Is this a Dream or is that really my LS7? Page 7 of 10




Is this a Dream or is that really my LS7?

CAC Does the Corvette Engine Building Experience - Page 7 of 10

by Hib Halverson
© September 2012
No use without permission, All Rights Reserved

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Click on the images for expanded views - it's much easier on the eyes. 

LS7 Heads: Too Darn Pretty

The next major task was installing the cylinder heads. The LS7 head may be the only production V8 cylinder head in the industry built in large numbers which has CNC-machined ports and combustion chambers. If you get to play with one of these heads before it goes on an engine, you'll relish its appearance and feel. Shining CNC'ed ports, gleaming titanium intake and stainless steel exhaust valves and the shimmering, silvery combustion chamber walls are sweet eye candy for we engine guys. The CNC-machining has that characteristic "fish-scale" feel anyone familiar with high-tech racing heads knows. Even the exterior surfaces of the heads have a "premium" look and feel because of the semi-permanent mold process used to cast them. Like the crankshaft, the LS7 head is one of those parts that's just too damn pretty to be run on an engine. Instead, it needs to be mounted on a chrome stand and sitting on my glass-topped, crankshaft-supported end table. All and all, the LS7 head is an awesome piece both in its performance and its appearance

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Image:  Mark Kelly/GM Powertrain

Mike, myself and Powertrain's Communications' Tom Read all agreed the LS7 cylinder head was a great looking piece. What I couldn't get them to do was let me take one home for the end table in my living room.
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Image:  Mark Kelly/GM Powertrain

MLS head gaskets-the LS7 uses a 3-layer and the LS9 a five-layer-are pretty much the industry standard these days for production high-performance engines. The edges are razor sharp, so use be careful and use gloves.

The heads and multi-layer steel head gaskets have edges so sharp, at the PBC, you're required to wear special gloves when handing them. We guest engine builders are given a pair of black, nitrile-butadiene-rubber-impregnated fabric gloves, which are resistant abrasions and cuts, and have to wear them during the head assembly portion of the build.

Next thing Mike Priest did was hand me another hammer (by then he seemed to trust me with hammers-amazing) a driver and four guide pins which I drove into the head decks. I pulled on my spiffy black gloves, put one of the MLS gaskets on the block, and lowered the left head in place.

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Image:  Mark Kelly/GM Powertrain

Head gasket in place, the driver-side head goes on. How 'bout those snazzy titanium intake valves and CNC'ed chambers, eh?
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Image:  Mark Kelly/GM Powertrain

The biggest Spindle Multiple of all tightens all the head bolts in one operation. Wonder how much that thing costs?

On the head bolts, again I used a power-driven, torque-angle sensing, spindle multiple, but this time, the unit was bigger than the engine itself and tightened all 15 head bolts at once. I grabbed the handlebars of that huge device, flicked the switch on the grip and the machine drove them home then tightened them the proper amounts. Ten bolts are M11s and five are M8s, each type requires a different torque angle and the big spindle multiple is "smart" enough to know which bolts are which-innovation and technology rears its ugly head. I repeated the whole process for the right head.

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