Hey i'm a newby to this site and was curious which heads you suggest for a used ls1 motor. I'm currently looking for a stock ls early (pre 2002) or late motor. I don't know if the power handleing is differant on the 2 motors, but it seems that the early camaro motors are by far the cheapest.

I'm looking for 500+ crank hp on a stock bottom end, if this can be achieved with a procharger, great, but i think i'd rather leave it all motor.

Slponline.com promises 525 hp (with the appropriate intake, exhaust, and tuning) with their 225's head and cam package...here's there specs:

Intake flow up to 304 CFM at .500 lift, 320 CFM at .600 lift @ 28” of H2O.
Exhaust flow up to 250 CFM at .600 lift @ 28” of H2O (using 1-7/8 inch exhaust pipe).
225cc heads with 65cc combustion chamber.
CNC ported intake and exhaust ports, and combustion chambers.
2.080 intake, 1.600 exhaust standard length valves.
3-angle radiused valve job.
2.080 intake, 1.600 exhaust valves.
7° titanium retainers and valve locks.
1.290 inch double springs, 135 lbs seat, .600 inch maximum lift.
Emissions-legal CARB EO #D250-4.
Fully assembled, ready to bolt-on.
Matched .590”/236º int. 590”/236º exh. camshaft.
Will require shorter pushrods (heads milled approximately 0.042”); SLP recommends always measuring proper pushrod length (for use with SLP 51014/51015 cams, PN 53107 pushrod is likely)

The 2.080 valves seem a little aggresive for a 346.

I also see mongoose, arp, and trick heads around quite a bit but i'm not famiar enough with the #s for these heads.

Basically i just want to achieve 500+ hp with the stock bottom end, which is obviously possible since trakday pulled 602 hp on a stock 2004 ls1 in his GTO.

Thanks Guys, Russell

 

2004 = LS2 4.00'' cylinder bore /1997-2002 LS1 3.89 '' 500 flywheel hp is easy these days swap in a cam , if that dont do it mill and port the stock heads . cheCK out TEA . you have a engine sitting on a stand change the rodbolts to Katechs

 

get afr

 

Correct me if Im wrong but I believe the heads you are talking about are the AFR 225 mongoose heads. Mongoose is the model of heads made by AFR. ARP does not make heads they make fasteners i.e. Head bolts, head studs, main studs.

Yes you are right the AFR 225's are a little bit big for the 346. You could easily make 500 flywheel HP with some AFR 205's (designed for the 346) and the right cam.

The trick flow heads just came out and look to make good power also. I would contact some of the sponsors to the right and tell them your goals and see what they recommend.

I dont want to sound like a dick but you should read the sticky's in the internal and external sections before making any major purchases. With 500 flywheel horspower there are other things you need to consider like beefing up your trans and your rearend. Do you have a m6 or automatic? Stock rearend?

 

Well i like the idea of swapping for an aggressive cam and milling and porting the existing heads.

"Yes you are right the AFR 225's are a little bit big for the 346. You could easily make 500 flywheel HP with some AFR 205's (designed for the 346) and the right cam."

I brought that up to larry at slponline.com tech support and he said these heads work well with a 346''-427'', i said that they were a little big and he said they are a good match.

"With 500 flywheel horspower there are other things you need to consider like beefing up your trans and your rearend. Do you have a m6 or automatic? Stock rearend?"

I don't know how well you guys would react to it, but it's going in the back of a porsche 911 and i want to put some serious power in it. Porsche guys are a little snooty sometimes so i wasn't sure if i was gonna tell ya. And no i won't have to beef up the rear end since the G50 handles 600 lb. ft of torque. I'd like to use every last ounce of power this thing will handle, but my budget is limited to about 10k including the motor, cooling, engine adapter, clutch... everything. I decided on the ls1 due the low weight (435 lb for the ls1 vs 540 lbs for the stock 3.6 ltr porsche power plant.), torque, efficiency, and wow factor when i open the deck lid.

Thanks for the input guys, this is my new favorite site and i have a feeling i'm gonna be broke very soon because of you.

 

Im sure Larry at slp is very well trained at reading his computer screen but this is directly from the Air Flow Research website:

"The 225cc is ideal for normally aspirated 396C.I. to 427C.I. For a wild 346 ci the 225 is a good choice, however some low RPM loss of torque might occur."

"The 205cc is ideal for normally aspirated 346C.I. to 396C.I."

It all depends on where you want your powerband. Is this going to be a race car or primarily for the street?

Some of the Porsche guys might put their nose in the air at the idea but most people here will agree that you made a good choice with the LS1. You should post in the Hybrid section to see if anyone else has/is doing the same swap.

If you are set on buying the 225's I would call the tech's at AFR and see what they recommend. If you are on a limited budget I would consider checking out other sponsors that can sell you a good set of heads that are less expensive than the AFR's.

How much power do you want to make to the wheels?

 

Also have you looked at the Dart heads? They are a very good price for an excellent head and will make good power.

 

I'm shooting for at least 450 but 500 to the wheels would be nice. I'm starting to think i should buy a complete motor off ebay with a bottom end knock, get some work done on the stock heads and get a forged stroker shortblock and enjoy the extra power from the extra cubes. Thanks

 

TFS just finished up testing their LS1 215cc head and cam packages. The Stg 3 cam is a 228/230 and made 542 HP 475 TQ with a Fast 90, the head also outpowered all other heads tested by 10-20 HP with the same cam, so you might consider that package. I will try to post all of the TFS head/cam package numbers when I get a chance.

 

i think im gonna have the stock heads port/polished from what most people say you can get them to flow in the low 300 range