Flat tappet to solid roller...

txstang84 said
That's interesting, I can't think of an older anything that ran solid rollers...solid flat tappet, yes, even into the 70s but adjustment of flat tapped solids vs rebuilding of the solid roller lifters are two different things. I'll try to find the article where I read it and post back.

Well not solid rollers. They did run solid cams as we both know. But I guess my point was more in the "whats the difference". Solid rollers have what, rollers on them. That's the only difference. With proper care and oiling. I see no reason to "rebuild" or "replace" them. If anything, a roller should last longer than the metal/metal of a flat tappet. I've never heard of this problem with hydraulic rollers. And they are under constant pressure because of the hydraulic lash.

I just read your article. And I see they mention exactly what I was about to post. Proper care and oiling is essential to the life. I think it's more to do with how "serious" these cams are. The small solid rollers, are considered large for hydraulic flat, and medium/large for hydraulic roller. Because of the lift, duration, overlap, etc inherent to these cams. Upkeep and inspection of the lifters is more intense. Like any "race" designed part put into a street engine. I would never hesitate to run solid roller on a street car. Knowing my own penchant for upkeep, maintenance, etc.

Miszny said
Thanks, now this helps me out a lot!
I see that I had wrong understaning of duration. My idea was to keep the valves open as long as possible to get more air/fuel mix in with my limited lift.
My guess is that flow drops over what the flowchart does not show... Just a guess.
I initially used 6800 limter, perhaps I should go back to it. I put 6400 to keep things live longer. I have forged rods and pistions so perhaps im overreacting.
Until now I had failures every single year this one included. I just recently blew up my converter and rebuilt the whole transmission. This was also a lesson about how important converter is. Getting the right one felt like adding 50hp or more. I did not expect this.

The goal of my changes is to optimize what is in there by putting best matching cam I can get for this combo with minimal changes to everything else. I hope I will end up with new cam, lifters, pushrods and timing set only. If I keep lift under 550 I can also keep my valve springs that I got new last year. I had no problems reving to 6800 with them.

If I wanted to get only power I would go with some forced induction, but parts avilability makes me want to keep it reasonable. The car is pretty quick already, just need more optimized and reliable.

About tires, I was using Hoosier 295/60/15 Quick Time DOT tires, but yes I recently got MT drag radials in almost identical size. Its a 29" tire. Hoosiers have great traction but dont last too long... Hope MT will do better about it but will probably be much heavier. I could not belive how light my wheels were with Hoosiers.

I will dyno the car before changes are made to see whats what after.

The link you gave is for small block cam but I see what you mean.

If I were to do custom grind that has 3000-6500 power band and lift up to 550 how would you spec it out?

I almost got this cam:
21-232-4(Single Bolt) - Xtreme Energy™ Mechanical Flat Tappet Camshafts

Then roller idea came to mind and I decidet to wait it out and ask people that know better.

The biggest thing to remember when making a cam change is that it will change your DCR - dynamic compression ratio - the bigger the cam, the more overlap, the less cylinder pressure you build. You then have to up the compression to compensate for those changes. More duration will raise your RPM. Smaller cam is the opposite, it will increase DCR. Something to keep in mind.

As for custom grind. I would call the cam guys. I'd start with hughes. Tell them exactly what you got and what you want. See what they say.