408 cam help

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jbomb408

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Want to see what you guys would suggest for a cam for my 408. It is in my 4x4 96 ram ext cab short box.

stock stall converter with shift kit
Magum block roller lifters
Indy stroker kit kb like pistons
9.2-1 compression
Engine quest heads (254 cfm intake 176cfm exhaust) mild bowl port
piston deck volume 26cc
head volume 63cc
head gasket volume 12cc
Hughes airgap intake
32lbs. Injectors
53mm tb
stock air box
stock coil
Pacesetter long tube headers
stock ratio rockers
Max lift is 530 with the springs/valves I have.
Truck has 3.55 gears and is used for daily driving
When I had the wrong rings that were givin in the stroker kit the truck had tons of low end to break the tires loose. Now with the correct rings and higher pressure the low end is poor.


Lobe lift .3200 .3200
Lobe seperation 110.0

sorry stupid scanner



With the cam I had in it the truck would detonate on the highway in od under load. And clyinder pressure was up to 170. I think my pressure is too high and I dont have near enough duration for a stroker.
 

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That's a pretty big cam for a computer to have to compensate for. Are you sure it's supposed to be computer compatible?
 
Yeah got an sct tuner and tuned it to the 14.8 a/f at idle and when I hit it it climbes down to 12.8 then my tunner guy adjusted the timing accordingly. The computer to my knowledge cannot pull timing because it cant sence detonation there is no knock sensor on these motors:pale:

what cam specs would you recomend?

already changed cam once and that still sucked.

More duration?
 
I think the injectors are about right, and your AF is good. With 26ccs I'm assuming those are a full dished piston? I'm getting a static somewhere around 9.8:1 which should be fine. However the dynamic is too high with that cam. 170psi "should" be ok if you have effective quench but if you have full dished and/or a thick head gasket you don't. So my fix would be a larger cam. However trying to run with the factory electronics is something I'm not real familiar with. So how big will work I would not want to guess. You need about .050 more lift and another 15-20° duration @ .050 to get the dynamic ratio down a bit. Sorry I couldnt be more help.
 
cant go more than 530 lift that is were I am maxed so I need to stay under that. Could I fix it any other way.

The electroinc are fine. I take a/f readings and get my fuel adjusted and then my timing gets adjusted after that.
 

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Then I put this cam in designed by a very well known shop but in there busyness I beleive they overlooked/screwed me by accident. Performance (low end) still sucks. I just think I need more duration. its hard to find a 360 cam with as little duration as these do for my 408
 

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If you have detonation in OD you have a timing problem. I'm just not surehow to fix it. I can give you plenty of cams, but I don't think any would work with a tweaked factory PCM. How do you adjust/set the timing?
 
I need cam specs.

I beleive i need more duration for a stroker correct?


My tuner in Florida pulls up my file and changes my timing all across rpm/throttle possiton range. (it ties into manifold pressure also somehow)

So i am positive the stock pcm can hadle it becase I have freedom to change timing and fuel, and re-program the pcm
 

Same cam cut on a 111cl
right now you have 41.5* of overlap which bleeds off cylinder pressure, but it's not bleeding off quite enough, so going to a narrower cl will give 47* which should just do the trick.
That or thicker head gaskets.

this all only if it''s not the computer tune issue.
 
No had several people including hughes look at the tune. Do i need more duration for a stroker
 
You need more lift and duration. You are limited on lift so duration will be it. But, the less lift you have, the less duration you can have, due to the rate of lift. Becasuse going too fast on the ramp means more spring, which you cannot get. Basically, the heads are killing you.
Everything I know (which is limited, I admit) about PCMs from Mopar is they are not reprogrammable. Mopar does not share the code to be able to break into the PCM programming. This was the case when I was running a dyno tune place. Dodges used to be a huge PITA because there was almost nothing you could change.
 
I can re flash it for fuel and spark. Also twist my distributor to control when the injectors fire.

I dont want a radicle race motor. its in my truck just a good work motor with a little play.

and what cam cut at 111 cl I posted 2
 
I would call Comp Cams and ask for advice or even download camquest 6 and see what it recommends for you.. Go to compcams.com and click on download camquest6 plug everything in and see what it comes up with. It may not be right on the money but it should get you in the general range.
 
114 was what crane recommended to me when I was i do'n a 408 in a r/t dak, cause of the fi/comp . I really think you should ask comp about tweeking the cam specs you have now to give more o lap/running duration of about 6* each.
Or thicker head gaskets.
 
If I go and replace the head gasket I would put different valves/springs on and a larger cam. Problem solved. I dont want to go that rout if I dont have to.

Tried cam quest 6 and it doesnt work for me when I enter stroke. It recomends these small cams for a dakota if I remember right. I just need to call comp and have a long lunch break.
 
Well I called up comp cams and they said that cly pressure should be no problem at 170. Think that is a timing issue. They also said that I would want less duration for low end torque. They recomended going back to my first cam 210/220 duration. I am also going to go back to the airgap intake.

Question any thoughts on how a carb/tb spacer would help low end on a fuel inj. engine? they do sell them but that does not mean anything.

What would you guys recomend for inital toatal and when the timing comes in at for my motor?

I believe the timing its way off. And I get a little nervous when hauling a very light load in overdrive it doesnt detonate loud but it doesnt sound normal.
 
first....if the motor is fi with injectors down by the heads and just a butterfly throttle body on top, a spacer is gonna do absolutely nothing but cost you money.

I know a guy with a dak that had bought one of those rippled looking spacers under the throttle body meanwhile injectors are in the manifold by th port windows....
I told him to take it off, he did and the truck went faster cause what the fk air/fuel are you rippling/mixing when the damn fuel is being mixed by the fk'n injector another 12'' down the line???

all you're doing is causes initial turbulence as the air enters the manifold=slowing it down and causing the air to whip and crash around...
 
just thought I would ask because the stock intake does so well down low because of the long 14" runner lenght. Didnt know if a carb spacer would help or be the same concept for adding runner lenght to the airgap?
the air gap does much better form 2500 and up over the stock intake but under that the airgap makes less torque.
 
I don't see it helping at all when you're at 14'' runners and a plenum the size of a shoe box all ready [if thats the case].
It's plenty and only the runner length is gonna hold back the r's. 'mainly speaking in the intake department.'

All of what I'm saying pertains to the barrel factory intake.

Now with an rpm intake and fi, you could improve the upper & mid range hp some depending on the cam and rpm range.
I don't see you gaining squat using a spacer with a lil cam, or a cam with lil overlap and high rpm in mind.

jmo
 
going back to the cam on my first post. (210/220)

And going back to the rpm airgap.

didnt know if a 1" spacer would be like adding 1" to the runner length and help a little with the low end
 
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