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I am dooing a 351C and cannot decide which to go with. without considdering price which is better, benefits, cons. I want the engine to put out about 400HP but it will be a daily driver. I am also putting 3.91 gears and a T5 behind it if that helps. anyways any imput you have is great.
 

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ROLLER ROLLER ROLLER. More lift are under the curve because the valves can lift faster. No break in period. Better idle with more power. A guy named MonsterMach built a roller Cleveland up to an estimated 537 HP, with a power band that would fit the rear gears you are using.

As far as the T5... good luck. A Cleveland will shred it like tinfoil. If you msut have a 5 speed, do no less than a Tremec.
 

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I have a solid roller and if I had to do it all over again, I wouldn't do it. A well chosen solid flat tappet cam can make just as much power. 400hp is easy for a cleveland. I know you said that money should not be considered, but for me it is a huge factor. Rollers are very expensive. You can estimate at least double the price and many times more than that. Not only the cam and the lifters need to be considered. ALL of the valve train needs to be TOP NOTCH. Springs, retainers/keepers, push rods and not the least, valves. You can't really skimp on anything because of the high spring pressures that rollers typically require.
Many people believe that rollers are indestructable. It just isn't true. I have wiped out a lifter and a cam in 2 separate incidents. I think that solid rollers should be used in all out competition with a good working budget, but for a street car, it just isn't nessesary.
I'm sure that I will be hammered for this post, but I have to comment on my own experience.
 

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I'd vote for the solid flat tappet also. At the power level your looking at a roller isn't needed. Plus the cost factor.
Right now Crower has a clearance going on for cams. Check out the web site.
 

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I've built both ... You won't catch me using anything but a roller valvetrain ... Ever Again.

Notice ... No one here is saying "Flat Tappet" is better ... If you are not afraid of the price tag ... Every single aspect of a roller is far superior to flat tappet.

Just about every engine put on the street today (in new cars) is roller technology ... Wonder Why???

Why rationalize your way to valvetrain HELL ... J/K ... Trying to get someone's goat


Good luck ... My two cents




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Larry Madsen
Las Vegas Nevada



<font size=-1>[ This Message was edited by: monstermach on 2/15/02 10:40pm ]</font>
 

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FLAT TAPPET
Larry, dont ever let me catch you at a stop light!!
The flat tappet will dominate
We'll see some day. See how good you are with that 4 speed


Take care.

PS Larry, and everyone else that has posted have FAR superior knowledge!!! I just posted what I have now


Jeff Given
 

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For just around the 400 HP mark a hydraulic cam can do that! A solid lifter will never make the power/torque of a roller or last as long. If $$$ aren't an object, go for the roller.
 

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I think he said ignoring the $$$ factor guys. There is no way a solid tappet will make as much power, live as long, and idle as well as a roller... unless the roller cam is one of questionable heritage.

Do you think it is an accident that Ford switched to rollers?

Now, most people aren't as mad as Larry here... I am, but most people aren't


<font size=-1>[ This Message was edited by: CantedValve on 2/15/02 9:33pm ]</font>
 

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Most solid rollers are WAY too aggressive to be used for street duty. They yank the valves open so fast, incredible strain is put on the whole valvetrain... Then they SLAM the valves shut. You want to wear a perfectly good valve job out pronto... install an aggressive solid roller!

Add to this the fact that roller lifters have a bad reputation of failing. Their links come loose, letting the lifter turn sideways (which wipes the lobe off the cam). The bearings come out of the little rollers on the lifter (which spreads steel through the engine). They just aren't for the long haul.

YES, they will usually make a little more power for maximum effort race engines that are taken apart and inspected regularly, but for the long term, a solid flat tappet is a much better option.

Another member of this forum (Kid Vishus) switched from a roller to a solid flat tappet after a couple catastrophic failures, and his times at the dragstrip stayed exactly the same... As a matter of fact, it was after the switch that he made his first 9 second run. And yes, both cams had almost identical specs.

Good Luck!
 

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I vote for flat tappet cam unless you have a lot of time and $$$$ repalcing valve spings.
we ran a roller for one season had to change valve springs three times we had a aggressive cam with a lot of lift .765 we broke 3 springs besides haveing to chang 3 set of spring that went away. but we did make lost of power and it sounded great.
but if you have the time to mess with it go for the roller it was a great trip down the track

Alan
 

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Now, some people have mentioned that solid rollers are vulnerable if left idling because not enough oil splashes the rollers, is this true? Why wouldn't the same apply to hydro rollers?
Hmmm ... I wonder if those are the same people that use oil restrictors to reduce oil flow up top ... and think it's "a good idea"??
 

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Old school here. I ran fairly aggressive hydraulic cams in street/strip vehicles, but for the all out race only I've always run solid flat tappets.
Maybe some day when I'm rich I"ll invest in a full roller setup, but until then, only solid flat tappets for me...........
 

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At this point I don't have direct experience with either type of cam, but I'm curious about the lack of discussion regarding the use of milder mechanical street roller cams or hydraulic roller cams. I'm sure some will question the value of spending the $$ on a solid roller on the street if you're not going for broke, but it appears that street rollers do employ milder profiles, which would address some of the harshness associated with full-on race roller setups. In general they use lower lifts and their durations that are more comparable to solid lifter cams. Similarly, the hydraulic rollers, to me, look like a good compromise in terms of being a roller style yet not using the radical profiles associated with mechanical rollers. The hydraulic feature, of course, cushions the valvetrain too. The biggest problem I'm familiar with regarding HR cams is their normally rpm-limited capability due to the heavier weight of the lifters. Then again, lots of street engines probably don't have any business going much over 6500 rpm anyway. Just my thoughts... Scott
 

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Most roller profiles are more agressive than flat tappet ... But to go along with that (from the drivers seat) those more aggressive profiles are very forgiving.

A more agressive "Roller" will often seem more "Streetable" than a less agressive "Flat Tappet". You should take this into account when selecting your cam.


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Larry Madsen
Las Vegas Nevada



<font size=-1>[ This Message was edited by: monstermach on 2/16/02 6:42am ]</font>

<font size=-1>[ This Message was edited by: monstermach on 2/16/02 8:28am ]</font>
 

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Why not use a hydraulic roller?
 

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Since we seem to be getting off the subject.
Why not install the Schubeck 1inch radius solid lifter. Roller lifters have a much smaller radius which means more pressure. They have needle bearings that WILL wear out or come apart. They come apart due to valve float. Bounce a roller lifter at 7k and the needles Will shatter. Those 500 plus open pressure valve springs don't last long under those conditions. They require a stiffer spring because of the aggressive lobe profile.
The Schubeck lifter has a space age material on the face of the lifter that will outlast ANY roller lifter on the market. It is micro polished for low friction, and lower spring rates can be used. At $640 a set that seems high. Take the added cost of replacing the roller lifter because of wear, and fresh springs to match, the cost doesn't seem so high.

<font size=-1>[ This Message was edited by: 85Mike on 2/17/02 5:30am ]</font>
 

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cost aside, I'd go roller. If it's street-driven and you dont want to do a lot of maintenance, go with a hydraulic roller. I used a Lunati Solid roller in my mav for several years, only had to adjust the valves once (right after I installed it.) Would never go back to a flat-tapped cam again! By the way, the lunati roller I used was a 248 @ .050 duration, .518 lift...worked flawlessly with the RPM heads.
 

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Well, as N2OMike stated, I had a solid roller in my cleveland at the start of this past race season. After shearing the pin in the front of the cam and bending every valve in the motor, 5 expensive pushrods, bending the trunion in 3 Crower stainless rockers, and wrecking a complete set of roller lifters, I switched to a comparable flat tappet cam. The car ran the exact same et. I was running mid 6.30's with the roller, still ran mid 6.30's with the flat tappet, (1/8 mile, low 10's in the qrtr.) And the car actually made its fastest pass with the solid cam, 9.97 @ 133 mph.
(After the season I also found that it cracked the number 2 main web when the pin sheared and the valves hit the pistons that hard)

400 HP with a solid cam in a cleveland isnt hard to do. Actually, it's pretty simple, and reliable.

As of now, I have lost my desire to run a high dollar roller set-up. Maybe one day it will come back. But for now, roller cams have definately lost their "appeal" to me.

----------
Rob Hetzler
1999 Pro track champion Eddyville Raceway Park
2000 R-up Mod ET Eddyville
2001, 5th place Top ET, 7th place Mod ET Eddyville
 

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Wow... if roller lifters suck that bad, there are gonna be a lot of pissed off 5.0 owners out there that are sitting on ticking time bombs.

Come on. If rollers didn't work, they wouldn't use them. Since they have become common place on newer motors, I have to believe they are superior to what they replaced (flat tappets).
 
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