Miles in Michigan

I've read a lot of old posts about the best advance to have a cam set at in an LS1. It seems there is a general consensus that ideally the cam should be neither advanced or retarded, and the way to accomplish this with a stock timing chain is to grind in 4 degrees of advance (unless you are going to degree the cam, which I am not <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> ).

I do however have a Rollmaster dual timing chain that I am going to put on when I install my cam. Taking that into account, how much advance should I have ground in my cam? 2 degrees? 1 degree?

What I am thinking right now is a XE-R 222/222 .581/.581 112LSA 110IC (which is 2 degrees of advance ground in). No smaller than 222 duration for sure, since the XE-R lobes have steep enough ramps that the adv. duration is only 271. The TR224 and MMS224v3 by comparison has 275 deg. adv. duration, and the MTI T1 has 280, so the XE-R 222 on a 112LSA ought to have less overlap and idle noticieably better than any of them, and most people are already satisifed with the idle/driveability of those cams in a 6 speed car. I don't want to go much bigger than 224/224 though, since I don't want the cam to be too noticeable.

I've got a LS6 intake manifold and 1 3/4" LT headers, and am going to keep the heads stock. Based on what I've read I shouldn't get a split or reverse-split cam, since the stock heads are pretty well balanced intake vs. exhaust.

Thanks.

Miles in Michigan

Well, I guess I am going to have 2 degrees advanced ground in, unless anyone tells me any different.

Thanks.

11 Bravo

iTrader: (3)

I don't know much about the Rollmaster timing chain. It will give you 2 degrees of advance? If so, I would also have the cam ground w/ 2 degrees. I believe Comp cams usually have +4 of advance. Mine does. That seems to be the norm.

xaon

iTrader: (12)

advance is used to shift your power band around. I personally do not believe that cam manufacturers grind in advance "to compensate for slop in the stock timing chain" since they recommend to replace the stock timing set with a beefier unit.

Also, if you buy (for instance) a regrind cam from GTP. These cams have no advance ground into them and it is "a must" that you buy an adjustable timing chaing so that you can advance the timing on it.

I talked with Trevor D over at LG motorsports and asked him about the 2 degree vs 4 degree when I was getting ready to install my cam. (We have the same 224/224 .581/.581 XE-R 112LSA cam, his is with 2 degrees advance, mine has 4). He said that his with the 2 less degrees of advance will peak 200-300RPM higher than mine will and suggested I install it dot to dot.

FWIW. I also have a rollmaster double roller timing set in my car.

Miles in Michigan

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by xaon:
<strong>I personally do not believe that cam manufacturers grind in advance "to compensate for slop in the stock timing chain" since they recommend to replace the stock timing set with a beefier unit.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Well, the cam manufacturer will grind it to any advance the customer asks for, right? So it's not really the manufacturer (Comp, Lunati, etc) who decides, it's the customer. Raughammer has said in the past that timing chain slack is the reason that MTI has 4 degrees of advance ground in.
https://ls1tech.com/ubb/cgi-bin/ulti...c;f=1;t=002409
I thought I remembered reading that other LS1 engine-builders do the same thing, but cannot find the post.

JS

iTrader: (4)

Yes but if your running a GOOD chain would u really need 4 degree's adv. ground into the cam?

I would think 2 degree's might be perfect when using a IRL,SLP, Jwiss or Cloyes IRL setup?

JS

<small>[ September 20, 2002, 11:54 AM: Message edited by: JS ]</small>

nthnwbr

The timing set shouldn't have any advance built in, unless it is adjustable(multiple keyways). The cam can haev advance ground into it and the easiest way to tell, is to look at your cam spec card...for example...if you are running 112 LSA, and the cam has a 108 intake center line, there is 4 deg. advance ground into the cam. (LSA-ICL=advance)

JS

iTrader: (4)

I realize the chain has no advance but most of the aftermarket gear sets do give u the ability to adv/retard the cam.

After talking to Comp they infactically told me for a N/A LS1 setup to stick with a single pattern with 4 degree's ground into it for most LS1 setup..

They have a XE-R 224-224 581-581 112 +4 that looks tasty to me...

JS

<small>[ September 20, 2002, 04:19 PM: Message edited by: JS ]</small>