rigger3006
Well-Known Member
Well i guess i better just sell it then and buy a "real" cam!
292/508 question
- Thread starter rigger3006
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Matter of opinion and what makes you smile! I am still driving with that grind and adjusted all to work for me. Nice lump and very streetable. Gets attention when I pull in the car shows. There are better grinds available today and just a deal on if you are old school and set in your ways or not.
Just understand the negatives and decide on what you can or cannot deal with. If I was to try to put air on the car at this point I would go a different direction.
QuickDart360
Well-Known Member
Better grinds is really not so. I went to a car show last year and I saw a really nice 68 gtx 383. It sported the more "modern" comp extreme grind. It sounded like pure crap!! It had lump but a crappy type of lump sound. I I am sure a purple cam can outdo it any day. But that is just my humble opinion folks!!
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I am a Purple kinda guy. There are better grinds believe it or not. They are hard to weed out to find what makes you happy and what makes your combo right. MaPar did good work for prescribed combos. I would suggest to follow them but read between the lines and remember what Mopar claimed and follow the recipe!
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A 68 GTX should be a 440 base engine, so if it had a 383 there is no telling what the guy/gal did to it as well!
QuickDart360
Well-Known Member
Yeah it was not #'s matching. Sort of a modified custom. I suspect maybe not even a factory gtx who knows. But wow the engine sounded all clattery and the exhaust note just dirty noisy not the sweet note one comes to expect from a mopar!
I too prefer a purple grind. I now have the 280/474 grind and also get compliments from people who hear my car run. I just need a "little" more lope so as to why I will go to the 292 to satisfy the thirst for more bump and lump!!! Just will change other components to make cam work good in street driver!!
I too prefer a purple grind. I now have the 280/474 grind and also get compliments from people who hear my car run. I just need a "little" more lope so as to why I will go to the 292 to satisfy the thirst for more bump and lump!!! Just will change other components to make cam work good in street driver!!
If you are that worried about what you Hurd about this cam to make you want to sell it and buy a “real cam” you should reavaluate your projo, there will always be a better bader loping cam smoother idle . The 508 cam is perfectly fine. I bump up the idle on mine and I never had a problem out of the whole. It has a good power band. If you want the real thump try wooplash or lunati cams. Ever comp has a awesome selection. I’m a mp /direct connection guy don’t worry about what every one thinks put the cam in fire it up and test it for your self see if you like it.
rigger3006
Well-Known Member
Im a purple liker also.wifes 340 duster has 474/280 and my demon has 284/484
I love the 484. 474 Is in my buddy dart. The 508 gets a lot of rip because people just don’t understand is a high preformace cam shaft you’ll like it for sure the 508 has a lott in common with 484
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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The best cam?
Firstly is application specific,
then engine and powertrain specific,
and
tempered by budget.
If you just want the sound;and care about nothing else, get you a ThumpR. That might keep you happy for a summer.............. Or a small cam with a lotta overlap.
Overlap and good fuel mileage do not co-exist ..... normally.
The cam is the key to unlocking power at specific rpms.
The 292 for instance, peaks at around 5800 depending.
The 284 at about 5600
the 276 at 5400
the 268 at 5200
and so on.
With an automatic, to get the best from the conventional cam at the next shift, the rpm is usually buzzed up 800 to 1000 or more past the peak, depending. If your engine spends a lotta time past 6000, you need to do some oiling mods to keep it alive.
The problem comes when a guy wants to run a cruiser gear and the top of first gear ends up at around 60mph. Then the daymn cam doesn't start until 40/45 mph; but worse is the first 30 mph end up being so soft, that a sharp teener comes along and embarrasses you. So now you have an engine with a killer idle that pretty much makes a useless streeter.
Ok so the solution to that is a 3500... or more, TC. And that comes with a new set of streeter's problems, and it still doesn't change the fact that the 3.55s are peaking at 60 mph. So you are still looking at changing the rear gear.
So now that big lopey cam is costing you, additionally; a TC, a rear gear, many mpgs,and a lot of other things, AND it has turned your $30,000 dollar cruiser into a weekend-only bomber, and a city-only car: and all because you want the sound.
And we haven't even talked about what has to be done to the engine to accept that cam, nor how much it's gonna cost.
If you are on a tight budget, you might be tempted to just toss the engine together, and so it ends up at or near the factory compression ratio. And then that big lopey cam, with iron heads, has no bottom end at all.
And if a TC and gears are not in the budget either, then your soggy-to-35/40 mph engine, with it's killer idle, is gonna end up being a constant reminder of what not to do.
IMO, it's a combo. An integrated combo of budget, powertrain, compression and cam size. If you can't afford the supportworks (TC and gears) to run that big lopey cam, or the gas to drive it afterwards, or the supporting engine changes, Or the chassis upgrades, then......... just maybe it's the wrong cam.
This is where the little ThumpRs come in. You just gotta remember the design philosophy behind them.
Or the small, high-overlap cams. At least with these you can put the power at a useful street rpm/roadspeed.
Take the 268 cam, for instance. It normally peaks at around 5200. And with an automatic the 1-2 shift might want to be at 6200 to drop in at 3660, for a powerband requirement of a tic over 2500. So now instead of building power with rpm, you need to put the power into the heads, and into the efficiency of the engine. But of course you will lose the lopey idle of the big cam. What you get in return is a stouter bottom end and much more fuel efficiency. So maybe you get to keep your gears and maybe also a lot smaller TC.
But hang on, if you order a custom cam about the same size, but with a much tighter LSA, four things are gonna happen; 1)the overlap is gonna increase, and so the rpm of peak power is gonna go up a bit, with attending bit more power. At the same time, a little lope is gonna creep into the idle,and 2) the cylinder pressure is gonna rise, increasing the low rpm performance, and 3) power stroke is gonna lengthen, increasing steady-state fuel-economy, and 4) because of the first three, you are gonna be a much happier guy.
Here is a comparison
These are all in a 340, with the Cylinder pressure adjusted to about 160psi for open chamber iron heads, to run today's pumpgas. OK;
First the regular oem 268/114 factory 340cam in at 110
Static compression ratio of 10:1.
Effective stroke is 2.57 inches.
Your dynamic compression ratio is 7.98:1 .
Your dynamic cranking pressure is 159.36 PSI.
V/P (Volume to Pressure Index) is 126
Notice the VP is only 126, just slightly more than a 5.2 magnum.(124)
Ok so here it is with a modern 268/110 cam in at 106
Static compression ratio of 9.7:1.
Effective stroke is 2.66 inches.
Your dynamic compression ratio is 7.98:1 .
Your dynamic cranking pressure is 159.36 PSI.
V/P (Volume to Pressure Index) is 130
Notice the VP went now up to 130
And again with a 268/104 cam now in at 100
Static compression ratio of 9.35:1.
Effective stroke is 2.78 inches.
Your dynamic compression ratio is 8.00:1 .
Your dynamic cranking pressure is 159.88 PSI.
V/P (Volume to Pressure Index) is 137 .
Again less Scr, and more VP; 137 is getting somewhere. Fun starts around 140/144. But now we have gone about as far as we can with shrinking the LSa
Ok so now lets put aluminum heads on it and a solid lifter cam equivalent to the 268/104 cam. This would be close to a maximum effort.
The 268 hydro is about [email protected], so we need a similar [email protected] solid and I get a 260 and it might lose 3 degrees in the lash so let's gross it up to 263 and still a 104LSA, but I'm gonna put it in at split overlap to take advantage of the nice overlap-created, header-augmented, power peak.I get an install of 102.5 ok then
that cam comes in at 263/271/104 in at 102.5
Static compression ratio of 10.5:1.
Effective stroke is 2.78 inches.
Your dynamic compression ratio is 8.97:1 .
Your dynamic cranking pressure is 185.35 PSI.
V/P (Volume to Pressure Index) is 159 .
Holeeeeeee, do you see that VP is now 159. And the combo of aluminum heads and 185psi, means it runs on 87E10. 159 is like a 1969 440 Magnum........ from idle to about 3000/3600. You can keep your 3.55s or 3.23s or even 2.94s. And you can keep whatever stall is in there.
Of course it's still just a [email protected] cam, so not making 430 hp. But the 104 Lsa is gonna push the power peak up some 300 or so higher than the oem 340 cam so now it's pushing 5400 or perhaps 5500 with those aluminum heads. If you also boosted the lift on that cam into the .550 range, then I guarantee you will never think about the 292 again.
Well except for the almost total lack of lope,lol. The above solid cam has overlap of just 59* compared to the 292/108 at 76* so bye-bye lope.
Well that's not entirely true. You can coax a little lope out of her with the tune; a low idle, retarded ignition timing, and a messy carb-tune. In my combo, I just installed a dash-mounted, dial-back, timing device, with a range of 15 degrees,lol. Hello rumpidy rumpidy.
Here are the other events of the above theoretical cam:
Compression is 126 degrees and power is 119; so not only will it burn 87E10, but now it has about 15 degrees more extraction on the power stroke, taking full advantage of the 185psi of cylinder pressure to drive many more miles per tank.
And finally, the 10.5Scr is easy and cheap to make, the engine practically falls together at that ,with proper pistons.
How many wins is that? I count ; plenty of power, a killer bottom end, great fuel mileage, burns cheap gas so drive it anywhere all the time,money saved in not buying gears or a TC with attending supportworks,nor an overdrive, windows down cruising because no stinky exhaust,smokes the tires to 50/60 mph,IDK whadImiss? Oh yeah; cheap/easy build.
How many losses? Maybe two; the loss of the killer lopey idle, downgraded now to mild lope, and the cost of the aluminum heads, which is offset mostly by the plusses..
Course with solids, I guess you could move up one cam size, cuz a VP of 159 is waaaay overkill. Ask me how I know..... ( I ran 162 for 4 years,currently 153 which is still way overkill)
Or you could go back to a hydro
Depends on where the Scr comes in at,
or how much you wanna spend on machining
....... lol
Happy HotRodding
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Wyrmrider
Well-Known Member
The whiplash/ thumper/ *** cams allow a bigger intake lobe at the expense of overlap allowing the intake to close earlier FOR A LOW COMPRESSION MOTOR
a special combination and not for everyone especially in the larger duration
the 292/508 series- horrible trade-offs for a high rpm bracket cam when used on the street
how often can you use that last 500 top end rpm? 4 speeds and gears yes- autos drop too much rpm unless very high rpm stall and low gears
other ways to make sound
a special combination and not for everyone especially in the larger duration
the 292/508 series- horrible trade-offs for a high rpm bracket cam when used on the street
how often can you use that last 500 top end rpm? 4 speeds and gears yes- autos drop too much rpm unless very high rpm stall and low gears
other ways to make sound
OMG AJ, can you take up anymore room?
Nut shell it some. Dang!
FWIW, from the Purple line of cams mentioned, the best street manored would be the 280/.474. Stepping up for a pretty good street stripper would be the 284/.484. Best use for the 292 in the street would require (for best street results!) a 10-1 ratio. A pretty high 3500 stall converter and steep gears like at least a 4.10 set.
It is a large hyd cam @ 248@050.
If you move it to the strip, it isn’t so bad. It is a good bracket cam. I have met more than just a few guys running low 12’s with that cam.
Making use of that in the street is mostly a wrong move for most people since making it work requires more than just some work.
Is it me or does half the world think every thing is an install and go part?
Nut shell it some. Dang!
FWIW, from the Purple line of cams mentioned, the best street manored would be the 280/.474. Stepping up for a pretty good street stripper would be the 284/.484. Best use for the 292 in the street would require (for best street results!) a 10-1 ratio. A pretty high 3500 stall converter and steep gears like at least a 4.10 set.
It is a large hyd cam @ 248@050.
If you move it to the strip, it isn’t so bad. It is a good bracket cam. I have met more than just a few guys running low 12’s with that cam.
Making use of that in the street is mostly a wrong move for most people since making it work requires more than just some work.
Is it me or does half the world think every thing is an install and go part?
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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If you punch "F11" one time and "Ctrl -", several times. you can make it small enough that you can almost not see my posts, which, for you, I highly recommend. Failing that, you can just put me on ignore, then you don't have to see my posts at all.
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The 292 works if you use it as intended. It's only benefit over a 484 cam is the last 500 rpm of range. Other than that, it's inferior to the 484. The 484 is streetable if you work with it. Install it way ahead in a stock compression 68-71 340 and it's a good runner regardless of theory. You make do with what you have on your plate and live with the choices.
You aren't making Filet Mignon out of a lump of ground chuck!
The 280/474 is a good cam for a streeter as well.
War and Peace ain't got **** on some posters on the board!
You aren't making Filet Mignon out of a lump of ground chuck!
The 280/474 is a good cam for a streeter as well.
War and Peace ain't got **** on some posters on the board!
Honestly if you run this cam you have to have the term high performance in the back of your mind. Look at the rpm range for the cam 2800 -6200 street strip. I ran this in a 4 spd worked pretty good I too seen people run the cam at the strip a lot of combos all in the high 11 to low 12 range. I’ve ran the 3500 stall before my buddy ran a 2500 stall with this cam and he dident run bad I think he pulled mid 12s with 10 to 1 Comp. x heads rpm intake. But he drove that for 30k miles all over the states and never complained and he only has 355 gears. And it wasn’t a dog that car really ran good and was a high preformance street car.
Bingo! Ran mine with a 4spd & 4.10’s.
AJ! Holy cow! I think you got it!
A nutshell post!
And no long drawn out math!
Je-zuz H!
A freakin MEN!!!!
Funkin A to that.War and Peace ain't got **** on some posters on the board!
More dribble than a baby during teething!
Completely pointless!
Works rellly good with 4 spd. I have 391 but with a cam that goes to 6200 bigger in this case Lower gear is always better
QuickDart360
Well-Known Member
There is an old thread/post somewhere here. That a member changed out the "ancient outdated mopar cam" for the ever so modern comp extreme series cam and didnt pick up anything but rather lost so many tenths in the 1/4!!! Wow! Go figure the extreme should have done soooo much better since it was a modern latest and greatest cam.
Binnnngoooooooo!!!! Lmao not suprised do you remember the post?There is an old thread/post somewhere here. That a member changed out the "ancient outdated mopar cam" for the ever so modern comp extreme series cam and didnt pick up anything but rather lost so many tenths in the 1/4!!! Wow! Go figure the extreme should have done soooo much better since it was a modern latest and greatest cam.
QuickDart360
Well-Known Member
Actually more than one member had this dissapointment happen. Just don't really remember when or who but it's in the forum somewhere. I guess it can be looked up on search engine here. But I found it by reading older posts to get ideas and pointers for my build. I'll stick with mopar cams. But also think racer brown and some lunati grinds are nice. However, most all lunati is ground on the typical 110 lobe so that kind of draws my interest more to mopar, racer brown, isky and even custom grinds like say bullet.
Here’s one for you hot rod mag did a dyno with a 340. It had and air gap 800 eddy and comp 477 -480 lift cam stock bottom end made 390 hp I built a exact 340. But ran a750 eddy and 484mp cam and made 402hp lol and my cam was used in previous builds. Not new might be a 508 I don’t remember
yellow rose
Overnight Sensation
WTF??? More dribble than a baby during teething!!!!!!!!!! Where do you come up with this ****? I love it! Reminds me of the old days and getting wore out like a 2 dollar hooker on coke. Love it.
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That HR dyno derby or whatever it was titled mag deal is complete and utter BS with a stock flowing head. Built and been around more than one that was similar. It's a 1hp per CI build at best. Track MPH proved that out in a VERY good chassis.
A loy of the BS in the mags have never proven it at the track. I recall another where they built some 600+ hp engine, put it in a 73ish Dart and it ran a whopping 117mph in the 1/4. Something doesn't smell right here. Even with a HORRIBLE 2.0 60's that should run 125+.
The 484 cam is 15about degrees larger at .050 than the xe268H cam in the HR build. That makes a big difference in output.
Did someone say Hookers and Cocaine? LOL
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Has anybody run a 10 to 1 360 with the 292 purple cam in it? Has anybody done it with an RPM airgap verse an M1 single plane?
Many many years back, I tried to 92 purple cam. My shot coming to the combo was I only had 202 “J” heads and a TorkerII 340. As the RPM-AG wasn’t yet made.
Many many years back, I tried to 92 purple cam. My shot coming to the combo was I only had 202 “J” heads and a TorkerII 340. As the RPM-AG wasn’t yet made.
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