Hello everyone, I am putting together a 468 with 10:1 CR, rect. port heads, RPM AirGap, 850 Holley DP. I am looking at getting a solid roller cam. Looking at the Lunati 502A1LUN, (244/255 at .050 dur., .630/.630 lift on 112 LSA) The car will be a street/strip type, with a TH350 with short low gear planatery and a 3.42 rear gear and a 3000 stall. How would this cam live on the street ? What vacum would it pull at idle, approx what RPMs would it idle at ?
Ihave power brakes. I am swiching to BBC from a healthy SBC that has a 244 at .050 dur. hydraulic cam with 110 lsa and Victor Jr. That motor runs OK, but it is a bit rough on the street for me. Idles rough, have to use a vacum can for brakes etc. Would this 468 be any better with this Lunati cam ? Thanks in advance for any input...

244 is pretty aggressive for a small block street engine, especially if ground with 110 LSA. Sounds like you've noticed that. smile.gif

I think you'll be much happier with that same duration in a 468, particularly in view of the 112 LSA. It'll end up idling around 750-800 with 14 or so vacuum. It'll be much easier to live with.

Tom

Don't forget that a hydraulic cam with 244 @ .050" and a mechanical cam with 244 @ .050" are not really equal in size.

You need about 6-10 degrees more duration with a mechanical cam to be equivalent to a hydraulic. That Lunati roller will act more like a hydraulic in the mid to upper 230's @ .050".

I currently running an Isky solid roller with similar size to the 502A1: 290/290, 248/252 @ .050, .602"/.646", 110 LSA. I also have 10:1 SCR.

My .030 over 454 idles at around 900-950 rpm with about 10-11 inHg.

Your cam should idle abit better than mine. Hope this helps. smile.gif

What about solid roller lifter durability ? I have read some posts about solid rollers, and there seem to be some issues with running solid roller lifters on the street, although I couldnt find much in the way of specifics. Can You guys tell me anything about that, what You know or experienced with solid roller lifters ?

I just read some stuff about some Red Zone lifters from Isky, that are supposed to be better then some others. I am wondering about these things since I have no experience with solid rollers. What are the drawbacks or associated problems with solid roller lifters. (besides regular lash setting of course) Are there specific quirks to some makes of lifters. What makes these 'Red Zone' lifter better than the others ? Its pretty hard to get straight up info from the cam companies...

The isky red zones or the crower solid roller lifters are where you want to be when it comes to a good lifter. They are just hands down stronger than most others, so they hold up well. Dont forget quality rocker arms either. Just one for instance, some of the cheaper roller rockers come apart cause the pin on the roller tip walks out on you. A good crane gold race rocker or comp pro mag will stay together well. There are many others too that do the job, but something like the cheaper, crane blazer roller rockers(for example) should be avioded cause they have been know to come apart if you dont catch it and press the pin back in. If they do start to walk out on you, and you dont catch it, the results can be pretty ugly.

Oh, one more thing. For a street driven roller cam setup, you might want to check into a street solid roller camshaft(just to avoid confusion, I dont mean hydro roller, they are solid rollers, but aimed towards regular street driving). If everything else is taken care of, the biggest issue with a solid roller camshaft on the street is simply valvetrain wear. Its not a super fast deal though, the valvetrain wont wear out tomorrow or anything so I wouldnt spend a whole lot of time worrying about it, but the valvetrain is worked harder so it does wear a little quicker than with a comparable flat tappet cam of any kind, so its a consideration. They can still make good power compared to a flat tappet cam of any type, yet they are a little less agressive than your traditional solid roller, so the valvetrain lasts a bit longer.

The street roller will sometimes give up a bit of power compared to a comparable "traditional" solid roller meant for racing, but its not much so it comes down to what you want most. The best power you can get with descent valvetrain life, or sacrifice just a little power in most cases, but still having great power in the end, along with a valvetrain that will last you a bit longer(in case you missed it, thats the street roller option). As far as your specs go, I like them, so if you were to look into any street roller grinds, Id look for something like what you have in mind now.

Thanks for the info. Yes, this smallish Lunati roller looks on paper like something I could use, having the wider lobe sseparation and I think it also has the pressed on iron distributor gear, so I could avoid having to use a bronze gear. I just wonder about the lifters. From what I gather so far, there is a low RPM oiling problem with some roller lifters and this is what is reducing their service life on street driven cars that have to idle for long periods of time etc...

I have had good luck with my Isky Street Roller cam in my big block. Been in over 4 years and between 5-6k miles. No problems. This was with Isky's standard roller lifter.

Recently I switched to their "Red Zones" (more for preventive measures), a fresh set of springs, and had the exhaust lobes reground for more duration and lift. So far, so good. It was time to check the lifters and I figured while I had them out I would replace them with a set of Red Zones. Heard alot about them and talked to Ron Iskenderian at Isky and decided it was worth spending the money. Ron told me the 3-point oiling system on his lifters solved the oiling issues when used in low rpm / idling /street driving conditions.

IMO, if you want a roller to live on the street good quality parts is a must (lifters, springs and rocker arms) along with choosing a cam profile with "gentler" lobes and don't get too crazy with the lift. The Lunati that you are looking at looks real good for a street type cam.

I am beginning to think that a solid roller may not be for me after all. I will drive the car on the street often, and sitting in traffic idling for long time will be unavoidable. Also, I already have a complete retrofit hydraulic roller setup from Crane with Gold Race rockers
(cam Pn. 139641, 234/242 at .050, .610/.632 112lsa)
i think I will try running before I take the plunge
with a solid roller...I know I wont be able to get the same performance with this cam as a solid street roller would give, but maybe I can live with it,and have a more reliable engine, just a bit slower... Thanks for all Your input, I will report how it works out. Is anyone here running these Crane hydro-rollers on a BBC ?

As far as the 278/290R, I have used it as a street-driven cam for over 20 years, with the only complaints people wishing it had a rougher idle. To the best of my knowledge, it works power brakes, or certainly can be made to work power brakes. Most people get years of driving out of it, and the 290 has gone over 2000 miles in 24 hours without breaking anything except some manual transmission gears.....
The Crane hydraulic roller will probably have less vacuum than my solid roller---much longer seat durations, you know.....
The Isky Red-Zone lifters have an excellent reputation....

UDHarold

Originally posted by UDHarold:

As far as the 278/290R, I have used it as a street-driven cam for over 20 years, with the only complaints people wishing it had a rougher idle. Hey Harold,

How does the idle of the 278/290R compare with the 276/284R (502A3LUN) if they were both ground on the same LSA?

In a 454, what kind of idle vacuum would I expect from the 502A3LUN if say ground on a 108 LSA?