vortec heads?

[Silence86]

ok so im wanting to switch to vortec heads? what all has to be replaced when switching over?

[bikes&bowties]

You will need a different intake manifold but i believe that is all.

[swb85]

Intake and centerbolt valve covers if your current heads are perimeter bolt.

[zac]

I keep reading that you need to modify the outside of the guides and where the springs sit and then install new double springs so that you don't get spring bind with a cam in it. Anybody been down this road?

[ironroad9c1]

Naaa your gonna run into lift problems long before coil bind.

[clinebarger]

You will also need guided rockers or guide plates & screw in studs. with a large cam the valve guides will need to be cut down

[trixter99]

If you use guide plates you will have to use hardened push rods do not try it without them being hardened.

[85 c-10]

Quite honestly, unless the heads are free I wouldn't use them on a stout engine with a big lift cam. They require specific items such as been listed. The valve guides will ned cut down for even moderate springs and seals. I built an engine for a Camaro I had. The heads came on a core engine I got from a friend at a Chevy dealer. I bought the cutters, and arbor to cut the guides. I bought the intake and guided rocker arms. I also had them machined for screw in studs. I screwed up here as guidplates would have been good as well, but I was a cheap ass. Anyway after all the work I put into them, I could have had a nice set of aluminum heads. They do work well, but just think before you choose them.

Josh

[mongoose]

big lift?

unless you port them out you're not gaining anything by running huge lift. and if you do port them out.. you can get decent power numbers out of them.. a buddy dyno'd his motor at 530hp and 480ft lbs.. on n/a pump gas.. but you could almost buy a set of track ones for what he has into them.. porting isn't cheap.

for a hot rod/daily type build they're good heads, you can get a decent intake for under 200.. and shouldn't be hard to find a set of valve covers from a yard, you canrun the stock rockers if you like.. just get them drilled for screw in studs.. or leave them if you're lazy like me. =p

mine cost me 200, plus 100 for decking and all im doing is taking a little off the boss for some clearence.. though i'm running a lunati 60102 and 981 springs.

so 300 vs 800... not that bad.

[Rollie396]

correct me if I'm wrong,but doesn't comp cams have a set of beehive springs that will work without machining the guides/bosses?
I bought my vortecs from summit,bought the cutter and arbor from comp cams.I took it to a machine shop to do the work.It was done the next day and they loved the cutter so they bought it from me for what I payed.Final bill was $10.
One other thing,your temperature sender probably won't work in the vortecs cuz they have a smaller hole.You may want to have the hole drilled and tapped for your sender before you put them on.

[Jim85IROC]

Scoggin Dickey sells new vortecs that have already had the valve guides turned down, and come with springs that will work up to .550 lift. I think a set with springs good up to .600 lift are available too. These heads are only a few bucks more than stock Vortecs.

[68 TT]

You can run the LT4 springs, locks & retainers on them and a little larger cam without having to cut down the guides for clearance.

I forget how much lift this allows but I think it was right at .500" maybe just a little more. I think it allowed you to run the LT4 hot cam.

I'm sure a quick search for Vortec head and LT4 springs will come up with the answer.

The set of LT4 springs, locks & retainers only cost me about $50 at the dealer so they are pretty inexpensive and allow it to rev to about 6300 rpm with a hydraulic roller cam.

[Mr.Scary]

silence86 are u really wantin those heads that bad after hearin all this?? i dont think so. u should take 85 c-10 advide and think if u want 2 go through all this trouble or not. if i were u i would just fix wut u have there already and b done wit it. u prolly get out spendin about a 1/4 of tha price that way rather then goin wit vortec heads. just my .02cents

[Silence86]

haha yeah i def agree, this is gonna be a pain i might as well just put money in the heads i have now.

[STOCKISH]

Alot of people just spit off what someone else told them about these heads and dont reall know any definate answers. I can tell you from experience. These heads are great for a street truck. Summit sells NEW vortec heads that accomidate .520 lift for $600 complete. The rockers on your truck now are self aligning and will work with your Vortec heads. Ebay has Vortec aluminum intakes for under $150. And we all know how cheap valve covers are. I used a stock 350 goodwrench motor, stock summit Vortecs, RPM airgap and a 750 Demon, and a XE268 cam and got 400 hp on the dyno. I followed the link posted below for ideas and that engine is nasty. It will boil the
295/40r20s off the back of my truck as long as I keep it to the floor. Vortec heads are awesome. As stated above, there is a set of $50 beehive springs you can use on the Vortecs and get .520 lift with no machine work. Buy a set off ebay for $250 and be done with it. If you read the link posted below I think It will answer all your questions.

http://www.corvettefaq.com/c3/goodwr...20part%201.htm

[68 TT]

Originally Posted by Silence86

haha yeah i def agree, this is gonna be a pain i might as well just put money in the heads i have now.

How big of a cam do you have or want to run?

[ironroad9c1]

Yea I would run self aligning rockers instead of wasting money on guideplates and hardened pushrods.

[68 TT]

Good info here:

http://www.chevelles.com/forums/arch...p/t-36483.html

A clip from this thread:

Here's some gold for you from Gary Penn of GM Performance Parts. I have several of his posts saved from a techboard somewhere on the net - I think it might be chevytalk, or chevelletalk or something like that.
Here is one of his posts that directly answer’s some of your queries. BTW - if you use Vortec heads you'll be flat amazed at how much power these things make for a truck head. I run them on a 413-cube small block and have nothing but positive comments for them.
Let's proceed directly to Gary's very detailed and insightful comments:
"Two years ago we undertook an exhaustive (no pun intended) study of the Vortec head in numerous modified states with different valve sizes, throat cuts, valve jobs, port mods, guide mods, etc. We used up about 10 heads, numerous valves, and about $50,000 worth of labor. The study generated 100+ pages of flow and swirl data, which I have at my desk.
Here is the short version. Out of the box, .480” valve lift, 350-400 HP dependant on the CR, cam, ring seal, oil control, blah, blah, blah.
More than .480” lift cut the guides down to clear the retainers.
Straight mill up to .060” safely, .080” with low CR of 10 to 1 or less. 0.100” is living on borrowed time. Always use flat top or dished pistons to enhance flame travel and intake swirl.
Angle mill up to 1 degree (about .110” off the exhaust side, .000” off intake side) safely for about 12 to 1 CR with flat pistons with little valve relief. Angle mill to 2 degrees (about .200” off exhaust side) if you like to live on the edge, it has been done.
Larger valves increase flow, chamber mods not needed, trade off between shrouded verses unshrouded valves not worth the decrease in laminar flow and swirl.
Throat cutting behind larger valves compliments the larger valves. Open the throat to the seat then remove the edge left by the cutter in the port.
Blend the seats into the chamber, you don't want an edge here to disrupt flow and create turbulence.
"Bowl blend" and shortened guide in port also improves flow. Taper and blend the iron boss.
Minumal porting increases flow, too much increase in port size or loss of the benefits of the shape of the stock port will decrease efficiency.
Vortec heads (and most others) like straight stemmed valves. Undercut valves create unwanted turbulence and a decrease in intake charge velocity (they add volume (slowing the gases) to the overall "port" volume just behind the valve where max velocity is required.)
Generally speaking, Vortec's stall at between .500” and .550” valve lift. This is where flow actually begins to decrease. But their true strength is low lift flow which gives more area under the total flow curve. And if you think about it how long are your valves at peak lift? They spend much more time at .400” and below, where the Vortec’s outperform most other heads. This combined with high velocity, lack of turbulence and superior combustion chamber design are where the Vortec’s stand out.
Unported, with all the other tricks in place, the Vortec’s will flow about 235-240 CFM at .500” I and 165-170 cfm at .500” E, on a 4" bore at 28" H2O, with clay radiused port opening. With some careful porting there is another 5-10 CFM or so to be had. But again the low lift numbers are unsurpassed at .100”, .200”, .300”, etc. lift. For example the Vortec’s flow as much air at .400” as .500” and no 23 degree head that I'm aware of can match them at .200”-.300” lift for the combination of flow and swirl. Even the Fast Burn head can't touch them at low lift, it's ports are too big (flow is similar, swirl is less), it does of course out perform them at lift over .500”.
Unported Vortec’s with the "tricks" can produce 500 HP on well built, high CR, drag race short block. 425-450 HP is more realistic for a killer street engine running on pump gas."

Moral of the story is that big lift cams that require a lot of work on the vortec heads really don't make any more power on them as the ports stall out at about .500" to .550" lift.

[68 TT]

More good info:

http://www.s10v8.com/showthread.php?t=1073759946

Another clip:

The main problem with the vortec heads as many people know is the lift restriction of .480 If you have the heads off the engine, I would recommend having the correct machining of the valve guide done and have screw in studs installed. However, you can make these heads work with larger lift cams without removing the heads. This is where Melonhead was a lifesaver for me. If you use the GM LS6 beehive valve springs (GM PART # 12499224), Comp Cams retainers 787-16, and change the umbrella valve seals to Sealed Power Part # ST2015, you should be able to get up to 0.550 lift.

[Silence86]

thanks guys i might just try and get some heads and see what i can do

[zac]

Good discussion. So in a nutshell, could a guy buy some good stock vortecs, put in an RV grind cam, maybe the beehive springs, and the proper intake, and have it be a worthwhile improvement over the standard truck 882 heads?

[mongoose]

yes, it would be a very good upgrade.

[STOCKISH]

Vortecs are good for about 40 hp over your stock heads.

[68 TT]

The big benefit is the gain in average torque & HP over the entire RPM band. They flow very well at low lift and tolerate higher compression for more efficiency. This is good because you typically get higher compression with them due to the small chamber size unless you are running 60's vintage closed chamber heads.

If you can find a set in decent shape at the pull it yourself wrecking yard and put the LS6 springs, Comp locks & retainers and new seals on them you could have them on your truck for right about $400 including a low cost carb intake depending upon how much the heads cost you. Mine only charges $50 for any set of heads, you just have to find what you need. A complete engine with all the accessories is only $135 so I usually end up getting a complete package just to have the spare accessories. The Vortec block and crank are better than the 86 to 95 blocks too plus all of them are roller cams with a decent profile similar to a TPI car. If you want to add a cam change to the mix the LT4 hot cam is great with them.

I ran a Vortec truck 350 long block in my 91 Z/28 with the S-D Vortec TPI conversion intake base as the only change in TPI system. Once it was tuned to match the volumetric efficiency of the Vortec heads that thing was amazing. It would break the tires loose at 30 mph with just a quick snap of the throttle. Before it would just chirp the tires on a full throttle 1-2 shift. After the head swap it would break the tires loose for about 20 feet on the same shift.

The change to these heads on a street car or truck is well worth the effort and slight added expense vs. rebuilding a set of original heads.