not **** in anyones cherios-

but if your AFR's are flowign 275cfm you have a big problem...

 

Supposedly the smaller heads (180-190cc LT1 heads) flow around or a little less than 275cfm. They even advertise it on their site.

 

ported

 

AFR 190s are a waste of money. If you've been around the f-body internet community long enough you know that it's not uncommon for them to flow way less than advertised (like 30 cfm less). The 195s are better but require the extra expense of a new intake, and if you don't get them hand worked after AFR does their work they will likely flow less than a well worked set of factory LT1s. The only good reason to get AFRs is if you are going 210+ cc (which doesn't make sense for most NA 350 applications) or you have a big power adder and need the deck thickness to keep the head gaskets in place.

 

well waht size are the combustion chambers on the stock heads?? And with the hotcam Who should I have do the work?? I'd rather someone send me some worked heads and I'll send cores back so I can keep drivin

 

54cc for stock LT1 combustion chambers. There's a guy here in Houston that puts the LT4 valve size (stainless Ferrera though) in your LT1 heads, then ports them to flow 280+, 3 angle valve job and strong springs for around $1,200. Want them to flow 300+? The price goes up to $1,800 or so. Using your cores. He just did a set of heads for me. He said he got 280+out of them. I'm taking them over to GTP to have Craig flow them as well. My current heads were ported by me. Using the LT4 HOT Cam kit and these heads, plus hooker Long tubes dyno'd 389 rwhp. My home ported heads are using stock valve diamters, plus a 5 angle valve job from GTP. Best all motor pass with the LT4 hot cam was 12.2 @ 111mph using ET STreets. Went to a CC224/236 cam with no other changes and had a best all motor of 12.0. Added a 100 shot of nitrous and went 11.1 @ 121 mph.

 

from what ive read...........LT1 castings simply do not have the cross sectional size available to flow over 300 period.

if hes claiming 300 on LT1 castings, id love to see a 3rd party flow sheet.


hell, im curious to see what your heads flow 3rd party if he claims 280, he must be damn good.

 

I must admit, I'd heard from two people that are quite involved in racing that you can't get 300+ from a stock LT1 casting. But I've heard from 2 others(the head porter in question being one and the guy that does the Pro Stock Dodge Teams heads being the other) that they can. I don't think any of us can afford the pro stock Dodge guy
He (my head porter) did intimate that it involves cutting new seats and going to something beyond 2.02 intakes. I don't remember what specifics or exhaust valve size he said. I was still picking my jaw off the ground from the 300+ flow for $1,800 statement.
The thing I don't like about Flow benching is it's kinda like chassis dyno's from what I've been hearing. That being, things can be applied (Tube size on the intake/exhaust ports, tube size for the psuedo cylinder, other "correctional" factors) that can affect the output flow figures and push them up(your porter) or down(the competitors shop where you took the heads for a second party flow sheet). The thing that seems to "lie" the least is the track. I went over the GTP to talk to Craig Gallant when I embarked on my head porting efforts on my original heads and saw an LT1 casting he'd done for a 396 using LT1 castings. It had huge globs of epoxy in the valve cover area to cover massive holes he'd ground to increase the cross section so I'm guessing it (300+ flows) can be done. My head porter has been doing Buick G/N heads for many years and has an outstanding reputation in that arena as well as with the 5.0 Ford crowd. The only drawback of using him that I've seen is the previously mentioned time constraint. It takes him awhile to finish them since he does this work afterhours. He has a full time job, wife and kids. He squeezes this in somehow. He did say he's *just about* got enough money to quit his employee job and do the head porting full time. He's got all his machinery paid for and he has a lot of machines. He's not using Dremels and electric 1/4" drills (Like I did LOL). He's got the whole normal automotive machine shop. Lathes, boring bars, Hone plates, Serdi, Presses, compressors, etc. All name brand commercial machines. For certain, he's charging almost a grand less for what equates to any other major porters "Stage II" efforts.

So, GTP will be seeing my heads this afternoon and the track will see them probably this time next month. (I have to wait for another paycheck next week to order the custom CamMotions Cam). I'll post GTP's readings when I get them.

 

Three things

1. Can's heads be TOO Bigh for the Application? I mean If I have 300+ Flowing heads don't I then Reach the limitations of the Cam? Or can too much flow not be a problem and the motor will just use what it needs?. In a nutshell will too much slow me down?

2. Combustion Chambers Sizes if the AFR190 is 190 CC's that will SIGNIFICANTLY lower my compression ratio and It's always been my understanding that Higher compression ratios are good.

3. Whoever I have do Headwork, One rule NO EPOXY!!! I have a freind who chased engine problems for a month and it was due to a piece of epoxt flew out of the head and into the valve and it never shut then it fell into the Cyl, no real engine damage, but what a pain in the ***. p If it was an LT1 I know there wouldn't have been enough room and he piston would have been wiped out, he's lucky he had a 30spew!

 

Apples and Oranges....
AFR 190 CC refers to the intake port total volume. In other words, the complete intake port from intake manifold flange to the back of the valve will hold 190cc of liquid/air.

The combustion chamber volume of 54cc refers to this,...
lay the head upside down and level. Put a 'smear' of grease around the perimeter of a combustion chamber. Take an 8 inch square of plexiglass and drill a small hole in the middle. Lay this square of pleixglass on the combustion chamber with the smear of grease around it(the grease will act as a seal). Now take a burette that's incremented in CC's, fill it with water, noting how many cc's you'd put in the burette. Now pour enough liquid from the burette into the hole in the plexiglass till the combustion chamber is filled. Add up(If it takes more than a single burettes worth of water) how many CC's of water you were able to pour into the combustion chamber. That figure is the combustion chamber volume.

Big PORT volume (aka AFR 220's) are for big cube motors that can benefit from that 'available' air. Using huge port volumes on stock 350's will rob your motor of valuable air velocity, especially at street driving RPM levels. Result? Your engine will feel sluggish. Drivability on the street will suffer. Low velocity means poor cylinder filling. Bigger is not *always* better (my wife disagrees How rude!)

 

So 190's are Comparabe to stock Heads? AND If I were to get 195 LT4 heads and an LT4 Intake, I'll still have the velocity for low-end Torque

 

I believe what you said is correct.

 

OK So I'm Getiin AFR 195's and An LT4 Intake! I'll place the Order first thing tomorrow w/NuTek! Anyone have objections PLEASE POST! when it comes to GEN II HEads, I'm Lost

Thanks for all info!

 

wow, I dont understand head flow that well, but there is more and confusion in this thread than i can comment further on...

Someone better pray phil or lloyd or someone gets in here...

Hell I could get insane flow out of LT1 heads too, I just wouldn't sugest trying to get power out of them

 

AFR's are a waste of hard earned money when someone can get the same power out of an LT1 casting. Why throw away all that money when Lloyd can port em and install bigger valves for just under $1000? Just do a search for the user name Nighttrain66 and you'll see.

Joe