VVT engine in a thirdgen (how I made it fit) - Third Generation F-Body Message Boards

V8Rumble · 11-01-2009, 01:01 PM

Hey all,

To the best of my knowledge, I'm the first (so far the only?) person to do an LS-series swap while attempting to retain the VVT. From everything I'd read, the prevailing impression was that it couldn't be done, since the VVT required the use of the truck accessories, which extend forward beyond the Vette/F-body placement, & placed the alternator above the hood line.

Well, I've pretty much gotten it done. With the possible exception of the P/S pump, my engine is in, & it clears the stock hood line & radiator just fine. This post (on LS1Tech) has most of the info, the complete build thread is right here.

I hope that this helps to "de-mystify" the use of these engines a bit, since the technology is just WAY TOO FREAKIN' COOL to not take full advantage of...!!

Quote:

While installing the VVT system on a single-cam OHV engine doesn't offer up any adjustability of intake/exhaust overlap timing, it should be noted that simply advancing or retarding the overall valve timing can have significant effects on an engine's powerband, as hot-rodders have known for decades.Typically speaking, advancing the cam timing offers more low-end power, while upper-end performance benefits from retarding camshaft timing.

Quote:

Although (Billy) Godbold returned to this subject, it quickly became obvious that he had other ideas aching to burst out of his mind. Ideas that can be summed up in the initials VVT-that's variable valve timing to you and me. "The L92 truck motor is incredibly impressive, making 400 SAE corrected horsepower stock and 430 hp with headers," he began. "With one of our cams and the phaser limiter kit, we made 500 hp, and it did not lose power anywhere. It's a great cylinder head, then you add the variable valve timing. We start out by giving the smaller cams lots of advance, up to 10 degrees, then you can retard those about 16 degrees. With the larger cams, piston to valve is tighter on the intake so we go down to 5 degrees advance. These designs run best with a sweep curve of about 12-degree retard, which helps the engine carry at high rpm."

With the cam phaser, you can advance or retard the cam centerline to the position it runs best at each rpm. That's cool, really cool. You can get a 60-plus horsepower gain, with no loss anywhere. You can have control of the cam timing by tweaking a curve in your ECU, just like typical electronic ignition timing. It's like going from points to coil-on-plug.

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cusz28 · 11-02-2009, 02:14 AM

dude... seriously... that is REALLY fricken cool!!! I wonder why nobody else has done this yet. variable cam phasers have been in the chevy aftermarket since the sixties, but it's always been a black art. i guess now since there isn't a distributor anymore it's ALOT easier to do, especially since it's computer controlled. great build, by the way.

iansane · 11-02-2009, 12:32 PM

I can't wait to see that bird out and terrorizing people.

I'd love to run a VVT engine later.

cusz28 · 11-05-2009, 01:05 AM

iansane, beautiful car. how'd you do the brakes? did you turn rotor off the stock hub? I love the wheels and the grand sport stripe.

91_5.7_TPI · 11-05-2009, 10:29 AM

Glad to see you got it in there. I've not been following the thread on Tech, but I'm glad you have it done. Keep us updated.

Aaron91RS · 11-05-2009, 12:27 PM

I've always been a fan of VVT on most any engine, I'm just to lazy to figure out how to make it work.

Props to you for getting it nearly completed. I know you've been working on it forever.