Best cam, before rough idle?

[Skunksmash]

Hi all I just wanted to ask what the biggest cam was that you could have, before you got a rough idle. This would obviously be considered a mild cam, but i understand there to be varying degrees of mildness. Im sure there are ones with taller lift durations than the factory ones, that would just barely be under what starts to give a rough idle. Anyone know which one would be the best for this? I want the most performance i can squeeze out, but i want the idle and ride to be smooth. There is sort of a line you can walk if you do it right.

[VileZambonie]

http://store.summitracing.com/partdetail.asp?part=SUM%2DK1102&view=1&N=700+

[eventhorizon66]

"Rough idle" is a relative term.  I've heard people (not me) refer to the Comp XE268 cam as having a fairly smooth idle.  Others consider cams in the size range that Vile posted above as having a mild lope.

If compression is 8.5:1-9:1 this is my idea of a good entry-level cam: http://store.summitracing.com/partdetail.asp?part=ISK%2DCL201264&autoview=sku

But I plan to use a cam like this one with a decent idle (slightly smoother than XE268): http://store.summitracing.com/partdetail.asp?part=ISK%2DCL201271&autoview=sku

[Skunksmash]

maybe i should have put it this way: Is there a bigger cam than the factory one, that will run as smooth (or close to as smooth) as a factory cam?

[VileZambonie]

The one I posted

[Lt.Del]

I have this....
Hydralic Flat tappet Cam
Advertised Duration is 280 Duration @.050" 214 .295" cam lift X 1.6 = .472" Valve lift
Ground on a 110 Lobe center.

I have 1.6 rockers --2.02 int; 1.6 exh

I love this cam.  It is considered an RV cam, taking advantage of lower rpms for higher torque down low for my 383 stroker.  She has a very slight lopey idle, just enough to sound fun.  My wife always thinks its getting ready to cut off.  She alway asks "what's wrong with it?"  I laugh.  She knows nothing about engines.

[eventhorizon66]

maybe i should have put it this way: Is there a bigger cam than the factory one, that will run as smooth (or close to as smooth) as a factory cam?

The one I posted

Yeppers

The ones I posted would both make for a "noticeable" idle but not a rough idle.

[Skunksmash]

Thanks. I want it to be on the lower end of noticeable. If it's noticeable at all, it should be just barely. Pretty much hard to tell it's not stock. What about a roller version? I was considering converting to a full roller motor due to the increased efficiency of them.

[zieg85]

I was talking to a buddy and he was talking about a cam he just got.  I think he called it a Thumper cam, sounds radical at idle but the power band is 2200 on up.  He was talking it is about the same lift as a stock cam and there is a web site that you can listen to it.  Supposedly meant for a stock engine.

http://www.compcams.com/thumpr/default.asp  click a listen...

[eventhorizon66]

What about a roller version? I was considering converting to a full roller motor due to the increased efficiency of them.

From a performance perspective, the difference between flat tappet cams and roller cams in that size range is minimal and not worth the investment.  Move up a few notches in size and the roller cam begins to really shine.  From a durability perspective the roller wins, but with such a mild cam I wouldn't expect problems, unless you neglect to break it in properly or run high spring pressure.

[SUX2BU99]

I have a Comp XE268 and it's noticeable idle for sure without being rough, (rought meaning it has to idle above 1000 just to not stall and still shakes the heck out of the car). Mine can idle around 700 in Drive and it shakes around nicely but smooths out when I put it in Park and the idle goes up to 900 or so. If you are looking for stock-style smoothness, the XE268 would be too much. The XE256 might be more for your liking.

[Skunksmash]

Yeah i am looking for stock-like smoothness in all RPM ranges. I just thought that ya might be able to go slightly larger than stock and still have the stock smoothness. You know how they always leave lots of room for improvement...

But now that we have established the cam, what would be the best most efficient set of aluminum heads to go with such a cam? There would come a point where i could overpay for heads, and not get the benefits out of them due to the mild cam.

[VileZambonie]

If you're gonna use a mild cam like that don't waste your coin on aluminum heads.

[eventhorizon66]

Go with 170cc ports and no larger.  And I'm with Vile; no reason to waste money on aluminum.  Vortec L31 heads would be a really nice choice.  With 8.5-9:1 CR and that cam, you'd have the makings of a snappy little 87 octane motor.

Though, if you are dead set on aluminum, I like the Edelbrock Performer RPMs or their E-tec 170s.  Also if you can get a set of good used Corvette L98 heads, those would be perfect.  Their flow numbers, while not spectacular, are good and they have tremendous swirl characteristics.  Perfect for making the most out of mild cams.

[Skunksmash]

Thanks. Though i doubt i will ever be able to come across any vette heads for any kind of decent price. What about a roller cam for this type of desired application? I would like a full roller motor if i can...