[Rock4451]

Car is an 86 5.0 Mustang.

Long story short, heard weird noise, analyzed under valve covers with rockers/girdle/pushrods removed and I can see through the pushrod tunnel in the heads (with a bright shop light) that exhaust lifter on cylinder 3 is slightly turned and it appears dog bone is broken. Will know more when I pull lower intake.

I don’t want to pull the heads and spend a half a grand for link bar lifters and new head gaskets so I’m looking for other options to keep my lifters straight. What are my alternatives? I really don’t like the dogbone idea, but a quick search online didn’t give me any help.

Thanks for any input.

 

[strokeme]

Dogbones, plastic tray used in explorers or link bars. Thats all, pick one

 

[Ed Curtis]

More than likely, if the lifter rotated, it took out the camshaft.

Let me know what you find. We can help with the issue.

 

[tjm73]

Learned something today. Ford put plastic lifter retainers in rhe last 5.0 engines. Did not know that.

 

[Burning Rubber12]

Me either

 

[Burning Rubber12]

I have never had an issue with the dog bones.

 

[strokeme]

Dogbones can definitely break a leg off, then the lifter rotates and its all junk in 10 seconds

 

[Enjoy_the_Ride]

if I could run dogbones and link bar lifters together, I'd do it.

 

[tmoss]

I lost a good stock SD cam to a dog bone failure........

 

[408foureye]

The weakness of stock dog bones is the material they are made from - sintered powdered steel. With a bunch of miles on them, they develope sharp edges as they rub against the flat spots of the lifter bodies. You can minimize this issue by smoothing and polishing the sharp transition where the dogbone stops contacting the two flat edges of the lifter body.

The other problem is the spider tray. The spring tension fatigues from constant vibration of the fingers that hold down each dogbone. It helps to bend out the fingers a bit to restore tension, but ultimately they can fatigue and break off, letting the dogbone jump around and allowing the lifter to rotate in the bore. Under normal operation the spider tray fingers dont move, but as the dogbones wear, they start wiggling around more at high rpms and then are more likely to pop out.

 

[Rock4451]

Thanks for the responses, all.

What I’m guessing, is the lifter collapsed and caused the play in the pushrod/rocker arm. I adjusted that and then either before that or after that, the dogbone broke allowing rotation of the lifter. There was no odd tapping after I adjusted the rocker, but then finally something let loose and I could hear a noticeable sound of a spun lifter for about 8 seconds at idle before I shut off the engine.

The odd symptom about a week earlier is that I would hear a random tap under the PS valve cover, it was about once every 10 seconds at idle, didn’t change with RPM (only eased it up to 2k to check) and when it made the tap noise my oil pressure (I have a mechanical gauge) would spike by maybe 5psi for just a second. No constant tapping and no odd valvetrain noise outside of that. I’m wondering what series of events that’s lifter related could have caused the oil pressure anomaly.

 

[64Cometkid]

Noooooo! Sorry to hear this man! I was still waiting to see track results from your combo! I hope it’s not too bad. Makes me want to just bite the $$ bullet and go link bar from the start.

 

[Rock4451]

Noooooo! Sorry to hear this man! I was still waiting to see track results from your combo! I hope it’s not too bad. Makes me want to just bite the $$ bullet and go link bar from the start.

I’ll get it all worked out, I appreciate it!
If I could go back and do it over, I would have done link bars from the beginning. Since I’ll be doing this repair outside my apartment, my primary goal is to get it back together reliably as soon as I can. Some guys on phasebook swear it’s the Motorsport lifters since apparently they’re junk after losing Eaton as their supplier.

 

[64Cometkid]

Just an FYI I have my dog bones/spider & some Ford Motorsport R302H lifters on the shelf still, if you’re interested. I think I’m going Link Bar now

 

[Rock4451]

Update, yep dog bone broke a leg and the lifter spun.

The cam is surprisingly undamaged aside from some light scoring, no raised areas or areas ground off. I’m assuming because I never had it past idle after the noise started. It’s cylinder 3’s intake lifter.

Upon inspecting the lifter bores down to the cam lobe, to the right of the cam lobe in the tiny space between the lobe and the bearing, it appears there is some buildup of some kind that I can’t identify, and it’s solid. I don’t have access to it to try to knock it out, nor would I, but when I stuck my finger down the bore and pushed on it, it feels solid. Could it be where the metal from the spun lifter accumulated? I’m going to get a borescope and take a look. The odd thing is the cam and engine spin freely and it’s not like it’s holding anything up, which is odd. Pic to show the area where this little buildup appears to be (but picture it installed in block, this buildup must be attached to the block or else the cam wouldn’t spin)

 

[90MarkVII]

Dogbones, plastic tray used in explorers or link bars. Thats all, pick one

Are the Exploder plastic trays a direct bolt in to replace the dogbones?
I've been looking around and can't find much on the subject.
And are they any more reliable than dogbones?

 

[mikeymac]

Are the Exploder plastic trays a direct bolt in to replace the dogbones?
I've been looking around and can't find much on the subject.
And are they any more reliable than dogbones?

Not to get too off topic but yes direct replacement. No bolts. They just slip onto the top of the lifters. They were in a craiglist engine I bought about 8 years ago, been running them since without issue. Not much cam but sees 6500 regularly.

 

[strokeme]

Are the Exploder plastic trays a direct bolt in to replace the dogbones?
I've been looking around and can't find much on the subject.
And are they any more reliable than dogbones?

Yes
Yes
But increasingly more rare as times goes on. They are not sold new like dogbones.

 

[90MarkVII]

Not to get too off topic but yes direct replacement. No bolts. They just slip onto the top of the lifters. They were in a craiglist engine I bought about 8 years ago, been running them since without issue. Not much cam but sees 6500 regularly.

Thank you.

 

[90MarkVII]

Yes
Yes
But increasingly more rare as times goes on. They are not sold new like dogbones.

Thank You.