Katech has announced a solution for owners of vehicles with GM LT4/LT5 experiencing early wear of guides on their factory cylinder heads.
It is unknown how many LT4/LT5 engines experience early wear, but there is a considerable percentage that do, based on inspection of the engines that come into the Katech Race Shop.
“A little over a year ago, we started noticing more and more LT4/LT5 engines with valve/guide clearances that were out of spec,” said Eric Suits, Katech lead engineer. “We saw engines with less than 2,000 miles and clearances greater than 0.0055˝. To be fair, we also saw an engine with 140,000 miles that were within specification.
“We inspect every engine that comes into our Race Shop, and so we began recording detailed clearances of valve guide wear of every set of LT4 or LT5 heads that we saw, and over the past year the numbers prompted us to develop and offer a solution.”
Katech leveraged its testing capability to design a proprietary Engine Dyno & Spintron Test for multiple LT4/LT5 valve/guide combinations.
“The testing consisted of an aggressive LT4 Dyno durability schedule, as well as extensive hours spent on Spintron. At the completion of the test we had a verified solution to fix the LT4/LT5 valve/guide wear,” Suits said.
The solution includes Bronze Manganese Alloy guides, and a Katech specified Titanium valve. For the exhaust valves, Katech offers both a factory replacement or a Ferrea Super Alloy (Inconel) upgrade. In low mileage, good condition engines the exhaust valves can be reused.
The problem and solution are similar to those identified by Katech several years ago with the GM LS7 engine.
“At this point, we’re not sure how far reaching this issue is or if it is of the magnitude of the LS7s valve guide wear,” said Suits. “But we’re in front of it and our solution will allow our customers to avoid putting other engine components at risk in the event a valve or guide failed.”
Owners of vehicles with LT4/LT5 engines can mail in their cylinder heads to receive the valve/guide package, or can drop off the entire vehicle to get the update and take advantage of one of Katech’ Engine Stage Packages offered in conjunction with the update at a discounted rate. During these uncertain times, please call in advance to verify accessibility: 586-791-4120, or toll-free at 866-Katech1.
