Russ, the xs282s cam is a real revver in a 383.
IMO, it's really a bit big for the rest of the plans for the OP's car.

Although, a small mid-230 solid single pattern on a 108 would likely do everything better than the xe274.

Several years ago when I had the 340 in my Dart I switched from 3.91's to 4.30's. The car averaged .006 better in 60' and carried it through the 1/8. There was no change in mph. A lot of money and work for so little gain.

At the time I was running a 9.5" converter from Edge Racing Converters that was built for the car. Very good converters for the money IMO.

3090lbs, is this correct or a miss print? with all those power adding parts to that 383 and 108mph @3100bs makes me think "where's the extra 60hp gone"? that thing should have 375hp or more, which should be around 113-114mph. before I spent a nickel on gears and converters i'd look for my lost power.

With that list of parts it should be making better power, from the parts list it should be a 425hp motor

Can you elaborate on this a little Dwayne? What do you normally see with these XE cams? Do they start to break up in the higher rpms or what happens exactly?

My experience with fast rate hyd cams is...... The lifters collapse more than "normal" on the opening side, and when the rpm reaches the point where lofting starts to occur, the lifters "pump back up", and if there is any appreciable preload, the valves hang open, and the power drops like a rock.
More spring pressure just exacerbates the situation.

What is required to get this type of cam to turn any real rpm are lifters with extremely tight internal clearances, and a very low quantity of oil below the plunger(limited travel), so enough spring pressure can be used to properly control the valvetrain, without worrying about how much collapse the added spring pressure brings.

Lobes that use longer, slower ramps have less of a tendancy to collapse the plunger on the opening side, so that's one plus if you're trying to achieve a higher rpm, plus the slower overall action requires less spring load to maintain control at any given rpm.

My personal experience is, I have never gotten any fast rate hyd cam to rev very high....... In any brand of motor.
I'll admit, I have zero LS or Gen3 experience though, and those platforms seem to not suffer from this situation as much as the old school stuff does.

Thanks for all the input/suggestions. Lots to consider & I think I will do 3.73 & a good converter & work on my 60' this spring. I will, down the road, think about making a cam/lifter change to get everything out of this set-up. The intake is good for up to 65oo rpm & I'm running a '65 steel crank, stock '65 rods & ARP rod bolts so the bottom end should be able to handle the higher rpm. I want to get all I can out of this combo but not get it too out of line for daily use since I drive it 75 miles a day.



That is correct, it was 3090# at Tulsa Raceway Park. I weighed it with open header(the exhaust pipes off) & 3/4 of a tank of fuel.

[quote=grancuda
I am considering a better converter, maybe a Dynamic Converter, to get it off the line & get my 60' down. I just want it to be a fairly tight because it's my daily driver.


[/quote]

The Stock type converter is your Main problem. With the 383 go with Dynamics 9.5" vert. They are Very Tight verts and work very well. They are reasonable as well, around $600 bucs or so. With the 383 Id probably go with the 4500 stall 9.5"

Leave the gear alone for now, but I do like your thinking on the 3.73 gear and 26" slick for the track and 28,s for the street.

That's a far more technical explanation than what I was going to say, which was the valve train comes effing unglued beyond a fairly moderate RPM.

I hate those hydraulic Xtreme cams... noisy, sh!tty valve train control at higher RPM... everything I DON'T want with a hydraulic cam. I went to solid lifters years ago and haven't gone back.

As did I back in 1984 with the 340 car, the .484 hyd. purple was ok but when I stepped it up from a street car to S/95% Strip it had to be an sft cam. the old DC. 590, which also ran great on the street on the few times I took it out.
I think the OP would do very well with doing the same thing and let that motor rev freely to 6k+ with a decent tight 4000 flash verter, then we would see how fast he could go as its capable of much more with the hp people say it has.

Thank you and BRADH for the input. This conversation couldn’t have been more timely. I have an XE cam in my car. I just switched to a different set of heads with different valve springs and when I’ve taken it out to dial it in, at around 5900 rpm or so, the car feels and sounds as if it’s breaking up a little. I had no issues before with my old heads and springs; everything was smooth up to 6300-6400 (as high as I’ve ever revved it). The valve train noise sounds louder than what it was with the old heads and springs too.

In regards to it breaking up at higher rpm, I’m not saying there isn’t possibly something else going on because I’ve only had minimal time to mess with it but, the cam did come to mind. I added about ¾ turn of pre-load when adjusting the valves this time; next year when good weather comes back, I think I’m going to go to a half turn.

The car has always performed well with the cam but, I cannot stand the noise it makes. It always sounds like something is wrong but, every time I’ve adjusted the valves or had things apart for whatever reason, there is never any issues. The noises are variable too (sometime I’ll have X ticking and or ext. but, sometimes I don’t). Again, I don’t think anything is wrong but, it drives me nuts. I’ve got probably around 2000 miles on the car and 15-20 passes. I’m going to keep plugging along with this combo but, when I freshen the thing up, I will definitely be going with a different cam.

FYI- Not that it was apples to apples given I re-curved my distributor at the same time but, I changed from 4.10's to 3.73's and picked up a tenth and a half in the quarter.

6200 is about the best I've ever gotten out of one, and that was a SBC with factory(pretty light weight) stamped rockers.
On the BB motors, they've never made it to 6k.

I did some experimentation on the dyno years ago, playing with different spring loads trying to see if I could get more out of one. Increasing the springs from about 120/310 to 145/370 netted maybe a 100rpm gain..... And when the valvetrain got unhappy with the higher spring loads, it happened even more abruptly.

I ended up swapping to a solid lifter cam, put in springs that were 135/345, and it would rev cleanly to 6500(as high as I was comfortable with on that short block) with not even a hint of a stability problem.

The one time I recall seeing this phenomenon play out in a magazine was in Mopar Muscle 2005 with that EZ headed 446 Dulcich built.

I had already been through what he was experiencing and knew how that was going to turn out.

About 20 years ago, before my friend was running Schubek lifters in his Stocker we were trying to find some upper rpm stability out of his motor.
The cams that showed the most promise just wouldn't rev high enough to be usable.
Around that time we had also played with spring loads, and got basically nothing out of that.
We swapped some solid lifters into it one time to see if it was lifters or spring load.
Set them at .004 lash....... And the motor would go almost 1000rpm higher before getting into some float. The problem was the lifters all along.
The next year he put Schubeks in it...... And that was the end of the rpm problems.

I do like the way you said it.

Mike I was anxious to try your 26" slicks but the 275 pro radial worked so good I'm just gonna stick with it. Thanks for the offer though.

This cam/valvetrain is really noisy, I have adjust & adjusted thinking I did something wrong but no, it's just loud. I would run a solid lifter cam but really unsure how often I should do valve adjustments on a daily driver. I know some factory Mopars had them like the higher performance 273 so they should live day to day.

I had an old Toyota pick up with a mechanical cam that went 200k and never had the valve cover off.

Slant 6's were all mechanical cams up until the last one or two years of production.

For a modern high performance street friendly mechanical cam in a traditional v8 platform, I'd say popping the valve covers off for a look-see every 3000-5000 miles is probably a good idea.

The right type of solid cam wouldn't be any noisier than what you're dealing with now.

my experience has been frequent adjustments are more due to the person doing the adjusting than anything. you can buy solid cams that are pretty quiet.

Been awhile. Welcome back.

yep. we need to catch up sometime.