I'm getting a set of the AFR 205cc Mongoose CNC ported heads with 66cc combustion chambers for my '02 WS6, M6. Before I go too far, I have two simple goals, which I hope are not mutually exclusive:

1. Be able to run with the '06 Shelby Cobra

2. Be able to drive it back and forth to work

I have been reading a LOT on choosing cams and valvetrain components. Some of the information contradicts other information I've read, and right now, I'm pretty confused. I want components that will work well with one another. Here is what I've been leaning towards:

1. Comp Cams SI2 custom cam 224/224, .581/.581 w/112LSA

2. Comp Cams cc26921 dual spring kit

3. Comp Cams cc7955-16 chromemoly push rods (7.4? 3/8"? 5/16"?)

4. Comp Cams cc875-16 Pro Magnum hydraulic roller lifters

5. Comp Cams Pro Magnum 1.7 roller rockers

OR

6. Yella Terra 1.7 shaft mounted rockers

7. ARP Head Stud kit

8. SLP timing chain/oil pump package

9. Thunder Racing cam/cylinder head swap GM gasket package

I've been told that the Comp Cams Pro Magnum hydraulic roller lifters have been experiencing problems. True? I've also read that if you plan on putting down more than 450 HP, the stock rod bolts should be replaced with good (ARP) aftermarket bolts. Can rod bolts be changed without removing the block's lower half rotating assembly?

Are the components I've listed above well-matched? I'll be doing the work myself. I have a 2-post lift in my shop, and I'm dropping the engine/tranny out the bottom of the car, as recommended.

I'm not sure about piston to valve clearance, or whether or not I can use stock-length pushrods. I've been told, and I have read that too stout a valve spring can cause valve "float" and lifter collapse. Should I go with a rev kit? Is the .581/.581 lift I mentioned for my cam choice too much? Are there definite advantages to shaft mounted rockers, vs stud mounted rockers? I've also been told to stick with a 1.7 ratio rocker, as 1.8 is "too rough" on the valvetrain.

Please, offer whatever advice you think I need. One thing I WILL NOT CHANGE, and that is the AFR heads. I'm willing to listen to advice on all the other components.

Mods already include: de-screened MAF, Jet Stage II programmable PCM, SLP lid, MSD 8.5mm plug wires, NGK TR55 plugs, Spohn chromemoly adjustable LCA's, Spohn H/D anti-sway bar, Spohn chromemoly adjustable panhard bar, Spohn shock tower brace, Kooks stainless long-tube headers, Magnaflow stainless cat-back, skip-shift eliminator, traction control reversal module, T/A Performance H/D diff cover, ROH 17" X 9" Snyper wheels, and Hawk ferro-carbon brake pads..

 

Without sounding cruel....

It's going to take some serious HP to run with a SC 5.4 Shelby...

That cam just ain't going to cut it unless you are planning some "juice"...

Ed

 

I was hoping the AFR heads, a good cam, and a well-matched valvetrain, along with my present mods, would gain somewhere around 100 HP, provided I can get a competent dyno tune. What would you install as far as a cam & valvetrain components to take full advantage of the AFR heads.

And you didn't sound cruel. I appreciate honest, to-the-point advice.

 

Great cam choice..you might want to conside the AFR 6016 cam. Its a 224/228 @114 but custom grinded by AFR to match the 205s flow characterstics. Very close to stock like behavior and can put down serious rwhp if combined with the right bolt ons!

 

I would keep the stock lifters and the stock rocker arms. We haven't experienced any problems with the stock pieces, and the cams you are thinking about are on the mild side. We have had noise related problems with aftermarket rocker arms, and the factory ones are good pieces.
I agree with the above post that you are going to need a bigger camshaft to make sure you stay ahead of the new Ford. Bob

 

Go bigger on the cam, flycut the pistons, and mill the heads. Still wont get you 100 HP, but it may get you close.

 

Mill the heads .030", use a .045" Cometic head gasket for tighter quench, use the AFR 224/228 114LSA 113ICL cam, and keep the stock springs that come on the AFR heads...they're awesome.

Stocker rockers and stock lifters will be fine too as long as you don't have too many miles on them. While you won't make the power of a SC 5.4L Cobra, you'll be in the ballpark from a power to weight standpoint. I hear those Shelbies are going to weigh around 3900 lbs.

 

Okay, looks like the stock lifters & rokers stay. I'll replace the pushrods. I do not want to get involved with milling, I'd like to keep this job as close to bolt-on as possible. Now, the only question that remains, is what cam? I need duration and lift numbers, along with LSA. I'm not brand-loyal, but if Comp makes the appropriate cam, that'd be great.

AFR's literature says that if you run .600+ lift, or plan to rev @6,600 or above, they recommend upgrading to the 918 spring. If the cam ya'll recommend to compliment the AFR flow characteristics (and the Kooks long-tube headers) comes close to, or reaches .600, would the 921 spring be a better choice?

I've also read that keeping the lifters firmly on the cam lobes at high RPM, especially with a hi-lift cam, can be a problem. Would a rev kit be a worthwhile upgrade?

 

That question was already answered above. Comp makes the cam I recommended. Use the springs that come with the heads. 918s would be a step down. 921s are very expensive (very good) but not needed. Rev kit not needed. Milling can be done by most of the shops selling the heads so it won't involve any additional effort on your part (just maybe a few more dollars). The .045" Cometic head gaskets are a must too.

 

"That question was already answered above. Comp makes the cam I recommended."

I saw the 224/228 duration and 114 LSA, but no lift numbers. The cam in your sig looks close at 231/234 duration, .644/.598 lift, and 112 LSA. Is this the cam you mean? If not, could you give me the lift numbers for the 113ICL cam?

I have 23,000 miles on the car...low enough to keep OEM rockers/lifters? Also, with milling the heads and using the .045" Cometic head gaskets, were there installation problems pertaining to piston to valve clearance? Will my stock injectors be adequate?

That 2000 Pewter Ram Air looks like a bichin' ride. Did you get a dyno tune after installing all your hi-performance parts?

 

Sorry for not disclosing the lift. Since the cam is so well known on this site, writing the lift seemed unnecessary.

Here are the complete specs: Comp Cams XE-R lobes 3722/3724 224/228 .581/.588 114LSA 113ICL (+1 advance ground in).

No piston to valve clearance issues with the .030" milled AFR 205s and the .045" Cometic gaskets. Your miles are low enough to reuse your stock lifters and rockers. Stock fuel injectors are borderline at this power level. If you upgrade to a FAST 90mm intake with a Nick Williams 90mm throttle body, you can expect to need an injector upgrade as your power should approach 450 rwhp.

My Trans Am was professionally tuned by Geoff at Thunder Racing and I use HP Tuners for minor tweaks.

 

No need to be sorry....I'm a newbie on this site so I've got some catching up to do. A lot of the guys from FBody.com, where I've been a member for 2+ years, recommended I register on this site. They all said LS1tech members are numero uno for accurate LS1/LS6 tech info, and are friendly, to boot.

I've always like FAST products, I just hope my upgrade budget will allow me to get the intake and throttle body. I figured as long as I had the engine/trans sitting on the floor, that would be the ideal time to throw in a new clutch.

Injectors are no big deal to install, right? I like the idea of 450 RWHP. At that power level, I should at least be competetive with the SC Shelby Cobra. The stock bottom end, including rod bolts, should be fine with 450 RWHP, right? Would the new timing set and upgraded oil pump still be necessary?

Assuming I can get all these parts installed, including intake/throttle body and injectors, will the car even start once everything's all buttoned up? I have a 2-post lift in my shop, and I planned on doing the install myself, and hoped the car would run just well enough to get it to the dyno tuner.

I've looked at screen-shots of the fuel/air/spark tables on HPTuners and LS1 Edit web sites. I think that part of the job is way over my head. The dyno tuner in my area (Kennedy's Dynotune) lists Electromotive, DFI, and FAST in their ad. Is one better than the other? Oh, and while I'm on the subject of tuning, when all of this is said and done, I'm probably going to have to get rid of the Jet Stage II programmable PCM I now have "piggybacked" onto my OEM PCM, right?

Sorry for the long posts and all the questions, but I figure the time to get stuff nailed down is before I start the project, not when I turn the key to try and start 'er up for the first time.

 

hey..where in buffalo are u bichin95redta?...im from orchard park..

check out wnyfbody.com local forum, lots of meets..lots of nice cars

 

Whatever you do, just have a bottle on stand by just in case. 5177 NOS kit and a 125 shot, no need for extra tuning if you run 93/94 Octane.
BTW I would mill the AFR's .20 in order not to have any issues with p-rod selection. 7.40's, 5/16. (AFR casting are .015 more than stock)

 

I agree, mill the heads for additional 10-12rwhp and it will cost you a minore 80 bucks or so.