Comp cam reccomends this cam

[moper]

IMO - that one's a little large for my tastes given stock ports. You will also need to machine the heads for those springs. They won't just drop on. You don't say what the compression ratio in the engine is (was it ever rebuilt?) but I'd got with the XE line, the XE268 or if you wanted a little more romp the 280H. They can both make use of stock heads and valve seals, the springs just drop in place. If it sounds like a sewing machine, you either have worn lifter bores, or not enough preload on the lifters, or both.

 

[5.7 hemi]

The XE cams have a fast ramp rate, that’s why they sound like a sewing machine.

 

[BSB67]

What is your idle rpm and vacuum? Is that a 383 or a 440?

 

[Mike67]

What is your idle rpm and vacuum? Is that a 383 or a 440?

Thats not mine, I have the whole cam kit that came with a shortblock I bought. I asked a lot of the same questions the op has , so I know where to look for reference material....
As far as sound goes the Xe285Hi sounds a lot better but is a bigger cam...
I ended up going with a roller...
The silver car is a la stroker, here is a 383 with the 275

 

[Hemi 354]

I have the CCA 21-292-4 H cam. .501 Lift, 292 Duration. 106 centerline, 110 lobe separation - single bolt, Overlap is 72 degrees RPM range 3000-6200
Dual Springs are: Comp cam: 924-16
11.1 CR
906 heads were ported.

 

[moobster]

I have the CCA 21-292-4 H cam. .501 Lift, 292 Duration. 106 centerline, 110 lobe separation - single bolt, Overlap is 72 degrees RPM range 3000-6200
Dual Springs are: Comp cam: 924-16
11.1 CR
906 heads were ported.

Now that's my idea of a street cam!
I'm going to use a .520 lift, 320 duration, 107 centerline, 112 lobe seperation, solid lifter cam in the Max Wedge, for the street. I know it's, kinda big, But 4.10's, a 4 gear, and 28" tall tires, I think I can make it work.

 

[sabre67]

Now that's my idea of a street cam!
I'm going to use a .520 lift, 320 duration, 107 centerline, 112 lobe seperation, solid lifter cam in the Max Wedge, for the street. I know it's, kinda big, But 4.10's, a 4 gear, and 28" tall tires, I think I can make it work.

Im now looking at Comp cam #23-224-4
.488 Intake/.491 Exhaust lift 274 duration 1800-6000 rpm. Will this work with stock heads without modifying springs? thanks

 

[beanhead]

Im now looking at Comp cam #23-224-4
.488 Intake/.491 Exhaust lift 274 duration 1800-6000 rpm. Will this work with stock heads without modifying springs? thanks

That is the 3-bolt version of the cam I run (21-224-4) it has the same specs. You need the 911-16 comp springs or equivalent. If the heads are truly stock you really need to check how much clearance you have for aftermarket performance springs, some machining may be necessary..here's an article to check out on the subject
https://www.google.com/amp/s/www.hotrod.com/articles/mopp-0012-valve-spring-installation/amp/
..and the 'sewing machine' noise they're talking about is just a clickity-clack of the valves, not the 'lope' of the idle. These cams are a little noisier in the valvetrain but no big deal.

 

[sabre67]

That is the 3-bolt version of the cam I run (21-224-4) it has the same specs. You need the 911-16 comp springs or equivalent. If the heads are truly stock you really need to check how much clearance you have for aftermarket performance springs, some machining may be necessary..here's an article to check out on the subject
https://www.google.com/amp/s/www.hotrod.com/articles/mopp-0012-valve-spring-installation/amp/
..and the 'sewing machine' noise they're talking about is just a clickity-clack of the valves, not the 'lope' of the idle. These cams are a little noisier in the valvetrain but no big deal.

Thanks bean Im going to have to check the heads when Im home away working now how do you like he cam? thanks

 

[beanhead]

It works real nice with my (older)setup, a 440 somewhere around 9.5-1, with Edelbrock RPM heads, 850 DP carb and 727 with 2500 stall. 3.73 gears and 28" rear tire, street car but there's some good wide country roads nearby, so...ya know....If I had it to do over again though I would likely use that XE275HL cam for a little more lift, if we're just talking Comp off-the-shelf stuff. The heads will use it..that cam wasn't really around when I was gathering parts though. It's been a decent combination of street manners and power.

 

[wyrmrider]

Take a step back
you are going to have to do spring seats unless you really compromise on the springs
and cut the guides for clearance for the keepers, not just the retainers
decide on which valve stem seals and cut accordingly
That XE274HL should work fine as long as you do not have a late low compression motor you want a REAL 9-9 1/2 to one motor (open chamber iron heads)
It's on 110LCA (all LCA's are a compromise) so overlap is not near as bad as with 107 like a THUMPER
There is NO reason to ever use the XE268 or the 268-276 Magnum Muscle (which is the better of the two) or the old 274H
you are looking at 106 ABDC for intake close at .006 which is what you want to match up with your mechanical Compression ration to get your dynamic compression ratio
here are a couple of similar seat duration lobes from Howard

first if you do have lower compression (like rebuilder pistons in an early motor) and need a 268-270 class cam
(and I am not talking about 400 like below 8:1 low compression which is another discussion)
721141-08 CL721141-08 267 267 220 220 .506 .506 108 104
1600-5400 Good low & mid-range horsepower. Needs 4 barrel & headers.

and a couple on each side duration wise of the XE274HL com
721941-12 CL721941-12 271 281 224 234 .518 .543 112 108
1800-5400 Fair idle, Hot Street & mild Bracket Racing. Strong mid range.

720581-10 CL720581-10 277 283 230 236 .531 .547 110 106
2400-6200 Lopey idle, Strong mid range. Good throttle response. 2400+ stall.

Here are several from Lunati note you can get whatever LCA you need to get your intake closed point
10230702 60302 1400 - 5800 .475"/.494" 220/226 265/271 112/108
10230703 60303 1800 - 6200 .494"/.513" 226/234 271/279 110/106
10230704 60304 2200 - 6400 .513"/.533" 234/242 279/287 110/106
so where do you want your torque curve (then step back one) what gas do you want to run/ have available hopefully you do not have to deal with "winter blend"

note that if you have a REAL 10:1 motor then maybe closer to a 280 class cam depending on your gears, converter weight and how you want it to drive

 

[forphorty]

What kind of rocker arms do you intend on running? I'm of the opinion that if you are using stock stamped rockers, that the fast rate of lift, .904 lifter specific type lobes might be a detriment to reliability. To me, valvetrain reliability/longevity is more important in a street car than gaining perhaps a few more hp with a very aggressive lobe. For a mild street car, I don't feel that you are really losing much performance by running a .842 lifter designed " Chevy cam". After all Chevies seem to run okay

 

[wyrmrider]

actually .842 chevy lobes can be more radical than .904 lobes- they have to be
stock rockers are ok up to almost .550 lift as long as you get the pushrods correct length
since you are going .100 more lift (about) you want your stem about .050 longer so it also goes down about .050 more
that's not a bunch thin lash cap
up angle at valve closed is same as down angle at valve open rocker tangent to valve stem at half lift
now if you have put in 2.14 valves your stem may be short so measure before and after and pick lash cap thickness
also I like AMC/ Magnum lifters and hollow (oil through the pushrods) pushrods
helps on the "push the pushrod through the rocker" syndrome which IMHO usually starts with lack of lube and heat
the cams suggested do not require BIG springs
Chevy's run ok mostly because of much lighter reciprocating parts
build a light Piston/Rod mopar and they rev quick too
will be fine
also setting the valve stems or rocker height for mid lift lessens the need (or amount)to clearance the pushrods- which needs to be checked in any case the mid lift rocker and the lash cap also helps on lifter/ retainer interference
I'd suggest the the OP strongly consider Iron rockers on banana grooved hard chromed shafts (triple chromed = copper/ nickel/ chrome) not those cheap flash chromed crap (CHROME DOES NOT STICK WELL DIRECTLY ON STEEL) nickel does the work the actual chrome can be thin
Ever had a cheap tool or bumper with the chrome pealing off? you do not want this with your rocker shaft (no rollers on chrome shafts)
now with high spring pressure we would have to add heavy wall and with roller rockers directly on the shaft they have to be deep case hardened
(not surface hardened/ electro/ induction hardened crap)
chevy guys pay extra for .904 lifters- never give a sucker an even break)

 

[sabre67]

actually .842 chevy lobes can be more radical than .904 lobes- they have to be
stock rockers are ok up to almost .550 lift as long as you get the pushrods correct length
since you are going .100 more lift (about) you want your stem about .050 longer so it also goes down about .050 more
that's not a bunch thin lash cap
up angle at valve closed is same as down angle at valve open rocker tangent to valve stem at half lift
now if you have put in 2.14 valves your stem may be short so measure before and after and pick lash cap thickness
also I like AMC/ Magnum lifters and hollow (oil through the pushrods) pushrods
helps on the "push the pushrod through the rocker" syndrome which IMHO usually starts with lack of lube and heat
the cams suggested do not require BIG springs
Chevy's run ok mostly because of much lighter reciprocating parts
build a light Piston/Rod mopar and they rev quick too
will be fine
also setting the valve stems or rocker height for mid lift lessens the need (or amount)to clearance the pushrods- which needs to be checked in any case the mid lift rocker and the lash cap also helps on lifter/ retainer interference
I'd suggest the the OP strongly consider Iron rockers on banana grooved hard chromed shafts (triple chromed = copper/ nickel/ chrome) not those cheap flash chromed crap (CHROME DOES NOT STICK WELL DIRECTLY ON STEEL) nickel does the work the actual chrome can be thin
Ever had a cheap tool or bumper with the chrome pealing off? you do not want this with your rocker shaft (no rollers on chrome shafts)
now with high spring pressure we would have to add heavy wall and with roller rockers directly on the shaft they have to be deep case hardened
(not surface hardened/ electro/ induction hardened crap)
chevy guys pay extra for .904 lifters- never give a sucker an even break)

Hello wyrmrider I am going to take a step back,heres my story my brother had this 383 built by a reputable engine shop 8years ago the engine has never run since rebuild unfortunately my brother passed away and I inherited this engine. All I can tell you right now is the engine is a 1966 383 built up to factory 375 hp. I am going to have to take it all apart to verify what they have done inside piston, bore, cam, ect ect.I will then know what Im dealing with and where I wanna go from there. Thank you for all your input ill keep you posted with what I find

 

[wyrmrider]

ok check the valvesprings the ones that have sat open may have taken a "set"
on the cam see if it was liquid or paste moly cam lube I like paste better
best to loosen rockers b 4 you turn it over (much)
where in Canada I get to Vancouver

 

[sabre67]

ok check the valvesprings the ones that have sat open may have taken a "set"
on the cam see if it was liquid or paste moly cam lube I like paste better
best to loosen rockers b 4 you turn it over (much)
where in Canada I get to Vancouver

Im on Vancouver Island Port Alberni Thanks

 

[Bighead440]

This is a great MoPar specific (.904" lifter only) cam for street use. 15 years ago, I used one (XE275HL) in a MoPar 360 shortblock (came with a .508" PurpleShaft, too big for the customer's application) and Edelbrock heads. It ran fabulous and still does to this day. Great bottom end (his '72 Duster has 3.23 gears) and never-ending pull past 6000rpm. You will like it! I used a custom variant of the XE285HL in my 500+hp all iron 440 (same intake lobe, longer exhaust lobe on a 112*LSA). Very satisfied!!