Sorry, another 383 cam choice question

[Q5XX29]

So, over the last few years, my oldest son and I restored his first mopar- a 1968 charger. It is originally a 383 2-barrel car, but the car now has a factory-style 4-barrel intake, and a stock-type rebuild, although we have added a MP electronic ignition, hooker 1 7/8 headers (with cutouts- he sure loves them!), and a Holley 780. I believe the compression ratio is around 9:1. All of the cylinders are at 130 psi static compression. It is an auto (727), and I just installed some 3.55s. Factory converter, I believe. Somebody must have installed a shift kit in it at some point, because it chirps the tires under full-throttle upshifts.

I think my son is ready to step up to a little more power, as he is used to this now, and is tired of his friends with their imports all being quicker than his otherwise-awesome muscle car.

For his birthday next month, I told him I would put on the Performer RPM intake manifold (I have one on my '70 charger 383 and I LOVE it), but I think I will also surprise him and have a different cam installed.

My question- is it worthwhile to do a cam swap with a fairly low-compression engine? I would love to have his 383 pull to about 5800-6000, sound mean, and still make enough vacuum to run his power brakes. I was wondering about the comp cams xe274, or a Hughes grind, perhaps.

Thank you for any advice you can offer.

[69wannabe]

The XE 268 will work with you stock converter and give you some good power. The XE 274 sounds good and will have enough vacuum to run power brakes but you may want to install a good 2500 stall converter with it. I had a XE 274 in my 383 and it sounded great with just turbo muffler's and 2 1/2 exhaust. Had a good lope and good driveability.

[firefighter3931]

The Crower HDP 271 is a very nice cam for a mild 383 build. Lots of torque and strong throttle response with excellent top end pull. Has a nice lope at idle and pulls enough vacuum to run a brake booster. 

I've recommended that cam to several members and the response has been very positive. 

You will have to upgrade the valvesprings and I would recommend a heavy duty pushrod and good double roller timing set. The Johnson hy-lift lifters get the nod for new lifters with that cam. 


Ron


Ps. Nice Charger....my first car was a 68 with a 383 4bbl/727/3.23 SG 

[Q5XX29]

Thank you both for your suggestions! Sounds like I have several good options.

I did also call Hughes Engines yesterday, to get their recommendations too. They recommended either their Whiplash cam (#2942), which is tempting since is should sound great and offer good performance, but I am skeptical about enough engine vacuum, although they didn't think that would be an issue for me:

http://www.hughesengines.com/Index/products.php?browse=category&level0=RC0gQmlnIEJsb2NrIChMb3cgRGVjayk=&level1=Q2Ftc2hhZnQ=&searchmode=partnumber&page=3&partid=30172


The other option he said to consider would be their more conservative #2428 cam:

http://www.hughesengines.com/Index/products.php?browse=category&level0=RC0gQmlnIEJsb2NrIChMb3cgRGVjayk=&level1=Q2Ftc2hhZnQ=&partid=30254



Do either of you (or anybody else) have any experience, or comments about the Hughes cams they suggested?  Thanks again!

[firefighter3931]

The whiplash cams don't make a lot of manifold vacuum so running a PB booster is iffy. Both of those Hughes cams use very aggressive lobe profiles which requires increased spring pressures to keep the valvetrain stable. When using increased loads it's very important to run quality oil and there is a risk of increased wear. With valve lifts exceeding .510 you must trim down the stock valve guides and install an aftermarket valve seal. Failure to do so will result in retainer to guide interference and failure 

The Crower HDP 271 will work fine with unmodified factory heads so no machining required. It's a moderately aggressive cam profile designed for stock heads with a wide split pattern. The unported factory casting is weak (comparatively) on the exhaust side and this cam helps by hanging the exhaust valve open longer allowing the engine to exhale better increasing power and efficiency. 

Depending on what the current valvesprings you have installed....the Crower might be fine in terms of seat pressure/open pressure and coilbind ? The Comp Cams #911 spring is a good choice with this cam.



Ron

[303 Mopar]

Lunati Voodooo Cams are a good choice as well - http://www.lunatipower.com/ProductGroup.aspx?id=362&cid=62

I would recommend choosing a cam that makes plenty of vacuum so you avoid having to add a pump.  I had to add one to my '71 Challenger and hated it. 

[Q5XX29]

Thanks, guys. Appreciate the input!

[firefighter3931]

Lunati Voodooo Cams are a good choice as well - http://www.lunatipower.com/ProductGroup.aspx?id=362&cid=62

I would recommend choosing a cam that makes plenty of vacuum so you avoid having to add a pump.  I had to add one to my '71 Challenger and hated it. 

The VooDoo cams work really well too !

Several years back I helped a member sort out a 383 and picked the 220/226 for his combo which is pretty close to Q5's setup. That cam worked great in Jackson's car 

https://www.youtube.com/watch?v=BAWpWcgqX6w


Both the Crower and Lunati are great cams and work fantastic with the right combo and proper tuning 



Ron

[c00nhunterjoe]

Imo, if you only have 130 psi on a stock engine, you cant afford to put a larger overlap cam in it with a wide lobe to save power brakes AND not have it a dog. You will need a tighter lobe like a 106-108 to get your dynamic compression up if you want it to have any streetability.  In this particular application, based on the very low compression readings, oversized headers and 3.55s posted, i would personally run the voodoo cam and install a vacuum canister for the brakes.

Plugging the basic math into a compression calculator and assuming your elevation is higher then sea level based on the charger's license plate, im coming up with a static compression of 8:1 and a dynamic of 7:1 in its current state. This is assuming you have a basic stock style resto cam in it. Cam choice is critcal at this point.

[BSB67]

So, over the last few years, my oldest son and I restored his first mopar- a 1968 charger. It is originally a 383 2-barrel car, but the car now has a factory-style 4-barrel intake, and a stock-type rebuild, although we have added a MP electronic ignition, hooker 1 7/8 headers (with cutouts- he sure loves them!), and a Holley 780. I believe the compression ratio is around 9:1. All of the cylinders are at 130 psi static compression. It is an auto (727), and I just installed some 3.55s. Factory converter, I believe. Somebody must have installed a shift kit in it at some point, because it chirps the tires under full-throttle upshifts.

I think my son is ready to step up to a little more power, as he is used to this now, and is tired of his friends with their imports all being quicker than his otherwise-awesome muscle car.

For his birthday next month, I told him I would put on the Performer RPM intake manifold (I have one on my '70 charger 383 and I LOVE it), but I think I will also surprise him and have a different cam installed.

My question- is it worthwhile to do a cam swap with a fairly low-compression engine? I would love to have his 383 pull to about 5800-6000, sound mean, and still make enough vacuum to run his power brakes. I was wondering about the comp cams xe274, or a Hughes grind, perhaps.

Thank you for any advice you can offer.

What can you tell us about the cam you have in it now.  Factory original 2 bbl?  Factory original 4 bbl?  Aftermarket?  If so, size or part number.  It is kinda important for what to recommend and more importantly, what to expect.

[Q5XX29]

Thank you, BSB67 and coonhunterjoe for chiming in.

The engine internals are a mystery, unfortunately. When we got the Charger a few years ago, the engine (original 2-bbl 383) ran quite nicely, so we didn't tear into it too deep. We just stripped off the incorrect orange paint, put on some new dress-up parts and gaskets and headers and carb, painted it turquoise, and reinstalled it after the rest of the restoration. We have a few photos from the guy I bought it from (kind of an unscrupulous, shady dude) that show the car during a previous restoration, and there are photos with the engine torn down to the short block, and it looks like probably the factory pistons still in the block. So, I assumed, a top-end rebuild, only.

Assuming that is all correct, and since the '68 383 2-bbl engines had 9.2:1 compression, and the fact that the cranking psi is all uniform, I thought the short block was all still in decent-enough shape to try increasing the output without tearing off the heads and shaving them down, or going even deeper into changing pistons, etc. 

Of course, the cam is a mystery too, but it sure seems like a tame one, and may very well be the factory 2 barrel cam. It runs out of steam at about 5000 rpm. So, I can't believe the cam is bleeding off too much cylinder pressure when I get my cranking readings. Also, I am at about 1600' elevation, so atmospheric pressure is only 13.9, which should make my 130 psi a little less bleak.

I am not opposed to putting in a higher stall converter (or a vacuum canister if I must). I have no idea what converter is in there now, but again, I believe it to be the original 2-bbl 383 converter.

[BSB67]

I do share c00nhunterjoe's concern on the low cylinder pressure.  But your options are limited.  I think the Huges Wiplash is too much for your application, although Dave intended this cam to be used in applications like yours.  If you had a low compression 440 and wanted a bunch of rumpity rump, I would say to give it a try.  

The Hughes H2428 cam, the Crower HDP 271, and Lunati 702 are all in the same ball park of each other.  I could not tell you which one would be best.  Of the three I would call the Lunati the smallest, and the Crower next followed closely by the Hughes.  And that would probably be my priority, Lunati, Crower, Hughes.  Install with an ICL of 106° to 108°

If you have a factory 2 bbl cam in there now. the difference should be noticable.  If there is already a mild aftermarket hipo cam in it, you might not notice much.  And either way, don't get your hopes up too high.  If the car is getting clubbed now, it probably will after the cam swap, just not quite as bad.

Finally, the Performer RPM is a good manifold in a lot of applications, but at you power level, it might actually hurt overall performance.   Currently your bottle neck is the cam, and it still will be after the swap. I would stick with either the Performer, or DP4B.

Good luck.  Don't let any of what I said keep you from spending some under-the-hood quality time with your son.

[firefighter3931]

 
And that would probably be my priority, Lunati, Crower, Hughes.  Install with an ICL of 106° to 108°

I would have to agree with Russ.....the 220/226 Lunati is probably the best choice for this build, assuming it has the original 383 2bbl pistons. It's a bit smaller than the Crower and has less seat timing so it'll idle nicer and be easier to tune. I would definitely recommend degreeing in this cam on a 106* intake centerline to help it build some cylinder pressure. 


The youtube link I posted above was of a members car with a very similar low(er) compression 383 build and that cam makes lots of bottom end grunt based on the burnout vid 

The stock 383 4bbl tq converter is an 11in unit which stalls higher than the 440 converter which is a 12incher. I would try it first and see how it runs....then upgrade if you need more. 

With regards to the intake manifold : I would opt for the RPM if I was in the position of having to purchase something new. This will be reusable when you decide to upgrade in the future. The RPM won't give up much if anything at all on the bottom end yet still move lots of air up top when it sings past 5500 rpm.

What intake is on there now ? aftermarket aluminum or factory iron ?



Ron

[Q5XX29]

I don't mind purchasing a new intake; it currently has an old Edelbrock Performer 383, which I believe is basically like a stock 383 Magnum intake, correct? Would have the heads taken off and shaved a bit help, and/or thinner head gaskets? Jeez, I don't want this to snowball too much, but if now is the time to do a bit more, I don't mind. I wish I knew for sure the internals of this 383. I figured we would play around with the 383 for a few years, and maybe at some point, put in something a bit more exotic. We're just having fun here, but part of the fun is planning the mods! Thanks again, folks.

[BSB67]

.........it currently has an old Edelbrock Performer 383, which I believe is basically like a stock 383 Magnum intake, correct?

No.  It is taller, larger runner volume and plenum volume.  Mine pulls to 6800 rpm with a cam a little larger than you planning to get.  If you were on the sunny side of 375 to 400 hp, I would say get the RPM.  You are probably around 250 hp.

[Stegs]

sweet looking 68

love those plain jane rims/hubcaps on these cars...looks so basic, yet so nice


My 2 cents is to listen to these guys...they know their stuff

Ron just listed off a bunch of parts to me for my lower compression 440 that i have. Trust what they say...your car will make good power

Love to see more pics of your sons car, your garage!

very sweet setup you have!

[Q5XX29]

.........it currently has an old Edelbrock Performer 383, which I believe is basically like a stock 383 Magnum intake, correct?

No.  It is taller, larger runner volume and plenum volume.  Mine pulls to 6800 rpm with a cam a little larger than you planning to get.  If you were on the sunny side of 375 to 400 hp, I would say get the RPM.  You are probably around 250 hp.

I stand corrected, then. Physically, it doesn't look dramatically different, so I wouldn't expect it to perform dramatically different than the hp OEM manifold.

Wow, sounds like YOU really should get a Performer RPM. 6800 rpm with a plain Performer intake?

I have some experience with the Performer RPM intake, and have NEVER seen anything but an improvement across the entire rpm range (whatever that may be, for the given car- and I have had several).

[Q5XX29]

Thank you! I did post a few pics a while back on this thread:

http://www.dodgecharger.com/forum/index.php/topic,104155.msg1241633.html#msg1241633

I have an entire level below this floor, too, with another group of cars. When I get a chance, I'll post a few more.

sweet looking 68

love those plain jane rims/hubcaps on these cars...looks so basic, yet so nice


My 2 cents is to listen to these guys...they know their stuff

Ron just listed off a bunch of parts to me for my lower compression 440 that i have. Trust what they say...your car will make good power

Love to see more pics of your sons car, your garage!

very sweet setup you have!

[Q5XX29]

Well, old cam is out. Turns out, it DID already have an aftermarket cam in it- a comp cams 270H. So, good news and bad news, I guess. The low cylinder pressure WAS with an aftermarket cam, so that is better than if it was only 130 psi with a stock 2-barrel cam. But, bad news is the cam I went with probably isn't too much better than what was in there. Similar specs; hopefully the updated cam profiles with the more aggressive lobe ramps translate to a noticeable improvement. I am still banking on the Performer RPM manifold to improve the performance. I know some of you guys don't seem sold on it, but I tell you I was pleasantly shocked when I went from the factory 383 magnum intake on my mildly modified '70 charger engine, to the Performer RPM.

My friend/mechanic is just about done, so I hope to post up the conclusions soon!

[BSB67]

The 270H is a good cam, but if you went with the Lunati 702, that is still probably a little better choice than the 270H for this application IMO.

[Q5XX29]

Glad to hear that. I did indeed go with the Lunati VooDoo 702. I also told my guy to install it on a 106 degree intake centerline, as Ron recommended. I do value the advice I receive here! Thanks.

[firefighter3931]

The VooDoo stick is much better than the old school Magnum grind. There will be some improvement with the cam and intake swap....guaranteed ! 

I would set it up with 16* of base timing and 38* at 2200-2400rpm to get the most out of it. 

Keep us posted ! 


Ron

[rt green]

Vermillion or Brookings?

[Q5XX29]

The VooDoo stick is much better than the old school Magnum grind. There will be some improvement with the cam and intake swap....guaranteed ! 

I would set it up with 16* of base timing and 38* at 2200-2400rpm to get the most out of it. 

Keep us posted ! 


Ron

Will do! thx

[Q5XX29]

Vermillion or Brookings?

I've actually lived in both towns. I live in Sioux Falls now. You know the area?