Solid roller on the street

[bvlahov]

I've been reading a lot for last couple of days about solid roller cams
and more important about solid roller lifters and their premature wear
or failures when using them on street engines.

I know about pressurized oiling systems and even newer style lifters,
like Isky e-z roll, that don't have needle bearings.

What I'd like to know and hear from you is what is your opinion on
using solid roller on street.

Some manufacturers even name their series of camshafts as "street
rollers", so how big cams would fall into that category?

Here is the combo that I'm planing to build.
I allready have some parts, but not all.

- splayed mains block
- Callies 4340 crank 3.750" stroke
- Carrillo 4340 6" H-beam rods
- JE forged pistons
- AFR 210 eliminators
- Super Victor intake
- carb or 4bbl TB efi (haven't decided yet)

My goals are close to 550 hp at the crank and 7200 rpm redline. I know that
maybe I could find that power with lower rpms, but I would really like it
to rev to 7200-7300. This will be 50/50 street/road race car.

I'm still not 100% sure about what kind of cam/lifters should I go
with, but I'm leaning towards solid roller. It'll definately make most power,
but I'm worried about longevity.

I've posted on some other forums as well, and it looks like there are more than
a few cars running on the street with solid roller, with even more aggresive cams
than what I'm considering.

Here are a few cams that I'm looking at:

http://www.lunatipower.com/Product.aspx?id=1994&gid=290

http://www.compcams.com/Cam_Specs/Ca...?csid=307&sb=2

What do you think?

 

[grumpyvette]

your reasonable piston speed, limits, before stress increases dramatically,with that 3.75" stroke and the port flow rates, with a head with that cross sectional area,will both tend to peak out UNDER 6500rpm, now you can spin the engine faster but you'll gain little if any power doing so and you'll add significant stress,the secret to increasing durability is increased lubrication, efficient cooling and reduced stress levels.

READ

viewtopic.php?f=52&t=333

http://www.superchevy.com/technical/eng ... to_06.html

NOT that it matters, but,IVE used a cam very similar to the LUNATI cam your posted with EXCELLENT results ,in the past.BTW
heres the cam I found to be the best compromise in my 383,its a hydraulic roller and with the springs I use 6400rpm is max, now I can and do find that works out fine in my application, but Id also have selected the LUNATI or a similar cam if I spent more time at the track, but my car is a 99% street driven car and its designed for a 200 hp shot of nitrous.

http://www.cranecams.com/index.php?show ... vl=2&prt=5

if you have a 3.90-4.11 rear gear and a 3200rpm stall converter, an 10.5:1-11.5:1 cpr and are willing to put up with fairly bad street manors to maximize the hp of your 383-427 sbc this HYDRAULIC ROLLER CAM is a good selection
http://www.cranecams.com/index.php?show ... vl=2&prt=5

If I was building your combo, Id have selected a can similar to that lunati, you posted,but, Id suggest concentrating on maximizing the torque curve under 6500rpm,and gearing the car to operate in the 4000-6700rpm range, as that will tend to significantly reduce stress and not hurt power much.
remember that the valve train longevity or a valve trains reasonable rate of expected wear is the result of the heat and the friction, it is expected to work with, and the heat and friction are largely the result of spring load rates,and geometry, and the quality of the parts used and how well they are cooled and lubricated,, the component mass, and resulting inertial loads, caused by higher rpms and component weight and lower clearances, that those loads cause on the oil film protecting the parts and preventing them from direct contact that can result, from the higher load rates, will generally reduce component life expectancy.Id select the LOWEST spring load rate that will maintain valve control, and Id discuss the cam selected with the cam manufacturer of your choice, simply because the cams ramp acceleration rates have a good deal to do with stress levels,the lifters and valve train will be subjected too.

solid rollers have a bad reputation, for street durability mostly because guys use them with far higher spring load rates, so they can maintain valve train control at higher rpms, and the lower oil volume washing over the parts at lower rpms, tends to reduce lubrication and cooling.
in many cases a lower spring rate will reduce wear and heat and you can still maintain valve control if a more gradual cam lobe ramp rate is selected and used and lower total lift is selected as the shock loads or inertial loads, on both the lifters and valve train, are significantly reduced.
Now this will generally reduce both the potential peak hp and rpm levels SLIGHTLY, but you might be surprised at how little in peak performance potential might be lost for significant gains in durability.
generally if you let your cam manufacturer know that long term durability is more important than getting the last possible potential hp, you'll find that the components they suggest changes and, you'll also find that, finishing races beats starting out in the front row but not finishing
your standard flat tappet and many hydraulic roller cams have spring load rates in the 120-140lbs seat and 290-340lbs open range, and generally are expected to operate at under 6500rpm.
generally solid roller valve trains will have significantly higher spring load rates, and operate under higher heat levels, and under far higher average rpms,and cooling will be reduced,especially if oil flow to the valve train has been restricted.
IF the goal is long life on the street you'll want higher oil flow rates cooling the valve train and LOWER spring load rates, BEEHIVE valve springs , light weight valves, roller rockers and light weight push rods and the smaller and lighter retainers can occasionally be used to significantly reduce the load rates for street use, this is also a good place to point out that high oil flow rates and an additional oil cooler and high capacity baffled oil pan and a rocker stud girdle can all be used to aid in valve train durability


read these


http://www.aa1car.com/library/performan ... etrain.htm

viewtopic.php?f=52&t=1716&p=4250&hilit=beehive#p4250


viewtopic.php?f=54&t=2601

viewtopic.php?f=52&t=333

viewtopic.php?f=54&t=2187

viewtopic.php?f=54&t=52

viewtopic.php?f=52&t=181

viewtopic.php?f=52&t=1489

viewtopic.php?f=52&t=1716

QUESTIONS, THOUGHTS?
THINGS I FAILED TO ANSWER?