i have looked all over the site and i have heard you can get casting 416 heads to flow like vortec heads. is that true? what has to be done to the heads to get that kind of flow?

 

In a word (2 words actually), everything possible.

Absolutely maximum worked-up 416s will flow like a set of Vortecs straight off of a truck in the junkyard. Almost.

The highest flow numbers I've ever seen anybody claim for 416s, with any kind of anything resembling "proof", is about 225 CFM on the intake; after extensive professional-grade porting (not yerbasic backyard enthusiast with a Dremel). Stock Vortecs flow about 229 CFM untouched. The exhausts are about the same, given the same state of prep. Vortec exhaust ports are no different from 1955 model exhaust ports.

 

https://www.thirdgen.org/techbb2/sho...hreadid=117410

 

can i take the heads to a shop and have that kind of porting done?

so i would need the heads ported and polished to flow that kind of numbers.

ok great i will have them flow tested and then ported if needed. the guy i am getting the heads from said he did some porting on the intake side so when i get them home i will check it out. thanks for the help.

 

Port work is EXPENSIVE. It takes a long time, and requires a skilled person. In other words, a high hourly rate, times lots of hours. By the time you pay for all that, you will have more money tied up in them, than just buying a NEW set of ALUMINUM aftermarket heads outright.

A realistic flow # for 416s that an average well-done home porting job could expect to attain, would be 205-210 CFM.

 

The last set I did flowed 240+ intake and 180+ ex.

Yes you will have to fully port the 416's to achieve these results. DOOOO NOTTTTTT pay someone to port these heads for you.. Do it your self. If you have to pay some one to port these heads , it wll cost way too much,, or you won't get even close to the results. Cause it takes time to do it.
$$$Time is money$$$

Buy the cylinder head preperation book by David Vizard and read it. do what he tells you to do. If you don't want to port them your self, buy aftermarket heads that will flow the numbers out of he box.

I had the heads on my 350 in the car. These particular heads flowed mid 230's @28" It was fast, The engine broke a piston on the way to the track, so didn't get a time slip. I would estimate the power to not be an ounce over 350RWHP probabily a little less. More like 325-330 area. Thats around 410-420 Gross flywheel HP. Not bad for an 10 year old throw together 350 flat top motor with "305 heads". Still got the heads, one got destroyed.
The motor is totally rebuilt now and for sale in the Ontario region classifieds with camel backs on it.

 

i pmed you.

 

I have PM's dissabled..... email is russ_q@hotmail.com

 

Hmmm. Thats funny because mine flowed 210@ .500 and all I have is bigger valves with a 30 degree back cut. I will get the guy who did them for me to email me the exact numbers if he can and then I will post them.

 

yea sorry thats what i meant. i thought i clicked on pm but now that i remember i emailed you. sorry about that.

 

My "601"s (almost the same as the 416s) flowed 218 cfm @ .425" out of the box. The only thing not stock was the Precision Engine Parts stainless undercut PRO series valves. 1.84" & 1.50" valves. With mild intake port work they flow 242 cfm @ .425 and heavily moded exhaust ports 183 @ .443 on the exhaust.

They support my 355 with a cam that should die at 4,500 all the way to 5,300 rpm.

 

yeah see when you say untouched vortecs thats not saying alot. you can't really port vortecs and gain alot out of them. i've seen people try to port vortecs and they flowed less then they did stock just cause they flow extremly well out of the box for a gm head. but i've also seen guys port vortecs with succsess but 8 cfm succsess and i don't think it was worth the whole bunch of money they throw into the vortecs to get them to flow that much more. they ported them and better vavles and did a whole bunch of stuff and not muhc for a gain. but enough with that. i'm using 416 heads and i'll be flow benching them soon so i'll post my numbers soon

 

It is true its really hard to inprove the intake of the Vortecs, One thing you can do is add undercut valves for a little added flow. Really only the exhaust can be imporved. It is really poor from the factory and responds really well to porting.

 

did i mention porting vortec heads? cause thats where i see this moving towards and i was asking more about the 416 casting not vortec heads. would it be better for me to just buy aftermarket and sell the 416s? what aftermarket heads are cheap and flow well enough to get mid 12s if supported by the right components in other areas?

 

Don't give up on the 416s!

You CAN do the port work yourself, lots of us who thought otherwise are stroking around in much faster cars now

Follow the link at the end of my sig. A fellow posted it earler in this thread but you apparently didn't follow it. DO IT

 

yea i followed that link. looked interesting although i keep getting a lot of red xs which i assume are smilies and the info seems a little scattered.

i cant really follow along with it because it isnt compacted into first you do this then that and it should look like this. when there is an interruption (other people posting or something similar) in the directions it throws me off.

do you have a straight out format? im not trying to be rude or whatever but i could do without some of the "fluff" and by that i mean anything that doesnt show me something i need to see or tell me how to do this.

 

A lot of posted photos were lost in the outage.

Try this http://www.sa-motorsports.com/diyport.shtm . Basically what Bull did. I printed that out and studied it for months, then got their Deluxe Porting Kit and discovered the same instructions are included in poster form. Tacked it up over the bench while I did the job.

Only thing I'd add is to get some carbide burrs as well. And, if you work any aluminum (intake manifold, for instance), lubricate it or the burr will gum up on you.

 

I think it was 1bad91Z or something, guys name is Kevin. He has a set of Vortecs that flow, good. Had them ported. Look for his old posts.

 

would it be better to home port 198 casting heads and put the valves from the 416 heads in those? i know stock 350 heads have 1.94 and 1.5 valves and thats what the 416 casting has in them. the 198 casting heads i have i got for 10 bucks off a friend and they need cleaned but would i be better off using those?

 

Don't know of any 198 castings.

However, if they're really 193 (14102193), they're truck TBI "swirl-port" heads. You just gave away $10 to charity. Throw them in the trash.

 

yea thats what they are

 

They are one of the best heads to help hold down the garage floor though, thats what mine are doing. I am pleased with how they are performing now.

 

The 416s came with 1.84" valves right?
The 193s should have a set of 1.94"s in there that you could re use in your 416s, then port them and have the valves back cut etc, and you're off to the races!

 

the 416s already have 1.94 valves in them. they are unported tho.

 

sorry for the post jack but whats the casting number for tpi 305 heads is it the 416?

 

Yes, that is the casting number; for 85-86 only. 87-up motors use the centerbolt valve covers and the different bolt angle on some of the intake bolts. The casting # for those is 081.

 

r the 081 a better head than the 416's or the 193s thats are currently on my motor

 

Don't know about the 081 vs 416 part, but the TBI heads have a huge obstruction in the port that makes them very difficult to work with.

 

081 ~= 416.

Or, to put it a different way, 416 ~= 081.

 

According to mortec.com and the casting number of my 416s I just got, stock they are 1.84/1.50 valves... I also have a set of truck heads of a 75 chevy 4x4 (came with my engine that I am rebuilding) and those valves are bigger than whats in the 416s....

casting number 14014416.

 

193 TBI heads really aren't too bad for a stock head and really respond well with porting. Read my post in the TBI section.

 

Those are garbage too. Even though they have the stock size valves for a 350.

There's a helluvalot more to what makes ahead "good" or not, than the diameter of the valves that the factory (or anybody else for that matter) installed in them. You CANNOT look at a set of heads, and assume that just because it has bigger valves, that it's going to put out more power. Life simply doesn't work that way.

People need to realize, the reason that these old cars from the 70s and 80s run so bad no matter what you do, is BECAUSE OF THE HEADS. They're terrible. Nothing else that you can do to the motor will make up for it. The only cure is to throw them away and get better heads.

The 305 heads may suck in stock form, but they have the right port and chamber shape, and the right amounts of metal in the right places, to have some degree of potential for improvement. You can work on those crap truck heads from now till Doomsday, and you still never get an engine to run really good with them, no matter how many hours you put in them or what little valves they came with stock. The 305 heads will reward you a little bit, if still far short of good aftermarket ones; the smoggers won't even get you close. No matter what valves they came with.