Without opening the wiped cam lobes on flat tappet cams can of worms, I beleive I just wiped another cam. The first one went on breakin, this one has about 7,000 miles on it.

Cam specs were 280, 230/230, .48 lift. I was running 1.6 rockers on the exhaust. This gave me .48 lift on the intake and .51 lift on the exhaust.

I was happy with the way this profile performed, as for as driveability, idle, and vacuum.

Question is, how much hyd. roller cam can I use and still have the same driveability.

Engine is a 383, 9.5 comp. she dynoed 325hp at the rear wheels.

Thanks
Dennis

 

You can keep the same 050 duration and get about the same drivability. A hydraulic roller with 230 duration will have more lift and more duration at 0.200 which is where the power comes from.

 

A little wider LSA will also smooth out the idle and give you a little more dynamic compression (less overlap). That is one of the ways they are pulling 505 HP out of the new Z06 and still be streetable. Look at the Comp Cams XE 282 with 1.5 rockers on both sides. Will give you a little more lift and duration on the exhaust side and good streetability especially if you open up the LSA to 112 or so to smooth it out. www.ryanscarpage.50megs.com/combos1. Check out this site. I am using Combo #17 with a XE 288 and wider LSA for my nitrous.

 

I recently ordered the comp HR286 retrofit hyd. roller package.........It has 230/230 duration but has .560/.560 lift which is a real step up from a flat tappet at the same duration....go roller

 

I am burnt on Comp Cams, the first cam you could say the breakin was bad, however the second cam had a lot of miles on it. I put 8 dyno runs on it and it ran great. This happened very quickly friday as I drove home from work. I'm thinking of going crane.
This cam had a 110 LSA, I'll check out the 112 LSA

I appreciate any advice, as I have very little knowledge of roller hyd. cams. What I do know has come from reading the forum.

 

Comp cams hydraulic roller version has no problem with wiped lobes. The problem is the non roller cams and lift, duration and fast ramp rates that wipe the lobes. I am sure crane makes a comparable setup but Comp might give you a credit toward a new setup if you call them and explain your situation. Haven't heard any issues with the roller cams from Comp.

 

Are there any other effects that widening the LSA from 110 to 112 will have, besides smoothing out the idle

 

Wider LSA flattens the torque curve. This means better off-idle power, slightly more top-end but less midrange. The area under the curve stays about the same. I'm a fan of wide LSA. Running 115 dgr in my 454.

 

OK, Comp has a Magnum 286HR grind it is a 230/230 w/ .56 lift intake and exhaust.
Can I run this much lift and still have the same driveability.
Also can they grind this on 112 LSA

 

I used the XR282HR-10 in my stroker rebuild, been very happy with it.

Comp P/N 12-432-8

Specs:

Duration @ 0.006" 282 / 288 Duration @ 0.050" 230 / 236
Max Lift w/ 1.5RR .510 / .520 Lobe Separation 110
Lobe ID#'s 3315 / 3316 Intake Centerline 106


Nice lope at idle, provides plenty of vacuum for lights and brakes.

Also using the Comp Pro Magnum rockers, 1.52:1, they're worth a look as well.

See this article:

http://www.compcams.com/Community/Ar...ID=-2032559807

 

More lift does not hurt drivability, duration does. Yes, comp will grind it on a 112. Takes them a week or so (special order).

 

This Crane cam is a nice 383 grind.

Camshaft Specification Card BACK TO LIST
Part Number: 119661 Grind Number: HR-230/359-2S-12.90 IG
Engine Identification:
Start Yr. End Yr. Make Cyl Description
1957 1987 CHEVROLET 8 FAIR IDLE, PERFORMANCE USAGE, GOOD MID-RANGE TORQUE AND HP, 3600-4400 CRUISE RPM, 10.0 TO 11.5 COMPRESSION RATIO ADVISED, .900" BASE CIRCLE FOR LONG STROKE CLEARANCE. BASIC RPM 3000-6500
Engine Size Configuration
262-400 C.I. V

Valve Setting: Intake .000 Exhaust .000 HOT

Lift: Intake @Cam 359 @Valve 539 All Lifts are based
on zero lash and theoretical rocker arm ratios.
Exhaust @ Cam 372 @Valve 558
Rocker Arm Ratio 1.50

Cam Timing: TAPPET @.004
Lift: Opens Closes ADV Duration
Intake 35.0 BTDC 77.0 ABDC 292 °
Exhaust 83.0 BBDC 37.0 ATDC 300 °

Spring Requirements: Triple Dual Outer Inner
Part Number 99838
Loads Closed 112 LBS @ 1.650 or 1 21/32
Open 327 LBS @ 1.120
Recommended RPM range with matching components
Minimum RPM 2600
Maximum RPM 6600
Valve Float 7000

Cam Timing: TAPPET @.050
Lift: Opens Closes Max Lift Duration
Intake 8.0 BTDC 42.0 ABDC 107 230 °
Exhaust 56.0 BBDC 2.0 ATDC 117 238 °

 

GKULL

This seems to be a higher rpm cam than I need, plus it is recommended for 10.5 compression, mine is 9.5. I have been looking at this one.


Part Number: 119831 Grind Number: HR-284-2S-12 IG
Engine Identification:
Start Yr. End Yr. Make Cyl Description
1957 1987 CHEVROLET 8 FAIR IDLE, MODERATE PERFORMANCE USAGE, GOOD MID-RANGE HP, MILD BRACKET RACING, AUTO TRANS W/2500+ CONVERTER, 3000-3800 CRUISE RPM, 9.5 TO 10.75 COMPRESSION RATIO ADVISED. BASIC RPM 2500-6000
Engine Size Configuration
262-400 C.I. V

Valve Setting: Intake .000 Exhaust .000 HOT

Lift: Intake @Cam 339 @Valve 509 All Lifts are based
on zero lash and theoretical rocker arm ratios.
Exhaust @ Cam 352 @Valve 528
Rocker Arm Ratio 1.50

Cam Timing: TAPPET @.004
Lift: Opens Closes ADV Duration
Intake 31.0 BTDC 73.0 ABDC 284.0 °
Exhaust 79.0 BBDC 33.0 ATDC 292.0 °

Spring Requirements: Triple Dual Outer Inner
Part Number 99838
Loads Closed 112 LBS @ 1.650 or 1 21/32
Open 313 LBS @ 1.150
Recommended RPM range with matching components
Minimum RPM 2000
Maximum RPM 6200
Valve Float 6500

Cam Timing: TAPPET @.050
Lift: Opens Closes Max Lift Duration
Intake 4.0 BTDC 38.0 ABDC 107 222.0 °
Exhaust 52.0 BBDC (2.0) BTDC 117 230.0 °



Tell me what you think
I have clearanced my rods but will probably want this in a small base circle.

 

use a regular base cam if you have clearanced your rods the lift
you have picked out is very mild, small base cams work but if you
don't need it run a standard base cam. 509,528 lift is very mild for a hydraulic
roller 1.6 rockers would be a plus with that cam.

 

Are you running some kind of dished piston or 76 cc heads to get your 383's compression so low?

My first 383 cam was the same the 230/238 only i bought the SR small base circle. It was a broad TQ good mileage cam. I later went to the 240/248 and finally settled in on 236/244

 

Yes, I am running Sportsman II iron heads and SRP pistons.
Of course I want my cake and eat it too, all the power I can get and good drivability. Also I am running a TKO600 for a tranny. I want as much power as I can get and still be able to drive in traffic, headlights, brakes, etc work and have A/c

 

73383 With a 383 for torque and a TKO trans, I think you will have
plenty of Torque on the bottom to use the cam Gkull suggested.
9.5 compression wont hurt you that much with all the torque
multiplication you have.

 

 

This cam would be right for your 383,and with a 112 lsa it would idle smooth in your 383,if I were you stick with a 110 lsa it'll pull alot harder than the 112 and youll notice it alittle more

 

Well if your worried about your compression when you put the new cam in do what i did on my old crate motor and put .022 head gaskets in to bump it up a lil . It brought mine from 9.6 to 1 almost to 10.5 to 1. Some of those larger cams above will run just fine as longs as the timing is done correctly. Just my 2 cents thought.