LT1 camshaft suggestions?

[Lynn]

JMHO, but if you want a lumpy idle, you don't want an LT-1 camshaft. Just know this; without variable valve timing or computer controlled opening, there is no "best of both worlds" once you go to the lumpy idle. You may have issues with vac for power brakes. The engine is finnicky, and more difficult to tune. But, it that is what you have your heart set on, your car, your money.

Personally, I would go with a roller. Anything radical will require pretty stiff springs. With a flat tappet cam, you will need to break it in with just the outer springs, then pull the springs and install the inners as well. Not that big of a deal if you have an engine test run stand, but a PIA to do it with the engine in the car; especially if you are working on a freshly painted car. Pucker factor increases significantly. Even then, and even with EDM lifters, you STILL run a chance of wiping a cam lobe, especially if it sits for long periods of time.

[LT1vette]

Originally Posted by napa68

This is a great article to take note from. One of the fellows who penned this article, I have come to know through the years. There is a good amount of common sense knowledge that avoids the typical magazine camshaft of the week BS.

It explains why these LT-1's just flat scream and have manners at the same time.

I'm sure there are others here that have different opinions (which is fine). This just happens to be mine from a good amount of past experience.

Tim

Originally Posted by Lynn

JMHO, but if you want a lumpy idle, you don't want an LT-1 camshaft. Just know this; without variable valve timing or computer controlled opening, there is no "best of both worlds" once you go to the lumpy idle. You may have issues with vac for power brakes. The engine is finnicky, and more difficult to tune. But, it that is what you have your heart set on, your car, your money.

Personally, I would go with a roller. Anything radical will require pretty stiff springs. With a flat tappet cam, you will need to break it in with just the outer springs, then pull the springs and install the inners as well. Not that big of a deal if you have an engine test run stand, but a PIA to do it with the engine in the car; especially if you are working on a freshly painted car. Pucker factor increases significantly. Even then, and even with EDM lifters, you STILL run a chance of wiping a cam lobe, especially if it sits for long periods of time.

A little info on one of the authors, Duke Williams. I have met him and had numerous emails back and forth with him when I built my LT1.
He worked for Chevrolet and with Zora Duntov. He knows the "LT1 cam" like no one else. He has valve timing set up specs that changed the characteristics of this cam, he KNEW how to set it up to get it to work. A humble but extremely knowledgeable man.

As for the vacuum problem..... What problem?? There was not another model built that needed more vacuum than a Corvette. Power brakes, vacuum headlight doors, vacuum windshield door, distributor.... If you had a lack of vacuum it was because of leaks in those specific systems, not the camshaft....