[Blackhauk90]

I have a simple question i know someone can answer. i'm wanting to upgrade the camshaft in my engine... Can i just swap out cams and just use the same lifters that are in there? I planned on swapping it out with the same brand cam just bigger specs.. The old cam isn't very radical so i don't believe too much wear has occured..

[Greg T]

Originally Posted by Blackhauk90

I have a simple question i know someone can answer. i'm wanting to upgrade the camshaft in my engine... Can i just swap out cams and just use the same lifters that are in there? I planned on swapping it out with the same brand cam just bigger specs.. The old cam isn't very radical so i don't believe too much wear has occured..

No no no no...........did I say.........no?? You can,only if you have rollers. Never reuse flat tappets on a different cam.

[Blazin72]

Originally Posted by Greg T

Never reuse flat tappets on a different cam.

Even if you could reuse them why would you want to? They really aren't that expensive. I think you can get a major brand cam and lifters for about $160. You can get a Summit brand cam and lifters for right around $100.

How much larger of a cam are you thinking about going with?

[docvette]

Doc here,

Only if you like the old sound of "Good Ol' Paint heading for the barn..." ...Clippety...Clop...Clippety...Clop...Clippety... Clop...Whao!!! Ol' Paint...Time fur some new shoes...Couldn't sneak up on a Bear in a Thunderstorm..as a Train passed..



Doc

[DoubleVision]

They can be reused IF you do the proper technique of doing so, which is a figure 8 on a piece of sand paper to rebuild the crown of the lifter that promotes spinning so they don`t let the cam move and so a break in pattern can be achieved. But honestly the work you`ll put into them, you may as well just buy new lifters. Don`t forget to break in the new cam with Diesel oil, otherwise it`s a promise it`ll go flat.

[sam-missle]

Originally Posted by DoubleVision

They can be reused IF you do the proper technique of doing so, which is a figure 8 on a piece of sand paper to rebuild the crown of the lifter that promotes spinning so they don`t let the cam move and so a break in pattern can be achieved. But honestly the work you`ll put into them, you may as well just buy new lifters. Don`t forget to break in the new cam with Diesel oil, otherwise it`s a promise it`ll go flat.

flat tappet lifters should never be reused, cam lobes are ground convex, lifter face is finished concave. sam-missle

[DoubleVision]

I Know what your saying Sam. And I myself didn`t think it was possible, but some of the old hands on this site steered me different. David Vizard even shows in his books how it`s done. The figure 8 brings the crown back to the lifter as well as a new finish. At the time the subject was brought up, I had to swap cams, and the lifters didn`t have but maybe a 1000 miles on them and I didn`t want to buy new lifters as then I was out of a job so I had to make it as budget friendly as possible, so I did as they told me to do, I stuck them on my new crane cam and did a regular break in, when I pulled that engine in favor of a roller cammed 350, the engine had over 25,000 miles on it, and the lifters and cam were still fine and could still be used more. I had mentioned it to my brother in law who`s been a mechanic for 25 years, he had always did the same thing to his lifters and never had a issue.

[ernkazern]

Back in the day I would encourage the customer to use new lifters with a new cam. If they wanted me too though I would reuse the old ones if the bottoms of them were still concave. I never had a bad lifter come back to haunt me. Keep in mind though, these were street driven grocery getter and commuter cars. Personally I wouldn't reuse them in a performance application, they're not very expensive and who wants to replace them twice?

[lookatme]

okay, but. do you have to do another break in for new lifters on an old cam, or also reused lifters on a different cam? or is the initial break in on the camshaft itself all that you need?

[ernkazern]

I always did, you're breaking in the cam to the lifters

[oldbogie]

Originally Posted by Blackhauk90

I have a simple question i know someone can answer. i'm wanting to upgrade the camshaft in my engine... Can i just swap out cams and just use the same lifters that are in there? I planned on swapping it out with the same brand cam just bigger specs.. The old cam isn't very radical so i don't believe too much wear has occured..

Given the small cost for a set of lifters against the cost and effort of replacing the cam if the missmatch sends everything south , not replacing the lifters is false economy.

Remember one of Bogie's laws; "the easy or cheap way out leads back in".

Bogie

[DHMag]

Originally Posted by sam-missle

flat tappet lifters should never be reused, cam lobes are ground convex, lifter face is finished concave. sam-missle

actually, cam lobes are ground with a front-to-rear taper. this promotes lifter rotation (with the crowned bottom) as well as pulls the cam towards the back of the block.

[BOBCRMAN@aol.com]

As I stated previously. In the old days I would re use lifters if they were not worn. I used a curved piece of glass, sandpaper and a lube to get a nice CONVEX surface. This worked very well. When broken in on light spring pressures. IN THE DAY!
Now, with the crappy oils and aggressive cam profiles, I do not consider using old lifters. And never on a used cam.. It's hard enuff to get a new on new combo to break in!!!

[sam-missle]

Originally Posted by DHMag

actually, cam lobes are ground with a front-to-rear taper. this promotes lifter rotation (with the crowned bottom) as well as pulls the cam towards the back of the block.

yes you are right, .001-.0015 taper front to back, back to front depending upon engine rotation. this info came from eric at erson cams. i am not to old to learn new things. sam-missle

[ernkazern]

LOL, I guess that tells you how long it's been since I reused an old lifter. I remember I used to lay a straight edge across them, and you're right, they are supposed to be convex.
I disagree with your statement about the oil today though. It's way better than anything we ever had in the past. What stinks about it is they took something out of it that helped protect cams during the break in period. I think it was sulfer, but I could be completely wrong about that. Once they're broken in though engines last much longer than they ever did. That is a good reason to put in new lifters with a new cam nowadays. I think the sulfer in the oil shortens the life of the catalytic converter, that's why the amount of it in the oil has been reduced. The manufacturers must put in a special break in oil. Is that why I see people mention using diesel oil during the cam break in period? The diesel oil still has whatever chemical in it that's been taken out of regular engine oil?