[thebigblueox]

first off i'm in the process of building a motor for my truck to run in a sand drag race.the motor has to be able to tach up really quick and make good torque off idle, so i was thinking of a roller cam with roller rockers dry sump pan 4barrel throttle body injection setup.does anybody know any thing about roller cams? who makes one for a SBM and do i need special bearings for it? correct me if i'm wrong but with a roller cam u don't have to correct valve lash unless u run roller rockers right? please help. as always any help is apperciated
~zach~

 

[Smokey]

Just get a Magnum motor with the factory hydraulic rollers...
If you don't have a Magnum, aftermarket roller lifters have been typically solid, and require adjustable rockers, whether the rockers are needle bearing and/or roller tip is up to you and you pocket book. These require frequent checking, especially if you operate at high RPM.

I honestly haven't looked, but I'd imagine that by now, there are probably aftermarket hydraulic roller lifters; in which case you wouldn't have to set the valves so often, unless you do a lot of high RPM running; in which case setting the valves becomes part of the ritual.

Call the tech line at several cam manufacturers, and talk to them about you idea. Take notes.
Roller lifter cams allow steeper ramps on the cam lobe, which gives a faster opening rate at the valve which inturn allowed really long duration (the valve open period). Long duration is good for top end and high revs.

The "roller cam" itself rides in the stock bearings, and doesn't look a whole lot different from a stock cam, except that the lobe shapes are fatter and less pointy... The "roller" part of the name actually applies to the lifters.

 

[Guest]

Actually, Mopar began phasing roller cams into the LA's in 1985 to improve efficiency a whole 4 percent (in an otherwise stock wheezer that redlined at 4500rpm). WooHoo! No special bearings. Okay, now for a question. Why would you want to add almost a full kilogram to the valvetrain? If memory serves, just a little over 900 grams. That's 2 pounds that the roller lifters add. Weight in the reciprocating assembly costs power, especially in the time it adds to a rev. Racers spend, literally, thousands of dollars to lighten their systems that much and you want to add it? Yes, ultimately, roller cams are necessary for truly radical cam profiles, and the power those cams generate cannot be achieved with lesser cams, so the question is, how radical do you need it to be? With over 650hp possible in a 340 with a flat tappet cam (very hot street cam), do you really need a roller cam? Check out the Xtreme Energy line at CompCams, and if you must, ask them about a roller. They have some standard grinds, as well as custom ones. Keep in mind that the black moly coatings on flat tappet cams cuts friction, so it's not as big an issue as it once was. Lighter lifters mean better control with lighter valvesprings, which in turn, means it takes less power to turn the cam. Hydraulic lifters eliminated the need for routine valve lash adjustments, regardless of flat, mushroom, or roller cam type. You only need this if running solid lifters. Roller rockers are a plus, but pricey. How high you runnin' the engine rpm? Reinforced stock-style are fine through 6,000 rpm, and banana-grooved shafts add to the package. Bonus? They're cheap.

 

[thebigblueox]

I'm looking for my engine to make tons of torque off idle and be able to "get out of the hole" quick. since the track is short (100 yards) so the engine will need to wind to a pretty high RMP to reduce the # of shifts it will make going down the track. I'm not looking for a really radical cam lift just some thing that will be able to tach up quick. i guess low end torque is not as nessecary as long as it is able to tach up quick, since u'd rarley see low RMPs going down the track. so i guess i'm looking for some thing that would be able to make good horsepower and torque in the upper RPMs rather than the lows since its a drag race not a rock crawl competition.oh yeah and does anybody have any suggestions to what pistons should i run? i was thinking a set of domed speed pro aluminum with valve reliefs cut in. what do you guys think anybody out there run in a sand drag before? or even better anybody ever build a motor for a sand drag?thanks again

 

[ramchargerrunner360]

you want somthing to rap up fast with good tourqe and horsepower go with a short stroke and for a cam gom with a Power maxx cam by Crane Cams it will run 169.99 for short stroke rods go with eagle esp rods that wil run 495.99 and for pistons the ones u mentioned should be fine

 

[Guest]

Short strokes do not necessarily make a good performance engine. Rather, a rod ratio in the 1.80 range is what you're looking for. The 318 and 340 have these ratios, which makes for a quick rev design that can really romp on the big end. The 340 Wedge didn't earn the nickname "Baby Hemi" by being pokey.
As for pistons....you really need to figure the HP you're planning on. You can build 400hp in a totally streetable 318 with 9:1 flat tops and the CompCams XE268 (flat tappet cam). How much power are you looking for? Figure that, and then decide what compression ratio you'll need. THEN, look at pistons.

 

[Smokey]

And if you're doing only sand drags, have you estimated your tire size yet? Wide rather than tall for sand, with beadlocks, or at least screws into the bead. Go crazy on the differential gearing... 5.xx, as you are only running 900 feet.

 

[AndrewT]

I think Crane makes one, Hughes, http://www.straightline-perf.com/ custom grinder (I was thinking about using him for my roller motor). I got what I think was a 90 block and heads from a JY. It had the 308 heads which are suppose to be some of the best non-mag heads. It also came with a roller cam. You can reuse the stock hyd rollers as long as they work. You don't have to do any machine work to the block. I figured that a custom roller cam wouldn't cost to much more than a set of hyd lifters and hyd cam would cost. I think that is the cheapest way to run a hyd roller cam. Try moparts.com for more info.

 

[Evildriver-3]

How much money do you want to spend, how much hp do you want to make

 

[thebigblueox]

I'm looking at a 33 inch Bfg all terrain tire probably just 12.50 wide since thats what all the other guys who are serious about it run. I'm looking to spend between 2000 and 2500 dollars on the motor and make somewhere in the ball park of 450 horsepower. horsepower isn't a great concern but torque is where the wheels are turned at! so i'd rather have a high torque motor than a high horsepower even tho when you have high torque u often have high horsepower along with it. the guy that currently hold the record at the track has a 360 in his truck but other than that i'm not sure what he has done to it. these guys are senesitive about what they tell other people.

 

[Evildriver-3]

Sorry man i can't help you, but when people race to win were all sensitive and tell no one anything, i usually tell you what you want to hear, about 10% is the truth.

You might want to explain this class alittle maybe there are rules to these motors, what are these trucks running as time goes and there weight limits

 

[Guest]

For all we know, that record-holding 360 could be nothing more than a tweaked 360 Magnum crate motor with 5.xx-series gearing.
Anyway, if all you're looking for is a smallblock with hp and torque in the sub-500hp range, you don't need the added expense, and valvetrain weight I'd mentioned that comes with a roller cam setup.

 

[thebigblueox]

for the most part the rules go if you have an inspection sticker on your truck you can run it in the street class. so obvioulsy u'd need to have tires under 44" brakes a winshield lights blinkers and the normal stuff. as far as restriction on motors go there is none. once you start running faster than a 5.00 flat you need to have a driveshaft loop and wear a helmet. faster than 4.50 u need all that stuff and a fire retardant suit. before the race a tech inspection is done to each truck to look for dangerous and faulty equipment. yes GEN1DAK a friend who runs his powerwagon in the modified class has a set of custom built dana 70's with 5.72:1 gears and spools front and rear. although he runs cutom cut 34inch paddle tires!

 

[Evildriver-3]

For all we know, that record-holding 360 could be nothing more than a tweaked 360 Magnum crate motor with 5.xx-series gearing.
Anyway, if all you're looking for is a smallblock with hp and torque in the sub-500hp range, you don't need the added expense, and valvetrain weight I'd mentioned that comes with a roller cam setup.

What the hell, what added valvetrain weight from full roller gear, you mean less wieght , friction , heat, faster valve off seat and on seat times, a roller set up is the way to go to alleviate all of this, and then using all titanium locks and keepers

 

[Guest]

Have you ever weighed roller lifters and compared them to the weight of flat tappets? That's a hair over 900 grams, meaning close to a pound. A pound that has to be controlled by heavier valvesprings. A pound more on the entire reciprocating assembly. More power is absorbed redirecting that extra weight with each rotation. It takes more power to turn against heavier springs. Now, the rollers offset this with very low friction, but a flat tappet cam with that black moly coating is pretty slick too. Side-by-side, all else being equal, the flat tappet cam will rev a tad quicker. Might not seem like much, but in something where victory can be determined by thousandths of a second, the difference can be huge. Remember, in the past, roller cams were used to gain power by using (very radical) cam profiles that a flat tappet couldn't follow, not strictly for friction issues, and the whole reason they appeared in factory units is the very small gains in efficiency that the auto makers gained in their attempt to meet ever-tightening CAFE regulations. RIP CAFE. We're talking about low rpm running. To them, every little bit helped them avoid massive fines. I'm not against roller cams. Don't get me wrong, but some things cannot be changed, and in the areas revolving around this thread, rollers aren't the best choice. They are, in fact, overkill. A seven-second Pro Stocker? That's a whole different animal, and one would never win without a roller, but that's not what we're talking about here.

 

[Guest]

Ooops! What am I saying? 900 grams is more like 2 pounds. I need sleep.

 

[Guest]

Went through the archives and looked up the article I was drawing from. The numbers have kinda glommed together since I read it (3/97). Turns out, the Magnum lifters are 632 grams heavier than LA flat tappets. So that's like, 1.25 pounds right there. I had 900 grams in my head. The remaining 280 grams is the difference between the Magnum valves, and LA 2.02/1.60 valves. All told, 912 grams.

 

[Evildriver-3]

Those are factory lifters

 

[Guest]

Yeah, and?
Keep in mind the budget is $2500 for the entire engine.