It's kind of like SEX....
 

patrickt it's about what kind of sex you want to have. Just like what camshaft and lifter you want to run in your motor. 8,000 rpms solids win out, street motor with a 6,200-6,500 limit making alot of torque, hydro rollers. If you have the money, Schubecks in aluminum and any size camshaft and spring combo you want. I believe a hydro roller with proper maintain ance will last 100K miles. In the old days a solid motor would last 70-80K miles with todays cheap metals, mileage is less, some because of the oil and lack of zinc and other needed sliding materials needed. What works for some doesn't work for others.%/ You like solids and I see no problem. Only lash is your enemy and how much lash is in the valve train. Rick L.

But the most important factor...
 

... the sound. Solids, be it flat or roller, just sound so much better than hydros. For a Cobra, you just gotta have that sound, IMHO. And adjusting the lash is really a joy. I can take all day adjusting valve lash (in fact, as slow as I work, it does take me all day to adjust 16 valves...).:cool:

Patrick,
I can't agree with you more. To me, the sound of solid lifters tapping away in close knit syncopation is the soundtrack of my youth. It still gives me goosebumps when I hear a raucous idle and solids tapping in the back round. Certainly hydraulic rollers, for most FE's, make a lot more sense. However, to me a Cobra is not a car that makes a whole lot of sense, instead it's a visceral, joyful experience. This is the only reason my engine (if it ever runs) is equipped with a solid roller cam. I can't wait to hear it. Keith Craft, who speced out the whole engine and supplied all the technical parts, is predicting in excess of 625 HP and over 600 Ft. Lbs of torque. With that on tap, I can't wait to feel it, either!:p

If you don't mind me asking, what are specs on your solid roller and what springs are you going to run? Thanks!

Nah, I don't mind at all. The specs are 255/262 at .050 with .383 lobe lift and a 112 lobe separation. It will be installed at 4 degrees advanced at 108. This cam should give .674 lift on both the intake and the exhaust before lash with 1.76 rockers.
As far as springs, I don't know!:confused: I bought the Stage II heads from Keith, and he installed the proper matching springs on the heads with titanium retainers. I never did ask him for the spring specs. The cam, as you can see, is big enough to make lots of power, yet small enough to not be too difficult. Should be fun. The rest of the valve train and intake is a set of Harland Sharp roller rockers and stands, and a port matched Performer RPM with all the markings and logos ground off and bead blasted for a more original look, with a Quick Fuel 950 carb, all original gold color, with LeMans bowls. Should run good and look good too. If I can only get a darned block now......:mad:

Me thinks I was one of the first to scream loud and often about using solid roller cams in an FE. I have had extremely good luck with the second solid roller cam I used...not one problem with it. It sits on a shelf at Joe Boghosian's shop where it's been for the past three years after I swapped the third bronze gear in less than 2,000 miles and had Joe pull the sumb!tch and put in a flat tappet of similar grind (.680 lift, 270/270 at .50)...not one problem since whether in stop and go in high heat, long cruises all over California, or hauling ass at the track (and that's hauling one big ass).

Oiling...if you keep the splash up by constantly tapping the throttle at idle, should be ok. Failure to do so will result in the creation of one of the finest cutting tools known to man...a solid roller lifter sans needle bearing.

Distributor gear...if they finally have stopped experimenting and have come up with a good composite...great! As Duane notes, it's not as if this is a new problem, so the mfgs have had enough time. Every now and then we have some Chevy or small block person tell us how they use a steel gear on their solid roller...but that's irrelevant simply because the cam mfgs press on stronger steel cam gears for those applications because they sell more. Yes, some folks never have a problem, either because they use a dry sump (and thereby relieve the distributor gear from double duty) or just plain have good luck (usually drag racers though...it's a bit tougher on the street IMO with idling, etc.).

If you want a roller cam setup...hydraulic roller cams offer the best apllication for street use. If you're on the track the majority of the time, then a solid roller will provide great runup for high rpms with a little forethought in replacing the bronze gear regularly (or finding the elusive composite gear).

So, what are the benefits of a solid roller over a flat tappet?

1. No break in. BFD.

2. No fear of a flattened cam down the road. BFD.

What are the downsides?

1. Fear of not getting enough oil on the lifters...so you need to constantly tickle the throttle to create splash at idle.

2. Fear of broken distributor bronze gears...a PITA on a trip (had one go out on a 10,000 foot pass in the Sierras)...unless you get your hands on a composite.

3. Higher costs.

4. No higher revs than a flat tappet.

Just my considered opinion based on personal experience. BTW...no expense was spared on my motor (TDI, Velasco, etc.) and it was built by one of the best (Boghosian)...who, along with Tom Kirkham and George Anderson told me NOT to use a solid roller, but I did not listen because I wanted the latest/greatest.

Anybody want a solid roller FE cam with big numbers? I'll throw in several highly sharpened bronze gears for free. I'll sell it to folks I don't like, but not to friends.

I'm not all that educated on this whole distributor gear problem. Honestly, all I did was tell Keith Craft that when he shipped my MSD distributor to custom curve it to spec for the cam and application, and to put whatever gear he thought was best for the cam he was supplying. It came with a bronze gear on it. Are you saying that this bronze gear will be a problem? Are you also saying that hydraulic roller cams don't have a distributor gear problem but solid roller cams do? I wasn't aware of that. Any idea why they would be different? Thanks.

I can't provide first hand experience, as I still have a solid flat-tappet cam in my last three FEs in different cars, against my short block engine builder's 1st recommendations. However, I keep studying this topic along with all of you. :JEKYLHYDE If I do a future FE build with a different block, i'll be shooting for a hydraulic roller myself.

Thanks for the info. Are you looking to get a new Al or iron block? I'm pretty happy with the Genesis iron block but a lot of people like the Pond and Shelby blocks. I just like iron blocks. :)

I've been running solid rollers on my street car for awhile now. I ran 3 different ones in my 428 and have a Lunati roller very similar to your cam in my new motor. 256*/264*, .3965 lobe lift, 110* LSA. I think it's just right for my car. I had a 264*/270*, 108* LSA roller in my 428 and it was little bit radical for driving around.

I think the pin oiling feature in a lot of the new solid roller lifters is helpful. The Comp lifters have that feature now. All the Cranes had it and it's optional on the Crowers. I used to run the Crane Ultra Pro lifters before but am running the Crowers with pin oiling now.

The hydraulic roller cams for the FE still require a bronze gear. Crane had a special steel gear for use with steel roller cams but Crane is no longer there...
I use a bronze gear and have had no problems with it. I've got several thousand miles on it and it has a bit of wear but is still fine. You just have to check it every so often. Just make sure the gear is located correctly on the distributor shaft so it doesn't bind on the thrust surface of the block.
I have one of those steel Crane gears but haven't used it.

Ok, see my first post on this link. :p ;)

http://clubcobra.com/forums/search.php?searchid=952333

The hydraulic roller cams typically do NOT require a bronze gear since they have hardened steel cam gears...and can therefore take steel (or iron) distributor gears.

That is one of the benefits of going with hydraulic if one wants to go with a roller cam.

767...even when the distributor gears are perfectly mounted on the shaft (and drilled for the larger Chevy pin), the bronze gear is designed to be a disposable piece to protect the relatively soft steel found on solid roller cams made for FEs. Remember, distributor gears are doing double duty on wet sumps, and are even more strain given the HV pumps we tend to use on these beasts. When the gear goes...you cease from going, wherever the hell you are, and then you start fretting over the little bronze pieces in your oil until you get a chance to drop the pan (always fun in Cobras). The FE market is not as widespread as Chevy or various small blocks, and that is the reason given by the mfgs over the years for dragging their asses on the the solid roller sticks.

Again, there will always be a few folks who have had good luck on the street. I've heard of exactly five now, given the above post, and one of those had a dry sump, while two were talking about FEs in their drag racing sedans which occasionally found their way on the street. I'm sure there may be others...maybe dozens.

Here's my thinking...these damn little cars have enough stuff we need to watch, and the motors (at least mine) can cost what a nice little new Mustang GT with few options runs. Why in the hell would someone want to introduce a weak (or at least questionable) link to worry about. When a roller lifter lets go, it is nasty...the little arms (sans the needle bearings) just starts cutting into the cam, and the little needle bearing pieces just travel around the motor. Yes, all kinds of ideas of getting oil to the lifters (to keep the little bearings happy)...scribing, pin holes, etc.

Why not either stick with the technology of the day...flat tappet...or come all the way forward to a hydraulic stick? You haven't put anything together yet. Keith was one of the first proponets of the hydraulic stick, and how he could make the power and produce the revs approaching (in some cases surpassing) flat tappet sticks.

If I was building a brand new motor, I would go hydraulic roller. Thankfully, the tin lump Boghosian built me five years ago has survived my solid roller fixation and just pours out the power with the lovely ticking of the flat tappet. Having said that, it will commence to blow apart the next time I'm on a run...it's an FE kharma thing.

OK, I read it, and after I read it, remembered it from the first time I read it (it's copied below for everyone's convenience). I think I would tend to agree that rollers are better than non-rollers if, and only if, they have conquered the limited lifespan and distributor gear issue. You know as well as I that you can get a ridiculous amount of power out of a solid flat tappet cam in an FE. If we just skip over the "I'm afraid to break the cam in" issue then the increased potential power from a roller would have to be such that it offsets the limited lifespan/distributor gear issue (if those issues still exist). Would you agree with that?


__________________

OK, so I'm a thick headed Italian and it takes me a while to get things through my skull. I'm still confused a bit. If I understand correctly, the cam mounted gear that drives the distributor gear on a hydraulic roller is harder than that same gear on a solid roller????? Why? :confused:

As an aside, I distinctly remember some small cam company somewhere that had a setup that mounted their flat tappet cams in an electric motor driven device of some sort, and mounted the lifters in their proper position, and loaded the lifters down with springs. They then spun this contraption and broke in the cam on it before they sent it to you. Obviously, you would have to keep track of which lifter went onto which lobe, but that shouldn't be too difficult. Does anyone remember who this company is and if the technique works? I don't see whay it wouldn't be successful, and if it is why isn't everyone with a flat tappet cam doing it? It rather the lobes, if bad, went flat on the break-in machine than inside my engine.....

Jockey-
I think you are thinking of Cam Research. And just as an FYI, I know if at least one person who had them break-in their cam as you describe prior to delivery and they still wound up wiping a cam lobe. There are no guarantees.

Patrick- Fair 'nuf ;-)

767 Driver...the hydraulic rollers tend to have iron or hardened steel gears pressed on the cam, even for FE applications. The mfgs are less inclined to do this on solid roller FE cams...just a smaller market and because they tend to be utilized more in racing environments where regular engine teardowns minimize the need for anything more durable than a bronze gear.

That's all generally speaking, of course...and composite distributor gears which are more durable and yet won't eat the billet of a solid roller cam may be the ultimate answer, but five years later, the adjectives "new" and "experimental" always seem to be in play during discussions of them.

Remember...this thick-headed Armenian ignored three FE gurus and tried the solid roller anyway. Trial and error be an asspensive method of learning stuff.

So then you would agree that if one felt he could get sufficient horsepower for himself from a solid, flat tappet cam then a solid, flat tappet would be superior to a roller, for that person, if there was any additional maintenance required for the roller's distributor gear or if there was any shortened life of the roller's lifters, no matter how small that might be, correct?

BTW, I'm mindful of the fact that you are intending to use an iron block, which is not going to be hydraulic ready. As others have noted, getting oil to the needle bearings on a roller rocker is a prime consideration in an FE block...so make sure all the tricks are utilized...a bit more oil pressure, etc., and remember to keep blipping the throttle to create splash.

This is why, IMO, solid rollers tend to have an easier time running down the quarter mile than in stop and go down a highway. It's the idling and slow speeds that kill them.

Are you stuck on an iron block? By the time you get one sleeved and cleaned up, the arruminum blocks end up costing about the same. Just something else to think about.

As Jamo says, sounds like you've asplained it to your satisfaction. ;)

Kidding aside, I don't necessarily agree. I will agree that if someone is willing to deal with the potential break-in issues because they prefer a solid flat-tappet, there is nothing wrong with running a solid flat tappet cam, as there can be no argument that they can make more than sufficient power.

However, remember, we're talking hyd roller, not solid roller. Production cars have been using hyd rollers with no issues for years in cars that see more mileage in their lifetime than your average 10 Cobras will see combined. Crane is making (or at least was making before they closed down and were bought out) a steel distributor gear to use with FE hyd roller cams that is advertised to wear like a factory steel- i.e, last 100k plus miles. I have one of their new steel gears on my dist now and will let you know how it works out (so far about 1500 miles and no issues at all (knock on wood)). But, even if Crane were not making the new steel gear and you had to replace the distributor gear periodically, that is a much easier (and faster) task than adjusting the valves. With the right tools and an asspert techinician you can change a dist gear on the side of road! Just ask Jamo. :p Try adjusting your valves on the side of the road. So for that reason, and the others mentioned, I still say a hyd roller is superior to a solid flat tappet for general street duty.

But if you like solid flat tappets, there aint nothing wrong with them at all.

Is that question for me, Jamo? If so, my block problems are legion. I started with a factory iron sideoiler block. Long story, but that was ruined in the process. Then I went to an aftermarket iron block. That blosk is drilled for hydraulics, but the block arrived with heavy porosity problems. I'm trying to work a resolution to that now, and it'll be replaced with either another aftermarket iron block, or an aluminum block from the same manufacturer. It's in their court now......for the last three months. :mad:

767...hmmmm, iron aftermarket block from an mfg that also makes arruminum...hmmmm, wonder who that could be. :p

So, either iron or arruminum from that mfg...the block could take a hydraulic roller. Talk to Keith some more. ;)

Chappie...tell me about the gear on the cam itself...is it a pressed on iron or hardened steel?