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BBC Solid mechanical roller or solid mechanical flat tappit???

5K views 15 replies 6 participants last post by  Hacksaw 
#1 ·
Building a 489 stroker engine for street use. It will see time on the strip, and will only be a weekend cruiser. Trying to decide on a cam. Which set up would hold up better> Mechanical roller or mechanical flat tappit? If I go flat tappit, I will be using the lifters with the small holes in the tappit face. Anyway, which one??? Thanks
 
#2 ·
Hacksaw said:
Building a 489 stroker engine for street use. It will see time on the strip, and will only be a weekend cruiser. Trying to decide on a cam. Which set up would hold up better> Mechanical roller or mechanical flat tappit? If I go flat tappit, I will be using the lifters with the small holes in the tappit face. Anyway, which one??? Thanks
IMHO...if you want to eliminate all your worries about breaking in the cam...go with a roller. The controversy regarding flat tappet cams going flat has gone on for years. I had the front 4 lobes on my L72 427 go flat after I took all the precautions such as removing the inner springs, putting in oil addative, starting immediately etc. Good luck.
ZAPPER
 
#6 ·
I worry about running a solid roller on the street. I have been told that in racing apps the mechanical roller stuff lives in a world of low rpms and high rpms. Fast acceleration, and stoping. This driving gives the lifter plenty of oil. I was told that using a mechaincal roller on the street at constant rpms would starve the lifters/cam of oil and cause problems. True or false???
 
#8 ·
Hacksaw said:
I worry about running a solid roller on the street. I have been told that in racing apps the mechanical roller stuff lives in a world of low rpms and high rpms. Fast acceleration, and stoping. This driving gives the lifter plenty of oil. I was told that using a mechaincal roller on the street at constant rpms would starve the lifters/cam of oil and cause problems. True or false???
Constant rpm's will not hurt the cam/lifters,so long as the constant rpm's are not at an extended idle.Part of the oiling to the cam & lifters comes from windage,so,IMO,1200-1500 rpm will help provide additional oiling.On the highway,mine runs at 2500 + rpm for hours at a time with no issues so far,after more than 3 years and 15,000 miles.And as was pointed out,a lot of lifters today have direct oiling,or it is available as an option.Proper valve spring selection is critical for longevity,check with the manufacturer.
Guy
 
#9 ·
I ran a solid roller in my 427 for years on the street, it was a Herbert roller, .638/.657 lift, with Norris stainless roller rockers, Bo Laws push rods, and Crane stud girdles. Never had a minutes trouble out of the valve train, checked the adjustment about every 3 months, and SELDOM had to adjust ANYTHING, and even then, only a thousandth or two. That motor saw 7500 on a regular basis, and 8000+ on occasion. The 360ci. SBC I'm building now for my daily driver S10 is getting a mild Comp solid roller too, .525/.525, 224/224@.050. :cool:
 
#10 ·
Sounds like a roller set up is the way to go then. I've never ran roller stuff before. I'd be putting this in a non roller gen v 454 block. This was a 94 model engine and had a hyd flat tappet from the factory. Every other aspect of installing a cam is the same on this engine except for the timing cover being designed for a one piece oil pan gasket. What do I need to look for in the aftermarket to solve this. I believe a double roller timing chain will fit, I just don't know if it will be strong enough for a cam button? A ihra pro mod guy here in my home town said thy used to weld a socket on the back of the water pump to add support on the timing cover to keep it from flexing...poor mans trick I guess. He said it works...
 
#13 ·
Stud girdles are ALWAYS a good idea in my book, but not really necessary for a motor like you're talking about. I really liked the Herbert cam. At the time, I talked to all the major, (and some less well known) cam makers, and they were ALL trying to talk me into a smaller roller than the flat tappet I had to begin with. That was NOT what I had in mind when I decided to go roller. I approached them all by telling them the specs on the flat tappet I was currently running, and where I wanted to go with the roller, and they all tried to talk me into going smaller, except Herbert. When I told them what I was running, and that I wanted to go with a little more duration and as much more lift as I could get, they suggested a grind number, and the specs were pretty much exactly what I had in the back of my mind, so I ordered it. I was using a set of "good used" roller lifters acquired from a friend, and one of them went bad, taking out a cam lobe with it. Herbert repaired the cam like BRAND NEW for $75 (if I didn't know better, I would have SWORN it WAS brand new), and sold me a new set of roller lifters for like $175, I was so happy with their prices and service, I also ordered new springs, retainers and locks from them as well. :thumbup: :cool:
 
#15 ·
Not right now, I seldom buy new stuff cuz I'm too cheap, :D :D I got a really good deal on a solid roller with the right specs for the race car, it's a Crower, I've had the mild Comp roller for about 10 years, just never had anything it would be right for till now. I had planned to go hydraulic roller on that motor, but almost $400 for the cam alone cured me of that idea pretty quickly. I do know a few guys running Herbert stuff though, and they are pretty happy with it. Chet is the father, Doug is the son. I think the son branched out more into all kinds of parts sales, where Chet stuck mostly to valve train components. :cool:
 
#16 ·
My cousin has a set of Comp Cams EndureX roller lifters and a Comp Camp roller cam for $350. It is a blower grind though. I thought about getting it anyway and a set of rockers For $100 and selling the cam. 300-br 14 is the number on the cam. It's for a BBC. I don't know if I would be able to run that cam being a blower gind?
 
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