New Roller Rockers
 

Hi everyone,
I have a '90 lx 5.0 and wanted to get a little more hp out of it. It is a daily driver, and my job requires driving a lot, so I don't want to do anything that will sacrifice dependability. I was thinking of upgrading the rockers and was wondering what would be a good choice to go with and what is all involved in changing them. Thanks in advance.
Josh

My humble experience is that none of the rollers fit under stock valve covers. You'll need to get new covers in addition to the rollers. As for instalation, not too bad. You'll need a big breaker bar with a socket to slowly rotate the engine to get each valve fully closed as you bolt it down otherwise you'll not be able to properly set the torque and the valve will hang slightly open.

You CAN fit rockers under stock valvecovers. I did...1.6 full rollers. How? Grind out all the baffling inside the valvecovers. But unless you want oil in your intake and IAB valve, you're gonna have to plug the PCV return lines and run a breather. It's ghetto but hey, works for me.

Thanks for the info. Do you guys know what ratio the stock rockers are and what a good upgrade would be?

I run 1.72 rr under stock valve covers, but use stack two valve cover gaskets so that they fit :D. Seems to work just fine.

I was wondering if there is a way to find out cam lift with the cam in the car b/c i want to put 1.72 rr on but I think my car may have a small cam in it. What type of hp gain can I expect from a 70mm tbody, typhoon intake, and 1.72 rr on a 5.0 with 9 lbs of boost??

Hethj7 - do you know if I can run those rockers with a stock cam, at least I'm pretty sure it is stock.

Unless the lift on the cam is higher than stock, like approaching maybe .500, Im pretty sure you could run that ratio without a problem.

You still have the valvecover thing to worry about.

I've got 1.7 lift roller rockers under my stock vavle covers. I just removed the baffle.

I would recomend a set tall valve covers though, because my PCV system sucks oil. I've got is plugged off for now.


-Josh, aka the tireburner

I've got 1.7 "cobra" RR's under stock V covers as well, use 2 gaskets as mentioned above, hold cover down, turn motor over by hand. If they still hit the baffle bend it up with a hammer and punch mine barley hit on the edge of baffle, easy fix KEEP THE BAFFLE!!

P.S. remove all spark plugs to make turning motor over easier

Lift on stock cam with 1.7's is .472" 1.6's= .444"

Thanks everyone for all the replies - now all I gotta do is sell just a little more crack to pay for them.

If you dont change the cam profile but simply change the distance that the valves open, what does this actually do? If it is this easy to pick up hp, why didnt ford simply stamp 1.7 steel rockers on the stock engines?

I got new roller rockers and i also got the tall valve covers from ford. But the problem is both valve covers have holes in them. What do i have to do to use with EFI. Do i have to plug the old PVC and get a new one for in the one hole and use a breather cap in the other?? I really have no idea.

Breather holes! Honestly, if they dont squirt oil....leave em be. If you need to get it inspected at any time, plug both holes. The pcv system takes it's fumes from the back of the intake.

What he said. I'm used to GM's that had the valve in the valvecover...I got all confused when I first bought the Mustang. A tip though....never plug BOTH holes. You need at least one of them venting, otherwise you'll buildup crankcase pressure which can potentially cause blowby. Plug one and run a breather on the other.....or put breathers on both. Since you won't be able to reuse your stock oil cap and PCV return line. Oh, and you DID plug the manifold fitting right? :D

What manifold fitting??? but other than that you are basically saying plug then one hole and put a breather cap in the other?

On the front of the upper intake manifold, there is a vacuum return line fitting. That your PCV return tube connected to. Plug that or you'll have a major vacuum leak. I just use a large black vacuum cap. I'd put a breather on the passenger side then, and plug the drivers. It'll be like stock then, except you have a vented pressure release instead of a draw-through. Mine is set up this way, with the stock valvecovers, and I have no problems whatsoever.

Okay, thanks.