To keep a long story short about 8 of us were over a friends shop drinking and yahooing while he swapped out the cam in his 455. He decided to reuse the old OEM lifters with his new cam. Hence a big discussion commenced as to the pros and cons.
Question: What are your thoughts. As i never really thought about it, i always used a new set of lifters with a new cam

 

Not a good idea.

 

IMO: Not a good idea. Lifters get worn out both on the exterior and the interior portions, that combined with the desire to break in the cam and lifters together in order to get better contact between the two means new cam equals new lifters.

But with that said, if his lifters are fairly new he my not ever notice an issue, kind of like when someone replaces a single bent lifter or a single bad valve spring.

 

Few among us are THAT, uhm, what did Johnny Carson used to say?

Frugal?

 

Not a good ideal to use new cam and used lifters! JMO

 

My point with this thread is to think, what can you really get away with?
Sure new cam new lifters. But as others said what if you needed to replace one lifter in a motor? Or how about if you replaced all the lifters in a motor but left the orig. cam in. I don't think that sounds as crazy?? HHMM

BTW the motor is up and running we will see over time his success.

 

You can run new lifters on an old cam. It is not recommended to run used lifters on a new or used cam. The exception to the rule is if the used lifters were already with the used cam and were returned to the original lobes in which they belong.

 

I have replaced one or even two lifters with a used cam when the cam is still installed with used lifters. That motor is a race engine. The reason was for some reason two lifters cracked at the top not at the same time but did happen. After i replaced them with used ones i have had no problems.

 

I like the fact you guys have thrown caution to the wind, and are going against conventional wisdom.......but, what is this replacement cam you are putting in? My engine building mentor did the same thing years ago with a stock 305 with a lazy, tiny stock cam. Junkyard lifters with a new stock cam. Worked like a dream for another 100,000 miles.

If I were to attempt this......and I still might, I would take each lifter and run it over some sand paper in a figure 8 motion, turning the lifter a 1/4 turn at a time, so as to reface the lifter surface.

Using a modern cam with a more aggressive profile seems like you are playing with fire.

If you really care about this engine, use new lifters and break them in accordingly to the used cam you have. If this is a science experiment, have at it, and report back with the results.