RhinoSS

I ran across a nice set of ported heads locally. This coupled with a lifter knock I can't seem to get rid of has hastened a head/cam swap on the LQ4 in my Avalanche.
The heads are 853 casting LE2 heads with 2.02/1.60 valves and 64cc chambers. My SCR should be roughly 10.2 on the stock LQ4 bottom end with an MLS gasket. The truck is just my DD, so I'm not at all interested in peak numbers. I'm looking for a cam that will retain good low end torque. Once another of my projects is done, this truck will be used as a tow vehicle.
If at all possible I would like to retain the stock TC for now. Not for cost, but simply convenience. I'm not planning on pulling the motor short term. I'm assuming the trans will go somewhere down the line, and I may plan on a converter at that time.

What cams should I be looking into?
I currently have a TSP Torquer V2 114 LSA that I've been planning on installing in a different vehicle, but if it's a good fit, I'll run it. My current thought is that it's not my best choice. It's straight up +0, If I were to use the V2, I'd at least like a few degrees advance ground in.

budhayes3

iTrader: (19)

If you plan on sticking with the stock converter and towing, I wouldn't consider anything bigger than the Vinci Trucker (216/224 .551/.551 115). Even that cam in a 6.0 would benefit from a mild converter (2400ish), but I don't think that you'd lose anything down low, maybe gain a slight bit. I'd think that a 212/218 might even gain down low in a 6.0 and definitely wouldn't need a torque converter, but most will say that cam is too small for a 6.0 (totally neglecting that you mentioned that you have a heavy Avalanche, aren't looking for peak numbers, want more torque, and plan to tow). Just my opinion though...

RhinoSS

Thanks Billy, after a little research it seems that there is rarely a bad review of the Trucker. Searching for the trucker I also found a few other cams that have been added to the short list. Vinci Ultra Torque is another at the top of the list.

Thinking a little more realistically about my goals, I'm not 100% certain that I'll really require this much head for my needs. Torque is produced by velocity, not CFM. I'm almost contemplating finding a set of stock 243 heads or decking these 317's just to raise the compression to LQ9 levels, maybe clean the ports up a little. I could easily use these other heads for another project.

Will I be getting my money's worth out of these heads knowing I rarely turn the motor over 5k? Would I gain nearly as much with the bump in compression and cam swap?

budhayes3

iTrader: (19)

Since you're looking for torque, you don't need big CFM numbers like you mentioned. Any decent bump in compression will help though, that's always good for torque and power across the board. If it were me, on a budget, I'd probably stick with my 317's, take maybe .030-.040 off (not sure what that will net you compression-wise, but if you can get to 10.5ish, 10.6:1 with the right tuning you should still be good on pump gas), and have a little polish and bowl work done.

I'm curious how the valve events of the Trucker would work out with the slightly higher compression...there isn't a lot of overlap in that cam for the "natural" EGR effect, so it may be interesting (or I may be over-thinking it also). It may be worth a call to Roger Vinci to inquire about your cam options and your plans. He's a great guy to talk to, but also a great salesman, as I've found out from a few conversations with him (so don't have your credit card in hand when you call or you may find yourself hanging up the phone $400ish poorer lol).

The more that I think about your goals, I like the "Ultra Torque" for a combo with the stock converter. Even though "cubes eat cams", I think that the added duration of the trucker won't provide the gains down low that you're looking for. I also feel that you could run the yellow LS6 springs with either of those cams, which is nice since their reliable and don't put a lot of stress on the valvetrain. You won't need a ton of seat pressure since I don't believe that those Crane/Vinci lobes are overly aggressive, and you won't be spinning the engine to the moon every time you get in it.

I know that Roger himself runs the Trucker in his 5.3, along with a Yank TT2600, or at least he did last time I talked to him.

budhayes3

iTrader: (19)

What gear and size tire are you runnin?

(btw, 853 heads are LS1 heads correct?)

RhinoSS

You're echoing exactly what I've been thinking myself. This thread states I can get by with milling them up to .040.
Looks like .040 would get me to about 66cc chamber volume, .030 roughly 68cc. That would put me somewhere in the 10.0 to 10.1 range. If I wanted to go a little higher I can probably switch to the cometic gasket, depending on what my true deck height ends up being once I pull the heads.
I think I'd have to end up milling a set of 243/799's to get to 10.5.

Without having the cam in hand, is there any way to determine possible PTV issues? I doubt I'd run into any with the LQ4 dished pistons and a small cam, but I'd like to be certain for my own piece of mind.

I'll have to give Roger a call. I'm definitely itching to pull the trigger on this.

I'm running stock gears and tires. 3.73 gear with 265/70/R17

budhayes3

iTrader: (19)

Not sure if there's a way to determine PTV clearance without bolting it all together and checking, but just by going on what I've read around here, I *doubt* that there would be an issue with that small of duration, hopefully someone who's been there done that can chime in.

That's basically the same tire and gear combo that my truck came with stock (except my tires were 265/75-16's...I believe that they're both about 32" tall tires IIRC though)...nice middle of the road combo for a daily driver without having the RPM's screaming on the highway, and well suited for the power band of the Ultra-Torque IMO.

I thought that you'd be able to get more compression from milling the 317's off the top of my head, but guess I was wrong (again lol). Still, 10:1 is nice for an easy low-buck upgrade.

RhinoSS

I'm trying to get the compression nailed down, but I'm finding a lot of conflicting info. This thread states that at .030 I'd be at 9.75:1. Using this compression ratio calculator comes up with very similar (low) numbers

Using average LQ4 numbers I've seen floating around here I come up with 9.5 with a .030 mill. To get over 10.2:1 I need a 63cc chamber on a standard MLS gasket (.054). If I moved to the .040 cometic I could get by a 66cc chamber, which would be a .040 mill.

Figures I've been using
Bore: 4"
Stroke: 3.622"
Gasket Thickness: .054" and .040"
Deck Height: -.007"
Piston Dish: 8cc
Combustion Chamber: 62 - 68cc

I think I'm leaning toward the Ultra Torque at this point. I'll see if I can pick Roger's brain tomorrow for a little guidance.
As far as heads are concerned, I think I'll have these guys for a later project. If I can get a set of stock 243 or 799's I'll go that direction, otherwise I'll mill the 317's all I can.

Sorry I missed the 853 question from before. Yes, they are LS1 heads. Very similar in port design to the 241's, but had a rougher port texture. Once ported you'll find very few differences between them.

budhayes3

iTrader: (19)

The 243's would probably be your best bet, as they start off with a 64cc combustion chamber stock...not sure what would have to be done to the combustion chambers to make them work with a 4.0 bore after a mill though...unshrouding of the valves maybe? wish that one of the guru's like 1Bear were awake right now lol. I'd think that the 243's wouldn't be that hard to come by...when I went to the swap meet in Englishtown NJ I saw about 5 sets of them for sale and I wasn't even looking. One set was all boxed up in TrickFlow boxes and ready to go (I assume that someone pulled them off of their Vette and installed the TrickFlow goodies in their place).

I've also heard guys recommend PRC Stage2.5 5.3 heads to up the compression and retain flow for a 6.0, they're supposed to be great bang for the buck. Might want to compare prices between those and stock 243's with some mild work, if you have a local machine shop that you know and trust.

Wish I could help you with the compression issue...another great guy to talk to is Richard from WCCH, he's about the most knowledgeable guy that I've talked to when it comes to this stuff, and he's an awesome gent to talk to

RhinoSS

Just got off the phone with Roger. He's leaning me toward the "Butt Kicker" along side his HD springs and Crane rockers.
The largest difference between the two is that the Ultra Torque is a 116 LSA, where the Butt Kicker is 114. Both are +4.

Technically, wouldn't the 116 LSA give me greater low end torque I'm looking for?