Specs / replacement for stock 6.2 mpi cam?
 

Hi all - trying to get anyone who can recommend a cam for a stock 383 rebuild? Heads are 906 stockers - so in the .45to .46 lift at 1.5- I did measure a lobe of 3 and about 3.1 (4.5/4.65) - bot thats all I could get. Any shelf cams that would work with stock programming/heads?

I did find a Crane 104224 reference here: (cant post link)

Lift: Intake @Cam 301 @Valve 452 All Lifts are based
on zero lash and theoretical rocker arm ratios.
Exhaust @ Cam 310 @Valve 465
Rocker Arm Ratio 1.50

Cam Timing: -- @---
Lift: Opens Closes ADV Duration
Intake --- --- 270 °
Exhaust --- --- 276 °

Cam Timing: TAPPET @.050
Lift: Opens Closes Max Lift Duration
Intake 0.0 BTDC 34.0 ABDC 107 214 °
Exhaust 47.0 BBDC (7.0) BTDC 117 220 °

This information is from bobl/FTM.
Thanks goes to him.

Not happy to drop near 600 on a roller cam. Other places ive looked seem to indicate around 218-224 dur..

thanks

Eyeing these 2 cams at the moment - both wide LSA .. little short on the dur and not too aggressive.. will keep digging

Summit Racing Part Number:
Chevrolet Performance 14097395 (stock L31/HT383 cam?)
NAL-14097395
Basic Operating RPM Range:
Stock
Duration at 050 inch Lift:
196 int./206 exh.
Advertised Duration:
288 int./308 exh.
Valve Lift with Factory Rocker Arm Ratio:
0.431 int./0.451 exh.



SUM-8800:
Summit Racing Part Number: SUM-8800
Cam Style:
Hydraulic roller tappet
Basic Operating RPM Range:
1,500-6,000
Intake Duration at 050 inch Lift: 204
Exhaust Duration at 050 inch Lift: 214
Duration at 050 inch Lift: 204 int./227 exh.
Advertised Duration: 257 int./267 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.450 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.450 in.
Lobe Separation (degrees): 112

I don't think you you have that Crane cam Bobl stated if you have the normal 320hp 6.2L. Maybe I'm confused. Been very recent threads on this engine and the Scorpian and Merc reman 383....so a little confusing.

Also, that GM vortec truck cam you listed with 196* intake duration at .050" has a 109LSA. It's therefor, not 'wide.'

sorry yes missed the 109 lsa- found varying threads but many are for HO and custom builds - I want sth that will work with stock heads and stock ECU-

What is wrong with the present camshaft ? Is this a late model step nose type cam ?

step nose yes - for a roller 350 L31/880 block. lobes pitted from standing- motor got seized. Put the cam on the lathe and tried to grind it but small pits everywhere - i cant post a pic or a link yet - sheesh admins seriously annoying lol.

1 more post, you can post pics

Any numbers on your cam at all ? Melling has a couple that are very close but I didnt check availability. Is the rest of the engine together ?

I am pretty sure that only paying members can post pics :(

number on cam is the merc number - over $600! I am looking at this cam now on ebay # : id prefer a shorter dur but from what ive read this was very close to the oem cam? Im all over the place, but it seems merc used the same part number in the later 90s and up 350s and 383s..

Cam I can score for $200-
Crane 2303 / 104224:
LIFT 0.452 / 0.465 IN - DURATION 270 / 276 - 112 LSA - 1800 / 5800 RPM

Matches the lift almost exactly to what I measured on mine-

OP - did you look up there OE cam part # using your engine serial # ? If not, do so, and maybe we can look up specs from there.

The Melling is a liitle less at .050 ( 201/208) but the same "advertised" (270/276) If the engine is together can you stick a degree wheel on it and see exactly what you have for sure ?

No specs - its all hidden -

HOWEVER i just found this from dennis moore on his store page: (hes up the road from me fwiw- and VERY knowledgeable )

Puts the crane cam I referenced just about on these specs-

"This is a VERY powerful camshaft!

fits

Chevy/Mercruiser V8 1987-PRESENT

305 350 5.0L 5.7L



Hydraulic Roller Camshaft

Replaces Mercruiser Part Number

431-811658



The original hydraulic roller lifters,

push rods, rocker arms and

valve springs can be reused.



This new hi performance camshaft has

220 degrees intake duration @ .050

224 degrees exhaust duration @ .050

.474 inches of intake lift

.474 inches of exhaust lift

111 degrees of Lobe Separation Angle

This replaces the stock marine camshaft:

197/207 intake/exhaust duration

.430/.450 intake/exhaust lift

109 degrees of Lobe Separation Angle

This Hi Performance replacement camshaft is a direct replacement for the stock camshaft and requires no additional modifications to the engine.

The stock carburetor jetting and ignition timing are maintained.
"

How would the reduced duration compare to the higher duration? Create more dcr / trap more cyl pressure perhaps? I would think the prime torque range on a 383 would be a little less critical due to the stroke already making these torquey-

After 10 post anyone can upload pictures.

If that is true then I need to find out why I cant :(

OP excuse the slight hijack.
1) Hit the "double mountain" box next to the smiley. 2) The upload screen appears. 3) Browse your device for an image or insert a URL where the file is hosted. In this sample it's from my device. 4) Hit the upload tab.
Screen grabs of the process in order below.


https://cimg8.ibsrv.net/gimg/www.off...15b83506e0.png
https://cimg9.ibsrv.net/gimg/www.off...1442099fa0.png
https://cimg0.ibsrv.net/gimg/www.off...c470271f4a.png

Dummy me :) I have been looking at the bottom where it says "you may not post attachments" Thank you !!!!!!!

Happy to help! Dummy my ass. :blahblah: You always have good sound advice and are knowledgeable any time you chime in.