Shagwell

...the age old "which is better" put into a different light.

I'm building a new motor for my daily driver. 350, escalade cam(slightly bigger than reg. Vortec hyd roller) either 1.5 or 1.6 roller rockers(depending on what works best) around 8.5:1-9.0:1 compression, port injection(probably Megasquirt controlled) and using a GTP roots blower. I'm not looking for big performance. I want to use the blower to get me rolling/keep me rolling w/ less effort. - I'm figuring a max of 6-8 psi and a max rpm of about 5200. Now for the question. Would Vortec heads be more efficient than 083's? Either would be bowl blended, and smoothed, probably minor exhaust port work, and typical, 3 angle w/ decent valves, springs, etc. This will be going in my suburban(I know, not 3rd gen, but the insite on this board is great) 33 tires probably 4.10 gearing making for about a 2300 highway cruise, plus help me get rolling easier in town. I could go 3.73, but I figured a couple more r's would help keep/get this brick moving. Again, this is being built for fuel economy/decent performance when the boost control is up. So what do you guys think? What kind of margin are we talkin?

thanks in advance, justin...

305sbc

iTrader: (3)

IMO not a huge difference between the two iron heads, but the vortecs would be cast better quality and have the advantage with power.
For efficiency you definately want to polish everything in the chamber, valves, and piston tops. I'd also polish the exhaust port as well.
Run as tight a quench as you dare.

Shagwell

I figured tight on the quench, but I don't want to get too greedy w/ compression on boost. The GTP blower is waste gated, so the idea is good, but we'll see. - My 81 K5 Blazer(2wd) is an LB9 w/ a L98 cam(advanced 6 degrees) and ported stock heads. Port work consisting of smoothed bowls/ runners/slight guide work. With a 700r4, 3.08 gears, aprrox 26" tires, Q-jet and performer intake I see about 18 town/21 highway. I just built a 95 4wd tahoe for a neighbor, TPI, vortec heads LB9 cam w/ 1.6 roller rockers, headers, good exhaust and he's seeing 17 mpg average on a stock 305 tune/TPI. His is 33 tires, 3.73 geared. I know the 4wd drive line(front cv's) will absorb some mileage. I'm just looking for all I can get.(of course...)
Any other opinions?

thanks, justin...

Shagwell

anyone?...

Fast355

iTrader: (2)

The escalade cam is the same as a standard 350 Vortec. The same 245 net FWHP and 330 ft/lbs. The F-body LT1 cam is hotter than the Vortec cam (Stock B-Body LT1).

Shagwell

could be. I noticed that it had different intake than the standard vortec, and I was told they had an additional 25-35 hp. Could be wrong though. Either way I was just looking at this cam because I figured it'd be pretty good for the goals I'm setting(fuel economy over performance) and w/ a 1.6 the specs look decent for what I'm trying. oh yeah, and the fact that I have one...I also looked at a marine hyd roller. 196/206 @ .050 431/440 115. any thoughts?