Dakota Durango Forum banner

1 - 20 of 23 Posts

·
Registered
Joined
·
409 Posts
Discussion Starter #1
Okay.. This is my first rebuild but I have my grandfather guiding me through it.. I am buying a new comp cam with .480 lift.. I'm looking for some 1.7 roller rockers but not sure of a good set. I'm not looking to spend tons of money.. Where can I find some that fit my motor? And do I need to get more springs? It's gonna be a stock rebuild except for cam/ rockers and ported tb..
 

·
Registered
Joined
·
696 Posts
just try the 1.7 rockers first is that
4.80 with 1.7's
480 lift is not much (so why are you changing cams???)but
- do you have to notch pistons or cut valve guides for stem seal/ retainer clearnce
you wil lneed a spring change and Dodge has short springs
If computer controled and in a smog state BVVC about duration and overlap
Witha 4x4 stock converter and gears keep it short
RT type duration is plenty - just a fatter lobe
If you are rock crawling stock duration is plenty
do you tow?
 

·
Registered
Joined
·
409 Posts
Discussion Starter #6
.480 lift has to be better than the .410 lift that is stock. I have 4.56 gears.. I'm not looking for a race motor, my current motor is wore out. I just didn't want more torque from the 360 being that my stock 318 has more torque than a stock 360.. I do not tow very often I'm putting new springs on.. No smog here in Florida!
 

·
Registered
Joined
·
696 Posts
Just depends on your budget
you can go bigger with the 4.56's
some 318's had a bigger cam than 360's but IMHO 360's pull harder
260 @ .006 to compare with comp 262HR-12 264-HR-12
Intakes
199 @50 480 w 1.6 comp 254
206 @50 4801.6 comp 262
[email protected] 512 1.6 comp 264
208 @50 [email protected] 556 with 1.7 (522 1.6)
210 @50 [email protected] 532 with 1.7 (500 1.6)
would be bigger than I'd go
254HR 12 w 1.7 should work
BTW you only need the 1.7 on the intakes
BTW the 340 Magnum cam is 209 and looses a lot of torque

Comp also makes a Tri power extreme TPX254HR-16 and 4x4 X4258 for Chevy in thsse duration ranges different LCA's

you get in the 210 range and you are just asking for a looser converter even with the gears
 

·
Registered
Joined
·
409 Posts
Discussion Starter #8
I'm on a tight budget.. All said and done Ill have like $1200 invested in it.. I don't have much more money to spend.. All my money is going to the Fire Academy..
 

·
Registered
Joined
·
422 Posts
Since your replacing the cam anyway, why didn't you just buy a cam with the lift you want and reuse the stock rocker ratio? That wood save you several hundred dollars. You really don't need rollers for a mild build.
 

·
Registered
Joined
·
696 Posts
On a tight budget
Congrats on the fire Academy
One of my young friends is currently working Ambulance but looks like he's on at a major LA area city. Has long time girlfriend waiting and planning
just use the hotter of the stock 318 cams with 1.7 on the intakes unless you can find a rt cam on e-bay (but too much duration for rock crawling)
if you are you pocket porting your heads I might say something different but stock heads do not respond to lots of lift just quicker action.
more duration just moves your torque curve up (and gives more HP at the top end- but less down low)
lotsa bucks for cam, springs, rockers- not worth it with stock heads if you are on a budget
you can do your own heads - 80-20 rule
you can get 80- percent of the benefits
then think about a cam
just my 2cents
 

·
Registered
Joined
·
409 Posts
Discussion Starter #12
I'm just gonna do cam, springs, ported intake and headers.. And have it tuned.. Will be good enough for what I do..
 

·
Registered
Joined
·
422 Posts
Good choice, clean up the intake/exhaust ports a little would help a lot.
 

·
Registered
Joined
·
160 Posts
I take it this is for your 2002? If so, measure you actual cam lift on the stock cam - the later 5.9 stock cams were almost if not identical to the 5.2 cam, esp. on the lift. I know for certain my 2001 5.9 cam is.

If yours is the same, just using 1.7's will give you the lift you want.

IMO there is more power in changing the pistons than changing the cam. Well torque at least. Same goes with the tune, there is power to be gained on the low end using a SCT.

Check your stock heads closely if you haven't yet - check for cracks and sunken exhaust seats.
 

·
Registered
Joined
·
696 Posts
Did you check out those other comp cams (in the early sbc section not LT?
Dodge has a longer rod than SBC therefore has longer dwell at TDC
Therefore later intake opening and earlier exhaust close is required to have the same events at the same piston motion - less overlap.
If you look at comps details and look at the timing diagrams at .006 you will see overlaps (add the Intake overlap and exhaust close) of 33 to 39 degrees-
the Thumper cam is around 80! (107LCA)
You will see one of the cams has a longer exhaust but also wider LCA and still has a smaller overlap than one of the others
and lift varies all over the place
compare 252XFIHR13 and XR252HR for example

Also X2
If yours is the same, just using 1.7's will give you the lift you want.
at a lot less money
 
1 - 20 of 23 Posts
Top