ericdwong

Hello- I've done countless hours of searching on here, LS1 Tech, the F body and GTO forums etc and think I'm getting close to zeroing in on a new cam. Some background:

The car:

• Daily driven, 205k miles
• M6 car, stock 3.42 gears
• I do have access to another car, so it's not my only form of transportation
• Only 2 engine mods- Calloway Honker and z06 Ti mufflers. I have mild suspension mods.
• Is already taken apart to change balancer, leaky steering rack and AC compressor
• Never been dyno'd to get a baseline I originally didn't intend to do this while doing my project, then thought, dang this is a great opportunity while everything is out

The Driver

• 99% street driver
• very rarely winds out the engine- thus low/mid torque would be more important than peak HP
• I don't race other cars on the street, just like to have some fun on sunday afternoons
• Most the time I'm stuck in rush hour traffic anyway, so drivability is important

The goals

• NOT interested in top HP- I'd be happy with somewhat better than C5 z06 performance
• It's been stock since I got the car in 2002, I'm not "tired" of the performance, just looking to add some punch after having the car for so long
• Reliability is VERY important
• Fuel economy is moderately important- esp when gas was close to $4 a gallon
• Must idle and drive somewhat close to stock
• Not interested in louder exhaust or rough idle
• We have smog, but it's OBDII, not the sniffer style- also not interested in stinky exhaust

The plan

• Looking to do 243 heads
• LS6 intake
• Likely leaving the stock manifolds and Z06 exhaust- don't like the heat or raspiness of headers
• I'll change out the springs, lifters, perhaps trunion, ARP head studs etc
• I'll have it dyno tuned

The cams I've narrowed to:
- Comp Cams XR265HR 212/218 .522/.529 114 LSA http://www.compcams.com/Company/CC/c...csid=1085&sb=2

- Vengeance Racing VRX1 Camshaft- 220/220 .581/.581 114+4 http://vengeanceracing.net/1997-2004...1-581-114.html

The ThunderRacing 224 looked like that was a popular one but we all know what happened to T Racing...
I've heard differing opinions of these cams are too small and I won't be happy or it's not worth the $/effort but I'm looking to maximize reliability, thus from my research looks like 2 teens to low 220s,

Paul 75 L82

I have the Texas Speed 228R and I wouldn't want anything bigger for street driving.

ericdwong

Thanks for the reply. For some reason my message got cut short. I was going to say the Texas Performance models all have lifts .600 or higher, which I'm trying to avoid, to be easy on the drive train, and keep it around .575 or lower with 114 LSA.

frodo84

http://store.cammotion.com/catalog/search

I would give these guys a call for a recommendation....you know their rep from the LS1tech board I imagine....good luck.

enoniam

I've got the high-lift version of your Comp choice in a chevy Avalanche that I'm happy with. Mine has a degree more lobe separation and is 3 degrees advanced compared to what you are looking at. The lift is still within your 0.575 limit. Truck has more torque than stock, although the early 5.3 truck engines had very conservative cams from the factory. Cam idles pretty close to stock - you may require a tune. The truck needed to have a bit more idle rpm and air flow added.

For what it's worth I put the this Comp in my auto vette this summer with 228/230 duration:

http://www.compcams.com/Company/CC/c...csid=1091&sb=2

This one definitely doesn't idle like stock!

I've had a Crane cam with 216/224 duration in another Avalanche. Could definitely hear the cam in its idle. I assume your Vengeance racing choice would also have a "cammed" idle.

tblu92

With a M6 trans you can get away with a larger duration cam than with an automatic
I assume you have no smog laws where you live as states like calif will limit your cam choices if you need to pass smog
Old school thinking is to do all your research 1st- and make a choice---THEN go one size bigger !!!! Most everyone who does a cam swap wishes they would have chosen something more aggressive.
Being your car is a DD type car and you want reliability and to retain some fuel economy I would recommend something like this
Duration----something in the low 230 range at .050
Lift--- for reliability keep it under .600
LSA---On a manual trans you can get away with a lower LSA--I would shoot for something like a 112---Higher LSA's tend to have a smoother idle( stock is like a 117) and easier to tune --more stock sounding and a sleeper type cam
Lower LSA's than stock will give you a lopier idle and require more precise tuning as the overlap is increased---Best all round choice for a somewhat lopey idle---better economy and smother power band would be a 114 LSA---

dagon138

Everyone has their limits on what is acceptable as a DD cam.
For me, I realise lots of factors go into Drivability (overlap etc) but in general I think that low 230's duration cams are getting a bit much to be considered good DD cams for a 346ci.
I say this becuase even my 223/227 114LSA with LSR cam has is really slight bucking that I'd probably find annoying in a DD.
His cam choices are probably in a good range for what he wants.

Do some searches on LS1-tech for guys that used stock exhaust manifolds.
There is some consideration there in regards to cam duration split if I remember.

Also, the more you invest in heads you typically don't have to use as big of a cam. Have those 243 heads CNC'd, add some compression, light-weight valve train (nothing crazy like Ti valves) and you're going to be able to get a nicer driving DD cam, and still make as much power as the donkey-dick Cam-only guys. Nothing crazy as the LS6 intake will limit you anyways.

ericdwong

Good stuff guys! That really helps, leaning towrds the Comp XR265- though I found one more potential candidate the one enoniam mentioned (the high lift XR265), but here's a kit available. I couldn't find this kit on Comp Cam's website but:


Specs:
Xtreme RPM High Lift; Camshaft Kit; Hyd. Rlr;1400-6700rpm (instead of 1200 to 6000 rpm) ;Adv.Dur. 265 Int./271 Exh (still 212/218 at .50) .;V.Lift .558 Int./.563 Exh. (instead of .522/.529) ;Lobe Angle 115 deg (instead of 114).

The actual cam: XR265HR15 (didn't realize XR265 had more than one version)
http://www.compcams.com/Company/CC/c...csid=1089&sb=0

This one looks like it may have a LITTLE bit more peak power and higher RPM but slightly less down low torque. Any thoughts on one vs the other? And Any comments on the kit? or am I better off piecing it together myself?

This would be my first time going into an engine- I've rebuilt manual transmissions before (including my T56) so I'm not afraid to poke around

enoniam

I'm not crazy about that kit - I can't see any details on what it has other than the cam and the pics. Seems strange they have springs and locks but don't show retainers. You don't have to replace the lifters. It's not a bad idea to replace them but to do that you have to pull the heads which isn't needed to put the rest of those parts in.

I'm also not to crazy about the price of the kit. You can get comp cams for under $400. Quality springs suitable for that cam for under $200. LS7 lifters for a bit over $100. Locks, seats and seals combined for about $100. That adds up to $800. I'd upgrade the pushrods which aren't included it seems and if I'm changing lifters I'm also putting in new lifter trays for under $40. I'd also consider upgrading the cam timing set - at least upgrading to the LS2 timing chain.

Don't forget gaskets and if pulling the heads for lifters new head bolts unless you've already replaced with non-torque-to-yield bolts or studs.

ericdwong

Thanks for the reply. I'm going to call Comp Cams to see if any more info is available on the kit. According to the Amazon description it says: ;Incl.Cam/V.Sprng/Ret./Lock/Seal/Timing Set;
which seems like it includes the retainers.

I didn't mention this in my original post but I do plan to do the push rods, lifters, lifter trays, and add the comp cams trunion kit.

I know Bill Curlee and others are adamant about using the ARP head studs, but at ~$300 a set might just go for the ARP bolts- but that's a separate discussion

I already have the LS2 timing chain, sprockets, oil pump purchased etc. And I'll have the heads off anyway to put on the 243s. Ahh my list keeps getting bigger

ericdwong

After much thought I'm going to go with the lower lift version- mentioned in my original post. Granted it doesn't flow as well around 6k RPM, but I'd prefer the better torque down low and the lower lift for longevity. I can't even remember the last time I wound out the motor I also have a sport bike if I ever feel the need to accelerate.

Next question- for the 243 heads- given what you see with my setup here, I am considering having them sent to Advanced Induction. I have a few options for the heads- most are around 30k-40k miles. The comment about having a small cam but high flowing heads had me thinking. Then again, through the stock exh manifolds and z06 Ti mufflers, don't want to go past the point of diminishing returns

Should I:
1) do nothing and just add them in (but have them checked out by local machine shop)
2) get the Performance Rebuild package for $595

Described as: Our Performance Rebuild option includes our high end CNC'd valve jobs, precision valve grinding, milling to any chamber volume, cleaning, inspection, and professional assembly. Typical gains are 10-20rwhp.

3) 218cc CNC package for $795
Described as: Gain a typical 20-30rwhp over the unmodified GM 243 along with the benefit of a complete professional rebuild.

http://www.advancedinduction.com/LSX...inderHeads.php

S.C. vette

Great thread to follow, hope someone will reply to your latest questions. Not sure why you have backed off to the ultra mild cam?

ericdwong

I'm still undecided actually- there's sooooo many choices After speaking to Comp Cams, they actually said the lower lift cam is a truck cam- and I should definitely do the "higher lift" (relatively speaking) cam, to take advantage of the extra displacement.

With my 200k miles, I just don't think putting in a large cam is a good idea. Other considerations are the Brian Tooley Stage 1 and the Comp XR275HR. Or just forget the whole heads and cam thing and slap a S/C/ on it

S.C. vette

Did they give you the model # and specs for the high lift?

cv67

Sounds like youre on the right track dont get sucked into big cam syndrome (like I do lol)esp with your driving style. Add some headwork/tune and call it good;not like you want to be pushing a high mile bottom end anway
Think most dont get what they expect from a cam most times what they want is more stroke and dont realize it. Useable torque is king on a DD.

ericdwong

Yeah this one:

Specs:
Xtreme RPM High Lift; Camshaft Kit; Hyd. Rlr;1400-6700rpm ;Adv.Dur. 265 Int./271 Exh ( 212/218 at .50) .;V.Lift .558 Int./.563 Exh.; Lobe Angle 115 deg.

The actual cam: XR265HR15
http://www.compcams.com/Company/CC/c...csid=1089&sb=0

I also spoke with Advanced Induction, they are recommending their 226 cc package even for the small cam and keeping the stock exh manifolds - but at $995 (not including the cost of the heads) this project is really starting to add up Ahhh I'm kind of chicken to pull the trigger and have buyers remorse later, but then again it might be "why didn't I do this years ago"

http://www.advancedinduction.com/LSX...cGMLS2Head.php