idle considerations on a xe274 cam

[johndezman]

plan is to build a 406 with the above cam (rest of the specs - 10:1 cr; superram; good heads). my question is how will this engine idle in front of a automatic? will it shake itself apart with a stock converter? will a higher stall be necessary?

[bence13_33]

The cam that you listed really isn't that radical (considering it's going in a 406). Idling shouldn't be a problem. As for the convertor, that would depend on how big you go with the heads and what ratio rear end you plan on using.



[Modified by bence13_33, 3:06 PM 1/21/2003]

[johndezman]

rear end is 3.08 the heads are trick flow twisted wedge

[The Money Pit]

I used the XE-274 on my 406 the first time around and thaught the idle was too smooth. Flattened the cam,and put in the XE-284. With the initial timing set at 10 degrees the idle is still smoother than I thaught,but backing down to 8 degrees,and the whole car shakes like a Pro Stocker.I'm working on a distributer recurve as soon as the cold weather lets up. Since the option is open at this stage,what is the rest of your combo? If you have the stock 3.08 rear,you may want to keep the XE-274 idea. Mine would pull 30+ feet of smoking tires off the line with the 3.70 gears and P295 50's,but at the top felt like it was letting off at around 5300 rpms.The XE-284 pulls easily to 5700 in drive,and once I blipped an easy 6000 in the garage.

[johndezman]

the chip in the computer is set for a 700 rpm idle so i don't want it shake too bad at a light

[johndezman]

let's see. 84 c4 with automatic....

406 ci; 10:1; trick flow twisted wedge heads, superram manifold; 30 # injectors; 7 qt pan and diamond stripper tray; 1 3/4" long tube headers; 2 3/4" borla off road exhaust no cat; 58mm throttle body; air pump eliminated.

basically a summer daily driver with a little grunt

[Pat71vette]

I have a 383 with that cam and in my opinnion its too mild in my car it will just be a waste in a 406. I have 373 rear

[johndezman]

let me try to refocus the original inquiry.

i am concerned about how the cam will IDLE when hooked to an automatic (at 700 rpm) and whether a higher stall converter is needed or can i get away with the stock converter.

i know a bigger cam will yield more power through the band but as mentioned i am looking only at idle quality!

[gkull]

As I understand it. Or so I have been told. Even ported superrams have reversion issues with cams hotter than mid to high 220 deg. intake and low 230's exhaust at .050 The cams overlap is the big problem with the tuned intake runner length.

I would take this question to the C-4 section. Because i don't have all the specs on a XE274 cam

[johndezman]

i had accessed a site at some point in the past that had a compilation of engine tests (with relatively complete recipes) for small blocks.

in it there were a pair of 420ci superram motors - one with the 219/219 , .525/.525 with 112 lobe ctrs cam and brodix track 1's and the same short block with ported afr 190's and a comp cams mechanical roller 236/244, .549/.549 with 110 lobe ctrs.

the 219 had greater peak torque 561 ft/lbs @4400 vs 543 @ 4500 while the comp cams did hp better - 525 hp @ 5500 vs 509 @5200. really pretty close considering the difference in cam specs and i have to believe the 219 will idle a lot better than a 236/244 especially in front of an automatic! if i had a manual i wouldn't sweat the longer duration but i'm stuck with the auto (for now) and momma does ride with me on occasion...

[gkull]

I think that 's right along with what i always heard. Superams like mild cams with 112+ lc

[Clink69]

I have that Cam in my 383. I idle at around 850 and pretty smooth, little lump... I think you will be fine with stock setup...

Chris :flag