Cobra 302 1987 Ranger

[JoeyB]

Alright motor people I have a questions about lifters. I built my engine and have driven it few hundred miles. I have started hearing a pretty good knock from under the valve covers. I was told I need to adjust the lifters. Here's what I've got. It's a hydraulic roller motor. I'm using a stage 1 cam from trick flow, springs from trick flow that go with this cam, and OEM lifter from Ford Racing. the The lifters I have are not self adjusting lifters. Anyone know how to adjust these things to make my engine quite and not hurt it?

 

[baddad457]

If it's got the stock heads and pedestal rockers, there's no adjustment in the rockers. The lifters ARE "self adjusting". If you're hearing a knock, then either you've got stud mount rockers (you never specified what heads you're running) and a rocker nut came loose. Or if you've got pedestal rockers, one or more of the rocker retainer bolts has come loose. Either way, you need to remove the valve covers and see what's up ASAP before you grenade something.

 

[JoeyB]

Thanks for the response baddad457. The motor is a 1991 cobra HO and has stock heads, nothing fancy. Made sure all the rockers were tight as the specs call for and they were. Did the entire engine but, a few of them are a little lose even when they are tightened down. It looks like maybe a few of the push rods are a little worn? Could that be were the looseness is coming from?

 

[red85]

You may have a collapsed lifter.

 

[JoeyB]

Would there be any other signs besides the little noise I'm hearing? Would there be any power loss, back fire, smoke, etc.?

I have about 4 rocker arms that are slightly lose after being tightened. I would think maybe push rods are a little warn at the top where they mate with the rocker arms. No?

 

[fordmike1]

The motor is a 1991 cobra HO and has stock heads, nothing fancy.

Ford never made a 91 Cobra so it might be a 93, 94 or 95 . Just thought you would like to know.

 

[JoeyB]

When I took the casting numbers to Ford that's what they said it was. They told me the engine was made for a thunderbird. If it's not this, Ford through me a line of BS. Which at this point wouldn't surprise me. Through this whole conversion I've been told one thing and it ends up being something else. Do you know anything about push rods?

 

[baddad457]

Thanks for the response baddad457. The motor is a 1991 cobra HO and has stock heads, nothing fancy. Made sure all the rockers were tight as the specs call for and they were. Did the entire engine but, a few of them are a little lose even when they are tightened down. It looks like maybe a few of the push rods are a little worn? Could that be were the looseness is coming from?

It's normal for a few to be loose while the engine's not running after they're all torqued down (25 ft lbs). They should all be tight while the engine's running, with nothing but that "sewing machine" sound with the Cobra rockers. The pushrods do wear on the rocker ends with a roller cam, as they do not spin in operation like flat tappet pushrods do. If they have anything over 100K miles on em, change em. New ones are cheap (Ford Racing $35)

 

[baddad457]

When I took the casting numbers to Ford that's what they said it was. They told me the engine was made for a thunderbird. If it's not this, Ford through me a line of BS. Which at this point wouldn't surprise me. Through this whole conversion I've been told one thing and it ends up being something else.

It's impossible to tell exactly what vehicle any Ford motor came from based on the casting numbers alone. Many parts were used in many different applications, very few are vehicle specific. E7TE heads were used for 10-11 years in trucks, vans, lincoln Mark's, Mustangs, etc. The blocks were used for all applications, regardless of casting numbers. The 2001 Explorer 5.0's timing cover was first used in the 88 T-Bird 5.0.

 

[JoeyB]

That's exactly what I'm talking about. I don't think you'll ever know what you actually have. You need to go with the best info presented.

I did talk to another guy today about my engine noise. He said they make little spacers that fit on the rockers to help with the slack or lash (not sure which term to use). Anyone ever heard of that?

 

[Mac]

You'd be talking about these.
Dave
http://www.jegs.com/i/Ford-Racing/397/M-6529-A302/10002/-1?parentProductId=761160

 

[Psychopete]

I did talk to another guy today about my engine noise. He said they make little spacers that fit on the rockers to help with the slack. Anyone ever heard of that?

He may be referring to the rocker shims.(?) The manual for my Crane pedestal mount rockers indicate that the rockers should be tighten to 0-lash, then torque to 18-20 ft. lbs - and the amount of turns it takes to reach that point can hint if the push rod length is not correct. Less than 1/4 indicates the push rods are too short, more than 1 turn and they are too long and can be shimmed. But that's for roller rockers and not the stock rocker arms, not sure if you could use this method, but sounds like the amount of pre-load needs to be determined and go from there to verify if the push rod length is correct. Method above is what I used, ordered both the cam and the recommended push rods from Summit, and I was just a little under 1/2 turn.

Pete

 

[JoeyB]

Thanks Pete & Mac. That might be what he's talking about. I used the stock rocker arms in a roller motor. That would mean they are roller rocker arms correct?

As for the tightening of the rocker arms...that's what I did. I stated with TDC#1 and would rotate the crank 90 degrees and work on the next set. I worked my way around the engine in the correct firing order. I loosened the rocker nuts and started over. I would tighten the rocket arm until there was 0-lash and I would go 1/2 turn past "which was between 18 - 20 ft. lbs. The information I got was you want a 1/2 turn for street use and if your revving in the high RPMs (drag racing) you only want about 1/4 turn past. I carefully worked my way around the engine and there are about 4 rocker arms that I could never get 0-lash. They are a little lose. If they are lose I would assume the shims should work?

 

[baddad457]

They may have been loose due to the lifter plunger not having enough residual oil pressure in it to keep it pumped up. The stock stamped steel rockers are not roller rockers. The Cobra 5.0 had full roller 1.7 ratio rockers made by Crane, which they later marketed as their Energizer series rockers. I've never used the procedures y'all listed when I bolted these down. The last time was about 4 years ago in the Ranger's 5.0. It's been running daily ever since with zero problems. And the Cobra rockers there had over 100K miles on em when I bought em.

 

[JoeyB]

I've got a guy who is going to look at it tomorrow for me. He doesn't think it's a big deal. Hopefully he can figure it out. Like I said, it's not running bad. It runs really strong, but the little ticking noise is going to drive me nuts.