What about roller lifters and 1.6 ratio roller rockers for 318 build?

[cudaracer]

218 and 224 duration at 0.05" is what is listed from the 268 and 276.

List is low, but I plan on adding roller rockers with 1.6 ratio, which boosts to 0.5088 and 0.512".


Thoughts?

[HP2]

I just read your first post again and realized that everyone thinks you have too much cam...

The best number to list when talking about cams is duration at .050".  You listed:
I'm guessing you listed the advertised duration, which probably puts your .050" duration right around 210.  I think you will be happy with that duration, but there isn't a whole lot of lift on the cam.  I would think you would be able to get over .500 lift with a Lunati or Hughes off-the-shelf or a custom cam (not much more expensive).

If you need a compression calculator, send me a PM and I can email you an excel spreadsheet I made up to calculate it.

The cam's duration isn't awful, until you put it in a stock pistoned 318 with 360 heads. That combo with the small, stock cam would be a dog because of the compression, but then you bump the duration up and you'll loose even more cylinder pressure.

Extra lift, no big deal, more duration, big problem.

[barracuda7199]

Those 308 heads are good head they just have big combustion chambers which killed your compression. The best 318 head to me is the 302 head with 1.88 1.60 valves ported with the combustion chambers opened up just a touch to unshroud the valves just a touch. I have a set done this way with a .528 mopar solid cam. It is a very strong running engine

[PlumCraZRT]

The cam's duration isn't awful, until you put it in a stock pistoned 318 with 360 heads. That combo with the small, stock cam would be a dog because of the compression, but then you bump the duration up and you'll loose even more cylinder pressure.

Extra lift, no big deal, more duration, big problem.

I agree completely.  A big cam (and I agree, the cam is on the bigger side) with no compression will kill it.

[cudaracer]

Thanks again all.

One more thought or question.  Actually two.

I am thinking of upgrading my cam now, and the Hughes whiplash for a 318 makes a ton of torque and not much hp, using the 8:1 ratio stock pistons.  Should I even bother then with 10:1 pistons, and if so, will that disturb the forumla that hughes is using?

2nd question, I see that they also make a 3.48" stroker crank using the 318 main journal diameter, but you are stuck using the 1.675" comp height forged pistons, which are not cheap.  So here is my question:  With my large open chamber 4" bore 308 heads, and smaller bore (3.950") pistons, could I use the stock height cast pistons at 1.74" CH, as they would  stick out of the deck by about 0.051".  Obviously P2V is a concern, so I am hoping to find them with same CH and valve reliefs.  I would use a thick gasket too, prob over 0.06". 

thoughts.

[cudaracer]

Just found out that silverlite makes flat pistons with a 1.685" CH, so with that 360 stroke, it puts me at 0.030" below deck. 

Best part is, they are cheap cast pistons, good enough for my 390hp target.  CR goes way up because of longer stroke too.  And my torque target is now 440ftlbs.


Nice

[Chryco Psycho]

if you still want a roller cam & lifters I would start with a 88-92 block already set up for that

[cudaracer]

if you still want a roller cam & lifters I would start with a 88-92 block already set up for that

sooooo, getting newer short block assy & probably heads & intake manifold, makes more sense than retrofit roller lifter kit?

[Chryco Psycho]

IMO yes , if you want the Hyd roller , the lifters are approx. $40 each & you can get a bucket full  in a wrecking yard , you could still do the stroker crank & use the same pistons & use the 302 heads on the roller 318 , the intake is a barrel type Efi intake so that may not work for you unless you also want to run EFI

[bandt]

I have a Hughes cam in my 340.

I mostly delt with there tech staff who were great guys. I had to deal with Dave once and he was an a$$. He talks to people like they are idiots.
That being said I am very happy with the top end that was put together with there advice. I had similar complaints with my 340 that you are having with your engine. Long duration cam was bleeding off torque. I got a set of closed chamber heads and a cam with more lift and less duration on both sides. My car is an auto, the converter flashes at 2500 rpm.
The result was power where I wanted it, far more bottem end. A good spec'ed cam + 4:10 gear + 10 to 1 compression= shredded tires with no foot breaking.
I think if you raised your compression and planned a cam based on the rpm range you want make power in, you would be closer to your goal for less money. You will notice in cam specs the more duration a cam has the higher its rpm operating range.
Don't think roller lifters will be of any benefit as far as power is concerned. They decrease friction, reduce wear, and don't require a break in but your not going to see a power increase from them.

You also have the option to mill your heads to raise your compression.

[73restomod]

I agree with chryco factory roller block is the best option for going full roller. It also allow you to use Rhodes vmax roller lifters and get some more bottom end and MPG if that's a consideration. My 87 pickup uses a Roller with Vmax's, and it runs as hard as my 79 pickup with a 440. Only it gets 22-23 mpg on the highway and 16 around town.