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Thread: New Heads: Vortec 2.02" / 1.6"
11-04-2013, 08:31 PM #11
A few pics from recently swapping the heads again. May as well update an old thread then create a new
I was running into piston to valve clearance issues, the marks were caked under a layer of carbon from burnt oil. I suspect it was valve float.
The replacement heads are a set of Pro-Comp, aluminum 210cc runner/58cc chambers, angle plugs. I opted to use head studs to help remove variables.
The reason I chose budget castings were because I wanted to experiment with a few internet myths. Somender Singh grooves and chamber dimpling.
Starting with the 58cc chambers and assuming going as large as 61-62cc's after groove and dimpling, with the .026" MLS head gasket the static compression should be around an even 11:1 with a .030" quench. Before bolting the heads down I checked piston to valve interference with playdough in the valve reliefs. Bolted the heads down without a gasket and then made a simulated "solid" lifter from an old hydraulic one and ran half a dozen cycles on the intake an exhaust. The valves barely made an impression in the play dough. PTV clearance checked good.
Increased capacity oil pan:
Proform 2 piece valve covers, new MSD cap/rotor & custom made wires to sneak under the headers.
Painted the engine bay, cleaned up some unused wiring harnesses. Tucked away and hide the remaining wiring. Right now I have the heater hoses removed, I'd like to come up with a creative way to plumb and hide them.
New MSD digital 6a, Mallory coil. Still trying to hide as much wiring as possible.
The day I got it fired up and on the test drive it grenaded another 4L60E, the third one for this truck.
The torque converter cracked at a weld on the snout too.
Ordered a new converter. a 10" 2800-3200rpm stall, non-lockup & anti-ballooning plates:
In the process of getting it back together and will hopefully be able to drive it, cruise it and hammer on it without any other major problems.
I've got a few more toys to play with once it's up and going again. I have a few carb spacers to run through and even stack different ones. Also have an oil catch can to mount, I'm debating installing an electric vacuum pump to draw through the crankcase too.
I plan to spend a very long time dialing in the carb tuning with use of a wideband O2 gauge.
Vortec 357ci Small Block Chevy: Big cam, high stall, long headers, rear gears. The typical formula.
11-04-2013, 10:59 PM #12
Wow! Sweet truck.
1995 Silverado 4x4
6" BDS Suspension Lift-3" Body Lift-Add A Leaf in rear -Trailmaster SSV Shocks-Duel Steering Stabilizer Kit -AirAid Cold air intake-
4.56 Gears with Detroit Auburn Locker-Pro-Comp Traction Bars with duel shocks-Aluminum Skid Plate Kit-38.5" x 16.5" Mickey Thompson Baja Claws-Constant Dropping fuel gauge
2005 Yukon XL Jet Power Programmer, Bilstein Shocks, Bilstein rear springs, Helwig Anti-sway bars, EGR Window Visors, EGR Hood Shield, Denali Headlights, Headlight harness upgrade, GE NightHawk Bulbs, White Night Rear lighting system, Russell Braided SS brake lines, PowerStop Brake pads, PowerStop cross drilled and Slotted Rotors, http://www.gmtruckclub.com/forum/sho...5-GMC-Yukon-XL
2002 Silverado ext cab 2wd (Sold)
2003 Yukon XL (Totaled)
11-05-2013, 02:59 AM #13
damn. Very nice truck man. Hope all goes well and you actually get to drive your toy lol! big fan!
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Kind of curious to know why you did away with EFI.. always see people putting EFI on rides that were Carb'd, but hardly ever the other way around. It seems as though you have lots of insight into the hot rodding portion of the site, so I'm interested in hearing your reasoning!
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Another question. Did you go with solid mount? That thing didn't budge at all in the engine bay! If so, are your trans mounts solid as well??
"If you're not living life on the edge, You're taking up too much space"
"Truck Norris"- 2008 TX Edition Silverado
- McGaughy's 4/5 Drop Kit
- Apline Type R 10s & Amp
- Pioneer 6 Disc Touchscreen Deck
- Nightmare Breed Motorsports custom tune
- Custom 3" dual exhaust through x-pipe dumped at axle
- Airaid CAI
- Badges and molding removed, roll pan, Truxedo roll-up cover (compliments of GMTC!), 3pc billet grille, factory fogs upgrade
"Kristine" - 1991 Nissan 240sx
- Cut to pieces, LS build pending
11-05-2013, 07:35 AM #14
Rado Rocker, (Usually I get asked why did I install a genI SC and not an LSx) there is a looong answer and then a simple one to your EFI question. The simple answer is, cost. It would cost 3-4 times as much in EFI components to go this fast with the carburetor alternative.
The looong answer. When I first built this engine in 2008. I didn't really have a purpose or a home for it. The block fell in my lap and I took it on as a project to build and maybe flip or perhaps drop it in a future rod project. Then I got this idea to replace the 4.3L V6 in my silverado with a mildly built vortec/L31 fuel injected engine:
Afterall, I'd be keeping a similar style fuel injection and engine design but just two more cylinders right?
It was a tuning nightmare. I even re-wired and re-pinned the wiring harness for an 0411 PCM. Still couldn't get it to run right. Months of dataloging, tweaking, adjusting the tune. Even with the fuel trims withing 2%error and what I considered an aggressive ignition timing table just below the threshold of knock. It was gutless, could barely keep up with traffic and was drinking 10-ish MPG. Admittedly the L31 vortec fuel injection isn't a known performer, but it's not nearly as bad as this engine was acting.
I checked cam timing, fuel pressure, crank to cam correlation, to no avail. I finally decided to make the jump from EFI to carb. I picked up a chinese performance intake manifold, edel carb and inexpensive distributor. Bolted then down, dialed them in, fire it up. And peeled the tires off the rims on the test drive. From there I was carb hooked (on this engine).
I installed better heads, a bigger bump stick, increased compression and bolted down a highly tunable Mighty Demon 750cfm.
Going from EFI to carb shaved over 3 seconds off the 1/4 mile time.
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