I've seen the self-guided small block V8 motors turn 7200 + rpm no problems. I doubt that our light valve train would have any problems.
You don't want to use both guide plates and the self-guided rockers, any mis alignment will snap the push rods.
I'm using the self-guided rockers on mine, just remove the guide plates and add a thick 10mm washer, to make up for the difference in stud height. With out the washer, the poly locks didn't have enough thread engagement, for my comfort, so I used the washers to shim the stud a little higher up. Watch the washers under the exhaust studs, if you don't grind them on one side you will have to remove the stud to get to the head bolt next to it.
i am buying a set of proform tomorrow so if any one wants in with me email me at brushforhire@the3dcanvas.com
http://www.helpelijah.com
Well if a SBC with the heavy valves and longer pushrods can do it, than I'm not worried about these.
So if the guide plates were machined correctly it would just be a safety factor then. How much extra plate clearance do you think would have to be allowed for our engines, given an even lighter valvetrain, but much stiffer springs, and say stock pushrods?
Anyway, I'm in for a set of the Proforms, just PM me, whoever.
fortune cookie say:
better a delay than a disaster.
OHV notec wrote:So if the guide plates were machined correctly it would just be a safety factor then. How much extra plate clearance do you think would have to be allowed for our engines, given an even lighter valvetrain, but much stiffer springs, and say stock pushrods?
Considering the roller tip is much wider than the valve tip, the guide plate would need to be machined/ground out atleast as far as the roller tip will pivot on the valve tip, plus a few thousandths more for push rod flex. The only way to determine how much the push rods flex is with a Spintron, such as Comp Cams uses to evaluate their valve train set ups.
This is why I just eliminated the guide pltes on mine.
OHV notec wrote:So if the guide plates were machined correctly it would just be a safety factor then. How much extra plate clearance do you think would have to be allowed for our engines, given an even lighter valvetrain, but much stiffer springs, and say stock pushrods?
Considering the roller tip is much wider than the valve tip, the guide plate would need to be machined/ground out atleast as far as the roller tip will pivot on the valve tip, plus a few thousandths more for push rod flex. The only way to determine how much the push rods flex is with a Spintron, such as Comp Cams uses to evaluate their valve train set ups.
This is why I just eliminated the guide pltes on mine.
^^ owned by the double-post
MadJack wrote:OHV notec wrote:So if the guide plates were machined correctly it would just be a safety factor then. How much extra plate clearance do you think would have to be allowed for our engines, given an even lighter valvetrain, but much stiffer springs, and say stock pushrods?
Considering the roller tip is much wider than the valve tip
Not with a lash cap
I still need to figure out how wide the roller is, but first I have to decide which rockers to go with
And to do that I need to know what ratio I need, which I need cam specs for...arrgh
fortune cookie say:
better a delay than a disaster.
I just found this in my e-mail
Crane Cams Newsletter wrote:“Pushrod Noise” Can Cost You Power and Fuel Mileage
Whenever 1.6 (or higher) ratio rocker arms are installed on small-block Chevys, the pushrod is tilted more toward the rocker stud or shaft. This tilt can lead to interference between the pushrod and the pushrod guide hole in the cylinder head. Knowing this, Crane R&D always checks for adequate pushrod-to-head clearance whenever we perform any dyno tests. Recently, we installed a new set of aftermarket performance heads on our dyno engine, visually checked for adequate pushrod clearance, and proceeded with our tests of some new street hydraulic roller grinds. Immediately, the knock sensor on our dyno console was activated. We didn’t hear any detonation, but we retarded timing and richened the carb as a precaution. The detonation sensor still indicated detonation.
On a computer-equipped vehicle, when the knock sensor is activated, the computer starts pulling timing out of the ignition, killing power and fuel economy. After a significant amount of detective work, we found that the “heavy wall” pushrods were deflecting just enough on the initial lift phase that they were making very slight contact on the “valley” side of the pushrod hole. We were unable to hear this contact. In fact, the contact was so slight that there were no marks on the cylinder head and only an incidental contact mark on the pushrod. We removed the head, ground out some extra clearance and the problem was gone. The moral to the story is: Just because it visually looks like there is enough clearance between components, don’t forget about flex, thermal expansion, etc. Today’s “knock sensitive” systems will respond to all types of metallic taps and noises. Whey they respond, they retard timing, which causes power loss and poor fuel economy. Remember: “Keep it quiet out there!”
Wow, imagine what standard .040" wall pushrods would have done...
Too bad they don't mention what they considered "adequate clearance"
fortune cookie say:
better a delay than a disaster.
MadJack wrote:I just found this in my e-mail
Crane Cams Newsletter wrote:“Pushrod Noise” Can Cost You Power and Fuel Mileage
Whenever 1.6 (or higher) ratio rocker arms are installed on small-block Chevys, the pushrod is tilted more toward the rocker stud or shaft. This tilt can lead to interference between the pushrod and the pushrod guide hole in the cylinder head. Knowing this, Crane R&D always checks for adequate pushrod-to-head clearance whenever we perform any dyno tests. Recently, we installed a new set of aftermarket performance heads on our dyno engine, visually checked for adequate pushrod clearance, and proceeded with our tests of some new street hydraulic roller grinds. Immediately, the knock sensor on our dyno console was activated. We didn’t hear any detonation, but we retarded timing and richened the carb as a precaution. The detonation sensor still indicated detonation.
On a computer-equipped vehicle, when the knock sensor is activated, the computer starts pulling timing out of the ignition, killing power and fuel economy. After a significant amount of detective work, we found that the “heavy wall” pushrods were deflecting just enough on the initial lift phase that they were making very slight contact on the “valley” side of the pushrod hole. We were unable to hear this contact. In fact, the contact was so slight that there were no marks on the cylinder head and only an incidental contact mark on the pushrod. We removed the head, ground out some extra clearance and the problem was gone. The moral to the story is: Just because it visually looks like there is enough clearance between components, don’t forget about flex, thermal expansion, etc. Today’s “knock sensitive” systems will respond to all types of metallic taps and noises. Whey they respond, they retard timing, which causes power loss and poor fuel economy. Remember: “Keep it quiet out there!”
wow, that sounds eerily like what PJ's OHV was doing in its final days in the car.... i'll have to check that out when we tear it down...
Arrival Blue 04 LS Sport
Eco
Turbo
Megasquirt
'Nuff said
i just bought a set of 1.6 proforms if anyone is interested in going half for the other 8. email me or PM me. brushforhire@the3dcanvas.com
http://www.helpelijah.com
Um, I wanted them...
fortune cookie say:
better a delay than a disaster.
I did...but I want another
fortune cookie say:
better a delay than a disaster.
Hey Josh,
Now that I'm felling better (been sick last couple of days) and I'm thinking a little more clearly, I've been thinking about the pushrod noise.
The pushrod noise is probably one of the reasons GM switched over to the self-guided rockers, they did start coming out shortly after they started to put computer controls on their cars and trucks, well, 3 years later anyways. That and it's cheaper to produce the self-guided rockers than it is to produce the rockers and guide plates.
As far as on the 2.2/2200s not getting them till '98, remember they use a shorter and thicker pushrod. The 2.2L uses a 7.406" X 3/8" pushrod and the 2200 uses a 7.448" X 3/8" pushrod as opposed to the SBC's 7.800" X 5/16" (flat hyd.). The shorter pushrod (although only slightly shorter) pushrod has less length to deflect under load. Being thicker,the deflection is even less. Remember, the thicker the tube (even with the same wall thickness) has a greater compression and tensile strength than a narrower tube. This strength increases exponentially as opposed to shear strength, which only increases with the percentage of size. This is also why the pushrods seem to break so easily when under the slightest shearing load, i.e., busting pushrods when the roller rockers don't clear the valve cover breather baffles.
Just a little more insight into some pushrod/guideplate/rocker issues.
And yes, I'm looking into the pushrods available!
Hmmm, the pushrod noise guided vs guideless theory is very interesting. I've never heard anyone think that way before, but it definately makes sense. Since nobody has really built (correclty) and run a 2.2L yet w/ guideplates, we really don't have a way of knowing how much deflection there is, or if there's enough noise to trigger the knock sensor. It doesn't seem like the stock motors have had problems like this, but an aggressive cam would obviously be a different story.
A lot of the tech articles I've read so far have talked a lot about how pushrod deflection is one of the biggest killers of engines because if the force of the pushrod straightening back out occurs at the wrong time, it will collapse the lifter, wipe cam lobes clean, or wear out springs. I know Juicedz4's built engine was quickly taken out of business due to collapsed lifters, this may have been the culprit.
I figured that since custom length chromoly rods are only like $10 each from Crane, it's cheap insurance against problems here.
fortune cookie say:
better a delay than a disaster.
okay i got the proform 1.6 roller rockers today. but they came with a sheet saying they are for guide plates only not self-aligning. so should i use my guide plates or does that info apply only to the SB's?
http://www.helpelijah.com
What part number did you get?
The only narrow bodied ones listed were for the self-aligning rockers, in the 1.6 ratio is PN 778-66915C. I can't tell you if the other rockers would be narrow enough to fit under the rocker cover. I do know the self-aligning rockers are narrow-bodied, to clear the center bolt valve covers.
If you have a '97 or older 2.2L, if the body of the rocker is narrow enough, you should be able to use them with the guide plates. Remember though, even with the Crane Rockers I had to do a small amount of grinding to the breather baffle to prevent interference with the rockers.
i think they are right now that i look at them.
also are our rocker studs push in or bolt-in. like to replace them should would i have to get them rethreaded?
http://www.helpelijah.com
The rockers that are shown in that link are the correct ones. The roller tips should have a guide on each side of them.
The rocker studs are screw in, see the listing further up this thread for the part numbers. ARP's are them most economical and will just crew in place of the stock studs.
BTW, get the washers, like I stated on the top of this page.
okay i am posting way way to much but they did have the little guides on either side of the roller tip so they are good.
thanks for the help
http://www.helpelijah.com
Okay, I decided to read this since this is my next engine mod, along with the header. Some of this is a little confusing, but here we go. Now, Jack, I know we pm'd about this a bit, but I just want to make sure. You're saying on the pre 98 LN2 (mine is a 97), to use the self guided rockers, is that right? I understand the deflection theory, a friend of mine has been dealing with it on his Firebird. So I need to get self guided rockers and self guided pushrods, and shim the studs with washers, right?
