Big roller cams on the street

[Boport]

I'm building a maximum effort street engine, but have had problems in the past with solid rollers on the street. One failure cost me a whole engine when a lifter came apart at 8500 rpm. This was in a BBC pump gas engine with a lot of cylinder head that liked a lot of cam 780+ lift. Since that last failure I have stayed away from aggressive rollers on the street. In fact the cam grinder Erson was surprised it lasted as long as it did on the street. I had almost 2500 miles on it.

Factory BBC blocks are natorious for having cam/lifter allignment problems, so I even paid the machinist extra for having bronze sleeves installed in my lifter bores and then the lifters were properly indexed to the cam. Spring pressure was near 750# open, crane severe duty rollers were used.

I am building a turbochardged small block chevy this go around, and plan on going with an 18 deg. dart head, but if I cant open the valve enough, what's the point of a exotic head? I would be happy with a 700ish lift for this head, but am I dreaming to get 5-10K miles out of a cam that wild on the street? I hear comp has some new lifters out that are supposed to be "the new thing" but I haven't heard any feed back yet.

My question is....What is the ultimate 18deg. valvetrain combo out there that would survive a street-strip engironment for 5-10K miles? The engine is going to be a heavily stroked dart small block(450+in,), I dont expect to turn it over 7,000 rpm.

Roller lifters, cam profile, spring pressure, rocker system????


Thanks in advance

[ou812]

I like Isky roller lifters for endurance. Use a Comp extreme energy street roller grind, it has nice easy loading and unloading ramps. Rockers its either jesel or t&d. Use a good pushrod too, like Comps dual taper 7/16. I would also use Isky Tool Room springs, which are made by PSI for Isky. The key, is to replace roller lifters and springs often. Instead of pushing the mileage to say 10,000 Id replace the lifters and springs every 2500-3000 miles. It beats replacing the engine just once!
Brian

[Wolfplace]

Ditto on the Isky Red Zone lifters, only lifter I use anymore.
These & the Crower with the HPPO option are the only lifter I know of that have true pressure oiling to the needles & the heavy duty bearing assembly or whatever the trick of the week name is these days.

There are others that claim to have pressure oiling but it is not directed to the needles & the last time I checked squirting oil at the outside of a rotating object was not the best way to get it to the center of said object
Better than nothing but I don't feel near as good especially for street use.

I have a number of solid roller engines that have way more miles & or time on them then I am comfortable with without checking the lifters.
One small block has well over 50,000 for sure & a rat with 15,000 plus now & still counting, probably closer to 20,000 at a guess as I haven't seen the guy for over a year,, & a number of circle track engines with 3 & 4 seasons on them,,,,

The BB had Comp 4876/4877 lobes, 292/298, 254/260, .698/.666 with 1.8 rockers on the intake
This one has had the lifters out twice & sent them back the second time at about 10-12000 miles to be checked & rebuilt.
According to Ron the things were "as new",,,
Springs were 9365 Plus Isky

The SB had Isky R-412/R359 lobes, 284/290, 244/250, .578/.570 run with .020 clearance.
Don't remember the springs but they were right at 200/500 from memory.
As far as I know this engine is still going but I haven't seen the owner in a year or so,,,

[tjs44]

FYI,I run a couple Comp high lift hyd roller cams with solid rollers on the street.They are 400 lobe lift,set at 6 thou.Run great and are easy on lifters.One engine has Iskys and 2 others have Crowers.The cams are 245-252 at 50 and the other is 252-262@50.Tom

[katman]

One thing that is very critical on solid rollers though is spring pressure. If the spring won't keep the lifter on the cam you're in for big trouble. I'd guess that probaly 90+% of solid roller lifter failure is due to weak or broken valve springs.

Ken

So would a rev kit help?

[Wolfplace]

One thing that is very critical on solid rollers though is spring pressure. If the spring won't keep the lifter on the cam you're in for big trouble. I'd guess that probaly 90+% of solid roller lifter failure is due to weak or broken valve springs.

Ken

So would a rev kit help?

=
Just my opinions on street solid rollers but,,,
If you don't control the valves the rev kit will do little to nothing to keep from beating the crap out of the rollers, they will still be subject to huge shock loads when everything comes back to earth even if they are still being held on the lobe as will everything else in the valvetrain.

A rev kit will help as it keeps the lifters in contact with the cam so they don't "skid" as much but does very little to control valve float or bounce.
Weight on the pushrod side is just not a big deal.
Give me a big fat tree stump lookin pushrod in lieu of some spindly lightweight trick of the week deal anytime.

I suppose it does take the weight of the lifter out of the equation & in the case of a hyd roller this could be important but in my opinion it does nothing to alter what spring you would use & in the case of a solid roller I prefer to have too much spring rather than too little.

If I had access to a spintron or valid information that said I could run less spring with this lobe, lifter, pushrod, rocker & valve,, I may run it.
In any other case give me a quality spring that has been shown to control the valvetrain & this usually means running some pressure.

My personal preference is a minimum of 200/500 on a small block even for street use & little more on a rat
And I wouldn't recommend anyone run any kind of serious solid roller deal on the street with a new combo without at least looking at everything after a thousand miles or so to see that everything seems happy in it's new home,,,