|
Author
|
Topic: Urgent - 302 engine builder advice needed.
|
T5owner
Gearhead Posts: 724
From: Germany
Registered: Apr 2000
|
posted 08-04-2001 10:31 AM
 
Hi engine builders, need your advice on this one.
Let me say before, that I am a shadetree mechanic with only little experience in much smaller engines.
3 days ago, I heard a valve clattering sound, that disappeared with higher speed, the next day it was completele gone, so I thougt it was oil starvation due to some debris, yesterday it was back and unfurtunately I still traveleld about 30 miles at speeds of 60-70 miles.
Today I pulled the valve cover on the drivers side, as I located the sound to be there.
After some jumping the engine over I noticed that the rocker arm had to much play on cylinder no. 8 exhaust valve. I unscrewed the lock nut and there was no more valve stem tip.
Instead I found it (at least a broken part of it next to the valve in the oil.
The rocker arm looks still good and has no wear on the side rails, the push rod seems to be alright and the valve itself as well from an optical shadetree mechanics viewpoint without taking any measurments (that's what we usually do). The smaller broken part of the valve stem tip seems to have vanished in the oil drain on the rear side of the cylinder head.
Now to my questions:Can I go the easy way and simply put a new valve stem tip on, set valve lash (close to zero) and close the engine?
Where can I get a valve stem tip and which one do I need (specs of engine see below)
Can I forget about the smaller part of the tip, if it has enough room to travel down to the oilpan or is it stuck somewhere in the drain tube?
If it is stuck, how to get it out without pulling the engine?
Should I rather pull the cylinder head and let the valve,spring, push rod have replaced. The engine block is a D1ZM-6015 AA 71 or later mexican block, which was modified for drag racing once.
The cylinder heads are cast with 302 and a B on the other side (no 4V or 2V identification)
The cam is a Crane cam,
I could not find a casting code, but the date code is 0K29 (probably 29 Nov. 70) and the circular casting says L6 1 3 5 _ (sth.)
The valves have a blue (maybe blue/green) colour stripe, which is not typical for this cylinder head, or is it? Might they have been changed with the Crane cam? I think cams come with other lifters. Does this include push rods as well or are they then different for those lifters? Lots of questions, the more answer you have for me, the better I will feel with any decision. Pictures of the problem will be seen here soon. my server is down again, so please wait.
 [This message has been edited by T5owner (edited 08-04-2001).]
|
steve'66
Gearhead Posts: 9835
From: Sonoma,CA,USA
Registered: Mar 2000
|
posted 08-04-2001 04:12 PM
T5,The valve stem tip is the top of the valve above the valve spring. Is the broken piece from the rocker? If it is then just change the rocker. The top of the valve stem looks serviceable, a little chewed up, but it will work.  You could pull the oil pan and clean out the oil pum pickup screen. Good luck, and good pics. SteveW
|
SteveLaRiviere
Administrator Posts: 48752
From: Saco, Maine
Registered: May 99
|
posted 08-04-2001 04:28 PM
That appears to be a valve lock, not a valve stem tip. {You shouldn't have those on your valves} There is a groove on the other side of it, right? Can I see a pic of the other side of the piece? It kinda also looks like a bit of a broken valve guide.Look carefully at all the retainers to see where it came from. Don't run your engine until you find it. If you drop a valve, it's all over.  ------------------
'70 Mustang Mach 1 M code 351C 4V/FMX/3.25 open
'72 Mustang Sprint Coupe 351C 4V/FMX/4.30 Trac Lok
'94 F-150 XL 5.8L/E4OD/3.55 Limited Slip
'97 Probe GTS 2.5L DOHC
Ford. The closer you look, the better WE look!
|
Just Jim
Gearhead Posts: 381
From: So Cal
Registered: Feb 2000
|
posted 08-04-2001 09:10 PM
That piece looks like it might be a "lash cap",a little hat shaped part that fits over the valve stem.Try to get a new one from a local machine shop that does valve jobs.The other piece of it is probably in the bottom of the pan and won't hurt anything but it would give piece of mind to pull the pan and fish it out.It might come out when you drain the oil.------------------
"Just Falcon Around"
1962 Falcon 351W
1958 Morris Minor 289
|
T5owner
Gearhead Posts: 724
From: Germany
Registered: Apr 2000
|
posted 08-05-2001 01:07 AM
Thank you, I read my "How to rebuild your Small Block" book by now. My understanding is, that the 68 1/2 and later cyl. heads do have valve stem tips (steel caps or maybe called lash hats) only on their exhaust valves. This one is an exhaust valve of cyl. no. 8. The studs have a shoulder, so lash could be only set with longer push rods. What is a valve lock, Steve l.R.?
I attach another picture of the piece laying next to the other spring. Otherwise I might unscrew another rocker of another exh.valve to check it, how it looked in one piece.
Any more hint on the 302 "B" cyl. head and the blue spring colour code? And what about the L6 change. The book mentions only the L4 change, that is for the hardened steel valve caps and other changes. Early 68 valve trains are said to have been prone to extreme valve stem wear, that is why they put on the steel caps on the exhaust valves. [This message has been edited by T5owner (edited 08-05-2001).] [This message has been edited by T5owner (edited 08-05-2001).]
|
Gary
Gearhead Posts: 726
From: Sarasota, Fla. USA
Registered: Jun 99
|
posted 08-05-2001 09:57 AM
That little piece laying there in the last pic looks like a valve lock to me but from the pic of the spring next to it, it looks like the two locks are in place. Better do some careful inspection before you run your engine again to see if all the valves have there locks in place. Locks are the two half moon pieces just below the valve tip. They are tapered and basicly hold the spring and retainer in place on the valve/s. Hats, that Im not that fimilar with but have heard of them. I would compare with the others exh. valve tips and remedy the problem.
Good luck
|
69maverick
Moderator Posts: 1539
From: Thomaston,CT.
Registered: Jan 2001
|
posted 08-06-2001 07:52 AM
You can tell by the 1st and 2nd pic. that it is not a keeper or valve lock! I can see both of them in there!
|
T5owner
Gearhead Posts: 724
From: Germany
Registered: Apr 2000
|
posted 08-11-2001 09:09 AM
Pulled 2 more rockers.
Well, now I know it is indeed a part of the valve cap of an 68 1/2 and later exhaust valve. Here is one shown of another exh. valve
These are two rocker arms. The right one shows more wear pattern, so I probably have to exchange that one, too, right?
I have ordered already those parts. I check the oil channel down with a magnetic picker (as the other part was magnetic, too). Did not found it. Will drain the oil pan now and keep you updated. At least sb. might learn with a shadetree mechanic like me.
|
SteveLaRiviere
Administrator Posts: 48752
From: Saco, Maine
Registered: May 99
|
posted 08-11-2001 11:35 AM
Wolfgang, the valve lock or keeper are two split curved metal parts between the valve stem and valve retainer.This picture looks just like one:
But your other picture:
...seems to indicate I'm wrong. Just to be safe, please verify all of the valve have their locks for me. If the rocker arm shows any wear at all, it's a good idea to replace it. It doesn't look very bad in the photo, but photos can mislead. If you can't find the rest of the valve lash cap, you could remove the pan but if you have enough nerve, you could try just switching to a magnetic drain plug. ------------------
'70 Mustang Mach 1 M code 351C 4V/FMX/3.25 open
'72 Mustang Sprint Coupe 351C 4V/FMX/4.30 Trac Lok
'94 F-150 XL 5.8L/E4OD/3.55 Limited Slip
'97 Probe GTS 2.5L DOHC
Ford. The closer you look, the better WE look!
|
Ronster
Journeyman Posts: 11
From: Stockton, CA US A
Registered: Aug 2001
|
posted 08-11-2001 02:43 PM
I'll give this a try. This is the first time I've posted online so bear with me. I can tend to get to detail oriented. If I do, please yawn at me. First, a little background on 289\302 valves and rocker arms. Early 289's used "boat" style rocker arms. These rocker arms, where they touched the valve tip, have no sides on them. What keeps them on the tip of the valve is that the head has a slot in it where the push rod comes through. Since the push rod can't move side to side, the rocker arm stays on the top of the valve tip as it should. In 1966, Ford started using a different style rocker arm which is found on the 302's. It's called a "rail" style because the tip of the rocker, where it rides on the tip of the valve, has rails down each side. It's these rails that now keep the rockers on the tip of the valve where it's susposed to be. To accomadate this change, the tips of the valve had to be lentghened to stick up higher to give the rails something to not slide off of. Also, this additional valve tip height gave enough cleanence for the front most tip of the rails on the rockers to not hit on the valve spring, thus knocking the keepers out of the spring retainer and dropping the valve into the cylinder. The rial rocker heads had the slots replaced by large holes to stop the friction on the push rods and also to help with oil return. Now, your problem. The tips of the valves are what's known as "Hard Faced". This hard face keeps the rockers from wearing off the tip of the valve stem. When this hard face is gone, either from wear or by someone who's doing a valve job grinding through it, the tip wears down. Wear makes the tip of the valve shorter. If they get too short, the rails on the rocker arm hits on the valve spring retainer. When this happens, you'll hear a "ticking" sound, not as loud as a lifter but still noticable, that will sometimes go away and come back. If not checked and repaired, what can happen is that the keepers come out of the retainer and the whole valve drops into the cylinder. What I see in one photo laying there "COULD" be a part of this hard face, maybe from another valve, which has broken off of the tip of a valve. What I see in another photo definately looks like a keep. Before you drive the car again, be sure to check each rocker arm for wear on the tips of the rails. Check all the valve tips to be sure none are broken or show signs of wear. Check out the tops all the retainers and make every keeper is in place! Above all else, if you hear a noise, find out what's causing it! The engine you save may be your own! Good Luck and I hope it's just a simple fix!
|
T5owner
Gearhead Posts: 724
From: Germany
Registered: Apr 2000
|
posted 08-12-2001 04:14 PM
Thanks Steve and Ronster (you are the RON from Stockton, right? I have been at your shop and you showed me your backyard with Gary, you remember?, thanks again, Ron, was one of the bigger highlights of my US tours)
Well, I checked all valve keepers and they are still in place. Comparing the broken part and one of the valve caps, it looks identical. I am just still nervous about the bigger missing part. I have a magnetic oil pan plug screw already in, so I hope it is sticking right there. So this was good advice, which I read earlier in a mag. I will pull the other rockers as well.
Ron or Steve, one more question from a shadetree. I screwed one of the rockers back on and noticed, that when I unscrewed it, it was a little moving (very small lash) and the valve was closed. Now when I put it back on I could turn it more until the nut reached the positive-lock of the recessed stud. Can I simply torque it to the specifications, as the nuts are supposed to be torqued down to the stops? In other words are the lifters lifting further, after taking away a rocker or are they at their highest point, when you pull a rocker with marginal lash (pushrods just can be turned). Thanks again guys.
And by the way, found another ARI Pace car. Have a look at my website at http://people.freenet.de/pony/news.htm
|
SteveLaRiviere
Administrator Posts: 48752
From: Saco, Maine
Registered: May 99
|
posted 08-12-2001 04:19 PM
Hey, Ron! Welcome to M&M!Thanks for the tips! {Pun intended!  } ------------------
'70 Mustang Mach 1 M code 351C 4V/FMX/3.25 open
'72 Mustang Sprint Coupe 351C 4V/FMX/4.30 Trac Lok
'94 F-150 XL 5.8L/E4OD/3.55 Limited Slip
'97 Probe GTS 2.5L DOHC
Ford. The closer you look, the better WE look!
|
SteveLaRiviere
Administrator Posts: 48752
From: Saco, Maine
Registered: May 99
|
posted 08-12-2001 04:28 PM
Wolfgang, as you torque the nuts down, some will compress the lifters and some won't, depending on what point the lifter is on the lift of the cam lobe. The best way to torque the nuts is to follow the valve adjustment procedure in the shop manual. I can get you those specs if you need them.Is this what you're asking? ------------------
'70 Mustang Mach 1 M code 351C 4V/FMX/3.25 open
'72 Mustang Sprint Coupe 351C 4V/FMX/4.30 Trac Lok
'94 F-150 XL 5.8L/E4OD/3.55 Limited Slip
'97 Probe GTS 2.5L DOHC
Ford. The closer you look, the better WE look!
|
T5owner
Gearhead Posts: 724
From: Germany
Registered: Apr 2000
|
posted 08-12-2001 05:49 PM
Steve, I have the shop manual and I have read the instructions about jumping the engine over and setting the valve lash in the engine book, but you know I am a bloody shadetree wanting to go the easy way and I am still not figuring out, how to bump an engine over and get it stopped at the right position - as an advertising guy I simply used the key to bump it over, now picture it- doofus award to me).
Now, what I wanted to ask is, can I simply torque all rockers back on to the positive-stop recessed studs (that is what the engine book calls them) end without thinking about bumpint the engine repeatedly over. I know this is probably stupid, but would make it much easier, right?
|
SteveLaRiviere
Administrator Posts: 48752
From: Saco, Maine
Registered: May 99
|
posted 08-12-2001 05:54 PM
It may be easier, but not the correct way. When the cam lobe is up, it will affect the torque readings. It's not much harder to do it the correct way. For accuracy, don't bump it over with the solenoid. I generally turn it by hand with the fan, or a socket on the crank bolt. ------------------
'70 Mustang Mach 1 M code 351C 4V/FMX/3.25 open
'72 Mustang Sprint Coupe 351C 4V/FMX/4.30 Trac Lok
'94 F-150 XL 5.8L/E4OD/3.55 Limited Slip
'97 Probe GTS 2.5L DOHC
Ford. The closer you look, the better WE look! [This message has been edited by SteveLaRiviere (edited 08-12-2001).]
| |
