[richw40]

When I rebuilt my 289 I put on '87 302 heads with the bolt type rockers. I bought a set of rockers, fulcrum and bolts, but didnt realize that I also needed the fulcrum guide plate. I guess this keeps them straight when tightning down. I didnt install these cause I didnt know I needed them. Will this throw off the lift geometry of the cam/pushrod/valves opening ??? And will this will affect the engine running right ? If so, I guess I need the guide plates then ? thanks for any input..........Again

 

[BLISTIC]

Are you sure the head came with guideplates? My e5 heads didn't have them. The bolt down type...are torqued done at 24.lbs while the valve is closed. Simple and mainteneace free. Basically bolt down and forget.
The only reason for guide plates...1. to guide puchrod when non-rail type rockers are used ..IE roller rockers.

 

[fast67stang]

I'm assuming you have the pedestal mounted rockers. If there are reliefs in the heads for the pedestals to sit in then you do not need the guide plates. If there are NO reliefs in the heads for pedestals then you must use the guide plates, the idea is to keep the rockers perfectly straight in order to work properly.

 

[richw40]

there are NO reliefs in the heads. Tightning them is a pain cause they turn to the left when tightning. I was wondering if Ford made a tool for tightning, then I saw a diagram for the guide plates on the net. Also, I noticed today that the pushrods I built the engine with were for a 289 engine. The pushrods that came with the later 302 bolt mounts are 1/2 inch shorter than the 289's. Is this a problem with valve operation, or will the lifter/rocker/valve take a beating because of the extended legnth ?

 

[fast500xl1]

I think what you are reffering to and what you NEED is 8 stamped metal "valleys" that go under the fulcrums. they are what keeps the rocker/fulcrum from turning. they are found on ALL 302-351w engines from 79 up(I think) and should be easy to locate used or new. as far as the pushrods, too long OR too short will cause major problems. with bolt down type rockers you should be able to turn the pushrod with your fingers once the fulcrum bolt is torqued and both valves are closed(lifter on base circle of cam)
hope this helps and happy holidays :winkgrin:

 

[fast67stang]

To be positive on the correct length of pushrods you SHOULD remove the intake and check the lifter preload with the rockers tightened down. You must due this for every valve to account for variances in the heads.

Edited to reflect post below.

I see no reason not to check the lifter preload with the intake off after swaping heads, as is is the most accurate way to determine if the pushrods are the correct length. I didn't even think of I6 engines and was referring solely to 289/302

 

[70sportsroof]

I think "must" might be too strong of a word. For example, on an I6, there is no intake to remove. There is no way to visually inspect the lifters while the rockers are installed.

Basically, pre-load is the tension on the plunger in the lifter so that it reacts on a timely basis when the rocker isactuated by the push rod, which is driven by the lifter's ride on the cam lobe. Think of it as taking out the slack.

Basically, on adjustable rockers, instructions say to turn out the adjustment screw before installing so that when the rockers are installed, there is no tension at all against any of the push rods. This is a zero pre-load condition. You adjust the rocker until there is no gap between the rocker tip and the push rod, then turn the adjustment screw between 1/4 and 1 1/4 turn, depending on the manufacturer of the rocker. This sets the pre-load. This adjustment is made when the valve is fully closed, which is a condition found when the lifter is at the lowest point of the cam lobe.

If factory style rockers, which are non-adjustable on a 289/302 hydraulic lifter cam, proper torque on the mounting bolts plus correct length of the push rod sets the pre-load. In some applications, the factory manual states that it is unneccessary to set the preload. When it becomes necessary to do this on non-adjustable rockers (such as when the head gasket is changed to a different thickness or the deck of the block surfaced or head milled) it is done by changing to pushrods that are something like .060 over or under the factory length.

I've always adjusted my rockers with both the head and intake installed. True, I can see advantages to adjusting rockers with the intake off (on a V8). You can visually inspect that the lifter is at the lowest point of the cam when setting the adjustment. You can also make sure that you are not over-tightening the adjustment screw and starting to depress the plunger in the lifter. Thus, while this approach might be considered a best practice, it is not a necessity. Otherwise, one would never be able to properly set valve lash for I6 engines. (The 170 came stock with adjustable rockers, the 200 and 250 came with non-adjustable shaft mounted rockers. I6 engine builders will swap the 170 rockers onto a milled 200 or 250 head so as to adjust the rockers to compensate for the amount of material milled off the head and retain correct valve train geometry.)

good luck

 

[johnpro]

If factory style rockers, which are non-adjustable on a 289/302 hydraulic lifter cam,

289's had fully adjustable hydraulic lifters, except for the K-code wich had solid lifters. The 302 had fully adjustable rockers until 1970, when Ford changed them to the positive stop rockers.

All 3 of our F code '69's had fully adjustable hydraulic lifters.

 

[johnpro]

I doubt seriously if you'd be able to use 289 pushrods on late model 302 heads. The 289's had fully adjustable rockers, whereas the heads you have are pedestal mount rockers.