Competition cam for 05 4.0

[SkylinesSuck]

Are you trying to make more power to push bigger tires down the highway? Are you trying to be able to drag race faster? Do you just want it to sound meaner? Are you hunting for better mpg? Do you just want to throw money at it and tinker? These are some examples of what I was asking.

If you are looking for general anecdotal comments on what an Edelbrock head, cam, and header will do for you, the answer is not a lot. You'll feel the difference above 3k rpm and it'll sound a bit meaner, but it's not going to revolutionize how your jeep drives/feels/accelerates. And that's a lot of money to spend for not much practical gain.

 

[Jezza]

Thanks for the feed back. Question on thinner head gasket, that would be a different one than Edebrockl recommends for the head? I have been thinking about doing all the things you said, just hadn't thought on the head gasket. I looked at your turbo, but running 93 octane put me off and it's not sold around here.

The stock 4.0 has the piston 0.021" down in the cylinder at top dead center. Combine that with the stock head gasket that is 0.051" thick or so puts the quench at 0.072" which is undesirable. The Cometic 0.027" gasket puts the quench at 0.048" which is more ideal yet still undesirable. It also bumps the compression ratio from 8.8:1 to 9.3:1. Also if you run the Edelbrock head it has a 55cc combustion chamber that will bump the compression even more. Almost near what a modern engine had 10 years ago.

 

[Frankm]

Now that this has ventured in quench and compression ratios do a little reading and calculations on DCR (dynamic compression ratio). This takes cam timing, rod length, etc into consideration and will help you maximize your cam choice along with what quench and compression heights to shoot for while giving consideration to fuel octane requirements.

Good Luck. (BTW, there are various DCR calculators on line. )

 

[Jezza]

Now that this has ventured in quench and compression ratios do a little reading and calculations on DCR (dynamic compression ratio). This takes cam timing, rod length, etc into consideration and will help you maximize your cam choice along with what quench and compression heights to shoot for while giving consideration to fuel octane requirements.

Good Luck. (BTW, there are various DCR calculators on line. )

Finding the dynamic compression ratio is not hard. Getting folks to agree on what ratio is appropriate for a given octane is less easy. The calculator I use on the Jeep strokers site gives a dynamic of 8.17 with the 0.027" gasket, Edelbrock head and Comp cam that is recommended for the Edelbrock. Imo 8.17 dynamic is reasonable for 87 with an aluminum head and a good tune.

 

[05 White X]

Finding the dynamic compression ratio is not hard. Getting folks to agree on what ratio is appropriate for a given octane is less easy. The calculator I use on the Jeep strokers site gives a dynamic of 8.17 with the 0.027" gasket, Edelbrock head and Comp cam that is recommended for the Edelbrock. Imo 8.17 dynamic is reasonable for 87 with an aluminum head and a good tune.

Good info, thank you. Now how to go about getting a good tune. Any recommendations?

 

[SkylinesSuck]

Where are you planning on buying that head from? I still feel you would get more useful input if you would answer what I'm asking but you seem like you are already set on your course of action.

I'll also just throw out there, if you are going to the trouble of swapping the head and cam then having it tuned, it might be worth considering swapping those parts on to a stroker short block you could build on the side and swap the whole kit and caboodle in at once. Bonus points for having a known good running non-high-mileage not clapped out 4.0 assembled and on backup sitting to the side just in case.......things.

 

[Rickyd]

Finding the dynamic compression ratio is not hard. Getting folks to agree on what ratio is appropriate for a given octane is less easy. The calculator I use on the Jeep strokers site gives a dynamic of 8.17 with the 0.027" gasket, Edelbrock head and Comp cam that is recommended for the Edelbrock. Imo 8.17 dynamic is reasonable for 87 with an aluminum head and a good tune.

In your opinion what is the maximum dynamic comp ratio for 87? I have 8.67 dynamic in my build and have always felt it was optimistic to be told it was 87 friendly.eddy head

 

[Jezza]

Where are you planning on buying that head from?

Summit Racing has them in stock from the last run earlier this year. Edelbrock does not have any more currently.

 

[Jezza]

In your opinion what is the maximum dynamic comp ratio for 87? I have 8.67 dynamic in my build and have always felt it was optimistic to be told it was 87 friendly.eddy head

So many variables that apply makes it almost opinion. Aluminum head helps as does plug heat range. Personally I like low 8s for 87 pump gas, however with a good tune mid 8's should be safe. I have been told however that the old 5.3 ls has low 9s dynamic, and you see clapped out Tahoes running all over the place on bottom dollar peasant fuel.

 

[SkylinesSuck]

Summit Racing has them in stock from the last run earlier this year. Edelbrock does not have any more currently.

I had no idea they did another run. Very happy to hear that. Are they the same as far as you know?

 

[05 White X]

Where are you planning on buying that head from? I still feel you would get more useful input if you would answer what I'm asking but you seem like you are already set on your course of action.

I'll also just throw out there, if you are going to the trouble of swapping the head and cam then having it tuned, it might be worth considering swapping those parts on to a stroker short block you could build on the side and swap the whole kit and caboodle in at once. Bonus points for having a known good running non-high-mileage not clapped out 4.0 assembled and on backup sitting to the side just in case.......things.

Not sure yet depends on price and availibility. More smiles per mile is what I am after. Not my daily and even in winter I would have 3 rigs to drive plus another truck if I take the snowplow off.

 

[Rickyd]

Not sure yet depends on price and availibility. More smiles per mile is what I am after. Not my daily and even in winter I would have 3 rigs to drive plus another truck if I take the snowplow off.

If you want to put money into a 4.0l by doing a cam,etc and get it tuned consider the stroker route. It really makes it a different animal.

Its the aftermarket valvetrain reliability that gives strokers a bad rep. May as well go for the extra 40 cubes for a couple thou more

 

[05 White X]

So many variables that apply makes it almost opinion. Aluminum head helps as does plug heat range. Personally I like low 8s for 87 pump gas, however with a good tune mid 8's should be safe. I have been told however that the old 5.3 ls has low 9s dynamic, and you see clapped out Tahoes running all over the place on bottom dollar peasant fuel.

Peasant fuel LOL its all us rednecks can afford. I've had two 5.3 engines in the last twenty years and the older as in 01 are better as the 11 & 12's had oil pump problems and oil transmitter issue.

 

[05 White X]

If you want to put money into a 4.0l by doing a cam,etc and get it tuned consider the stroker route. It really makes it a different animal.

Its the aftermarket valvetrain reliability that gives strokers a bad rep. May as well go for the extra 40 cubes for a couple thou more

I had thought of that but, not gonna get it bored and all the rest on a good motor. I have had two 4.0 strokers and results have been hmm. Would almost do a LS swap but its almost a sin to do that to a 38K mile Jeep

 

[JPHikr]

Here is just about just about every cam cam made for a Jeep inline 6 .

Cleaning up the ports and smoothing the flow and port matching the head to the manifolds will help a lot.

Cam shafts are the soul of the engine.

Many variables in the set up will need to be factored in.

Fuel deliver ( fuel injector output) is just one as is setting the cam to TDC or advancing or retarding it.

https://www.moparpartscorp.com/oem-parts/mopar-valve-kit-p3690936
https://www.angelfire.com/my/fan/Jeep4.0Camshafts.htm
I can not post a link to

JEEP ENGINES PERFORMANCE MANUAL BLUEPRINTING RACING SECRETS DOWNLOAD​

But here is a bit of what it says.
Send me a message and I can send you the whole manual via email.

176 MOPAR PERFORMANCE PARTS Camshaft and Valve Gear CAMSHAFT
The engine camshaft is made of cast iron with twelve machined lobes and four bearing journals.
The camshaft has intake and exhaust valve lifts of 10.29 mm intake and exhaust cam lobe lifts of 6.43 mm and intake and exhaust durations of
For racers, choosing the correct camshaft to match the compression and carburetion of the engine is the most critical performance area to consider. The "3 C's" of engine building (compression, carburetion, and camshaft) must always be decided upon before the engine is built or, more importantly, money is spent.
In fact, one of the most common errors among racers is to choose a "hot" camshaft without considering the compression ratio and carburetion set-up to be used, all of which must work in complete harmony for the engine to perform at its peak level at all times.
The racer's camshaft choice will also dictate the rest of the valve gear.
The important areas in camshaft and valve gear are profile selected by application, installation centerline, clearances (especially valve-to-piston and clearance at coil bind), and valve spring loads.

 

[williambmac]

Peasant fuel LOL its all us rednecks can afford. I've had two 5.3 engines in the last twenty years and the older as in 01 are better as the 11 & 12's had oil pump problems and oil transmitter issue.

Please explain. Being a GM tech I've never heard or experienced an oil pump problem with 5.3 engines.

 

[Rickyd]

I had thought of that but, not gonna get it bored and all the rest on a good motor. I have had two 4.0 strokers and results have been hmm. Would almost do a LS swap but its almost a sin to do that to a 38K mile Jeep

If a stroker let you down then don't hold your breath over a mild cam and an aluminum head.

Honestly i would just go for a hemi or ls swap since you aren't in commiefornia. I wanted to but i can hide my stroker under the valve cover and still pass smog. I used good parts and it runs strong(eddy head,comp cam,forged pistons from russ pottenger). Its what tj's should have had power wise.

You'll be desecrating that low mile jeep no matter what you put in it. Being an 05 that hemi is calling your name....

 

[Jezza]

I had no idea they did another run. Very happy to hear that. Are they the same as far as you know?

The same as far as I am aware. Just a few hundred dollars more than before.

 

[MikeE024]

almost a sin to do that to a 38K mile Jeep

Have you considered running Jezza’s turbo to gain 100+hp with your low mileage 4.0L?

91 is all you need at higher elevation, and Ryan from Flyin Ryan Performance (FRP) could handle the tuning like he has for others in here.

Then smile away.

 

[Brianj5600]

https://www.motortrend.com/plus/detail/cams-how-small-is-too-small/5150927/

Engine Masters did a test of 3 different small cams. I don't know that the SBC and a 4.0 would react the same, but the dyno showed too small of cam 200 [email protected]" did not outperform the medium 212 [email protected] cam. The smaller cam had only a few pounds of torque more than the medium, but the small cam fell off at around 3400 rpm.

I have a Comp 163-201-5, I might have gone up to the next larger cam had I saw the video before my combo was set.

Advertised Intake Duration:250
Advertised Exhaust Duration:258
Intake Duration at .050 Inch Lift:205
Exhaust Duration at .050 Inch Lift:213
Intake Valve Lift:0.450
Exhaust Valve Lift:0.450
Lobe Separation:113