please help

[tims91pony]

I have 91 5.0 mustang that i just put a e303 cam in stock heads gt 40 intake no cats h pipe 70 mm throttle body my problem is that it sounds like a bunch of sewing machines its not hitting valve covers the rockers are all torqued right ck 5 or 6 times are my lifters not pumped up or failing pushrod length wrong not sure where to look nextvalvetrian is all stock except cam hope i have given enough info for help if not please ask and i will provide thank you

 

[jka]

Check your header/exhaust manifold bolts and tighten them if they are loose and check the smog crossover tube behind the heads and make sure the two bolts are tight. Then see if you still have the noise.. and if you are still hearing it .. you may have a rocker/ pushrod problem.

 

[RangerJoe]

With both valves closed on a particular cylinder, how much play do you have with the rockers and pushrods? Check each cylinder. Some like them to be looser than others, but I like to just be able to spin the pushrods by hand with the valves closed. Others may chime in with more detailed responses.

 

[tims91pony]

rocker noise

there is alot of play i can actually move the rockers back and forth and slightly up and down the noise is for sure coming from the valve covers it does seem to be on the exhaust side?

 

[2000xp8]

It's probably the rockers. What type are you using?
An e cam with stock heads and stock valves springs isn't that great of an idea, yes you can do it, but the springs aren't going to last long.

 

[tims91pony]

all stock, except cam(lifters,rockers,springs and pushrods) would 1.6 roller rockers and springs solve the problem? thanks for your help

 

[RangerJoe]

Sounds like you need longer pushrods. You should be able to turn the bolts on the rockers by hand until they stop (this is with both valves closed), then torque the bolts 18-20lbs. I believe you should turn 1/4 turn or so before it hits torque. Did you shim the rockers by any chance? If you did, try taking the shims out. Many things can affect pushrod length, changin a cam is one of them.

 

[tims91pony]

I did not shim the rockers i would agree that i need longer pushrods i was told that i would not need to change but that seem unlikley at this piont any suggestions on length or will i have to get a measurment between rocker and valve stem also it seems that my play is all on the exaust side of things at this point any other advice would be greatly appeciated thank you so far you have been very helpful

 

[2000xp8]

Goto summit racing and get a pushrod length checking tool.
Might as well get some ford racing 1.6 rockers while you are at it.

Changing the cam while leaving the stock heads generally isn't a good idea.
It can create headaches and provides very little power gain.

Consider if you have a few more bucks available buying a set of gt40 irons off a cobra based engine or an early explorer 5.0.
Then upgrade the springs and use the 1.6 rockers. At least this way you will get something for your money.

 

[tims91pony]

I have the heads from the explorer that the intake came from i could use gt 40p heads i just cant seem to wrap my head around the idea that the length of the pushrods would change from just a cam swap but anything seems possible at this pointthanks for you help