416 cast number heads help! - Third Generation F-Body Message Boards

dvardaman85 · 05-25-2009, 06:52 PM

so this is my deal, im puting a k kit in my car and upon removal of my 85 lt4 heads i found that they are 416 cast heads. i read up on these forums and fuond that lots of people like them and say a mild port is good for them. my question is what exactly would i tell my machinest ? and why would i tell him that specificaly. what i mean is like you know if your stroking an engine you say like .30 over or something like that so how would i tell them what i want on my heads? help please

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dvardaman85 · 05-25-2009, 06:58 PM

oh and one more question.... how much should i be asking for my old stock intake man rebuilt q-jet and stock distr combo .... or does anyone even buy that type of thing anymore

Tobias05 · 05-25-2009, 07:53 PM

i think you should give everything to your best friend that just spent his memorial day with you tearing that sweet ride apart and look into an LS1 swap...

bubbatwo0_0 · 05-25-2009, 08:33 PM

The heads you have a great for raising compression cause they have a small combustion chamber, but on the other hand if want them to really perform then them ported. The stock intake runners wont flow enough air for a built engine. If you want to make them bad ***, then get a 3 angle valve job, ported, and big valves installed. Id hang on to the carb and intake, cause if you get another car that needs one you will already have it. Just get all the gas out of it and wrao it uo with some saran wrap and it will be good as new when you ready to use it.

camaronewbie · 05-25-2009, 08:47 PM

For what it would cost to pay a machine shop to do a good port/polish job on the 416's, you could just buy new heads. Machine shops aren't cheap anymore! Those of us that did the 416 heads did them ourselves, as it takes hours to do and it wasn't worth paying a shop.

bubbatwo0_0 · 05-25-2009, 08:52 PM

I think the best bang for your buck is a set of vortec heads. they are cheap and they have small combustion chambers and they flow like a mother. Only drawback is you have to buy a intake that will bolt to them.

dvardaman85 · 05-25-2009, 08:58 PM

hm well does anybody know approx what i might expect to pay for a good cleaning at a machine shop

tony_cogliandro · 05-25-2009, 09:00 PM

you forgot to mention new ss valves, ss full roller rockers and some new springs. about 350.00. valve job 150.00. increasing intake to 1.94 - 50.00.
if you use the right springs you wont have to spend money to pin the studs or drill and tap them.
but if you buy quality stuff you can use them on a really good set of heads - 1,200.00

dvardaman85 · 05-25-2009, 09:22 PM

new vortec heads wont offer much on my lg4 will they. isnt it a wast of money? not sure just sounds like something for a more high speed motor. welll i think that i will prob take all the casting marks off of my heads but not to knowledgable about porting so i will prob stop at smothing and losing casting marks..feel safe with just that from me..ha ..... how about a good cleanign from a machine shop for my heads anyone know a round about cost for that ... they will do that right

tony_cogliandro · 05-25-2009, 10:36 PM

go to the junk yard - pay 5.00 for some head that looks like crap and is cracked. thake it home and practice.
and use the search key they have some great porting and polishing links.

Sonix · 05-26-2009, 11:53 AM

I got 993 heads with my 350 that I bought. I practiced porting on those, plus I stole the 1.94" intake valves out of it. I had to buy new 1.5" exhaust valves, since exhaust valves don't last as long as intakes...
I paid my machine shop about $400 for work on my 416 heads. I had a 3 angle valve job, intakes cut to the larger size, decked for flatness, and bronze guides installed.

Buy an electric die grinder, and build a speed controller. Buy a few carbide burrs and a few sanding drums, etc. On your practice head, leave one port eau natural. Then port the next cylinder until it looks nice on ONE cylinder. Just ONE. Then do the one next to it, and go further... Until you're a bit spooked. Then get to the fourth hole and port it until you hit water jackets. All the way. You need to know how much you can take off. Remember, certain areas can be epoxied, certain areas cannot. Don't be shy to raise your intake runner until you see daylight. Epoxy works fine there. Remember it's a practice head, you never know until you DESTROY IT.

tony_cogliandro · 05-26-2009, 12:00 PM

Quote:

Originally Posted by Sonix

I got 993 heads with my 350 that I bought. I practiced porting on those, plus I stole the 1.94" intake valves out of it. I had to buy new 1.5" exhaust valves, since exhaust valves don't last as long as intakes...
I paid my machine shop about $400 for work on my 416 heads. I had a 3 angle valve job, intakes cut to the larger size, decked for flatness, and bronze guides installed.

Buy an electric die grinder, and build a speed controller. Buy a few carbide burrs and a few sanding drums, etc. On your practice head, leave one port eau natural. Then port the next cylinder until it looks nice on ONE cylinder. Just ONE. Then do the one next to it, and go further... Until you're a bit spooked. Then get to the fourth hole and port it until you hit water jackets. All the way. You need to know how much you can take off. Remember, certain areas can be epoxied, certain areas cannot. Don't be shy to raise your intake runner until you see daylight. Epoxy works fine there. Remember it's a practice head, you never know until you DESTROY IT.

that is a pretty good idea - intentionally go into the jacket - so you know how far to go. excellent idea. i have a practice head - old 6 cylinder - cracked. 5.00. took it apart. had nice paying time.
but i have to disagree about the valve change. you can get a nice set of SS valves for under 80.00 and you can use them in a different head - stock ones are not as good and tend to change shape - a minute amount and you will get bettr flow from the SS ones.

Sonix · 05-26-2009, 12:27 PM

Buy new valves if you want. I didn't think i'd get $80 worth of benefit from it. I chucked up my intake valves in a drill press and used some sandpaper to give them a hand-made backcut. David Vizard explains this in his how to rebuild an SBC book. Exhaust valves get a rounded edge on the front face, and intake valves get a non-rounded edge. intakes also get the back of the valve smoothed off.

dvardaman85 · 05-26-2009, 08:44 PM

wow all this seems pretty complex to be honest i removed all of the casting marks i could reach with a die grinder in the intake and exhaust side but thats about it i am suddenly being pressed for time so i have to get my beast back together. getting the springs put in at my local machine shop and getting the heads cleaned up real good. there was so much carbon buildup it took about five mins per exhaust hole on the heads before i could even get to the metal. so think i was suffocating the engine a little maybe.

however that is going to be all cleared up and the intake and exhaust match the gaskets as close as possible so even if i dont get a gain i will be happy with myself for putting for the effort that i did with such minimal experience. put the cam in today but havin trouble taking off the small gear for the timing chain cause it needs to be replaced by the one in my k kit. any suggestions

tommy z-28 · 06-03-2009, 10:34 AM

If you did not touch the bowls within 1/2" of the valve seat, I would say your gains will be minimal to none. Also taper the guide bosses if you still have a chance.

Atilla the Fun · 06-03-2009, 10:45 AM

forget roller rockers, if you're not going to 1.6:1 there's no point.