To install more lift you will need to..... Replace the retainers with aftermkt +height units. Eliminate the rotators and shields.
Full Answer
How to add more hp to stock heads?
A good trick for stock heads to add a little better HP is to replace all the Intake rockers with 1.6:1 rockers. It takes you to the edge of the valve lift for stock heads but it helps pack a fuller charge in the cylinder, which gives up more Hp.
What is the maximum lift on a stock Chevy head?
Bone stock Chevrolet, nothing special heads, maximum lift is under .5" I can't say exactly how much I suppose some of it does depend on the head casting but then if they're old heads then that number will change from new specs. Now Vortec heads are capable of .5" and with a little better springs much more.
How much lift on a Vortec head?
Now Vortec heads are capable of .5" and with a little better springs much more. They flow better than any other Chevy Stock head except maybe the fast burn. But basically you're limited to under .5" lift and roughly 6000 RPMs.
What is the valve lift on a stock stock Cam?
The lift on the stock cam is .383/.401". I had to have the valve guides machined down in order to run a comp cam 268H which has valve lift of .454". You will also have to have your springs checked to see what height they coil bind at and if spring pressure is adequate for the new cam your installing.
How can I get more lift out of my head?
0:467:03How To Run More Lift With Vortec Heads - YouTubeYouTubeStart of suggested clipEnd of suggested clipThey are 26918 springs and then you have the comp cams 787-16 retainers now what these retainers letMoreThey are 26918 springs and then you have the comp cams 787-16 retainers now what these retainers let you do is run a beehive style spring which will allow you to run more lift.
How much lift can stock Vortec heads handle?
around 0.420 inchThe factory Vortec heads use a light, single-wire valvespring with a damper that generates between 70 and 80 pounds of load on the seat. Because these heads are meant to work with a 1.5:1 rocker, their tall valve guides can only handle maximum valve lifts of around 0.420 inch.
How do you cut a Vortec valve guide?
2:243:36COMP Cams® Quick Tech: Valve Spring Seat & Valve Guide Cutting ...YouTubeStart of suggested clipEnd of suggested clipUse the Arbor to align the cutter up and down before drilling to help keep you from removing tooMoreUse the Arbor to align the cutter up and down before drilling to help keep you from removing too much material. Move the drill down slowly at a low to medium speed.
What size valves are in Vortec heads?
Both GM factory and Chevrolet Performance Parts' Vortecs come with 1.94-inch intake/1.50-inch exhaust valves.
How do you shorten a valve stem?
0:3311:27Shortening Valve Stems - YouTubeYouTubeStart of suggested clipEnd of suggested clipGot a little bit of rub. There. And so that value is 4.307 and what i want them they all need to beMoreGot a little bit of rub. There. And so that value is 4.307 and what i want them they all need to be down to is 3.575 so here's one that i've. Done and just got a slight rub. There.
What are valve stem seals?
Valve stem seals provide a defined metering rate of oil to the valve stem interface of internal combustion engines to lubricate the valve guide and minimize engine emissions. They are available for diesel and gasoline engines with and without boosting.
How much load does a Vortec head put on a seat?
The factory Vortec heads use a light, single-wire valvespring with a damper that generates between 70 and 80 pounds of load on the seat.
What year did Chevy introduce the Vortec cylinder head?
In 1996 , Chevy introduced its Vortec cylinder head on the L31 truck engine and it didn't take long for enthusiasts to bolt them on their engines and find out how good they really are. The cast-iron Vortec heads offer a 170cc LT1-derived port, making them great performance pieces for street engines when tons of torque is key.
What is the goal of engine builders?
The one goal that most engine builders share is making the most power for the least money. Since cylinder heads are typically the bottleneck of an induction system, that's where the smart money usually gets spent.
Do GMPP studs need guideplates?
The GMPP screw- in studs don't require guideplates when used with rail-type rockers. ARP screw-in studs require guideplates. To prevent binding, do not use rail-type rockers with guideplates. It's also wise to enlarge the pushrod holes to a 1/2-inch diameter for increased clearance.
When did the Vortec head come out?
For those who may be new to the game, the Vortec head was first introduced on the L31 350ci truck engines in 1996. Despite their journeyman use, these heads flow dramatically better than any other small-block Chevy production head, which makes them popular with just about anybody who wants to build a mild street small-block.
How much compression does a 350ci have?
With a common, four-eyebrow flat top piston and a .041-inch thick head gasket on a 350ci engine, the Vortec head will bump the compression to around 9.5:1 depending upon the deck height. There are other, smaller points that are important to know because they affect cam selection.
Is the small block Chevy still the king?
Let’s get this over with right now – if you will accept the concept of strength in numbers, the small-block Chevy is still the king. Sure, the LS family deserves all the hyperbole. But that doesn’t change the fact that there are more traditional small-block Chevys running around wild in the streets in hot street cars than all the others.
When did Chevy add accessory holes to the front of all its cylinder heads?
Beginning in 1969 , Chevy added accessory holes to the front of all its cylinder heads to facilitate mounting alternator and air conditioning brackets to the front of the engine. Older heads like the 461 and 462 heads do not have these bolt holes, requiring the use of a short water pump and different brackets.
When did Chevy start using aluminum heads?
In 1986 Chevy introduced the first production aluminum small-block head on the Corvette, but it has turned out to be mediocre at best. These heads were used only on Corvette TPI engines used between 1986 and when the LT1 engine debuted in 1992.
What year was the Vortec head made?
The Vortec head was first produced for light-duty trucks in 1996 , and at first no one really gave these new castings much more than a cursory look. But the word soon spread by way of the performance magazines, especially with one story that pitted the venerated Bow Tie performance head against the Vortec with the Vortec coming out on top. Considering that the Vortec came with conservative 1.94/1.50-inch valves and a mere 170-cc intake port, there were many who were skeptical. After all, the Bow Tie sported a bigger intake port with larger 2.02/1.60-inch valves. So how could this puny production head be better than the Bow Tie? The answer lies hidden in the confines of the port design and with the GM engineers who paid attention to a couple of keys, not the least of which was that intake velocity is a key player in the torque game. And after all, this was supposed to be a truck head, so midlift flow and high velocities were key. Along the way, it didn’t take long for performance enthusiasts to learn that the head was a perfect replacement for those older iron castings.
Where to look for cracks in Chevy head?
Places to look for cracks include the combustion chamber area between the valves and also in the top part of the head around the spring pockets. The big cork for better horsepower is really on the exhaust side of all production small-block Chevy heads.
When did GM introduce the L31 Vortec?
Even the older performance “double hump” heads are now considered passé. Then, in 1996 , GM came up with the L31 Vortec engine package for light-duty trucks, using a new production cylinder head that quickly gained favor first among the roundy-pounders and then on the street.
Do Vortec valves need centerbolts?
By lowering the guide height, this increases the retainer-to-seal clearance, allowing more valve lift. The Vortec heads also require centerbolt valve covers. There are adapters that allow you to use perimeter style valve covers, but the adapters are prone to leak and are more expensive than most valve covers.
