whitez406

iTrader: (5)

Im helping a friend out at his shop and we were talking and im gonna be freshing my 383 up again and swaping cams and i have a set of 416 heads that i would like to use on it instead of my 882's. Im not paying for labor at all. Im gonna have them surfaced, install 2.02/1.60's, port them, and flow them. The small chamber makes in a great head to get my compression up. My question is what kind of flow numbers can be acheived with these heads? What kind of power level will these heads support etc etc. Any info would be apreciated.

Sonix

iTrader: (1)

The chamber is undoubtedly too small for your 383, unless you have soup dish pistons, and intend on enlarging the chambers on the heads. Also, don't plan on fitting 2.02/1.6 valves into them, they aren't 350 chamber heads.

They work great, and with a good port job and valve job can support 350-400HP when properly cammed up.
See sig.

whitez406

iTrader: (5)

Im kinda figuring there small. Can a 2.02 be used or no? Id like to get my comp up close to 12.1 now w/ comp xtreme 294H (250/256@.050). Im thinking the motor will put out low to mid 400's at best since the bottom end is not the beefiest. Iron eagles are looking a lil more promising.

Sonix

iTrader: (1)

12:1 ? You going to run methanol or something? This is a zero street car then right?
you can port up the 416's. Just install 1.94" valves. Thinking that the biggest valves you can possible cram in there is old school thought. It doesn't always make the most power. You *might* be able to physically cram them into the head, but it won't work as well as 1.94's.

327_TPI_77_Maro

iTrader: (8)

Seriously, just get a pair of 64cc Dart or World Products iron heads. Around $800 a pair new. You couldn't get 305 heads rebuilt and performing nearly as well for the same price. I would never ever try to run little weeny heads like the 416s on a 383. For super budget performance they work well, but on large displacement engines, I wouldn't consider it.

I still have a set of ported and polished 416s/081s that I ran on a 327 for a few thou miles before yanking them. They made the engine detonation prone because the tiny 305 sized chambers hang into the 4"+ bore and make hot spots. Not an ideal setup.

Sonix

iTrader: (1)

With a 383 (and flat tops?) I'd look at 70-72cc heads. If you have moderate dished pistons then 64cc would work great.
But yea, if you want to rev it and make power, you'd need to be a really good porter to get the most out of those heads. You'd be enlarging the ports and bowls up A LOT.
What?? I'd have to disagree with this, I don't think this happens.

327_TPI_77_Maro

iTrader: (8)

It most certainly does. Any sharp edges in a combustion chamber can get red hot while the engine is running because the small cross section at that sharp edge.

Sonix

iTrader: (1)

It's not a sharp edge though. You smooth it off with sandpaper. It's effect is minimal, on the same lines as the valve lip, valve seat, piston crown edge, etc.

F-BIRD'88

The chambers of a 416 head are no more smaller than the chambers on the origional hi perf 327 heads.
If your so called sharp edge theory was correct, vortec heads or any other head like it would not work.
If you had a "sharp edge" in the chamber that had any chance of glowing or creating preignition, its because you did not deburr the edge of the combustion chamber after resurfacing decks. I have run 416 heads on many large bore motors.

if you had a problem on your 327 with 416 heads it was most likely from lean afr possible vacuum leak on 1 cylinder, over advanced timing, wrong spark plug heat range, thin valve margin, a very sharp edge created after machining.
Combining with a dome piston (excessive cr)

Do not use a 2.02 valve in these heads. A 2.02 will just weaken this head between the valves. A 1.94x 1.60" set is bet.
Usually your chamber volume is a little bigger than stock when you're done.
low 60's is typical.
In stock form they flow 188cfm in 136 ex.

With full porting and larger 1.94x 1.60" valves mid 230's in a 190cfm ex is typical. I've gotten as high as 243cfm.

You get more power if you fill the void in the roof of the intake ports under the rocker stud with epoxy and fill the exhaust heat riser passages in the center ex ports with hard block or molten aluminum (old melted down pistons)

For high compression hi perf use use a cooler spark plug ACR42T, champion RV8C autolite 144
You can finish the chamber size ranging from 51cc with max milling, to around 65cc with generous valve deshrouding w/o milling.

you'll need high octane racing gas to run 12:1 cr. As long as thats ok, go for it.
If you don't mind the work requred to get them up to snuff, they will work pretty good for you.

whitez406

iTrader: (5)

I have a 355 i run 12.1 comp with 87 octane and zero pinging or problems. I have run high comp in many engine without race gas. I will be daily driving this car back and forth to work, the track, wherever i gotta go. Im gonna go wtih a set of dart heads.

Sonix

iTrader: (1)

Ah, you must be the lucky winner, while the rest of us poor SOB's have to live in the real world eh?
I believe there's a smiley just for you .

five7kid

iTrader: (14)

All that good scoop on 416's, then this.

whitez406

iTrader: (5)

Guess you dont have the rite combo then. My engine builder drives his 14.5:1 motor on 93 octane. Radialtireking on here runs his 8 sec 436 sbc on 93 octane. Theres quite a few ppl doing it. Guess im just a lucky sob then huh?

Sonix

iTrader: (1)

I was pretty sure radialtireking runs 110 octane, and I have no idea the CR he runs.
You must be a heck of a lucky SOB. Or you could cough up the details and we can go from there? I generally don't like to think of guys as outright liars, I was hoping I could bait you for details on your setup eh?

whitez406

iTrader: (5)

Radialtireking runs 93 unless the car is sprayed. It just works. The right cam, good ignition and good heads. Works everytime for me. Never had a motor ping or detonate BUT i had some issues with power a long time ago and i thought the dist was messed up so i dropped a stock hei in there and it didnt like that at all it pinged and it wasnt good. The petronix 50,000 volt coil and module make a big differance.

Sonix

iTrader: (1)

Hmm, will keep that in mind.
Well yea, a big cam, good chambered heads and maybe even throw in some altitude and you're fine. But those are the details. So, what are you 12:1 engine details eh?
My 10.3:1 engine runs peachy fine with a moderate cam and iron heads. 4000' altitude gives me a lot of safety margin.

81caballero

there is no way in hell you can run 87 octane safely in a 12.5:1 compression motor......416 heads are junk unless you run them on a mild 305.....the puny runners will not support a 383 , you will end up choking the motor off. go buy a set of patriots...190cc runner up here in canada they are 700 a pair complete. or if you have access to a set of 906/062 vortecs, build those up.

whitez406

iTrader: (5)

Im im not gonna argue with you about it but i have run it on 87 octane many times. Either way I can get dart iron eagle castings with pbm internals for $600 a pair from my engine builder so im gonna do that.

Im only 12 feet above sea level here. lol. The 383 is not a race car motor by any means it was more built for a daily driver everday car but im gonna get everything i can out of it and when it blows up ill rebiuld it. Its a powerhouse balanced rotating assembly w/ 2 releif flat tops, decked block, comp xtreme 294H cam now (Has a xtreme 274H, then i changed to a magnum 294S but had some problems), had some 882's opened up a tad bit, holley strip dominator intake, petronix HEI ignition, hooker 2210s, a modified and shaved holley 750 DP and some new iron eagles that will get some opening up rite away. Im hoping to see 375rwhp and throw a small shot on it.

Back on the 355 when i drove back and forth to pa every weekend. The car got 14mpg with a a3 and 3500 w/ 3.42's running 80 for 2 hours straight. I dont beleive this motor was 12.1 but when we figued the comp on this motor it was 11.6:1 i think.

five7kid

iTrader: (14)

Amazing the assumptions and misinformation out there. 416 heads had the same port sizes as the L98 heads. Not that 190cc heads won't flow better, but to say they'll choke off an engine just because the factory put them on 305's is nonsense.

Sonix

iTrader: (1)

ok, light car, big stall, cruising on the highway, CR just went down a tad, ok now we're getting somewhere.
Lighten the timing, and you can cruise just fine. Fill that 355 with race gas, dyno it and find the optimum jetting and timing. Then fill it with 87 octane and lead-foot it through town - you'll find it doesn't like 87 octane.

whitez406

iTrader: (5)

I used to run it at maple grove with 87 octane when i was in high school then and made like $70 a week. The 355 ran 34 total timing all the time, It had flattops w/ felpro head shims (.015 compressed) and the heads were shave to 55cc. It just worked.

So what kind of numbers can be acheved with the 416's? Im looking for a set of heads capeable of flowing 290-300 at .550. Best numbers i found on a search so far have been 231. I have 2 sets of 416's and 1 set of 601's. Anybody need some.

Sonix

iTrader: (1)

hahahahhaha! 300 eh? Good luck with that! The biggest best 23* SBC heads don't even flow that much! You'll need 15* heads with MASSIVE ports to flow 300cfm at .550" ! Good luck with that (~$3000 or so).

231 is pretty good for 416's. That'll make you 400HP if you set up the rest of the engine right.

whitez406

iTrader: (5)

I know 416's wont flow that. I got to many numbers going in my head rite now. I have seen some ported 23* afrs and brodix go 302-310 already. Im gonna be getting a set of the Brodix IK200's instead of the Darts. Gonna do some porting and matching and see what it will do. Should make over 450

Sonix

iTrader: (1)

Huh, they'd have to be ported like crazy. I figured it's hard for the home mechanic to beat AFR's CNC ported heads (what, 280cfm at .700" lift or something?). I sure wouldn't trust myself with a die grinder on $1200++ heads. Good luck, it'll be crazy fast one way or another.

whitez406

iTrader: (5)

Just cuase there cnc ported doesnt mean ppl dont port them farther. Home mechanic? I work at an engine shop part time. Ive seen some nasty afr 227's, old brodix heads, darts, etc. 300 cfm would be overkill for me now but down the road iam hoping for a bigger stroker. Jegs has High flow 220's that flow over 300 out of the box.
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I wouldnt say there junk by any means but i would like to see the link of where you can get the patriots for 700 complete.

Sonix

iTrader: (1)

Ah, well I have no idea of your qualifications. I can only speak for the majority of us members on here, shade tree mechanics for the most part.
Jegs eh? I'll have to check that out./

iroczracer07

iTrader: (2)

The A.F.R. 195's flow 280 cfm @ 0.550 lift, but the 215's flow 310 cfm @ 0.550, topping out at 325 cfm @ 0.700 lift. Small point, but worth mentioning. Sonix called it right on the cash outlay for in excess of 300 cfm at 0.550 lift. The 215's will set you back at least 2500 greenbacks if I'm not mistaken, which I could be. I'm open to that. Just thought I'd add my in case someone reading this thread was curious.