Helping a friend swap to aluminum heads on his 500EFIs and had to order longer pushrods. Now the poly locs seem too short, it almost contacts the rocker body and most of the locking nut is hanging out. These are 1.125 long I believe. Do they make longer ones or can I use the stud girdle type. The roller tips are dead center on the valve tip not sure what I'm missing...Been a few years since i've dove in these things
Is it possible that the rocker studs are too long?? That would cause the lock to stick out as well.
27formula
04-15-2020 10:36 PM
I’m assuming you ordered the right length push rods? The set screws are short so I wouldn’t want them to stick out any. I’d also say you might have to long of studs.
NHGuy
04-18-2020 02:52 PM
I think it's the other way. If the set screws are sticking out the and locks are way down into the rockers - the heads would need longer studs to get the locks raised.which will lower the set screws. Or do I have it bassackwards?
F-2 Speedy
04-18-2020 03:59 PM
The OE locks on the 500,525 are shorter than the after markets ones, what heads are you installing ?
Griff
04-18-2020 07:27 PM
Originally Posted by NHGuy
(Post 4734436)
I think it's the other way. If the set screws are sticking out the and locks are way down into the rockers - the heads would need longer studs to get the locks raised.which will lower the set screws. Or do I have it bassackwards?
Backwards. Sounds like he needs about a 0.2 shorter stud or 0.2 longer rocker nut. Which one depends on how much of the rocker nut threads are in contact with the stud threads.
MILD THUNDER
04-20-2020 08:33 AM
Originally Posted by kennyo
(Post 4733807)
Helping a friend swap to aluminum heads on his 500EFIs and had to order longer pushrods. Now the poly locs seem too short, it almost contacts the rocker body and most of the locking nut is hanging out. These are 1.125 long I believe. Do they make longer ones or can I use the stud girdle type. The roller tips are dead center on the valve tip not sure what I'm missing...Been a few years since i've dove in these things
How wide is the sweep pattern? What heads are they? You can be overly short on pushrods, and yet still have a centered pattern, it will just be very wide. I made this mistake years ago. I was told centered was good. Turned out my pushrods were waaay short. It worked, it ran. However, the next time I rebuilt the engines, I learned a thing or to. So I checked my old technique, against the mid lift method of setting them up. Sure enough, I was way off, and when checking valve lift with a dial indicator, I found I was losing a substantial amount of lift at the valve.
Theres many ways to do this, but without getting too deep, put your checking springs on with adjustable pushrod, and keep lengthening the rod watching the pattern get smaller. Eventually, you'll find it start moving towards the outside of the valve stem. This varies with different head brands, valve lengths, rocker brand, and so on. Or you can do it this way, like in the video.
