the full vortec treatment, the heavy duty models 3/4 and up is where you usually see the swirl port head with tbi or the tbi variations on a vortec head.
So you can see, the oem tune really chokes the potential vs carb. There are other, smaller points that are important to know because they affect cam selection. The vortec is more heart shaped. The cam is based on the maximum lift for stock vortec heads and is a single pattern 215d/470l on a 112 center. Generally for early production the half tons got the full vortec treatment, the heavy duty models 3/4 and up is where you usually see the swirl port head with tbi or the tbi variations on a vortec head. + up to.550 lift on vortec heads w/ no mods! I recommend you get a block off kit off ebay and remove the thing and tell me when you order a chip so that i can program the chip to run with the other 8 injectors. For stock cam, heads and cr that's very good. One way to tell is by the casting numbers on the heads and block, you can google them to find out. The true vortec 4.3 came out in the mid to late nineties. 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. Joined sep 19, 2010 · 120 posts. Modifying the heads to accept early intake manifolds is not recommended.
Vortec head modification for.480 lift. I ported mine and fully worked the exhaust port (bowl work and contouring the runner). 298 hp @ 5,500 rpm. Im trying to make them suitable for my selected camshaft. Lightweight hollow stem ls3 valves can be cut to 2.000 in.
89 Pontiac Transam GTA - Vortec 350 TPI from members.optushome.com.au Increased valve lifts require stronger springs. Tbi to vortec head conversion gmc truck forum / vortec heads also use a different intake bolt angle than traditional sbc heads and, as mentioned previously, camshaft lift needs to be kept on the low side, unless other modifications are made. We used up about 10 heads, numerous valves, and about $50,000 worth of labor. I ported mine and fully worked the exhaust port (bowl work and contouring the runner). Valve spring seat diameter is 1.280. Are you looking to get almost 100 more horsepower from your gm 350 crate engine? 290 hp (216 kw) at 4000 rpm and 410 lbâ·ft (556 nâ·m) at 3200 rpm. Discussion starter · #1 · sep 24.
Starting in 1996, on several gm trucks and vans, the l31 vortec heads came on the scene.
Discussion starter · #1 · sep 24. Just be careful with used vortec heads as they are prone to cracks after 100k+ miles of heat and cooling cycles, iron cracks. I recommend you get a block off kit off ebay and remove the thing and tell me when you order a chip so that i can program the chip to run with the other 8 injectors. + up to.550 lift on vortec heads w/ no mods! One way to tell is by the casting numbers on the heads and block, you can google them to find out. Lightweight hollow stem ls3 valves can be cut to 2.000 in. My cams gross lift is.559. The cam is based on the maximum lift for stock vortec heads and is a single pattern 215d/470l on a 112 center. The true vortec 4.3 came out in the mid to late nineties. Vortec head modification for.480 lift. Increased valve lifts require stronger springs. For stock cam, heads and cr that's very good. Comp cams recommends that its pn.
The real weakness of the vortec head is the exhaust port, a fact that is readily apparent when you get into porting these heads. This is the speed secrets episode for you! I recommend you get a block off kit off ebay and remove the thing and tell me when you order a chip so that i can program the chip to run with the other 8 injectors. Valve spring seat diameter is 1.280. Can be machined for 2.020/1.600 valves.
Vortec heads - The best option for me? - Third Generation ... from cimg5.ibsrv.net Discussion starter · #1 · sep 24. One way to tell is by the casting numbers on the heads and block, you can google them to find out. + up to.550 lift on vortec heads w/ no mods! This is the speed secrets episode for you! Im trying to make them suitable for my selected camshaft. A 28 hp increase over the stock heads, and the 305 engine now has close to 300 hp. I recommend you get a block off kit off ebay and remove the thing and tell me when you order a chip so that i can program the chip to run with the other 8 injectors. The deck surface is.450 and features 65 cc combustion chambers, 175 cc intake and 65 cc exhaust ports.
Lightweight hollow stem ls3 valves can be cut to 2.000 in.
Joined sep 19, 2010 · 120 posts. My vortec heads are good to.500 in/.530 ex (with 'forgiveness' in mind) with common components used and absolutely no machining done to the heads valve guides/spring pockets. Replaced stock cylinder heads with world products 305 s/r torquer heads. Im trying to make them suitable for my selected camshaft. Rocker arm studs can be pinned or drilled and tapped to 3/8. 1 of 2 go to page. My cams gross lift is.559. Vortec head modification for.480 lift. Featuring the comp cams xm270h ca. Upgrading lm7 cylinder heads the stock heads can be cnc ported for more airflow and milled up to.030 in. So you can see, the oem tune really chokes the potential vs carb. All the parts are included and they sell for about $680 a pair. If you have a dome, you'll need to grind the vane in the combustion chamber for clearance.
