geddy2112

I am trying to do my researching trying to figure out what is the best direction to go without breaking the bank on a LS engine build.

05 GTO, original 6.0 LS2 with 15000 miles, AFR 225 heads, 232-234 .598 cam, FAST 92mm intake, Kooks 1 3/4 headers, 6 speed with 3.91 gears. Tuned and is making 460HP, 435TQ.

Interested in buying a ERL 454 cu high compression 12.0+cr short block. Port the AFR 225 heads, properly spec'ed tight lash soild roller cam, 102 FAST intake, E85 will be the fuel.

Not looking for a max effort engine. Not my DD and never will be. Fun weekend cruiser. goal is around 625-650hp, no power adder. Trying to get my goat to run faster. The goat is a really heavy car.

Will the AFR 225 still be choking the engine if i have a reputable CNC shop port the heads?

Not too familiar with the LS7 type of heads but reading on it now. Trying to spend the funds wisely. How much HP will i be leaving on the table by not going to the rectangular ported LS7 head?

Thanks for the inputs.

NAVYBLUE210

With AFR 225s, Fast 92, & 1 3/4 LTs, 454" will be CHOKED Big Time!
Might get to 525+ RWHP.
Lots of torque everywhere though contact Tony and he can
Improve heads they are already CNC'd.

With TFS LS7 Heads and MSD Intake (MAMOFIED), 102 TB and moderate
Sized cam for the CI (245+* Intake Duration LLSR) & at least 1 7/8"
LTs, 2" if they fit should make easy 625+ RWHP.
My .02

redtan

iTrader: (5)

Ain't never gonna happen with those heads. Will they be ok for the engine, especially re-worked by someone else? Sure...but they ain't gonna make that kinda power.

But I have to ask, at this point why not go with something like the LS7? By the time you sell your current heads and all the money that you would invest in porting them all over again you can get yourself a set of nicely worked LS7s or the like.

Yes the goats are heavy, but having that kinda torque without being able to put it down doesn't make much sense unless you are tubbed and have a big rear end. Car will move just fine with LS7 style heads even if they won't make as much torque at 4000rpm as the AFRs.

Gray86hatch

iTrader: (83)

My 454 with hand ported ls3. Nothing special and a Hyd roller it made 590 at the tire. Made 750 ish at the crank

Tim

kinglt-1

iTrader: (26)

I find that odd when stage III 243's have made 600whp on a 440...525-550whp is fairly common with 418 LS3 blocks and worked 243's. Hydraulic stick taboot.

NAVYBLUE210

MAMOFIED AFR 225s, MAMOFIED FAST102, 102TB, don't know if they
Make 2" LTs for GTOs, Big Hydraulic, 560-580 RWHP with 454"
maybe 600 with LLSR. Much easier to sell heads, intake, headers,
Etc and go LS7 with MAMOFIED MSD INTAKE + 50 RWHP
For relatively comparable cam.

Rise of the Phoenix

iTrader: (27)

Guys, you didn't let the OP elaborate on the "porting" the AFR 225cc heads will get. For all you know, he may have someone like Chris Frank open them up a lot, which would be great for his build. I honestly don't think the straight out of the box CNC ported AFR 225cc heads would be a big restriction. Those are some of the best heads on the market, and with a proper cam, intake, and valvetrain, they would perform extremely well.

redtan

iTrader: (5)

Do you think they have enough meat on them left to open them up to a 235-245cc?

How would they compare to say a CF ported LS7?

brobinson216

iTrader: (11)

Those heads in the right hands will certainly provide what your looking to accomplish with no problem.

They are much better suited for 450ish ci vs. 364ci.

Rise of the Phoenix

iTrader: (27)

I would think so. OP said this is going to be a NA car too, so without the added stress that you get with FI, I'd say it will be fine. Maybe Tony Mamo will find this thread and chime in.

I've always been a fan of cathedral style heads, especially in a street application like this. In the right hands, I think the AFR 225cc heads will be on par with Chris Frank ported LS7 heads.

Tony @ Mamo Motorsports

Its really the wrong head for a 454 CID build....coming from the guy that designed the product line I hope that simple sentence hits home.....LOL

If you really wanted a cathedral on an engine that large, I have an MMS 255 head with a 2.200 intake valve.....highest flowing LS cathedral head I have personally ever tested no matter the runner size or the name on the end pad of the head (also a profound statement!).

That head flows 375 CFM in out of the box full CNC trim and 385+ if I "Mamofy" aka hand finish it to perfection. Thats ALOT of flow in a cathedral runner design and you have enough CSA to feed a larger engine. It would be wicked responsive and make big TQ numbers and solid HP numbers as well.....realistically around 600 RWHP on an honest dyno in a very detailed optimized combination.

You could and should also be considering ported LS3 or ported LS7 heads (both of which I can help with)....but obviously these require different rockers and a different intake manifold etc. and its kind of apples and oranges but a really well prepped rect port head (I would go LS7) would trump the cathedral in flow and top end power. Wouldn't be as insanely responsive as the cathedral head but really that will get old (and fun!) when your constantly frying your tires for hundreds of feet trying to hook up all the low RPM grunt.....LOL

BUT.....the main point garnered from my post here is don't wast your time with AFR 225's in either ported or stock trim.....its just not enough cylinder head to get it done and the money you would need to invest to even get them decent would be better added to the money you could get selling them and then you land in a MMS 255 or any of the other options I mentioned with a brand new head that's far better suited to the task at hand.....a 454 has a big appetite for air.....not fed properly it will make a bunch of bottom end and fall on its face when the RPM's come up....not the desired goal Im sure

-Tony

brobinson216

iTrader: (11)

Tony

What would be the linear graph differences and final numbers between say the 225 and the 255 you speak of?

454 ci

Curiosity killed the cat.

geddy2112

Thanks for all the replies guys!

These are the answers i was seeking for. I am going read up on the different types of available LS7 heads.

I think at this point, a Mast ported LS7 head or a Mamo ported LS7 head can easily accomplish my goals. This engine is not going to be a max effort engine, however, i do intent to run the compression high because of the availability of E85 at my local gas station.

What is the everyone"s opinion on the choice of 454cu or a 440cu?

The car is a 6 speed with 3.91 gears.

thanks again for all your inputs.

NAVYBLUE210

My choice 440", TFS LS7 Heads MAMOFIED 400+ CFM from
260 CC Port @ .600" (more flow/port size than any other rectangle
Port I know off), MAMOFIED MSD INTAKE, Holley 105 TB, CAMMOTION
LLSR, 2" ARH LTs, 12.5:1 E85.
Possible 650 RWHP!

Rise of the Phoenix

iTrader: (27)

Might as well go with the 454ci if you can afford it. There is a set of FRH ported LS7 heads for sale in the classified section. Those would suit those cubes quite nicely.

Tony @ Mamo Motorsports

Honestly, in the vicinity of 50 RWHP....

Have you ever seen a ported (forget stock) AFR 225 head get anywhere close to 600? Not a chance....low/mid 500's is and would be a respectable number for that head.

Perhaps one of the best examples of an AFR 225's potential was my 383 solid roller motor from years back.....of course like most of my personal endeavors, a VERY optimized hit all the details Mamo build including addressing driveline weight savings.....light rims and tires etc.....checking off ALL the boxes for being a hero on the chassis dyno. That engine put out about 540 RWHP and consistently pushed my C5 to 129-130 trap speeds in the crappy So Cal weather (crappy for drag racing.....comfortable for living.....LOL). Same car running in December at E-Town NJ would probably have been nipping at close to 132 traps with a DA 2000 feet lower. That's getting with it at close to 3500 lbs race weight

A 454 with a similar top end combo would have made more TQ (Alot more...) and similar power.....it just would have peaked earlier and rolled over faster. Alot more average power though due to all the improvements in the bottom and middle part of the curve but peak power would have been similar because that's airflow related....peak would just happen sooner in the big motor....probably around 6200 versus the 6800 RPM I saw in the much smaller 383 CID engine.

Good stuff!

-Tony

brobinson216

iTrader: (11)

Agreed good stuff and again that was my point in saying they would work well for a street driven machine.

I seem to differ from most around this forum in that turning 7k on the street really is not practical. I'm more of a roast the tires through 4th with ease.

Takes me back to the c5 z06 magna days 500ftlbs instant in a 3k lb. carving machine/ice rink special. They told me when we built it.........better invest in some diff parts and upgrades.

They were absolutely correct but all that torque instantly does something to a man?

Ever been in a big cube LT5 ZR-1? If you haven't.....put it on your bucket list.

Thanks for your contributions!

Tony @ Mamo Motorsports

Your welcome....

Understand that "feeling" with the small heads is more of a part throttle deal where the smaller head can kind of activate/come alive sooner when there isn't much air passing thru the engine.

BUT....at wide open throttle, my MMS 255 cathedral will make more torque and more horsepower at every RPM.....even as low as 3K if you were to test it down there. Its still a head that's on the small side in relation to the cubic inch in question here, its still a high airspeed design head with a modest CSA, but compared to the 225 will feed the engine with more more air at every RPM. Don't purposely under head an expensive big inch combination.....that's what you would be doing with the 225. The 255 will light the tires harder everywhere and run stronger up top when you want and need it to in a drag race (not playing around baking the tires....LOL)

It would be the perfect scenario for you based on what you describe compared to looking at the square port design which while making good power would feel lazier in comparison in the lower RPM range.

More good stuff and very important to the outcome of your proposed project

-Tony

PS....Shifting it earlier and making even more grunt down low and in the middle (if that's the area of the curve you want to focus on), is also more a function of the proper cam choice. Having the right heads on as well will just fatten and improve the curve even more.

brobinson216

iTrader: (11)

Maybe you could team with Bullet

Tony @ Mamo Motorsports

I normally grind all my customs utilizing Comp Cams lobes. They have an incredible amount of R&D and spintron/dyno testing invested and I'm personal friends with alot of the key players.....some for two decades. They have a huge budget for R&D and I have a good supply of proven lobe families that I have a solid history of making power with.....I tend to stick with what works.

Bullet is a good company.....Cam motion etc. but for me the right products and the right relationships keeps me a fan of Comp and FWIW I have never had a problem with any of their cams and I have purchased hundreds.

Cheers,
Tony