Corto

I have a stock 1980 L48, recently rebuilt 350, long tube headers.
The engine will be rebuilt to 383 with, there will be new heads (195cc, 64 or 70cc, 10 - 10.5 SCR), new intake manifold, hydraulic roller cam, 1.6 rockers.
I would like to have a street torquer, no strip, it will never see 6000rpms, want to keep stock converter, but I want max out of it.

I am considering following cams:

adv; @0.050; valve lift; LSA/ICL; RPM

Lunati Voodoo 270/278; 270/278; 219/227; .515/.530; 112/106; 1800-5800

Comp cams XR270HR; 270/276; 218/224; .495/.502; 110/106; 1600-5400

Or eventually these EFI or marine cams:

Comp cams 268XFI HR13; 268/276; 218/224; .535/.531; 113/109; 1800-5800

Comp cams XM270HR; 270/276; 218/224; .495/.503; 112/110; 1500-5500


Or eventually these, but they might be too big:

Comp cams XR276HR; 276/282; 224/230; .502/.510; 110/106; 1900-5600

Comp cams XM276HR; 276/282; 224/230; .503/.510; 112/110;
1800-5800

Please advice what which one would be the best for my config?
Thanks

PainfullySlow

Interested to see the responses as I have very little experience here and am going strictly by what I have read. To me (again, take with a grain of salt) looks like both would be very well behaved cams for street use. I wanted a little more bump out of mine and am going with the XR282HR with a similar setup.

claysmoker

What rear end gear? What tranny?

I had good results with the XR 282 HR cam in a 383.

keithl1967

I am running an XR282 in a 406, Dart Heads (200cc intake); 10.03:1 compression...
373 rear and muncie M20...
I am extremely pleased with the cam. makes great power, decent vacuum, great strret manners...
In a 383, that same cam will be a tad more "aggressive," but I suspect you would be pretty happy with it--great all around cam...

I'd bet the XR276HR would be very similar in a 383 to the 282 in a 406...

be careful with the 1.6 rockers, though...the cam already has a bit of an aggressive lift for the street @ the recommended 1.5...

63mako

XR 276 HR 112 lsa will feel and act like the 270 in a 383. watch out with 10.5 compression. you need the duration to avoid detonation even with aluminum heads.

Corto

Thanks to all of you.

I was looking what the cam vendors are saying:

Lunati Voodoo 270/278: "...Will work with stock converter in 383 and up size engines or 2200 RPM stall speed converter in 305-350 cubic inch engines. ..."

Comp cams XR270HR: " ..largest with stock converter, noticeable idle..."

Comp cams XR276HR: " ..2000+ stall, gears • Choppy idle..."

I am looking for the max cam that will still work with my stock converter (TH350 recently rebuilt), and the rears 3.08.
I am doing this rebuild first time, but here there are many experienced guys, and I would very appreciate if you can advice the proper cam, should I go for 270 or 276 would be just right?
When 270, than I might prefer Voodoo 270/276 than XR270, since Voodoo has more lift and a bit more duration @.050.
I am also not quite sure how the marine XM270 would fit in my config?



Right, on one side I am limited with the stock converter, so the cam should not have too much duration. On the other side the cam should have enough duration to avoid detonations. Most probably I will go for 70 or 72cc heads to have it under control.

CheezMoe

Just as another option, I used this Howards kit in my 383 combo'd with RHS proaction aluminum heads 200/72 and static came out at 10.25:1. The torque curve is really unbelievable and idle manners are excellent.

https://howardscams.com/i-24078751-h...ifter-kit.html

GOSFAST

Here's some input on a recent 383" build (this was an OEM "ZZ383", 3.800" stroke going in) we finished 2 weeks ago, dynoed, and installed in the ride this past weekend.

Came off at just over 492 HP @ 5700 and 480# Torque @ 4600. This was with some 2.000" int/1.550" exh valves and a 10.5:1 C.R. This was tested with a 1.000" carb spacer under the 780 Holley.

Used a Comp 08-467-8 (230*/236*-.540"/.534"-109*/113* LS) a dedicated fuel-injected grind but dynoed with a carb. Unit runs with about 14" vacuum with an 800 RPM idle. Used 1.5 rocker instead of the recommended 1.6's. Would have had .576"/.570" net lifts with these, made no less measurable HP with the 1.5 rockers (we tested this on our own).

Thanks, Gary in N.Y.

P.S. We also no longer use any cam buttons on our early retro-hyd roller builds, it's all done with a thrust-plate and bolted together with 2 small screws on the final ***'y! Here's a shot of a finished piece.

Corto

Thanks dosoctaves,
what was the converter? It seems to me that this cam might be too big for the stock converter?

cv67

Yep way too big
If you ran even a 24-2500 stall it will steel feel nice and tight, even some S-10s used them. Id go it with even the 218 type cams youll love it
There are cams that say "works wtih" but can drag it down when at a light or not respond the way you hope when you nail it epsecially with a tall gear like a 3.08

CheezMoe

Yeah my bad there I have a manual trans. But you might want to check the Howards site there are many profiles to choose from.

Alex66

I use this cam in my 383 (hydraulic flat tapped)


Lunati - 301A8LUN


1000 - 58000


276in / 286exh - 221 / 230 @ .050


112 Lope Sep.


.454in / .454exh with 1.5 Rockers




it is actually an older Ultradyne Grind that Lunati changed from 110 to 112 LSA




Has a lots of torque and pulls nice up to 6000rpm. I run a ED Performer RPM Q-Jet

Corto

You mean intake 218@.050?
These are exactly the Voodoo 270/278 and XR270.

Corto

Thanks Gary, this cam would be too much for my stock converter.
Regading thrust-plate, yes this is a good idea, I will go for it.
Tahnks

keithl1967

I guess another question would be whether or not you are upgrading the cam, with the engine still in the car, or are you pulling the motor?

If you are pulling the motor, you could always look to upgrade your converter (if that is your biggest limiting factor)...

depending on what you are doing, you don't need to spend crazy monbey on a converter--you can get a nice B&M Tork master, ne or two steps up form stop for under $250.00...

https://www.summitracing.com/parts/bmm-20404/overview/

Or, even a "house brand" converter for around $100--still a step up from stock:
https://www.summitracing.com/parts/sum-g2699/overview/

Just a thought--then you can run the cam you want, and keep things in the power band...


You could also give comp cams (or I'm sure Lunati as well) tech line a call and let them know what you are looking to do, and they can talk you through your needs, and make a good recommendation...

63mako

Point I am trying to make is the 276 in a 383 will have the manners and operating range of a 270 in a 350. You can not go by the cam description in the ad because they are describing the cam characteristics in a 350. A 383 has 9% bigger cylinder capacity to fill. A 276 cam is 2% higher in duration than a 270 at .004 off the base circle to .004 off the base circle. Go with 112 lsa. It will widen the torque curve, tame idle some and has a little later intake opening giving you a cushion on DCR. What is your rear gear ratio?

Corto

The motor will be pulled out.
What started initially as small engine refresh, is becoming a major engine rebuild... And to get all this parts here to Europe I have to add at least 50% on USA prices... :-(( , so I have to draw the line somewhere....

Yes, I am going to call them, but according to D.Vizard and also some experience from other people, the info from the cam vendors can be quite different.... I wanted to get some real life experience from the people who have or are building similar configs.


So you think the XR276 will be fine with my stock converter?
Stock rear gears ratio 3.07 .

63mako

XM 276 HR with an automatic. Wider powerband. That 1800 Will drop to 1500 in a 383. That and the increase torque from the 383 will work fine with your converter. http://www.compcams.com/Company/CC/c...?csid=170&sb=2

Corto

Thank you mako, I have now realized that you are talking about marine cam.
Its bigger LSA and later ICL might allow bigger SCR, but this discussion is for the new thread.

Thank you

ronarndt

I have a Lunati Voodoo part # 10110703LK cam in my 454. The grind is similar to what you are looking at for your 383, although the lift is a little more. Although Lunati claims the power band begins at 1800 rpm, it has excellent torque at lower speeds also. Obviously it really kicks in once the rpms increase.