Overheating Very Quickly
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mikestang63
SN Certified Technician
If it takes less than a 1/4 turn or you can't get to 0 lash then you need longer pushrods. Shims only help wihen the pushrods are too short and move the rocker away, and normally are good for maybe .20-.40 about 1/2 a turn.
What heads and rockers and pushrod length are you running,
I don't know the brand but they look common. The most I could get was almost a half turn after what I think was 0 lash. I'm not sure how obvious the drag should be this is my first time being in a motor unsupervised. Since these rockers don't have a lock down adjuster it would make sense that they would be pretty tight. I think I could get them tighter if I used an actual socket wrench not sure. As you will see in the pics below its pretty on center with that 1/4 turn of lash. Also is that long Bar that connects the two rockers a shim?
Went to the local speed shop today and they told me the valve springs on that are probably too stiff to use a a rod length tool. He offered to loan me a couple sizes if I bring one of mine in to reference. This will also inform the new rocker decision since these arent stamped with any ratio. He said they look like cheap chinese ones from Proform or something.
Went to the local speed shop today and they told me the valve springs on that are probably too stiff to use a a rod length tool. He offered to loan me a couple sizes if I bring one of mine in to reference. This will also inform the new rocker decision since these arent stamped with any ratio. He said they look like cheap chinese ones from Proform or something.
stang89bidges
Advanced Member
The long bar is not a shim. Its the pedestal.
Those rockers should have little lock nuts in the middle of the big nut. Is there not an allen keyhole in the middle of the big nut? If not then those are probably made for the type of application it was built for(hopefully). Meaning they are similar style to the stock rockers.
Setting lash is done several ways. It really all depends on what kind of parts your dealing with. For me, I couldn't really feel the drag on my push rods by spinning them as they spun too easy(i already had them oiled up pretty good). So, what your looking for(another way to find zero lash) is to start to tighten the nut down on the rocker. Then as you tighten the nut you can check the GAP on the exhaust side roller tip. What you want is zero play(lift) of the roller tip from the valve stem. So, you tighten it down till basically there is no GAP or LIFT(using your fingers to lift/wiggle) the rocker. Then turn your last turn of around 3/4, 1/2 or whatever your setup requires. Usually 1/2 turn.
If you still bottom out before 1/2 turn, you probably have an incorrect setup and it needs to be resolved. Otherwise, it could be since these are pedestal without lock nuts(allen keyhole) then they may work like the stock. You tighten them all the way down and check the lash.
If they don't have lock nut, and its like stock, you can tighten them all the way down and check your lash with a feeler guage. Read up on how to do this. You basically learn the right thickness for your setup and stick the feeler guage between the roller tip of rocker and the valve stem. If its tight its not right, if its barely snug your perfect, and if its too loose your screwed.
Now remember, take all this with a grain of salt. I'm an internet mechanic. My stepfather was a mechanic for his whole life and taught me a lot before his passing and everything else I learned on my own. I don't know all the specifics of your parts so you will need to dig into those for all the right details like feeler guage thickness and lock nuts and etc. But what I and others are saying should get you real close.
Good Luck!
Those rockers should have little lock nuts in the middle of the big nut. Is there not an allen keyhole in the middle of the big nut? If not then those are probably made for the type of application it was built for(hopefully). Meaning they are similar style to the stock rockers.
Setting lash is done several ways. It really all depends on what kind of parts your dealing with. For me, I couldn't really feel the drag on my push rods by spinning them as they spun too easy(i already had them oiled up pretty good). So, what your looking for(another way to find zero lash) is to start to tighten the nut down on the rocker. Then as you tighten the nut you can check the GAP on the exhaust side roller tip. What you want is zero play(lift) of the roller tip from the valve stem. So, you tighten it down till basically there is no GAP or LIFT(using your fingers to lift/wiggle) the rocker. Then turn your last turn of around 3/4, 1/2 or whatever your setup requires. Usually 1/2 turn.
If you still bottom out before 1/2 turn, you probably have an incorrect setup and it needs to be resolved. Otherwise, it could be since these are pedestal without lock nuts(allen keyhole) then they may work like the stock. You tighten them all the way down and check the lash.
If they don't have lock nut, and its like stock, you can tighten them all the way down and check your lash with a feeler guage. Read up on how to do this. You basically learn the right thickness for your setup and stick the feeler guage between the roller tip of rocker and the valve stem. If its tight its not right, if its barely snug your perfect, and if its too loose your screwed.
Now remember, take all this with a grain of salt. I'm an internet mechanic. My stepfather was a mechanic for his whole life and taught me a lot before his passing and everything else I learned on my own. I don't know all the specifics of your parts so you will need to dig into those for all the right details like feeler guage thickness and lock nuts and etc. But what I and others are saying should get you real close.
Good Luck!
These do not have any sort of locking nut built in. They are going in the trash. Bought a size up and size under pushrod and going with scorpion 1.6 rockers. Hopefully 1.6 is right because these junky rockers dont have any sort of label. My guess is the pushrods are fine but the rockers Im using are made to go with a 1/4 turn of lash. No matter since they are all screwed anyway. Held a scorpion rocker in my hand and it weighed about a 1/4 of the ones I have and had no side-play. Cant believe how much of a difference they felt like.
If I'm able to set lash better with a size-up on the pushrod I will go with those. SHould I have the new rockers in to measure that? The local speed shop said to make sure pushrods are long enough before ordering the new rockers.
If I'm able to set lash better with a size-up on the pushrod I will go with those. SHould I have the new rockers in to measure that? The local speed shop said to make sure pushrods are long enough before ordering the new rockers.
stang89bidges
Advanced Member
Oh crap, you were using the old rockers? Glad you couldn't get them to set right then 
lol.
Those new rockers at 1.6 should be fine. You will want to check P2V! And then study up on valvetrain geometry. Switching rockers could make a huge difference. Could be such a big difference they don't work with current setup. That's worse case scenario though. I forget, stock cam or aftermarket?
lol.Those new rockers at 1.6 should be fine. You will want to check P2V! And then study up on valvetrain geometry. Switching rockers could make a huge difference. Could be such a big difference they don't work with current setup. That's worse case scenario though. I forget, stock cam or aftermarket?
stang89bidges
Advanced Member
4 good links on valve train geometry.
Comp Cams
http://www.compcams.com/Pages/417/v...R1OnKpe5p__KiL7xg&sig2=YvcGh9fKjDrkWlQAE5NrMw
Engine Labs
http://www.enginelabs.com/engine-te...ySqYBISts2sg5Tklw&sig2=AKKGg4hT4gyHxPihK1ZFdQ
Lunati
https://www.lunatipower.com/Tech/Va...VGcmkOg9C4Ctcw74A&sig2=2G1yo7MTE7RPgaIoYJqhbw
Hot Rod Magazine
http://www.hotrod.com/how-to/engine...0deMdVqUAxVFrfDdA&sig2=FdZPtVq6xUKN0WOH7bU_6w
Comp Cams
http://www.compcams.com/Pages/417/v...R1OnKpe5p__KiL7xg&sig2=YvcGh9fKjDrkWlQAE5NrMw
Engine Labs
http://www.enginelabs.com/engine-te...ySqYBISts2sg5Tklw&sig2=AKKGg4hT4gyHxPihK1ZFdQ
Lunati
https://www.lunatipower.com/Tech/Va...VGcmkOg9C4Ctcw74A&sig2=2G1yo7MTE7RPgaIoYJqhbw
Hot Rod Magazine
http://www.hotrod.com/how-to/engine...0deMdVqUAxVFrfDdA&sig2=FdZPtVq6xUKN0WOH7bU_6w
stang89bidges
Advanced Member
Here's a few links on setting valve lash. Remember to read them all and combine the information related to your setup.
Mustang 360
Roller Rocker Arms - 5.0 Mustang & Super Fords Magazine
Summitracing + details
Video: How to Set Valve Lash - OnAllCylinders
Comp Cams
View: https://youtu.be/3gMYWLMAzao
Mustang 360
Roller Rocker Arms - 5.0 Mustang & Super Fords Magazine
Summitracing + details
Video: How to Set Valve Lash - OnAllCylinders
Comp Cams
View: https://youtu.be/3gMYWLMAzao
stang89bidges
Advanced Member
And this looks like your setup right here. Minus the cam knowledge. Still could help you out.
How To Install Roller Rockers and Pushrods on a Small Block Ford 302 | GT40P | 302 Budget Build | Building the Ford 5.0 302 on a budget
How To Install Roller Rockers and Pushrods on a Small Block Ford 302 | GT40P | 302 Budget Build | Building the Ford 5.0 302 on a budget
Oh crap, you were using the old rockers? Glad you couldn't get them to set right then
Those new rockers at 1.6 should be fine. You will want to check P2V! And then study up on valvetrain geometry. Switching rockers could make a huge difference. Could be such a big difference they don't work with current setup. That's worse case scenario though. I forget, stock cam or aftermarket?
I was only using them to check the pushrod length and try to figure out what went wrong. No way was I gonna fire it with those. I'm pretty sure these are what caused the cylinder scratches. The PO finally contacted me and found out that these were indeed proform 1.6 rockers. Stay the heck away from these!. Assuming I find the right pushrod length to get preload correct will I still need to pull the head and check p2v?
I plan on using the clay method to check the p2v. Is this accurate enought? I'll also need a nice digital caliper gauge. Any recco's for a good inexpensive one?
stang89bidges
Advanced Member
You really should check P2V clearance when changing any valvetrain part. You can pickup calipers anywhere that will work for what your doing. I picked up a pair at harbor freight.
Picked up a pair of Calipers from Amazon. Hopefully will be able to measure p2v today or tomorrow. I have one other concern I forgot about:
When I was turning the crank to check pushrod length I noticed a spot where the crank got a little difficult to turn. It was always followed up by a vacuuming type sound so I dont know if I'm fighting compression despite their being no plugs or if I have a crank problem. I suppose I should pull both heads off and double check but that would mean an extra $40 headgasket set for a potentially useless longblock. This has been a very stressful project so far gents :/ If the crank turns out to be bad she will be towed to my house to sit until I have the money to rent a garage. My friend has run out of patience for me using his place...
When I was turning the crank to check pushrod length I noticed a spot where the crank got a little difficult to turn. It was always followed up by a vacuuming type sound so I dont know if I'm fighting compression despite their being no plugs or if I have a crank problem. I suppose I should pull both heads off and double check but that would mean an extra $40 headgasket set for a potentially useless longblock. This has been a very stressful project so far gents :/ If the crank turns out to be bad she will be towed to my house to sit until I have the money to rent a garage. My friend has run out of patience for me using his place...
stang89bidges
Advanced Member
I think your just seeing compression. All the plugs were out? You should have that compression on all 8 cylinders when turning the motor over. The vacuum sound is normal. Maybe someone else can comment on how it happens with the plugs out but I'm guessing your still building compression in the cylinders or something.
Yea all the plugs were out and it wasnt super difficult just took more effort. This is all pretty new to me so Im not sure what Im supposed to feel. The only concern I have is maybe the lack of lubrication from having coolant in the oil could have caused a spun bearing. or maybe the overheating caused a crank issue. Im just going to stop worrying about it. Worst case is I put it back together and find I need a new shortblock. If thats the case I still have a great set of heads, turbo, and valvetrain and 302 blocks arent hard to find.
Okay went in with the two pushrod sizes the speedshop gave me to try. One was a size under (6.200) one was a size up (6.250). I was testing to see if I could set the rocker nut down to between 18-21 ft. lb. of torque at less than a 1/2 turn but more than 1/4 (is this correct?)
With the size up pushrod I got to about 18 ft. lb. at more than 3/4 of a turn... hmmm. With the original size pushrod I had I was able to get it set between 1/2 and 3/4... uhmm. Finally, with the size under (6.2) I was able to set preload to 18 ft. lb. at just under 1/2 a turn.
My confusion is that my original problem was that I couldn't get the rocker nut to tighten down at anything more than a 1/4 turn at best. There are a few possibilities here:
1. I could have accidentally set the screw on the rounded side of the rocker instead of the flat side. This would cause the screw to be just up enough to cause the screw to tighten way before bottoming out. This isn't super likely because I took the rocker off and put it on several times and tried 2 other rockers.
2. My test yesterday was not done at the base circle of the camshaft. I recently learned about how to make sure this happens by watching for the exhaust lifter to start to rise when adjusting the preload on the intake. I was pretty sure I had left the intake lifter at the base circle last time so I didn't bother to check it... but I've been mistaken before.
Number two is far more likely. If say the lifter was beginning to rise that would cause the rocker's zero lash to be off and the lash would be loose once the lifter reached the actual base circle of the camshaft correct? Would this not also cause the pushrod to act like a long
er version of itself? Can anyone think of a way that this would cause me to want to use an undersized pushrod? As far as I understood it, the pushrod length was likely too small before because it was impossible to set preload at over a 1/4 turn. Now the same pushrod tightens at close to a full turn.
Either way I am going to perform the test again at lunch and make sure im at the base circle of the camshaft. I will also double check the rocker is centered on the valvestem using the marker trick once more. Sorry of the long-winded response. Just wanting to learn more. (BTW this test was done with the original rockers. Holding off on ordering new ones until I verify pushrod length but will likely be going with scorpions that are adjustable.)
With the size up pushrod I got to about 18 ft. lb. at more than 3/4 of a turn... hmmm. With the original size pushrod I had I was able to get it set between 1/2 and 3/4... uhmm. Finally, with the size under (6.2) I was able to set preload to 18 ft. lb. at just under 1/2 a turn.
My confusion is that my original problem was that I couldn't get the rocker nut to tighten down at anything more than a 1/4 turn at best. There are a few possibilities here:
1. I could have accidentally set the screw on the rounded side of the rocker instead of the flat side. This would cause the screw to be just up enough to cause the screw to tighten way before bottoming out. This isn't super likely because I took the rocker off and put it on several times and tried 2 other rockers.
2. My test yesterday was not done at the base circle of the camshaft. I recently learned about how to make sure this happens by watching for the exhaust lifter to start to rise when adjusting the preload on the intake. I was pretty sure I had left the intake lifter at the base circle last time so I didn't bother to check it... but I've been mistaken before.
Number two is far more likely. If say the lifter was beginning to rise that would cause the rocker's zero lash to be off and the lash would be loose once the lifter reached the actual base circle of the camshaft correct? Would this not also cause the pushrod to act like a long
er version of itself? Can anyone think of a way that this would cause me to want to use an undersized pushrod? As far as I understood it, the pushrod length was likely too small before because it was impossible to set preload at over a 1/4 turn. Now the same pushrod tightens at close to a full turn.
Either way I am going to perform the test again at lunch and make sure im at the base circle of the camshaft. I will also double check the rocker is centered on the valvestem using the marker trick once more. Sorry of the long-winded response. Just wanting to learn more. (BTW this test was done with the original rockers. Holding off on ordering new ones until I verify pushrod length but will likely be going with scorpions that are adjustable.)
Bingo! Not sure exactly how far into the ramp the lifter was but it was definitely not at the base circle. I put the lifter down to the base circle and then set about retesting the pushrod lengths. Starting with the original pushrod I set the rocker to 0 lash and at about a quarter turn from there the rocker got tight by hand. Using a torque wrench I believe it got to abouot 20 ft. lb. at close to 3/4 turn. I had marked the end of the valve stem and when I pulled the rocker off this is what the centerline looked like:
After that I went to the Shorter 6.200 inch pushrod. This would not even let me get down to zero lash. Threw that one in the spare part bin.
Finally, I installed teh size up pushrod (6.250) This one was hand tight at 1/4 turn and reached 18ft. lb. at a little over 1/2 a turn. Here is the valvestem:
Not a huge difference overall. Now I'd like to have that rocker reach 20 ft. lb. more between 1/4 and 1/2 turn as I understand it but am afraid that going any longer on the pushrod will push the centerline too far inboard. Im trying to decide between going with the 6.250 or one size up.
In order to finish the car before I get kicked out of this garage I need to put in the part order before 5 today. I will have to take a risk on the pushrod length so if anyone has any suggestion on the sizing let me know. Even if the 6.250 is still too short, Im guessing that since the new lifters will have a lockdown nut and is basically more adjustable this wont be quite as critical. At least I know it is close to center of the valvestem and I will be able to set preload within a whole turn. Am I correct in my assumptions here?
After that I went to the Shorter 6.200 inch pushrod. This would not even let me get down to zero lash. Threw that one in the spare part bin.
Finally, I installed teh size up pushrod (6.250) This one was hand tight at 1/4 turn and reached 18ft. lb. at a little over 1/2 a turn. Here is the valvestem:
Not a huge difference overall. Now I'd like to have that rocker reach 20 ft. lb. more between 1/4 and 1/2 turn as I understand it but am afraid that going any longer on the pushrod will push the centerline too far inboard. Im trying to decide between going with the 6.250 or one size up.
In order to finish the car before I get kicked out of this garage I need to put in the part order before 5 today. I will have to take a risk on the pushrod length so if anyone has any suggestion on the sizing let me know. Even if the 6.250 is still too short, Im guessing that since the new lifters will have a lockdown nut and is basically more adjustable this wont be quite as critical. At least I know it is close to center of the valvestem and I will be able to set preload within a whole turn. Am I correct in my assumptions here?
mikestang63
SN Certified Technician
Ah yes! I reread and as I understand the shim will move the rocker tip out? So would it be better to have a pushrod slightly too long and then shim as needed to bring the rocker tip to the center of the valvestem? Or should I stick with the 6.250 (which I believe is stock length) and use the shim to bring the preload within spec?
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