Roller Cam ?

[Big69C20 Toy]

Hey all i'm planning ahead and was wondering the consensus and opinions on a roller cam or hydraulic roller cam. I need a special grind as i'll be running turbos on propane. I heard that the roller lifters wear out pretty quick (20k) so i wanted to know if there was truth to that. Anyone running a roller setup? This truck aint for racing but with the mods i'm looking at badass horses outa my 396. It's my driver so i dont want to be tearing into it all the time. Thanks fellas.

[MarineNav]

I don't know about aftermarket roller lifters, but the factory ones last almost forever. I plan on running one in my engine once I get to that portion of my truck build up. I am currently running one in my 2000 silverado though!

[Big69C20 Toy]

Thanks, yeah i figured on the stocker ones, but anyone out there use them on an old school block that didnt have em before?? TTT

[Big69C20 Toy]

TTT 5k members and no one with rollers? c'mon

[70shortnphat]

My boss has a 502 with solid rollers.He drove with that engine for several years before he had any problems.It developed a ticking noise. Pulled the motor down and discovered that one of the roller lifters had failed.(dont know how many miles).One of the tabs that the roller attatches to broke.

[sbc421]

There are four types of cams used most often...

Hydraulic Flat Tappet (used in most street cars, up to 1995)
Pros – Very reliable and generally maintenance free. Most affordable after-market cam available. Excellent choice for a mostly streetcar and some times weekend racer.
Cons – Limited to about 6500 RPM before valve “float” is experienced. Limited lift, (due to lobe angles).

Hydraulic Roller (used in almost all modern day motors by major manufactures today)
Pros – Very reliable and generally maintenance free. More expensive than flat tappet hydraulic cams. THE BEST choice when choosing a performance cam for a “daily driver/weekend racer. Lobe profiles can be ground more aggressive than a flat tappet. (Valves open quicker and close quicker providing more flow for the same duration as with a flat tappet profile) Roller provides less resistance and generates less heat than flat tappets.
Cons - Limited to about 6500 RPM before valve “float” is experienced. Limited lift, although not as limited as with flat tappets.

*NOTE – Rev kits may be used to bump up the RPM upper limit to around 7000 RPM with a flat tappet hydraulics and hydraulic rollers.
ALSO – A stiffer valve spring can be used in some applications to boost the RPM upper limit by 200 – 300 RPM as well, but this can reduce reliability dramatically.

Solid Flat Tappet (GM, Ford, and Mopar all had muscle cars in the late 60s and early 70s available with Solid Flat Tappet cams, although there use was limited)
Pros – Higher RPM range, up to about 7800 safely. (with the use of a good valve spring) Most cost more than a flat tappet hydraulic and less than the most expensive of the hydraulic rollers. Good affordable powerful cam, if you can do the maintenance to ensure longevity. Not recommended for a daily driver, more suited for the affordable weekend race toy.
Cons – Not as reliable as a hydraulic cam, valve lash should be checked at least every 7000 miles. (GM dealerships would present customers purchasing a car with a solid flat tappet cam in it a disclaimer that said if it was not properly serviced that GM was not responsible for valve train failure)

Solid Roller – RACE CAR or BAD-ASS street car!!
Pros – The best choice for an all out race application. High RPM cam.
Cons – Expensive (Cam, Lifters, Pushrods, Valve Springs and Rocker Arms can cost as much as $4000.00 for the setup). High maintenance, lash should be checked at least every 3000 miles (I check my lash after every 10-15 passes or a weekend of “streeting”) You don’t have to check lash ever if you don’t want to… BUT after an investment in a solid roller cam a feller feels compelled to do a little PM.

Sounds like it may be best for you to call Comp Cams and discuss with the custom shop about maybe having them grind you a good Hydraulic Roller. Tell them you plan on running propane and a turbo and see what they have to say. If you call them ask for “Scott” @ ext. 553 number is 800-999-0853. You may be surprised, a custom grind is not much more than a cam off the shelf.

[Big69C20 Toy]

Thanks sbc421 i knew most of that but good as a refresher, i was just really curious about the aftermarket lifter longevity i suppose.

[mikep]

OK i'll ask
Other than for the diference factor why would you want to run turbos with propane on a 396?

[sbc421]

Damn good question... WHY? The BTU value of propane is less than gasoline and there are some safey factors to be considered as well (in a performance application).

[Big69C20 Toy]

Well i dont mind the sidetracking. I came to school so i could be an auto engineer. and i like AFV technology. (afv stands for alternative fuel vehicle)

Propane i chose because it's abundant and easy to obtain at home (cali has propane sold at almost ANY gas station). Also the main reason is that it's MUCH cleaner burning. The difference between gasoline and propane is about 30k btu's 85k for propane 115 for gas.

You lose some power in the swap but only 10% and that could be made up for in a good CR and low overlap cam because propane has a octane of 104minimum.

Regarding turbos, well think any time you have forced induction you do just that "force" the fuel and air to do things. With a gaseous and a vapour fuel there is the problem that the gas (as vapor) will as it always does collect in liquid form and we all know that's even less efficient. With propane its a gas/gas mixture so there is a lesser chance of stratification. You dont have to worry about wet manifolds heads etc ect that rob power and cause worse efficiency.

I wanted to build this motor as i've never done one and i figure go all the way. i like turbos and with VATN stuff available there is very little lag and turbos dont put that huge loading on a crank like a blower does. Also i chose propane because with this old motor i'd have to have one heck of a dome to get high compression, and with domes you play with flame travel etc etc, which more dangerous with propane because it burns hotter.

Hmm i think that's it. WHEW. long story. ohh in the later future i hope to work on/with hydrogen technology as it IS the fuel of the future, funk all that fuel cell stuff, still too much reliance on fossill fuels. ok i'm done

[Mike C]

I have 10k miles or so on the solid roller in my Camaro, and 14 years. I have had no troubles, and lash stays consistent. (knock wood) It is LITTLE as far as rollers go. 236@.050 and .562 lift (.540 net after lash)One thing that is harder on mechanical rollers than the hydraulics is the lash which can allow the roller to come off the cam slightly and then get jammed back down, hammering the needle bearings. With turbos you don't need big rpm anyhow if they are sized right. I'd go hydraulic roller if I were you.

[Big69C20 Toy]

thanks for the replies fellas. yeah them turbos are gonna be beefy. i was already thinking the hydraulic roller cam, just wanted some opinions and experiences.

[Project1970]

I'll only go hydraulic roller in a buildup, even (especially? hehe) for my truck. I know the LT1 in our '94 Z28 has it from the factory and despite being hammered on for 80,000 miles (extremely well maintained but hammered on nonetheless...drag racing, autocrossing, you know the drill, hehe) it still runs like it did from the dealer lot. Maybe better. IMO, beating on an engine that hard and never having to do any major maintenance on it says a lot...

[REPO1]

As long as your cam doesn't have the really steep rams on it like the Comp Cams Xtreme energy grinds, your roller set-up would last for a very long time. The Xtreme grinds supposedly are hard on lifters because of the VERY steep lobes. I personally run a Xtreme 236/242 in my '97 Z28, but I opted for the Pro Magnum rollers to handle it. No problems here with it yet.


As for your propane/turbo setup, I just have to say WWOOOOHOOOO! I personally have seen some local cars running the same set-up. They kick major ass. To me, that is the way to go.

[mt Al]

Here's a propane twin turbo willy's for you.

http://www.truckworld.com/4x4-OffRoa...rboWillys.html

And a turbo powered land cruiser on the classic burban site

http://www.classictruckshop.com/club...o/charging.htm

Keep us posted on your project, its a great concept.

[Jesse 67 c-10]

that is asweet idea! I'm goin into engineering this fall and I'm also very interested in alternative fuel vehicles and such propane is great! very few emissions, those turbos will give some awsome torque, What kind of tranny will you be running with that setup? You should look into one of those lenco street five speeds, that would handle the power and lets you shift it yourself. Something else to think about, I think it would be really cool if someone could figure out a way to use even some of the waste heat our motors generate to make electricity onboard to turn accesories or even help drive the vehicle in a hybrid setup. ex a 300hp sb runs at around 20% thermal efficency, 80% of the energy available in the gasoline being burned is wasted as heat or goes out the tailpipe, therefore a sb running at 100% efficency should produce 1500hp! and get the same milage. Impossible unfortunatly. even if we could only use another 20% thats another 300hp supposedly, the problem is, how do we convert that wasted heat in to mechanical energy all in a package that could fit under the hood along with the regular motor? and without adding so much extra weight that the whole system is moot? How about turbos spun by steam generated in special "boiler" headers? I'm sure my theories are like sieves but feel free to point out the holes or have a brain venting of your own!
Jesse

[Big69C20 Toy]

i like the way you think Jesse, it's not too feasible but hey i like it. I understand your quarrell with efficiencies and stuff.

Regarding having turbos run electrical, heck easy: Turbinebladea on one side attatched with shaft to two balanced magnets and a wire loom on the other, instant electric power.

And you could have nice small turbos running that electric setup to recharge and or run electric motors at the wheels as the motor ran at idle. Anyways fun stuff.

Heat loss is a sumbiatch in internal combustion engines. In theory it woudl be best if they ran hot, way hot as you could obtain much more of the power from combustion. Thats' why pro race motors and other high top end stuff push the boundaries for heat and compression.

The one thing i dont like is all that hybrid vehicle jargon. Units weigh a fricking ton as you need about 300V systems and then the cells and all the other junk is huge and with stuff now it's not well priced or very feasible.

I say go for a clean fuel, go hydrogen, totally renewable and you could drink from your tailpipe

[Jesse 67 c-10]

hydrogen is the way to go! once we find a good way to produce it without burning fossil fuels we're home free. I guess the thing with turbos is that to produce say 6 psi of boost will add at least 6 psi of backpressure, am I right? The benifites out weigh the dissadvantages but imagine if you could have a blower of some sort that didn't run off the crank or use exhaust flow to make the boost! have the heat from the engine make steam to turn it, or some other thing like an alt or your water pump! Man, you could go lots of different dirrections with this!
anyways, later
Jesse

[Big69C20 Toy]

You can pull hydrogen from certain chemicals and even water through types of electrolysis i believe, so there you go. the pain in the arse is storing the hydrogen. however i read about a company in colorado i think that uses pellets that when you spray them with water they release the hydrogen. otherwise liquid is HELLA cold and pressurizing it woudl take some bad arse tanks and still has low capability. good stuff....

[mikep]

Several years ago I interviewed for a research assistant position developing manufacturing techniques with a company that produced hydrogen fuel cells . They werent paying enough and I didnt feel like moving to where they were located so I didnt take the job although in hindsight it may have been a good idea. I know their approach was to use natural gas and run it through a hi temp "cracker" chamber to liberate the hydrogen and then process the hydrogen through the fuel cell . exhaust would consist of carbon dioxide, water vapor and a few oxides of nitrogen which could have easily been cleaned up in a catalytic converter. They were shooting for a retail price of $10,000 per unit with the units being approximately the size of a small refrigerator for household use.

Wouldnt be hard to shoehorn one under the hood with a big ass electric motor where the rear end goes.