![]() I would like to know the camshaft specs for the 295hp Vortec 350 marine engine, the 1 with the marine intake. How knows? Why are the Vortec camshaft specs so hard to come by? Is is a secret or something? Maybe these slight differences account for the 5 hp difference between the 1996 being 250 hp and the 1997-2002being 255 hpthus netting a 5 hp difference. These contrast with tyhe 1996 specs I found I think they are mixed up a bit it should read. The 1.5 ratio doesnt work out to the 1.6 ratios listed. After tuning, the new combination belted out 543 hp at 6,900 rpm and 463 lb-ft of torque at 5,300 rpm.These are my specs as of several years ago. Completing the induction system was a Holley 950 HP carburetor teamed with an MSD billet distributor. Feeding the impressive Brodix heads was a single-plane Power Plus intake. in all regions, except in the Mekong, where oil engines dominate. To maintain the static compression, we took the liberty of milling the Brodix heads to reduce the chamber size from 68 cc down to 65 cc. safe water supplies and irrigation were the biggest issues related to poverty. As indicated by the name, the Brodix heads featured 225cc intake ports, and flow over 300 cfm (enough to support over 600 hp). The aggressive roller cam was teamed with a set of as-cast Dragon Slayer 225 heads from Brodix. ![]() It had 0.630-inch lift, a 264/270-degree duration split, and a tight 106-degree LSA. Though it was possible to produce this power with a hydraulic roller cam, we stepped up to a solid roller. Exceeding 540 horsepower from 355 cubic inches required a healthy cam profile, and the Comp 300BR-16 cam certainly fit the bill. This combination was skewed much more to the strip end of a street/strip buildup. The final upgrade netted nearly 300 additional horsepower over our baseline, but know that this combination certainly reduced driveability compared to the previous two. After installation of the new components, the 355 produced 449 hp at 5,900 rpm and 446 lb-ft of torque at 4,600 rpm. In addition to the cam, Comp Cams also supplied the necessary lifters, pushrods, and stainless roller rockers. The XR276HR offered a 0.502/0.510-inch lift split, a 224/230-degree duration split, and 110-degree LSA. A good portion of the extra power came from the cam upgrade, a Comp Cams XR276HR hydraulic roller cam. The same dual-plane intake and a Holley 750 HP carburetor topped the AFR heads. For this application there was no need to step up to the Competition package, but the Eliminator heads featured 65cc chambers, a 2.05/1.60 valve package, and flow numbers to support over 550 hp. The basic short-block remained the same, but the 355 received a new set of AFR 195 Eliminator heads. Off came the 100hp upgrade parts and on went a new set of heads and induction system. For flat tappet cams, I recommend the Davis Unified 12620bk then for Plug wires, if your running a stock engine then stock replacement wires are typically fine but any decent. ![]() Though we could get away with using the as-cast RHS heads at this power level, we decided to try a whole new combination. For roller cam engines use a new best brand distributor you can get at your local autoparts store for a 1992 Camaro 350 TPI Z28 which also uses a flat tappet camshaft. The first 100hp increase was easy, but each successive jump in power becomes more and more difficult. Yopu dont necessarily NEED to use a block that is machined for the stock cam retaining plate. This is how you use a roller cam in a NON roller cam equipped engine. On page 11 they talk about using a Nylon camshaft thrust button which holds the cam in the block by pushing against the timing cover. This trend continued with each successive step up in power. 232cfm-180cc intake ports 170cfm exhaust ports. Note that the engine produced peak power and torque higher in the rpm range compared to the two-barrel configuration. The mildly modified Mouse pumped out 347 hp at 5,400 rpm and 399 lb-ft of torque at 3,700 rpm. Topping the as-cast RHS heads and RV cam was a Speedmaster dual-plane intake and Holley 650 HP carb. Working with the 180cc RHS heads was a mild Comp High Energy 252H cam that offered 0.425-inch lift, 206-degrees of duration 0.050) and 110-degree LSA. Though this power level would easily be served by a set of ported stock or Vortec heads, we stepped up to a set of as-cast Pro Action aluminum heads from RHS. Toss in a mild cam and cylinder head upgrade and the power gains really start to add up. ![]() Replacing the 2G with a Q-Jet and intake alone can be worth 25-30 hp. The first 100 hp is the easiest since every component on the stock two-barrel engine is restrictive, starting with the diminutive carburetor. Obviously, coaxing more power out of a two-barrel 355 isn't particularly difficult, especially given the vast array of performance products available.
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