Long post. Sorry about my bad English, not my main language.

I have problems to align my valvetrain.

This is the componets involved.

1991 SB 355
Jegs ( canfield ) 197cc alu heads.
Hyd roller LT4 hotcam
Stock new hyd lifters
TrickFlow 1:6rrs

I measured the pushrod length using a modified hyd lifter ( that couldent collapsed under pressure ), when I hade my intake off. I whas aiming for the lowest wearpattern. I ended up with stock length.

The probleme I have now is the alignment of the rocker tips vs the valvetips.

I hade to change a valve seal this winter ( got a fouled plug on no8 cyl ). And when I took of the rockers I noticed strange wearmarks on the valve tips.

Its on the the intake valves I can se that something is not right.
The Jegs ( canfield ) heads has offset intake valves , ( I got this verified from Canfield tech as well ). So the intake rocker sits at a angel from the rockerstud ( se pic no:1 ).



The exhaust rocker on the other hand is "strait", so I have no probleme there..

The probleme I saw is noticeable on ALL my INTAKE valve tips wearmarks. It seems that only a small amount of the rockertip actual touch the valvetip under load. ( se picture no:2 )



Its amlost as if the rocker tips is tilted to one side ( se pic no:3 ). Allowing only half of the tip to actual make contact with the valvetip?




What I did now whas to get some adjustable guideplates, to se if I could align the rockers better against the intake valvetips. BUT I ended up with exact the same measure as with the Canfield stock guideplates. So no improvement there.

And now im a bit lost on what to do. And what I have missed.

As this is my first build, am affraid im perhaps over analyzing this, and that this perhaps is not such a big deal?

One more thing that strucked me is the amount off "internal" play I have on my trickflow rockers. That play also add some difficulty center the rockers over the vavletips during the installation of the guideplates ( se MOVIE link ). Perhaps that adds up to the probleme as well?

http://www.youtube.com/watch?v=521Ix9kUx28

My next ide whas to get rid of the guideplates and use self aligned rockers. But I dont know if there are any down sides using those. And im sure many others got this heads to work with guideplates..

Best Regards

Anders

 

Not sure what the problem is but that is wierd. I have Canfield heads as well with a bigger cam than the LT4. I have the Comp Cams pro magnum rocker arms and the wear pattern is the same intake and exhaust.

 

Yeah. Its strange.. If the wear patter whas "off" on 1 or even 2 vavles I could perhaps suspect a bad rockerstud. But this is on ALL intake valves.

Did you use the guideplates that came with the head?

 

Yeah I used the supplied guide plates. Do you have the guide plates on correctly? If I remember right one slot is longer than the other. This is for the intake valve.

 

Yep, installed it like that..

Do you also have the same kind of "play" in your rockers?

 

Side to side or up and down? With your cam there is going to be a little play side to side but none up and down. Your rockers should be tightened so that there is pre load on the lifters.

 

Got some "side to side" play. As shown in the video i linked to.. Thats with no load on it..

 

I can align the rockertip VISUAL perfect with the adjs guideplates aswell as with the guideplates that came with the engine, no change. Its under load that the intake rocker seems to "tilt"/"skew" some, allowing the rocker tip to only contact a small part of the valvetip. But visual I looks ok..
Its amlost like the studs on the intake sides where not in a 90 degree angel to the head..

 

Today I got some interesting update on my problem..

What I did whas to install a adj push rod, unfortantly I have the intake on, so I hade to use the hyd lifter. BUT the ide whas just to se trends.
I tried both to shorten and to lengthen the push rod, but the trend whas the same. The rocker tip wouldent make a wear mark all the way across the valve tip, it did just touch one side of the valvetip. As I posted abow..
What I did now whas to make sure the lifter whas on the bas of the cam, then I droped in the rocker on to the rocker stud. Then I gently pushed down the rocker, with my hands, and rocked it left and right, just to see the wear mark on the valve tip ( i hade painted the vavle tip with a magic marker first ). Here I found out the problem...

No matter how hard I pressed down the rocker, I couldnt make the rocker tip touch the entire valve tip, it did just make a mark on one side of the valve tip. Just as I showed abow!
This must mean 2 things.

1: The rocker stud holes are misaligned in the head, making the the stud NOT 90 degrees when screwed in.
2: The rockers are the problem. BUT i tried the abow method with 4 diffrent rockers ( all trickflow ). They all cant be bad?

Do guys have any more theory?

ps: I did the same with the exhaust valves with great results..

 

It would seem your logic is correct regarding the rocker stud not being 90 degrees to the cylinder head. It may be worth disassembling the stud/guide plates and checking to see if this is the case. A length of threaded rod (7/16-14) threaded into the stud hole and a machinists square should give an indication whether they are true or not.
I see on the Jegs web site that your heads may be remanufactured. That could present a few issues when they were reconditioned. Perhaps these heads had a previous history of pulling rocker studs.

 

God ide about the threaded rod, will test that at once...
If the holes does seem to miss aligned in the cylinder head. Other then re-drill the heads your only solution would be to adjust the stud i guess?
Using a rubber hammer

 

Yikes!!

 

Nah, but in all seriousness, the only other fix will be to bend the stud very little to re-align.

 

If you do find the hole to be misaligned (not the stud itself ) then a trip to a machine shop would be in order. They would be able to drill and re-tap using an insert much like a Heli-Coil and ensure the hole is perpindicular to the head. I wouldn't recommend trying to straighten the studs. Once you bend this type of material you've started a cycle of fatigue that could have very messy consequences with the engine running.
If the studs are bent, you will have to determine how they became so.
If you wish to continue with the testing, try swapping the intake and exhaust studs (you mentioned that the exhaust alignment is ok). This will show whether the problem lies with the stud or the hole.
Something I just thought of...what is the condition of the rocker assembly itself? Is it a situation where the fulcrum or roller tip has worn to the point where alignment isn't possible? I didn't see any reference as to their history. I would assume they are rebuilable as are my Comp Pro Magnums.

 

I dont think the studs are bent. I tried to use 4 diffrent studs from the head. The trend is the same..
I also tried the same procedure on diffrent intake valves. Same result...

My rockers seems to be in good shape. No excessive wear on the tip or somewhere else.
I do think the trickflow rocker trunions are on the loose side. They are holded with a c-clip on bothside of the rocker. And you can move it from side to side about 3-4mm.
But they been so when they where new.
I also tried to change rockers from my exhaust to the intake, same problem..

 

So it seems the issue is not with the studs or with the rockers although with 3-4 mm of movement I'm becoming suspicious.
I have an engine disassembled in my shop right now and just checked my Pro Magnums. There is zero play across the trunion. There is lateral movement, that is side to side play with respect to vertical however I'm not able to "twist" the rocker relative to the trunion.
The more I think about the less likely the holes are out of whack. With a hex base on the stud, once it bears down on the guide plates, any small misalignment would be taken up with torquing.
Do you have a fresh rocker (roller or otherwise) to experiment with? I saw in one of your previous threads that Canfield (you have reman Canfields correct?) offsets the intake valve. Perhaps this, in combination with a loose rocker gives the results you see. You mentioned that the exhaust is ok.

 

First, thanks for helping!

Yes, if i hold the trunion with my fingers, I can move the the rocker 3-4mm from side to side. Not twist it. Sorry if I whas unclear..
Yes this is reman Canfields with offsets intake valve.
This picture tells pretty much on whats going on. This is no:1 cylinder with both the intake and exhaust lifter on the cam base. And this is after 1 turn on the rocker after zero lash ( just as when you adjust your rockers ).

As you can see the exhaust rocker sits flat on the valve tip. BUt the intake rocker is slightly tilted to the left. And if you try to stick in a pice of paper between the rocker tip and the valve tip you can do so but only from the right, all the way to the center of the valve tip. But if you try the same from the left, you cant..

 

There seems to be only one option left and that's the valve is somehow angled in its seat.
I just read a short article ( a forum complaint actually) about someone describing how the seats in their Canfield heads were receeding into the cylinder heads. That would be the hardened seat inserts machined into the base aluminum material.
Maybe you can remove a pair of springs (intake and exhaust) and using an accurate level (such as a digital) see if there is a relative difference between the intake and exhaust on the same cylinder.
I'm not sure about Canfield's tech support but it may be worth a try.
For the record, if anyone tries to tell you that this wear pattern is ok, I would think that they either don't have a total grasp of the situation or they are very misinformed. You can imagine the strees this alignment would apply to the valve and the rocker.

 

Dart Pro1s come with off-set intake valves too and those heads come with special guide plates to address that change in valve positioning.

If it were me, I'd run the condition by Canfield's Tech Department. I'll bet you're not the only one who's experienced this issue and Canfield may have a fix for it.

Jake

 

By the way, why is it that one allen head set screw is extending higher than the other? Did you install the rocker trunnion with the correct (FLAT) side UP?

Jake

 

Is only because I dident lock the rocker bolt during this test session..

 

Yeah that could also be true, but on all intake valves? Hmm well I guess its happend before.. Just frustrating..

I will do the test with a digital level gauge on the tips of the valves. Good tips

I will also try a diffrent set of rockers, just to be sure.

 

I think I can give up on the Canfield tech support..

http://www.yellowbullet.com/forum/sh...d.php?t=136767

 

That would explain why their website is non existant.
What kind of spring pressure are you using? Any spring specs?

 

2.055'' Int/1.60'' Exh Valves
1.440'' Springs, .680'' Max Lift Soild/Flat Tappet, Hydraulic Roller Cams


Well im going to take off the heads.

I whas goin a diffrent route with this car anyways. But its sad that I just wasted around $ 900 ...

 

It seems that the intake stud hole wasn't drilled and tapped straight so as to be parallel to the companion exhaust hole.

If you measure the distance between the base of two companion rocker studs and the tips of the same studs, the distance should be equal.

I agree, also, that loading the valve stem the way it is now will accelerate guide wear and isn't "okay".

I can't think of any 'fix' other than having the stud holes welded closed, then re-drilled and re-tapped.

Jake

 

Thanks, will test that asap.. Well, I got my rockers left as a source for this error. Will test with a friends magnum rocker..

I can se my future.... Soon a topic on good heads for my combo

 

I measure the distance between the base of two companion rocker studs and the tips of the same studs. The distance whas the same. Verifyed this with all the other clyinders.. Im so total lost..

 

Have you tried the different rockers?
If the studs are parallel (with whatever method you choose to measure using a tape measure or digital level) and the rocker swap doesn't resolve there's really only one thing remaining that could be out of whack and that's the valve itself.
A related experience I just went through on a pair of Brodix Race Rite heads was finding that the valve guides were TOTALLY wasted on several of the intakes. This build had less than 10 000kms. Oddly, the exhaust were fine. What we determined after a (costly) rebuild was that the spring installed height was too high. Installed height should have been 1.8" however it was found to be 1.9". This additional tenth of an inch reduced the seat pressure to the point where the double spring was left to move around. Why it took out the intakes is still a question (perhaps the slightly higher lift ).
Before you get around to removing the heads, you may want to pull off a few of the springs and check for excessive play at the guide/ valve stem.
I'm interested to know the results of the rocker arm swap.

 

I made some progress today.
Took the pushrod out - THen I physically (with my hand), made the rocker contact valve stem, pull up on rocker at the back of the rocker, against locknut ,now i had a full contact pattern , then I rotate rocker left to right, the roller wheel can keep a full contact pattern for about .070 left to right movement, after that im forcing it to seperate from valve tip, sounds like I can solve this with offset rockers or offset lifters. But I still wounder why, as many others use these heads without offset rockers, or so I heard anyway..

What you think?

 

Sounds very unusual in that you wouldn't be able to "swing" the rocker in an arc and make full with the valve stem tip. At least up to point. Unless there is some binding somewhere, rocker against retainer for example, it seems that something is bent. I would think the pushrod would bind first however you've eliminated that from the equation by removing it. Can you see what is causing the rocker to tip?
That being said, before you go to the expense of offset rockers (you did say the intakes are offset correct?) I would still try a conventional quality rocker (like a Pro Magnum or similar) as you had suggested earlier.
With all the experienced engine assemblers that use this forum, I'm surprised that someone hasn't chimed in with a similar experience and remedy. I guess when it's all said and done, you will be that person!

 

Wow..

Found this thread, regarding the EXACT same issue as I have.. If you have some time to read.

http://speedtalk.com/forum/viewtopic...=16068&start=0

 

I really dont think offset rockers are your answer. As I said I have those exact same heads and I have normal roller lifters and normal rocker arms and my wear pattern is exactly the same on both valves.

I noticed you are using aluminum rocker amrs. They arent touching the top of the valve spring are they?

Edit: to be clear, the wear pattern on top of my intake and exhaust valves are the same. Both valves have a solid line across the middle of the valve. I'm not in any way saying that the pattern on your intake is normal. After reading some of the other post I started thinking that some people thought that I was saying yours is normal. I'm not. Something is wrong. Thats why I dont think you need offset rockers, because I dont have them and I dont have the problem you have. Just wanted to make things clear.

 

Interesting article however in the end there was still no solution. I can't believe that this is an acceptable wear pattern although I'll qualify my statement by saying that I'm no expert. I can only relate to what I've experienced (and never this situation) and by third party info (much like the Speed talk article).
If the guide is not perpindicular to the head then the valve is not either. It would mean the valve is bent otherwise and perhaps being rebent (to a small degree) every time it opens and closes. That's are sure fire recipe for a broken valve. THAT I've seen. Not pleasent.
To recap. The following should have been checked or measured:
stud alignment (intake and exhaust parallel to each other)
rocker interference (rocker to retainer, trunion on stud)
guide alignment (are the valves perpindicular to the head)
rocker arm swap (perhaps try a 1.5 ratio)
Beyond that it appears the offset intakes are creating the situation. How that can be remedied I'm not sure. Maybe offset rockers are the answer however popular thinking says that's not the case.

 

Update..

I mounted the stud without any guideplates. And when I did that, I whas abel to align the rocker square to the valve tip. Sooooo I remounted my adj guide plates, and screw in the stud with my hand, then I mounted the rocker and pushed it down against the valvetip so it made contact.
While holding the rocker in this position i screw the stud in place ( dont ask how i did that with only 2 hands, it whas a mess )..

With this method I mange to get a much much better wearpattern on the intake valve steam.
The rocker is still somwhat "tilted" but its better then before.
I enden up with the intake pushrod pretty close to the cylinder wall, but its around 0.19inch, dont think I need to grind that.

The wearpattern is not perfect, and something must still be wrong.
I attached a picture where you can se the pattern, its "pie" shaped, but now atleast it cross the tip.

I will still try with a diffrent set of rockers.


Im not yelling success yet. But its a big step closer a solution..

 

What do you mean by the pushrod being close to the cylinder wall?

What did you torque the rocker studs to?

Jake

 

WHen I moved the adj guideplate, I hade to move it pretty far to the right, so the pushrod got closer to the head from its "hole". Sorry for the bad English, cant find the right words sometimes

Torque the studs to 50 ft/lbs

 

Anything new to report?

 

Sorry for the lack of update. Im going to pull the head. Take it to a machine shop and have then checked out. I get back with results..

 

Is the under side of the rocker contacting the outside dia. of the valve spring retainer and is the rockers fulcrum riding on the shank of the stud or is most of it riding on the threads of the rocker?