I currently have a crane energizer 284H (228*@.050 .480lift) in my 406sbc. I also have vortec heads and all the other go fast goodies. I have yet to take it to the track, but I am already looking for a better time slip. I am looking at several possible but for the sake of comparison, which cam would benefit me the most performance wise? Comp Cams 274XE hydraulic or 274 solid? I am use to pulling my valve covers several times a year so periodical adjustments do not bother me.

chris

 

go with the solid cam. Valve train adjusment intervals are much less than you might think, and you will pick up a little rpm and horspower

 

being that my 406 still has the original 5.565" rods in it and the 274XE peaks power at 5500, I probably won't be able to take full advantage of the reving capabilities of a solid lifter. but if you say I will gain more power over a hydraulic, then solid it is. How much HP would you estimate the solid makes over the hydraulic?

 

I plugged both versions of the cam into desktop dyno and got an increase of 23HP and 19TQ. does this sound a little exagerated? I have heard one person say a solid cam is worth from 8-12HP over a haudraulic, but how about 23HP?

 

I'm confused:

I found a CC XE274H hydraulic flat tappet cam (230*236* .487/.490lift @ 110), but the only CC 274 mechanical was a roller. As far as special lobes (NASCAR etc.) there are a few '274' lobes, but they are not necessarily street-type cam lobes. For example, a '274 XTQ' solid has 244* and .519 lift with 1.5's. That's going to give much different performance. Just what solid cam did you mean? It's difficult to give agood answer without good data.

 

It's no different than trying to put a number on the percentage of drivetrain loss................you'll hear numbers from ~10% to 25%, but it totally depends on the flywheel horsepower output and the driveline after that (ie: auto or standard tranny). What I'm saying is you can't simply say "using solid lifters is going to give me XX HP more than using hydraulic lifters". With a ~200HP engine, using similar camshafts (but solid vs. hydraulic) you may only gain a couple or a few, but take an engine putting out 400HP, or 500HP using hydraulic lifters, if it had solids, maybe you would gain ~20HP --- who knows?!

The difference between using solids or hydraulics is the lobe profile of the cam...........while you can have two cams with identical lift, duration, etc., the actual lobe shape is different (solid cam lobes are steeper). Also, because the solid lifters allow for no "play" (hence, solid) you can run closer tolerances inside the engine (and higher lift with less fear of hitting the piston), and that's why they can usually be run to higher RPM's. As well, the steeper profiles give crisper, "snappier" response.

 

Sorry if I caused some confussion by not listing both cams as XE. on the bottom of the second page of comp cams extreme energy cams you will find the 274XE mechanical camshaft.
* Advertised duration: 274 intake/280 exhaust
* Duration at .050 in.: 236 intake/240 exhaust
* Gross valve lift: .501 in. intake/.510 in. exhaust
* Lobe separation: 110 degrees
I realize that the mechanical version has more lift and duration @.050, but isn't it true that solid cams "eat up duration" by as much as 5-10*? I still don't really understand it, but Im guess its true by looking at the extra 6* and 4* duration @.050. In adition to my original question, why does a solid camshaft eat up duration?

 

Sorry, but I'm still confused. Comp says, "Xtreme Energy Cams are COMP Cams newest series of hydraulic and hydraulic roller cams." Where did you find a solid flat lifter XE?

Perhaps we're not using the same catalog. Online catalog is the same as my paper version.

A solid cam has lash, or clearance between the cam base circle and the lifter to allow for change of length of parts with heat, and to let the valve close completely. The hydraulic cam doesn't have this; the variation is taken up in the lifter which effectively becomes solid after compressing a certain amount, say .006.

The net valve lift is the gross lift minus the lash, or the amount the cam moves to take up the slack (but measured at the valve). Confusing, huh? These ramps on solid cams are longer and more gradual than on hydraulics, hence they 'eat up' some rotation or duration.

Bottom line is choose a cam which gives the valve lift chatracteristics you need, not by whether it's hydraulic or solid.

I'm guessing you don't want to go to the expense of a roller.

BTW, 'all the other goodies' isn't quite enough info for an intelligent cam choice. How about running you car at the strip a few times, then decide what more you want.

The duration, lift numbers you mentioned aren't different enough to make a change worthwhile, IMO.

Vortec heads are good, but marginal for 406 cubes. How heavy is your car? what transmission? what axle ratio? what tires?

This stuff needs to work together.

 

Comp Xtreme Energy Solid Roller lobes - http://www.compcams.com/catalog/239.html

I couldn't find a solid flat tappet though. I ight've just overlooked that page.

 

I don't have the newest summit magazine yet, but on summits online catalog, on page 2 of Competion Cams extreme energy camshafts. It is the very last cam listed on that page. I would post a link to it but I don't think it is possible.

heres the rest of my combo:
- 3.42 gears
- 26"x10" ET DRAG
- TH400 with 2800 stall
- 780 holley vac.
- 10.2cr
- long tube headers (open at the track)
- 3735lb with me inside

I would really like to break into the 12's. that is my goal for this year. At this point with my current cam it feels like a mid 13 car. I know there is more left it it after some tuning, but I am unsure if there is enough left.

The cam I am using now is not to bad, but I don't think it is ideal. I just got this motor running a week and a half before the last test and tune of the year by borrowing the crane 284H from my old 350. All I wanted was to get it running and on the road so I could possiblly make it to the last race fo the year ( I didn't make it do to not enough break in miles). now that I have some money saved up I am ready to give it a proper cam . I would like to keep the valve lift under .500 so that I can use my current springs and not fork out the extra cash for machining, springs, retainer, etc. If I use the solid 274XE with .510 lift, after lashing it to the recomended .016 or .020 the lift while measure .494 or .490. This SHOULD work with my .500 lift rated springs, right?

thanks for the knowledgeable (<-doesn't look like a real word) replies and patience so far. I know what I want to hear is "get the solid cam! It will make tons more power than any hydraulic" , but what I need to hear is the truth and I need to actually listen to it

 

Found the cam where you said. I also ran your engine and several cams thru 'Engine Analyzer Pro'.

Torque was peaking at 4500 on all of them and power at 5000.
I'm gonna say there's more torque than DD predicted: around 500 peak, with hp around 455-465.

All 3 of the cams were within a few hp and ft-lb of each other. The Crane was a little lower, less than 10 lb-ft and 10 hp off the solid. In my opinion, don't waste your money chanaging to either of the listed Comp cams. That's the good news.

The bad news: Keeping the valve lift under .500 is the limiting factor. Your combination likes lift, which means spring changes and either rollers or quite a bit more duration on a flat cam. There is 30+ more hp in there, but it'll take $ to get it out.

The Vortec heads are great, but asking them to flow enough air for a 406 to peak power above 5000-5500 is a tall order. I'd stay right where you are unless you want to spend a lot of money for a few hp, and very little more torque. Besides, you'll lose some drivability, idle vacuum and some of that great torque just above converter stall.

I'll play a little with drag race predictions when I get a chance.

BTW, 'knowledgeable' is the correct word, and you spelled it correctly, which is rare. Many of us forget the middle 'e'.

 

When I put all 3 cams into my DD2000, the results are not nearly as flattering as the ones you showed me but Im not complaining I have always considered Engine analizer to be the superior program. With DD the 274XES peaks power at 426@5000 and torque at 488@3500-4000. Thats quite a difference in HP. Did you use a single plane intake on the tests? because I have the dual plane performer RPM intake. I know a single plane would help me out alot but they just aren't available to fit the vortec heads unless you go with the super victor.

I realize that the vortec heads are being streched to their limits on the large 406, but they were cheap and they do produce some very impressive torque

I was hoping to order the cam and have it installed by spring time, but I think I I'll run it at the track a few times first and see how she does.

 

I used Performer RPM-type manifold and vacuum secondaries starting in at 3000. I think your carb choice is excellent.


I agree; run it first and enjoy the torque!