huttler

I need help selecting replacement heads. I'm an amature at best for choosing heads so any basic knowledge you can impart would be helpful. Currently I have LS1 ported heads with 2.02/1.57 valves. I've had them for about 5 years and there are so many better options now. I will also be upgrading to a FAST 92mm w/tb.

Which of these heads will best compliment the rest of my mods?

Choices I'm considering:

205 or 225cc afr or trickflow
patriot performance LS6/LS2 2.08"/1.60" 64cc

Are afr 225cc or trickflow 225cc to big for my other mods? I've noticed that most people with similar mods as me go with 205cc heads. AFR's website also says you "might" lose low end torque with the 225cc.

Are AFR and Trickflow worth the extra money?

current mods:
ported ls1 heads w/ 2.02/1.57 valves
XE-R 224/228, .581/.588 LSA 114
LS6 Intake (upgrading to FAST 92 with new heads)
Lucas 36lb injectors
Haltech intake (I have a vararam in the mail)
Longtubes, high flow cats, x-pipe, b&b triflow
LUK Aluminum Flywheel (will be installing a monster w/still billet fw soon)
Underdrive pulley

vettenuts

I just swapped from Dart to AFR heads with a small cam. If done right, it can be a nice street package and still get good mileage to boot. If you are interested in AFR, send a PM to Tony Mamo (he is in the member list). Tony designed the AFR 205 and 225 so who better to offer guidance and help.

ncvettes

I vote for the AFR 205 heads. The Trick Flow heads are 215, and with the cam you've got, 215 is iffy and 225 is too big. There is no "might" about losing some low end torque with the larger heads. Unless you want your performance up high, stay with the smaller ports and higher velocity. Of course, there will now come the obligatory "a good tuner can make bigger heads work like smaller heads" post.

FYI, back in the day of performance Corvette engines, like a 350/350, 165cc heads were the factory norm, and a performance upgrade meant 185cc runners. Anything bigger and you moved the entire powerband up the rpm scale, ruined the low end performance, and had lots of disappointing results. Bigger is not always better, and matching your components is everything. .02

Corvette Don

Yes you lose some low end power, I choose 225cc heads (see full mods in sig) and I have no regrets, YES all my power is above 4k rpm but when you are racing thats where you need it and I like it, my buddies head (TFS 215)/cammed (234/236)/stalled (3200)/geared (3.42) C6 will eat me out of the hole till about ~70 then I am gone. PLUS when I get my 408 the 225cc heads will be perfect for it.

paint it black vette

trick flow 215's

Mark C5

A little unsolicited advice, I'd pass on the Fast 92 and get the LS6 intake ported instead. You should be able to get it done for around $350 and with your cam and other mods it will be more than enough. Don't get me wrong, the Fast is a great piece just more than you need. Of course if you're planning more serious mods in the future then that could change things. Best of luck

thehammer69

If staying with 346cid....Use AFR 205's over AFR 225's. I've seen the results of people who have tried both on their 346 and the 225's only gained around 5hp up top but fuel mileage and drivability was worse. And if you ever go bigger than 346, you can always have Tony Mamo work some finger magic on them...

0Tony Mamo @ AFR

Milled AFR 205's (62 cc's), an .040 gasket for better quench, and let me properly port/modify a FAST 92 intake for you along with an LS2 TB.

You already have the right cam (assuming your looking for a somewhat mild, powerful daily driver type set-up).....and with the heads and induction swap I think you can see an additional 30-40 HP with alot of area under the curve gains and much sharper throttle response at every RPM. Your buttmeter will think you gained more and some of that is the part throttle torque gains dyno's never measure.

The whole "ported FAST is too big for a mild combo's" is another Internet wives tale.....the heads determine whether a ported FAST is a wise move and with a really high flowing efficient set of heads it certainly is because a stock manifold (ported or otherwise) will chop off half the gains you paid for with the cylinder heads in terms of peak airflow....it simply cant keep up warranting the higher flowing intake.

Copy my former 346 package as much as you can afford to (arguably still the highest power I have seen from a 224 cammed combo) and you will be very happy.

Feel free to PM me if you have any questions or concerns. Or pick up the phone and drop me a line at AFR

(661)257-8124 Ext. 109

Cheers,
Tony

PS....And like others said, if your worried about the future when you may or may not go biigger, you can always send me the heads back to go thru by hand and still have plenty of cylinder head for a street/strip stroker motor. Check the results of Arkay99 and others with my ported/blueprinted 205 heads. They are even very effective on stock displacement builds if your looking for all the money from your combo (and your willing to invest more $$$ to get it).

vettenuts

Just noticed the OP is in California, the AFR's carry a CARB approval as well

Z28TOZO6

hey, you stole my blanky! I've been looking all over for that.

nice project. do you have a thread with everything you are doing?

SDLS1Rider

Hey Tony,

Where can we find the parts and specs write-up on your 346 package?

Will

Here?

vettenuts

I did that last fall. I had a few threads of some of the things I did but never did an overall start to finish. I took a crap load of photo's though.

As for the blanky, my kids old sheets sure come in handy for keeping out dirt and stuff, but I do take some crap for them

Ikester

nice thread hijack!

0Tony Mamo @ AFR

Actually that article does sum it up pretty well....

Its a good read....more technical than most

Steve Dulcich was the editor and covered the story himself

-Tony

AU N EGL

Tony
if we dropped the LSA on that cam to say a 112+4 or 110+4 would that move the torque and HP curve to lower rpm range? Or how would that effect 'the curve?"

tom

SDLS1Rider

I think I might have that issue of Chevy High Performance.

Okay I have to ask. Mr. Mamo, your in Cali, I'm in Cali, the OP is in Cali, so does that set up pass smog?

vettenuts

No, but barely. The next lower AFR cam should though, I think it is on a 220/224 and is part 6018 (from memory).

0Tony Mamo @ AFR

A hair more low RPM power, worse idle quality and emissions, slightly more peak TQ, similar peak power (or could even be lower), faster decline after peak power.

I have found the Gen III engines are not as effected (negatively) by a wider LSA than Gen II and especially Gen I carbuerated applications which really rely on the overlap more than EFI engines. Also, the better the head the wider the LSA typically (look at Pro Stock LSA's) so that's another reason why wide LSA's dont kill power much on these LS applications and offer advantages that I kind of prefer (better driving manners and idle quality and big power upstairs that really hangs on giving a very fat, flat, power curve in a combination thats really optimized.

Just barely but if you absolutely had to pass I would opt for a 220/224 or certainly no larger than a single pattern 224 which will kill about 4-6 peak ponies and make about 5 more ft/lbs at lower RPM's. The key there is overlap is reduced and it cleans up your emissions a bit more. That set-up would have a much better chance of getting past the smog police or should I say a much higher likelihood of passing. If the tune was right and the engine was healthy it should pass emmisions. With the 224/228 you had better be on your "A" game regarding the tune and get those cats (and the driveline) good and hot before its tested. It can and will pass but I usually tell people if they really dont have any other options, the smaller single pattern or better yet the 220/224 offers a little more room for error.

-Tony