JEB99TA

iTrader: (32)

I have opted to order AFR 205 heads. With the thicker GM MLS gaskets and the heads milled to 60cc chamber size, it appears I will get somewhere between 11.1:1-11.3:1 compression ratio ... does that sound about right? It's what I gathered from the sticky in this forum. Can I go any lower SAFELY with the milling ... for a higher compression ratio?

Also, would like to hear from someone who has a similar setup (sig below) ... just to know what the difference in power/torque was with the heads of the above configuration. Several dyno's show about 35-40 HP gains, however, searching those threads doesn't tell me how the car was setup when the heads were installed. I looking for a near-identical setup as mine ... with comparable power/torque.

gnx7

iTrader: (28)

If you want higher compression use Cometic gaskets that are thinner than the MLS.... about 4x the price though! Check your PtV. I ran a 233/239 with .603/.600 112LSA profile and had to flycut my pistons.

One thing I can warn you about.... cut the bottom non threaded part from the rocker arm bolts off.... or they will push thru the port roof (intakes on mine) and be in the port itself. Wish my heads cam with directions to warn me about that. Aside from that install is relatively simple. Follow the torque instructions... they are detailed.

I love these heads with an LS6 intake and ported TB with long tube headers thru the cats..... I made 439rwhp on 91 octane with about 10.7.1 compression.

I would put in a bigger cam than what is in your sig. That thing is tiny.

Beast96Z

iTrader: (21)

There is absolutly no reason for you to go with the thicker MLS gaskets. When setting up a head combo, you want to set a "quench" area. This is the distance between the the piston at TDC and the deck of the head. Most LS-1 shortblocks are .005"-.010" out of the hole. This would mean that you would want a .040"-.045" thick gasket to set a optimum quench of about .035". Once you get your gasket thickness, you can then determine the amount you want to mill. Milling the crap out of the heads and then getting a thick gasket is backwards. Figure your compression with a .040 gasket and then determine if you need to mill your heads to get more compression.

Mirek

That about summs it up. Better quench will also prevent detonation w/ that compression. Also if you are already cut to 60cc any more cutting may impact airflow.
You will have a fine combo.

PREDATOR-Z

From previous discussions with Tony Mamo, we came to the conclusion that:
1> Mill as little as possible for desired SCR (to keep as much of the flow characteristics of the head), with that cam I would go 62cc. (.024 mill)
2> Use their Cometic .040 (AFR) for better quench.

JEB99TA

iTrader: (32)

I just now went ahead and sent an email to the shop owner who is ordering the heads for me ... asking him to order them 62cc with the Cometics gaskets. With my cam, I wanted to do a swap for a 224/228, but, it just wouldn't net me much ... at least I don't think it would be worthwhile. What are your thoughts?

1QuickT-A

iTrader: (12)

Since you are spending the money on a set of AFR's, why not go ahead and pick out a new cam to compliment the heads? Are you wanting to stay with something small for good driveability or what? I would suggest a cam like the F13 or something close to that..

PREDATOR-Z

The 224/228 from AFR is the cam designed with those heads in mind.
IMO it should be worth a good 15+ rwhp over the 220.
Is it worth it? Well that is a relative question. If you don't care about having to dish out 350 (cam) + 200 (lifters), so another 500>600 $$ then get the 224/228 from AFR.

bigdsz

iTrader: (1)

Everything said above sounds good except for cam size, 224/228 is too small. I recently did a 228/230 XER, I wish i'd gone bigger. With those heads you need a decent cam!!!

Beast96Z

iTrader: (21)

The cam size is irrelivant. It's all in how the combo is put together. The AFR 224/228 cam seems to make the best power with those particular heads. I've seen people put in larger cams with these heads and they didn't seem to like it to much. You don't have to buy lifters unless your stockers are old. The stock ones can handle some abuse. I'd either run the AFR cam, or have EDC, a board member here, custom grind you one.

JEB99TA

iTrader: (32)

I was thinking a TR224/228 on a 115LSA (nitrous cam) because it's the largest I can go without cutting the pistons. Plus, I will be sharing the car with my 16 y.o. son for about a year and need it to remain somewhat streetable. If the cam would give me 15+ at the rear wheels with similar torque numbers, well, it would be worth it to pay the extra money, for sure.

My goal for this year is to have the motor forged, so, I wasn't anticipating lifters or any other internals, but, with a cam change, maybe this would be a good time to go ahead and change the lifters out. This will be a good thing. Next spring will be a strange 12-bolt. I believe the new factory 3.73's and HD Eaton posi will hold up on the Nitto's until springtime.

Next summer will be a racebuilt 4L60E. Then, I'll be ready to throw about 200-250 shot at it. This ****'s expensive, but, it's worth it.

Thanks for all the info and keep it coming ... love all the thoughts, opinions, and especially the experience.

smask04C5

iTrader: (1)

just received afr 205's 62cc, will install with .040 cometics and a crane 1449561 216/224 .551 lift on a 115 lsa with 1.8 crane rockers. tony is interested to see the end result, thinks this cam may work well with this setup.

JEB99TA

iTrader: (32)

I'd be interested in knowing what the results are. When are you going to install them and dyno? Make sure you post here man. I'm dying to see your resiluts.

smask04C5

iTrader: (1)

i will install end of next week, work permitting. I need to install guideplates and grind crane rocker stud ends to clear intake ports. will do a quick tune with handheld tuner then off to Vinci.

PREDATOR-Z

I would get the same exact grind that Tony has. It has to do with VE's. When changing the lsa, and advancing in the grind, you're changing the VE's, which in return will affect power output and power range of the cam.

I think his is a 113lsa +1 (or is it 114+1). It is in one of his threads.

SideStep

The cam Tony recommends is a 114lsa +1. I am not sure if "his" had the +1.

PREDATOR-Z

It does have the +1 and that came with R&D of different lsa, ICL's

Phil'sC5vette

iTrader: (4)

When it comes to my C5, Im a little conservative because I dont want to buy another one. ( more like my wife wont let me buy another one )
I just order AFR with 61cc. I bought the stock GM gaskets. that means they took off about .35 on a mill. I didnt want to take to much off the heads in case I did change cams.

Who knows whats best. I talked with 3 differant shops and got 3 differant numbers. One said go 63cc with .40 gasket, another 59cc and gm gasket, and another said 61cc with gm gasket. All 3 said id be just under or right at 11:01, and that where I wanted to be. I did not want to be over 11:01.

The price was right on the GM gaskets, and I can always buy a differant set of gaskets before installation for higher compression. Also, one of the shops I spoke with was having problems with leaks with the cosmetic gasket. I think with my application and finial compression, I wont have heads gasket issues. Throw jucie on it, and everything changes.

I wont be installing the heads until late winter.

I wasnt worried about clearance because I already had the Tr224 .564 lift last year. Im sure Im keeping 5 RWHP on the table, but that's ok

bigdsz

iTrader: (1)

Look at the .045 Cometic, it will put your quench at .037-.038 right were it should be. I used the OEM graphites which are .053 because there was a 6-7 week wait. Now I'm kicking myself for not waiting. The right quench is seriously important. A friend of mine is supposed to get his .040 Cometics this week, he's got the AFR 61cc milled .024. I told him to use the .045's but he wanted an even tighter quench. He figured since we're notching the pistons .080 anyway the tighter the quench the better.

smask04C5

iTrader: (1)

believe it or not, my pistons are out .006, that is why i chose the .040 cometics. is your friend milling afr 61 cc heads additional .024, or does he have a set milled .030 to 61cc?