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<------ likes mechanical roller

no more wipeing out lobes :yes: but i dont mind adjusting valves. if you run a good set of polly locks you shoudnt have to adjust the valves :yes:
 

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How much more performance do you get?
Many years ago when I was shopping for my first roller cam, Comp persuaded me to go with their solid street roller over the hydraulic roller I had been looking into--they said a similar solid grind was worth 25 h.p.
With flat tappet cams I'm not sure, but there is some power to be found over a hydraulic, although with today's modern grinds it's probably not what it was in the 60's.
 

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I ran the 30/30 cam in my '69 Corvette for 12 years with no issues at all. That cam with a four speed was SWEET! As an aside... after reading Smokey Yunicks book, I set the lash at .016" and .018", as the .030"/.030" was done for valve clearance on a 327 with 11.25:1 pop up pistons. I had 10:1 flat tops. Cool thing was, I didn't have to adjust them but once a year at the most.

Chuck
 

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For drivability I prefer hydraulic, if you want performance, then solid is the way to go, next, hydraulic roller, then solid roller will give the best performance.
Flat tappet Hydraulic is great for maintenance free driving, but as mentioned it will give up some performance to a solid tappet cam.
 

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The main gain in using a solid cam of any type IE: Flat tappet or roller is the use of a stronger better valve spring. When using a stronger spring you can have a more aggressive profile. This does not mean a "WILDER" cam. Just allows a more aggressive opening and closing ramp.

The end result is more HP & torque.

Another major advantage to a solid cam it's tunable.


IE: COPY
How does changing my valve lash affect the behavior of my motor?

Adjusting your valve lash by adding or subtracting a few thousandths of an inch will respectively reduce or increase your camshaft’s duration, thus affecting your engine’s performance.

Running tighter valve lash (reducing the amount of clearance between the rocker tip and the valve stem) will make the cam profile larger (more duration) and increase your upper rpm horsepower. Loosening the valve lash does just the opposite by decreasing camshaft duration -promoting low rpm torque and improving your 60-foot time and/or ability to accelerate out of turns. The general rule of thumb when adjusting valve lash is that 0.004” of adjustment from the valve lash specified in the cam card equates to a 2° difference in duration when measured at 0.050” lift.

Although the overall effect on performance is obviously not as dramatic as making a camshaft swap, knowledgeable racers have successfully used this tuning trick to win races by adjusting valve lash in order to take maximum advantage of track conditions.



Al
 

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Do you need guide plates?
yes and no, it depends on how aggressive the cam is and what rpm you'll be turning. Some of the milder cams don't need exotic pushrods-chevy ran solid cams for years with basic pushrods and guideplates weren't needed.
 

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For drivability I prefer hydraulic, if you want performance, then solid is the way to go, next, hydraulic roller, then solid roller will give the best performance.
Flat tappet Hydraulic is great for maintenance free driving, but as mentioned it will give up some performance to a solid tappet cam.
X2!! my thoughts exactly!
 

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Solids all the way if you don't mind the noise. The stock crimped adjusting nuts used to loosen by themselves. With modern polylocks you only adjust solids to compensate for wear. Unless your valvetrain is rapidly self destructing you can go years without adjusting it. Check it twice a year if you're the nervous type.
 

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Solids will make more power-it has been proven. If you build it with new slip-n-slide stock type rockers you can expect there will need to be lash adjustments for the first 2000 miles but it will eventually stabilize where lash won't change. Most people only need to lash the valves once per year if the build was good, quality roller rockers help a lot.

If there's wear in the rocker arms etc... a hydraulic cam will cover that up and compensate for the lash changes but the wear is the same on both.
 

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I wouldn't waste my time using a mechanical flat-tappet nowadays unless I was restoring an engine that originally came with one. And I was a guy who never used anything but a solid flat-tappet for many years.

Modern hydraulic flat-tappets are better for a moderate performance application. More reliable and maintenance-free. If I want ultra high performance, I always go with a mechanical roller. As a matter of fact, all of my hot rods have mechanical rollers. For me, mechanical flat-tappets are ancient history.
 

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Do you need guide plates?
yes because youll be running hardened pushrods :yes: 1 peice chromoly i would suggest.
I think you have it backwards. You can run hardened pushrods without guide plates but you can't run guide plates without hardened pushrods.

It's a good idea to use guide plates with a mechanical cam. If you use guide plates you will also need to use hardened pushrods because if you don't, the guide plates will whittle the sides of the pushrods down putting metal filings into your engine.
 

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Discussion Starter #17
What

What is the purpose of the guide plates its a straight shot through the head so you dont really need guides. And they donts strengthen the pushrods so i dont c what purpose they serve
 

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Im for the hydraulic lifters. Modern lifters are pretty darn good. My 350 is making 425hp with them. If I need more for my street car then a new engine is in order. 425 hp for the light nova is respectable. Not at the track though.. JR
 

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What is the purpose of the guide plates its a straight shot through the head so you dont really need guides. And they donts strengthen the pushrods so i dont c what purpose they serve
Im not all that sure, but I thought guide plates were used for specific rockers. What lifters you use doesnt govern the guide plate usage. And hardened plates with hardened rods.

At extreme pressures and rpms the rods will actually distort. Hard to believe. But thats why they are made from a quality steel, spring steel. So they can take repeated flexing, yeah, they do bend, without failure. So maybe the guide plates keep them from flexing way beyond a critical area. I dont know, hell, Im still trying to figure out this whole sting computer idea for the front end build LOL JR
 

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Guide plates are more accurate and can be adjusted to center the rocker on the valve tip, also having the guide higher near the rocker does a better job of keeping them in alignment. The factory slip and slide rockers aren't that critical when it comes to alignment since the contact area is wider than a roller rocker tip. Different rocker ratios will require different pushrod alignment and guideplates can make this easier. Stock type pushrods will wear when rubbing hardened guidplates-hence the need for hardened pushrods.
 
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