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 can a 1974 Chevy 350 Cam take?
So I've been building this 1974 Chevy 350 and I recently picked up a new cam from the Hot Rod Barn, and its a little too big for the stock valve springs. This Cam is rated at .510 Lift, I heard the stock springs for the 350 can take like .470-.495 lift without overloading (Mine are 882 Heads).
What kind of cylinder head does a Chevy 350 Vortec have?
The L31 heads from the late-model 350 Vortec engine, introduced early in 1995, is the other type of cylinder head you need to look for on the used market. This is probably the best cylinder head casting that Chevrolet has ever produced for a production small block Chevy.
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 lift on a stock 350 cam?
The 350hp/350 cam had . 450/. 460 lift. (GM has a newer version of this cam with less intake duration for use in 9.0 -9.5:1 compression engines.)
How do you measure lift on a camshaft?
0:346:34How to Measure Camshaft Lift - YouTubeYouTubeStart of suggested clipEnd of suggested clipAll you have to do is know the measurement from the top of the lobe of the cam to the heel sideMoreAll you have to do is know the measurement from the top of the lobe of the cam to the heel side which is the bottom side of the cam. Lobe after you have that measurement.
How can I get more horsepower out of my 350?
1:393:493 Cheap & Easy Ways To Increase Horsepower - YouTubeYouTubeStart of suggested clipEnd of suggested clipYou also need to let it get that exhaust a lot better also you'll see some people that throw headersMoreYou also need to let it get that exhaust a lot better also you'll see some people that throw headers upon their vehicle and that they just dump it out a three inch exhaust.
How do you install a cam on a Chevy 350?
2:1814:22Engine Building Part 3 Installing and Degreeing the Cam 350 Chevy ...YouTubeStart of suggested clipEnd of suggested clipAnd our cam button just goes in the middle just like that. And you have your holes lined up. And weMoreAnd our cam button just goes in the middle just like that. And you have your holes lined up. And we put our clink cam lock plate over the button like that we got three fasteners.
What does more valve lift do?
Increasing valve lift allows more open space in the intake and exhaust ports of the cylinder. Theoretically, this means more air and fuel can be drawn in. More exhaust gases can be pushed out.
How is total valve lift calculated?
Tip: Maximum valve lift can be calculated by multiplying the maximum lobe lift times the rocker ratio. For example, a 0.310" lobe lift cam yields 0.496" of valve lift when using a 1.6 ratio rocker arm.
How much horsepower do headers add to a Chevy 350?
Small Block Chevy engines can also benefit a lot from headers, especially since their stock exhaust systems tend to be weak. If you're wondering how much horsepower do headers add to a 350, it's about an extra 16 hp for long tube headers.
What year is the best Chevy 350 engine?
What Year is the Best Chevy 350 Engine?LT-1 – 1970. When the LT-1 hit the scene in 1970, it took the world by storm. ... L98 – 1992. Another fan favorite is the 1992 L98 350 engine. ... L31 – 2002. Last but not least, the 2002 L31 350 Chevy engine deserves recognition.
How much HP does a cam add to a 350?
Does a camshaft increase horsepower? Yes, a camshaft adds 10 to 20 horsepower depending on the setup. To get the full potential of the high-performance camshaft, you'll have to swap out additional components like the air intake, exhaust manifold, injectors, and valve heads.
Is installing a camshaft hard?
Installing and adjusting (or "degreeing") the camshaft can be tricky. It can be done using either: The theoretical centerline of the #1 intake lobe, or. The valve opening and closing events, based on a pre-determined amount of Lift (usually 0.050 in.).
How do you set the cam timing on a Chevy 350?
0:274:33Small Block Chevy Engine Build: Timing Set (Part 2 of 3) - YouTubeYouTubeStart of suggested clipEnd of suggested clipWe put on the cam. Gear. We've got our hex adjust pin adjustment on there this is our cam bearingMoreWe put on the cam. Gear. We've got our hex adjust pin adjustment on there this is our cam bearing cam thrust bearing it goes with the silver. Side towards the block.
Why do you have to degree a cam?
Is to achieve the correct valve opening and closing points for your engine. All of our new camshafts are ground to exact specification using the latest CNC machining processes but there are other factors that can cause incorrect camshaft to crankshaft phasing.
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.
What does proper valveguide clearance mean?
The key here is that proper valveguide clearance means the valves won’t dance around and beat up a good valve job. This should point out that investing in a performance 3-angle valve job is wasted if the guide clearance is not idealized to keep the valve centered on the seat.
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.
When did Chevy start using small block heads?
Since the introduction of the small-block Chevy in 1955 up to the late 1990s, a small budget meant a limited choice of heads for performance.
What size valves are used for 1.6 exhaust?
The most common highperformance valve size combination is 2.02 inch for the intake and 1.6 for the exhaust. If your existing valves have good stems, the use of 1.94 intakes doesn’t give away significantly to 2.02s. If wear dictates going to the 2.02s, then have the seats and chamber cut accordingly.
How heavy are L98 aluminum heads?
The L98 factory aluminum heads are, at 22 pounds, light and thin (iron heads are typically 47 pounds). Because of the effort to save weight, these heads are not as tough as their Bowtie brethren or any of the aftermarket heads. Also note that aluminum corrodes with age especially if the anti-freeze mix was not maintained properly. They can be very effective for specific uses if you can find a good set. However be aware they won’t last any length of time over about 11:1 CR.
What year did the L31 head come out?
The L31 heads from the late-model 350 Vortec engine, introduced early in 1995 , is the other type of cylinder head you need to look for on the used market. This is probably the best cylinder head casting that Chevrolet has ever produced for a production small block Chevy.
What compression ratio is a 305 engine?
They have relatively small combustion chambers, and the basic engine sports compression ratios of 9:1 or more. These heads will port out well, but be aware that 305 heads have smaller valves, so only look for 350 heads unless you’re specifically working on a 305.
Is it important to have a valve at full lift?
Sure, at full valve lift it may cause a little flow loss, but remember the valve is only at full lift once in a cycle. It’s at half lift twice, so what happens at half lift usually is more important. In addition to flow efficiency, swirl is also important, especially for a good all-around street performer.
