Has anybody run this cam? I'm talking about streetability, vacuum, idle charactistics, etc.

I understand this is a large cam for a 350, but this is for a 406. Along with that are some heavily ported 291 heads, Weiand Team G intake, and a 750 or 850 carb. Compression is about 12:1. The car has 3.73:1 gears and a 3000-3200 stall converter. Pump gas would be nice, but oh well.

I want something that I can drive the 10 miles to the track, and still make some good ETs. I am willing to sacrifice some streetability for the track. Thanks!

[ 08-26-2003, 05:22 PM: Message edited by: Silver69Camaro ]

Iron heads and 12-1 compression...nah, no pump gas for you :D Drop it down to about 10-1 and you should be able to run pump gas just fine, and still make good power. The 292H would be a good match for that convertor and gears, and in a 406 it should pull enough vac for power brakes. JMO, but if you have that much compression, and could stand another 500 rpm in the convertor, something like a comp 306s solid, or isky Z35 solid (260@.050 and 254@.050, respectively) would make a lot more power than the 292H.

Or consider a CC 294S solid at this compression level. And make good mid to lower-upper grunt!

Should run verrrry well, imho... pdq67

I had the 292H in a 350ci in my '68 for a couple of years. It was the first (and only) motor that I had ever built. It had double hump heads with 2.02s/1.60s, a Weiand single plane intake, a Carter 750, and I had a 3000 stall with 3.73 gears. I usually only drove it on weekends. It had a great lumpy idle which I loved. The motor didn't seem to respond to well to a heavy foot below around 3500 RPM, but past that, it ran like a scalded dog ! It would easily pull to 7000RPM, which eventually caused it's demise !

If I remember correctly, it pulled around 12 lbs of vacuum at idle.

This is good advice! I will check out all of those cams mentioned.

I bought this motor from a family friend who builds many engines, 90% are race-only build-ups. So, since I've got this motor on the stand, I thought I'd check out these cams and see how it would work with my combo. The only downsides to this motor is the 12:1 compression (I'd rather run pump gas), and it's got a stock crank which probably can't turn more than 6000RPM. So, I'm limited to that point.

Oh well, it's got one pass on it, and I got it complete for $1300. We'll see what happens. I'll try to 11's, but I'll post the time slips!

matt ive run a 406 and a 408 sb for about 6 years now no problems with stock crank, shift at 6200 on 406 and 6400 with 408. im with the other men put at least a 294s in it .ithink it has a 112 center line so should pull enough vacume for brakes. if it was my motor and useing it more for track with that compression iwould use the 306s.i sold my buddy a 383 with the 292 solid cam in it that he ran on the street.as for as i know he liked it.i drove his car and it ran fine for me .he did use a 3000 converter

It is hard to break even a cast crank. When a motor lets go it is usually due to a 'small piece' such as a wrist pin, rod bolt, or something in the valve train. If you run a big cam and only spin it to 6000 you are missing a large part of the power curve. I also agree with a solid cam. Big cams are made for high RPMs which benefit from the lighter weight and more consistant valve lash of a solid.

Good Luck

When my engine let go it was due to valve train failure (and my foot). I spent the extra cash to try to make it live longer (steel crank, forged pistons, balancing, the recommended valve springs - which I had to have the heads machined for, bronze guides, guide plates and screw-in studs, and full roller rockers). After a long period of high RPMs (in high gear) the engine just lost power. An intake valve in one of the cylinders didn't close soon enough, and got hit by the piston. The base of the valve broke off, and the valve stem poked a hole through a forged TRW piston. I've often wondered what caused this, an inproperly installed valve guide, valve float, or just one of those things ? I always thought that hydraulic valve float would cause the valve not to open, which was one reason that I chose a hydraulic cam, hoping it would be somewhat of a "safety valve" to prevent blowing the motor.

I think the only chance you would have of using pump gas would be with something like a gm -140 solid cam. It is 257/269@.050, 112 lsa, with 4 degrees advance ground in. The lift is a little short for a max effort drag car at .493/.512 (minus lash), but the gentler ramps would promote a long healthy cam life and wouldn't require a lot of valve spring to keep it under control. www.sdpc2000.com (http://www.sdpc2000.com) has this cam and lifters for like $120.

I use the 292H with 1.6 rockers (see sig). I drove the car every day up until the trans broke(and last night someone stole my sound system out of it). It pulled 9-10 inches of vacuum, so I used a compcams vacuum can which helps a whole lot. Its one bad *** sounding cam, turns heads everywhere.

If you want pump gas Elgin makes a 2nd design Z28 cam that has 325/335 degrees of advertised duration and 264/272@ .050 {i believe} and around .550 lift. A buddy of mine runs it in his 350 CRUISE car, no its not an all out drag car. Granted he runs a TKO tremec Of course its not going to allow for power brakes and such but for the money that race gas will cost, you could upgrade to manual disc in front and that should stop you fine.

I already run manual disc brakes, and I actually prefer the firmer feel.

The reason why I ask about vacuum is that this would be my first "big cam" motor. My current 350 pulls about 11-12", and I could tune the Road Demon pretty good. It seems as if the more radial the cam, the more troublesome it will be to tune. Maybe I'm just making a big deal out of nothing.

I really like the specs of the 294S...sounds like a real good cam. The valvetrain is pretty stout, it's got matching Comp Cams springs, lightweight retainers, 1.6 Crane Gold roller rockers, guideplates, 7/16" rocker studs, etc etc.

I also looked at the 306s to bleed off some of the compression. I think the bottom end of this motor can't take advantage of the RPMs that cam would make for good power.

I think I'll be purchasing a ATI Streetmaster converter (3000 or 3500 stall) and installing that at the same time. I cruise at 3000 on the freeway, and I hear these generate less heat. Hope that goes well!

Go wide on the LSA and long on the duration - that's the only way to get it to run on pump gas, and that's kind of a long shot IMO.

The GM grind Travis mentions is a good idea - also Crower makes a 294sf solid - 294*I/300*E advertised duration, 256*I/262*E duration @ .050, .528"I/.545"E lift on a 114* LSA.

Desktop Dyno shows this cam to have a 3000 - 6500 power band in a 406. Peak power is 515 HP @ 6000 and 493 lb/ft TQ @ 5000 RPM. I used Dart Iron Eagle 200cc heads to simulate "heavily ported" 291's so figures are aproximate.

Chevy makes or did make,(??), a -754 solid cam that is one step up from the -140 cam spec'ed as follows;

Advertised duration, 318/327, (the way they rate cams!!), 262/273, 112/108, .488"/.509"..

pdq67

Eric and Paul-
Boy, those cams are big. Real big, to me anyway.

Do you guys think that running a big cam like that will be moving the RPM band up past what my crank can handle? I would think a cam peaking at 6000 or slightly lower would be ideal, but this is just a guess. Opinions?

Thanks again for all the suggestions!

I use the 292H in my track only Camaro, no vacuum to worry about. I run it in a 327 with iron heads
and 11 to 1s my only issue was that this cam noses over about 6300 so I shift about 6200 the cars best time is 12.69 at 107 I use a 4000 stall converter and 488s out back.

Yes, these are two big cams BUT with the wide lobe separation they will act smaller than they look.

For example the Crower 290 SF that I mentioned has a 114* LSA which limits valve overlap to only 69 degrees. The 294s that I run has a 110* LSA and 294* @ .050 with 73* degrees of overlap.

With the Crower cam your Dynamic compression ratio would be roughly 8.8:1 which IMO is still too much for pump gas. With the bigger Comp 294s your DCR would be higher at 9.0:1 because of the later intake valve close timing.

I think the two cams that I mentioned are entirely driveable with a 3000+ stall. The problem though is the 12:1 compression - you will still be pushing it with iron heads but maybe you can get away adding octane booster to premium pump gas and running a conservative timing curve. I think the two cams I mentioned will be able to rev higher than the 6500 limit you mentioned but noone says you have to take them that high --- they should make plenty of power below your 6500 limit.

The other option would be to just commit yourself to running race fuel and go with a slightly smaller cam (like 245-250* @ .050 lift) that has a tighter LSA (like 106-108*). This would bring the RPM range down to where you want it.

Another option yet would be to disassemble the bottom end and go with a lower compression piston or different heads with larger combustion chambers. If you get your compression down into the 10:1 range your cam options increase dramatically.

My brother ran the 294S cam in his 406sbc w/ very ported #461 dbl. humps (2.02), 11:1 compression, Victor 4+4 intake, Hooker S/C's, 750DP, etc. It was in a full weight '79 Trans Am w/ 3.42 gears (3000 stall I think), suspension mods etc. He ran a 7.79 1/8 mile w/ a 1.79 60' time. The car screamed! I don't think he used additive for his fuel, just super unleaded.

BTW, a friend of mine has a 406sbc in his Chevelle w/ the 292H cam, ported 2.02 dbl. humps, 11:1 comp., Victor Jr, 750DP, 3.73's, TH400, etc. He has to back the timing off so it doesn't detonate. It's a very quick car.

Good suggestions.

The reason I gawk at the big cams is because I'm afraid I wont be able to tune them very well. I think I can live with a cam that makes 9 or more inches of vacuum, but in all reality, I don't know yet.

But, I can't have my cake and eat it too. I either have to step up to a BIG cam and use pump gas, or keep the current cam and increase the octane to 105-110. High compression motors sure do have a nice sound, though.

This motor will be installed probably November/December (not enough time to race it this season), and I will install the 3000RPM ATI converter at the same time. I'll run the motor and see what I think of it. I can slowly decrease the octane until it pings, so I'll know what kind of fuel I need to run. Thanks to you guys, I have a good list of possible cam choices in case I don't like the 292H.

The first pass this motor made ran a stock weight '70 Camaro into the high 11.70's. I hope I can do that with my car, although I don't know what my chassis needs to get there, or if my 3.73's are enough gear. Phew, I've got alot of work to do!

Well dispite the popular belief on this board and most magazines, and really most people in general you can run a huge cam on the street BUT, it takes the knowledge of a friend thats been doing it for 40 years to get it to run right, a manual tranny and some deep gearing and a few other things. I personally run a howard 302/310, 268/278@.050, .560/.570 lift on a 108 l/s. In my nova wich is more of a cruise/driver than a drag car. But i have a 5 speed with a 3.27 first gear and 4.11 rear gears. It starts making respectable power around 2500 and pulls like a bitch in the mid and on top, below 2500 its a little rough but not like alot of people would make you think. ALso how sure are you that you have a full 12:1?? Have you taken into concideration that your valves may be dished {dont know the exact term} you could run a "still acceptable" .045-.050 quench {i believe .006 is usually = to 1 cc. and between the valve dishing and quench that could be 2-3 cc's right there putting you probably around 11-11.5:1 I run 11:1 and have 90 octane in it, put the pedal to the floor going up a steep hill and have absolutely no detonation what so ever. Just somthing to concider, but if your stuck on an automatic id forget about the big cam, it would be no fun to drive with a 5500 stall and youde get 3 mpg.

I have ran this cam in a .030 over 327 with 461 castings untouched, Victor jr, holley 650 DP, headers, flowmasters with 10.0:1 and it made 314 at the tires. I ran a 4 speed manual brakes so I can't answer for the vacuum.

Sorry, I forgot to add that this cam was done making power at 6200 rpm, a balanced cast crank would be more than adequate.