I have recently acquired a set of Vortec Heads and a Hot Cam Kit
from GM Performance Parts. I know that I will have to have the
heads machined for the wider springs that come in the kit, but I have also heard that the valve guides them selves have to be machined for
retainer to guide clearance, does anyone know how much? Also
I'm thinking of having the valves bored for 2.05 / 1.60 Manley RaceFlo valves. Is anyone running this combination with Vortec
heads? And if so is it worth the extra cost of machining? By the way this is all going in a ZZ4 block with TRW forged flat top pistons and PM rods. I would appreciate any help in this matter.

 

I think they have covered those questions for you in one of the last three Chevy High Performance mags.

 

You could do all that. OR you could buy heads that are already equipped for those size springs and alot of lift.

I had a set of Vortec heads that I never used and sold for that reason. Why buy $500 heads that need $500 worth of machine work (guides milled, screw-in studs, spring pockets milled) just so they're up to par with most aftermarket heads that come that way? You're talkin big bucks especially after you buy $200 worth of big valves.

After all that mess you still get to buy a Vortec specific intake for horribly inflated price.

Seems like Pro-Lightning heads or Dart Iron Eagles would be a much better solution.

 

I have to agree with v8astrocaptain,

if you were to install the larger valves in the vortec heads you need to do a fair amount of work to them to realize gains, primarily unshrouding the valve in the chamber and enlarging the outer side of the valve guide along with all the other standard porting stuff.
All that and youll be flowing like a set of pro lightning 180s out of the box

 

Thanks for the responses, I guess I forgot to mention that I got
the heads for free. The porting and polishing will be done by a good friend of mine who works at one of the prominent machine shops in south Florida. The valves are about $175.00 from Jegs,
that looks like my only real cost right now. I saw a build-up with
this same combo minus the larger valves and porting and polishing, they got 425 horsepower! Anyone have an idea of how much of an increase I can expect from these head mods?
If anyone has any different ideas I'm open to suggestions.

 

They are right saying they will need some work, but not if you trust your own hands. You can buy the cutters, and mendrel to cut the seats, and guides down for under $50 from Summit. The valves you said are $175, but honestly, I wouldn't go bigger than the stock ones. That will incure some big costs. Get some 1.94/1.60 valves. I bought all my Elgin valves for about $100. Studs were $30, machining for them was $85. So, if you got the same prices, and you said the heads were free, your up to about $225 with misc. costs for a good set of heads. The specific intake is a down side. But if you ever change heads, sell the whole setup on eBay.

 

I thought you were gonna buy a new set and dump all that money into them. Sheeit if they're free then go for it.

 

getting larger valves for vortec heads probably isnt worth the money. thats what i hear anyway. we just grinded down the retainers ourselves with no problems. installed valve springs that supported higher lift too. no major machine work necessary. you could spend money on other things listed above, such as screw-in studs, if you need it.

 

I think it's high time someone wrote a good tech article
on buying, modifying and useing Vortec heads.
With lots of specs, how to's, and facts and not much opinions
and hearsay.

Al thou you can create a $$$nightmare$$$ out of any project,
Vortecs remain one of the best/cheapest bang for the buck deals going. Even with the required vortec manifold and valve train upgrades. They flat out work....

Could be included in the tech section of this sight and
eliminate 99% of the multi posting over and over again on the subject.

 

I was saying the same thing for the longest time. IT seemed like all I would see was regurgitated info on what so and so "heard" with no hard data. I even wrote an email to one of the car mags.

It just so happened that a week later I picked up max horsepower small block chevys on a budget by david vizard and let out a near giddy sounding giggle as I found a few pages devoted soley to vortec head mods. Very informative, he included flow data aswell. You might want to have a look at it. The rest of the book is great too.

 

Totally agree here. Anything written, especially
"How to build Chevy small blocks on a Budget" (David Vizard)should be required reading. Best $10 you'll spend on going fast.

 

Thank you for your responses. I do have Mr Vizards book, but I never read the cylinder head chapter. I have heard that porting your own heads is useless without a flowbench. I did however like his camshaft section of the book (altough I did buy a highly mass produced cam kit). As soon as I finish this build up I will write a tech article complete with dyno sheets ad comparisons between different intakes and headers. I took a set of Votecs off
a G-Van with a 305 today, maybe I'll do a 305 Voretch build-up for all of you with 305s. Don't be ashamed I had one in my first
Camaro.

 

OK first thing.. Rule #1 Forget every thing you ever heard.
Rule #2. EVERYTHING!!!!!! all bulls***!!!

Rule#3 read the whole book,, cover to cover 3 tiimes.
Vizard is very clear on how to home port your heads and get decent results. Just follow his guidelines. Everthing outlined
on porting the heads in the book is relevant to other "less
desireable head" like 305 heads etc.

The 305 L-30 vortec head is a little known $$superlow buck$$$
high potential head just ready to be bought for a song and tweeked by the do-it your selfer on a budget.

Rule #4 Rule 1 doesn't apply to me.... ha ha hah

 

Hey V8AstroCaptain..... do u live around phila?.... cuz down at the races in south phila there is an astro with a tree fiddy there sometimes.... wonderin if its you?

 

Fbird88 is right on,

Knowledge is power, read up.

Smokey Yunick has a good book too.

 

Someone should definately write an article about vortec heads.

I got the heads for cheap then used the valves out of my L98 heads, had some LT4 springs around, and got screw-in studs installed. I think I spent about $500 total on the heads + machine work

I think with the LT4 hot cam (if using the 1.6 rockers) you should definately have the machinist check out the guide/retainer clearance. With my .502 lift cam I was cutting it pretty close.

 

I play with quite a few race motors at our local dirt track and the modification of putting bigger valves in a cast iron vortec head comes up all the time. What I have seen with these cast iron motors, running 2 barrel carbs. and turning rpms from 6000 to 7200 is that the addition of 2.02 intake valves and 1.60 exhaust valves actually hurt these heads. The big valve heads lose so much off the corner torque, they can't keep up with the small valve heads. If you want vortec heads with bigger valves and higher flow numbers, get the aluminum vortec heads, aka fast burn heads. This is just my observations from racing these cars and building these motors.:rockon: