Jump to content

cams?


Recommended Posts

As a general rule of thumb...You MUST increase the ability to get air/fuel in and OUT to get any real benefit of a cam swap. You MUST be able to flow better to get the full benefit of the new cam.

 

 

Think of it this way.....

A 100FT of 1/2" hose with a pump smack in the middle. The pump is rated to flow max at top efficiency with X hp in a 1/2" hose.

 

Put in a new pump at 25% greater HP with the same hose...what do you get...NO real increase as it already was operating at top efficiency.

 

BUT increase the dia of the hose 25% up to 5/8" now you will be getting TOP performance form the new pump, (cam).. get it?

 

CW

Link to comment
Share on other sites

You can fudge on it though. A stock 4-oh header isn't too bad in the flow department. I think a guy can use the HO ones which are a little better, just they lack EGR.

 

IMHO, you'd see more performance in the exhaust side by port matching the head than changing the header.

 

 

The rest of the exhaust might be worth 'improving' though.

 

 

However, I know little about the cam choices for a 4.0.

Link to comment
Share on other sites

there are a few types of cams what duration should i get it i am runnig a stock engine, with a cold air intake

i want something that is still driveable but has a lot of power.

Define "power" as you mean it. Are you looking for low-end torque (pulling power), which would indicate one type of cam ... or are you looking for high RPM horsepower, which would dictate a very different cam. Like most things in life, there ain't no "one size fits all."

Link to comment
Share on other sites

so here are the cams i am looking at getting any advise would be helpfull on the desision

 

 

Product Line: Crane PowerMax Camshafts

Part Type: Camshafts

Cam Style: Mechanical flat tappet

Basic Operating RPM Range: 2,500-6,000

Intake Duration at 050 inch Lift: 228

Exhaust Duration at 050 inch Lift: 238

Duration at 050 inch Lift: 228 int./238 exh.

Advertised Intake Duration: 264

Advertised Exhaust Duration: 274

Advertised Duration: 264 int./274 exh.

Intake Valve Lift with Factory Rocker Arm Ratio: 0.533 in.

Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.555 in.

Valve Lift with Factory Rocker Arm Ratio: 0.533 int./0.555 exh. lift

Lobe Separation (degrees): 112

Intake Valve Lash: 0.028 in.

Exhaust Valve Lash: 0.030 in.

 

 

Product Line: Crane Truck Power Camshafts

Part Type: Camshafts

Cam Style: Hydraulic flat tappet

Basic Operating RPM Range: 1,500-4,500

Intake Duration at 050 inch Lift: 204

Exhaust Duration at 050 inch Lift: 216

Duration at 050 inch Lift: 204 int./216 exh.

Advertised Intake Duration: 260

Advertised Exhaust Duration: 272

Advertised Duration: 260 int./272 exh.

Intake Valve Lift with Factory Rocker Arm Ratio: 0.456 in.

Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.484 in.

Valve Lift with Factory Rocker Arm Ratio: 0.456 int./0.484 exh. lift

Lobe Separation (degrees): 112

Intake Valve Lash: 0.000 in.

Exhaust Valve Lash: 0.000 in.

Computer Controlled Compatible: No

Grind Number: H-260-2

Link to comment
Share on other sites

hmm both of those cams look to have low rise but I'm not to familiar with jeeps. id say the top one. or if you can get one thats good to like maybe idle to 3k you don't loose power its just that the cam is designed to operate better at those RPMs and youll make enough torque to get going pretty good.

Link to comment
Share on other sites

i am not looking for a motor that is NOT going to see any wheeling because its going in my lowered mj jamminz.gif i want to rebuild this new engine that i got for cheap the guy said it ran but hes puting in a 4.3 out of a chevy, i want to rebuild it and make more power for the motor and make it sound beefy :D

Link to comment
Share on other sites

To rebuild for power.. I suggest you start with the Jeep engines book 3rd edition. It is chuck full of ideas on how to squeeze the most power out of them. ON page 176 it has jeep part numbers and lift and duration numbers for the cams, it also has a few tips on buiding the 4.0 to be a reving motor.

Link to comment
Share on other sites

well if you want it to sound beefy and have some balls then i suggest hi-top or dome pistons (.30 overbore), stiff valve springs hydrollics rollers, high performance cam, oversize injectors and a nice header pipe and a high flow cat with a cherrybomb on the end. and youll have a nice looking, sounding and one fast Comanche!

Link to comment
Share on other sites

To rebuild for power.. I suggest you start with the Jeep engines book 3rd edition. It is chuck full of ideas on how to squeeze the most power out of them. ON page 176 it has jeep part numbers and lift and duration numbers for the cams, it also has a few tips on buiding the 4.0 to be a reving motor.

is this the book that you guys are talking about?

http://www.amazon.com/Jeep-Performance-Handbook-Motorbooks-Workshop/dp/076030470X/ref=pd_bxgy_b_text_b/103-5304937-5054241?ie=UTF8&qid=1187974611&sr=8-12

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...