New Engine Build - Huge solid roller valve train issues...

[Hissing Cobra]

I'll also add that my brother built my 347 stroker motor and I've had two major issues with it so far, neither one was his fault. The first was that after it was built, I installed the rear pilot bearing into the crank (my first time ever) and didn't know that it was supposed to be flush with the back of the block. Of course, it was sticking out because the stroker kit manufacturer (EAGLE) didn't drill the back of the crank deep enough to have it sit flush. Being a rookie at installing this bearing and installing the engine (first time on my own), I didn't pick up on it. A month after installation, I'm up at New England Dragway and on my first pass, the flywheel was hitting the back of the block and making a rapping sound. Yep, the transmission pushed on that bearing so badly, it moved the crank forward in the block and wiped out all the main bearings while also ruining the crank. One thousand dollars later, I had a new balanced crank that was drilled correctly and the car ran like an animal! Passes at the track were in the 11.50 - 11.80 range at 118 - 121. It lasted one year and then I lost oil pressure because a .30 cent snap ring broke off of one of my Comp Cams rocker arms, got into the aftermarket oil pan and matching pickup tube (no screen like a factory Ford unit) and into the oil pump, locking it up. WTF! Luckily, I heard the noise, looked at the oil pressure gauge, and shut it off immediately, saving my stroker kit and block!

We're about to dive into fixing it and I'll be making some changes for sure (single guide plates for each push rod instead of the standard issue guide plates that control two pushrods at once, steel rocker arms instead of the weaker aluminum bodied rocker arms, and a girdle on top of everything). Like you guys, we've had our frustrations with our own stuff and it happens. Yes, it sucks but perseverance will get you through it. Here's to hoping it gets fixed correctly and your dad gets to beat the bag out of it as much as he wants!

By the way, I called Eagle about the incorrectly drilled crank and they said that they make two stroker kits, one for the early four speeds that use a pilot bushing (which isn't as deep) and one for the later model five speeds that use a pilot bearing (which is deeper). Hmmm, how come they don't advertise that when you're buying a stroker kit? They also said that if we had noticed that BEFORE the installation of the crank in the block, they would have sent out another crank. My brother now checks EVERYTHING and doesn't assume anything is machined correctly when he buys something.

[Jerry peachuer]

Pilot bushing wasn't sitting all the way flush on my crank either

I was able to get through and spoke with a tech guy there and in short it was not drilled all the way because of a improved main oiling passage on cylinders 7/8 mains

So they said I'm good and once you put flywheel on it was flush to the flywheel surface and my input drive shaft of 5 speed (splines) were not touching the pilot bearing I should be good

Sooooooo 2900 later and 7 -8 months and not even a 10percent discount not even a quart of oil nothing just a email every other week saying we are still in process with it

They said cast cranks fail and you should buy steel so a 900.00 crank for a 300 hp iron headed street cruiser umm lol

Why do they sell them then ? Or what would you use it for ?
Understand I didn't set out to build a 331 it was offered as a thing to do and knowing a guy who knows a guy I had a fair discount on the build and other stuff I won't get into

Not trying to rant guys it's behind me and this isn't my post and for that I apologize for my car is welded up and painted and short block is in process ,good things happen when bad things happen so enjoy

It held me up for being in process 7--8 months and I'm on to the next engine build much wiser

If anything you will learn and grow self education is the best

Your dads car is clean and it will be a animal (it is now )

Happy wrenching wish you the best of luck

[Jerry peachuer]

After re reading my post I probably have someone scratching there head

The pilot bearing was not drilled all the way down (deep enough) to fit a OEM pilot bearing and this said company didn't offer there own style they said I will be fine which sounds reassuring because the drilled new oil passages on 7/8 mains to help flow of oil blah blah blah

If the pilot bearing was any deeper it will break into this new oil passage and that's not good

[Jerry peachuer]

Hissing cobra -
Damn you went through some stuff glad it's ripping again
Haven't seen the individual pushrod guides you have my attention

I was thinking about the adjustable guides from Dart

[n20capri]

Crazy stories fella's - thanks for sharing. We've been fairy lucky with both our cars in general so I guess I really can't complain. Just frustrated is all. I'll be getting to Dad's car tomorrow. Hopefully all is well!

[306gt]

There is not enough travel in the rocker arm bodies for the gross valve lift you are running. If you have witness marks on the poly locs and on the rocker bodies themselves you have binding issues. A shorter pushrod will help but it would have to be more then .050 shorter to do anything anyways. Then it will be so short the geometry will be all out of whack. These particular Comp rockers are known for interference between the rocker body and the poly loc. I would get a different set of rockers and try them. You will have to find a company that makes rockers for that size gross valve lift. Scorpion Race series I think are good for .950 gross valve lift. I would also measure the gross valve lift with a dial indicator at the valve spring retainer to actually see what you end up with. The shank of the rocker stud should also be fitted inside the rocker arm. The threaded portion should be above the hole in the trunion of the rocker arm not inside of it. You should also be using a girdle of some sort. In my opinion if it was mine I would switch over to a shaft rocker system. Also we need to know how much open spring pressure and seat pressure those springs are set-up at.

[Zap's 85 GT]

My new AFR 205s came with the two piece guide plates. They take 2x-3x longer to set up, but they are much more preferred as all of the rocker tip placements are exact.

https://www.summitracing.com/parts/afr-6103

[Hissing Cobra]

My new AFR 205s came with the two piece guide plates. They take 2x-3x longer to set up, but they are much more preferred as all of the rocker tip placements are exact.

https://www.summitracing.com/parts/afr-6103

Those are the ones I'll be going with. We have a sneaking suspicion that because the one piece guide plates didn't center things exactly, the "pigeon toed" rockers popped the snap ring off, sending both pieces into the oil pan.

[n20capri]

So it looks like the car had an offset trunion rocker on it moving the geometry causing the issue. Working on the solution still...I called Comp myself and they said a lot of guys just machine the poly lock and go from there. Trying to figure out what to do myself...

2 things...

1. Why they used an offset trunion last build I have no idea...builder said they wouldn't have and he doesn't know why either...(someone ordered the wrong part or wrong part was sent?) Either way, it worked fine on last engine...bigger cam now causing issues...

2. (and the most annoying part) Why it wasn't caught this time?

Either way at least now we KNOW the issue. I'm leaning towards just new rockers, poly locks and the appropriate pushrod...but it's been raining (finally) so haven't had time to investigate more.

Will update when I know more.

[Hissing Cobra]

Definitely keep us updated. It sucks to have to go through this and force yourself to "investigate" the issue yourself. But, you'll be better for it in the end as your knowledge will increase. I've had to do that for many things in my life and last dealt with this in regards to getting the air conditioning working in my Cobra. I know so much about it now that I should almost be an expert.

[Zap's 85 GT]

That is interesting and different. If it's easy enough to point out and identify, I would appreciate some pictures so I can log it into my brain for future reference.

[n20capri]

If your looking for it yeah I guess it's easy...but if not then no! lol. I'll try to get some pics next time we work on it.

[n20capri]

Update: With the machined poly lock and the shorter pushrods (7") we no longer have interference! Not even close now! WHOO-HOO! Valve tip wear pattern is just about perfect too.

The builder said he wants to go over it one last time before buttoning things up - that's fine with us it's raining still here so it's not like we are able to drive it. I went ahead and did them all and got all the valves adjusted. I'm sure he'll do another wear pattern test and then go over all the valves. Which is fine with me...god forbid something else goes wrong he can't blame us! lol

Now, forget seeing (or not seeing) the interference, I'm still trying to figure out how the initial wear pattern test passed by whoever assembled things initially...I mean we are 2thou shorter now...how on earth was it right before? Only thing I can think of was it wasn't traveling through it's entire cycle because it was hitting? idk that sounds scary - hopefully all is ok...

Anyway, it appears as if things are looking up. Hopefully one last update of the thing running!

Video - Looked good when I was taking it - hard to see it's not actually hitting though.



Oh and the rocker...you can see the machined surface for the polylock is slightly offset (to the left in the pic) - but that's of course the back of the rocker and where the interference was...

[Ethyl Cat]

Been lurking this thread, but it is good to hear that you issues are resolved.

My 2cents, shooting for a centered pattern on the valve tip is the wrong way to set pushrod length. This build proves it.

You have had three different lengths in this engine and said that each pattern "looked" good.

Rocker geometry must be set first and pushrod length should be the result of checking the distance AFTER said geometry has been established.

Enjoy that new build, sounds like fun.

[Hissing Cobra]

Good news. I'm keeping my fingers crossed that this is the culprit and that both you and your dad are in the clear. It's time to bust out some passes!

[Jerry peachuer]

Glad to hear it's sorted or non binding

Happen to have a pic of the machined poly loc ?
Underside of roller rocker ? But trunion in same orientation ?( flat towards the pushrod cup)

Was the other stud that broke have a offset trunion?

Is your roller tip pushed positively to one side or is that just angle of pic ?

Also you state it was off 2 thou you mean 20 or 200 or 2 ??

Either way glad to hear the good news

[Jerry peachuer]

Kinda makes sense it's offset with a ratio less than say 1.6 if that's what your using

It's more like 1.4 (or ??) and either way closer to your point of contact on the pushrod side
Which is the binding point so if you machined the diameter poly loc and changed p rod to compensate for a improperly machined trunion or (Chevy ) fulcrum mixed in with your ford set (not being funny) I can see this happening

And your compensating the contact point by changing the diameter of the poly loc

My only concern now would be no binding but your not getting all of your lift for that cylinder if your using that offset rocker

It's got a different fulcrum point (less lift)

Dial Indicafor will show this

[Jerry peachuer]

Correction
Not less but different lift than other cylinders
Maybe more even but not balanced either way

[Ethyl Cat]

The stud mount hole location does not affect rocker ratio. The trunion is the pivot and remains so.

My other issue with this is that Crower does not make a rocker of that type specifically for a Ford. Also the reason they are made is to move the roller back(toward the center of the engine) for better alignment when using longer valves.

To do this Crower drills a hole offset TOWARDS the roller tip, thus when installed the tip is pulled back. In your pic, the hole is in the REAR of the trunion.

I am thinking someone has turned the trunions around to possibly make them work in your application, or they were rebuilt and assembled wrong. Either way you might consider replacing what you have for something that is designed for a Ford to begin with.

[Jerry peachuer]

The stud mount hole location does not affect rocker ratio. The trunion is the pivot and remains so.

My other issue with this is that Crower does not make a rocker of that type specifically for a Ford. Also the reason they are made is to move the roller back(toward the center of the engine) for better alignment when using longer valves.

To do this Crower drills a hole offset TOWARDS the roller tip, thus when installed the tip is pulled back. In your pic, the hole is in the REAR of the trunion.

I am thinking someone has turned the trunions around to possibly make them work in your application, or they were rebuilt and assembled wrong. Either way you might consider replacing what you have for something that is designed for a Ford to begin with.

I see the trunion being drilled for the stud off centerline which will relocate where the roller tip lands on the valve is for my comment as different fulcrum point

Also I though these were comps off a 347 build ?

Offset roller rockers have a offset pushrod cup on the other side these appear to be inline top side

Good luck on the build glad to hear the bind is eliminated

[Ethyl Cat]

I see the trunion being drilled for the stud off centerline which will relocate where the roller tip lands on the valve is for my comment as different fulcrum point

Also I though these were comps off a 347 build ?

Offset roller rockers have a offset pushrod cup on the other side these appear to be inline top side

Good luck on the build glad to hear the bind is eliminated

Yes they were previously on a 347, but that does not mean they were correct then either. I do not think it was stated if they were purchased new or used. They could have been misrepresented if purchased used.

Offset roller rockers can also have the roller off center as well, but I am not sure why we are talking about them.

[Jerry peachuer]

Ummm cause a offset rocker broke a stud maybe 2

Did you read post ?

He was unsure how it broke so when he revealed questionable rocker then that's where I made comment

Not sure about the crower name that you brought up these were comp cams rockers he called and they said to turn the poly loc o.d down

Where my comment about rocker ratio came in is this
If you draw imaginary line through trunion centerline and through roller tip it will dimensionally not be the same distance (offset)as the other 15 or 14 cause he broke 2 studs


Why are we talking about them is they could be the culprit of snapping two studs along with p Rods as he just learned and corrected

Again glad the bind is out

[Ethyl Cat]

Offset roller rockers have a offset pushrod cup on the other side these appear to be inline top side

Your definition of an "offset" rocker. This is not one. That is why I was confused. Tomato, tomato either way.

My bad on the Crower thing, Crower is the only company advertising the moved stud hole. Any company that is doing it and not telling you is trying to make one rocker body fit several applications. This means more than likely the rocker is not designed for a Ford.

It would be hard for me to imagine that if this engine was checked,machined and assembled correctly that only 2 rockers were hitting. If everything is as it should be (equal) then why?

I am thinking that a .200" too long pushrod was the issue. Again, proper geometry must be established before pushrod length. If this was done to begin with the issue would have : A) Been found during assembly B) Not happened at all.

"If you draw imaginary line through trunion centerline and through roller tip it will dimensionally not be the same distance (offset)as the other 15 or 14 cause he broke 2 studs "

The problem was not on the roller side it was on the PR side.

I too am glad it does not hit anymore,but I believe that the OP is still operating his engine in a compromised state. The future will tell us the answers.

[Jerry peachuer]

Ethyl I agree
also I'm by far not a engine builder and was confused as the word offset came into play early (not by me) I believe and agree these trunions were made to work or they are not for this application

My definition of offset is on the other side of the roller rocker the pushrod cup is offset from center line

I wanted to see the other side OP only showed top side


My whole point I guess is the stud is closer to the pushrod side which is where the bind is (see mark on roller rocker) "push rod side " because the hole in the trunion is not centered it's off centerline by maybe .05/.08 thousandths

I'm willing to bet that's all the OP took off the Poly lock diameter was .05-.08 thousands
Which is already a thin walled tubing to begin with (not really thick ) it's hollow with threads I can't see much meat your able to take off


Anyhow, I'm certain you've been in more motors than I have Ethyl and all the info I gave was more less visual things that would concern me I'm not saying the fix is inadequate and I seriously wish them the best of luck that cam must have some serious spring pressures and the thinner you make that poly lock nut the risk factor goes up with opposing forces and add RPM and heat there's a lot riding on that little dinky nut


I'm very glad to hear they were able to look at it again more closely and in depth so my fingers are crossed for you guys for a successful build
Best of luck

[n20capri]

Been lurking this thread, but it is good to hear that you issues are resolved.

My 2cents, shooting for a centered pattern on the valve tip is the wrong way to set pushrod length. This build proves it.

You have had three different lengths in this engine and said that each pattern "looked" good.

Rocker geometry must be set first and pushrod length should be the result of checking the distance AFTER said geometry has been established.

Enjoy that new build, sounds like fun.

I agree - and as said before I have no idea how it was deemed "correct" prior...

Glad to hear it's sorted or non binding

Happen to have a pic of the machined poly loc ?
Underside of roller rocker ? But trunion in same orientation ?( flat towards the pushrod cup)

Was the other stud that broke have a offset trunion?

Is your roller tip pushed positively to one side or is that just angle of pic ?

Also you state it was off 2 thou you mean 20 or 200 or 2 ??

Either way glad to hear the good news

The new pushrod is 7" - the original one was 7.2" - net difference is 0.2" shorter. I don't have any other pics at the moment I will try to get more when I get back to the car. ALL the rockers have the same offset trunion...and they were all contacting the poly lock. Just happened to only break 2 of them. I'm guessing roller tip is angle of pic.

Kinda makes sense it's offset with a ratio less than say 1.6 if that's what your using

It's more like 1.4 (or ??) and either way closer to your point of contact on the pushrod side
Which is the binding point so if you machined the diameter poly loc and changed p rod to compensate for a improperly machined trunion or (Chevy ) fulcrum mixed in with your ford set (not being funny) I can see this happening

And your compensating the contact point by changing the diameter of the poly loc

My only concern now would be no binding but your not getting all of your lift for that cylinder if your using that offset rocker

It's got a different fulcrum point (less lift)

Dial Indicafor will show this

It's my understanding that lift isn't affected with an offset rocker.

The stud mount hole location does not affect rocker ratio. The trunion is the pivot and remains so.

My other issue with this is that Crower does not make a rocker of that type specifically for a Ford. Also the reason they are made is to move the roller back(toward the center of the engine) for better alignment when using longer valves.

To do this Crower drills a hole offset TOWARDS the roller tip, thus when installed the tip is pulled back. In your pic, the hole is in the REAR of the trunion.

I am thinking someone has turned the trunions around to possibly make them work in your application, or they were rebuilt and assembled wrong. Either way you might consider replacing what you have for something that is designed for a Ford to begin with.

I'm 99.9999% sure they are stock rockers through COMP - not Crower. Not sure if they are all chevy bodies set offset to work with fords or not...but they are 1.6's from Comp. Again the builder said he wouldn't have ordered an offset rocker so idk.

I see the trunion being drilled for the stud off centerline which will relocate where the roller tip lands on the valve is for my comment as different fulcrum point

Also I though these were comps off a 347 build ?

Offset roller rockers have a offset pushrod cup on the other side these appear to be inline top side

Good luck on the build glad to hear the bind is eliminated

Yes these rockers were originally used on the other motor (347) that was build by same guy 12 years ago. They were purchased new from comp - zero issues with that motor...

Yes they were previously on a 347, but that does not mean they were correct then either. I do not think it was stated if they were purchased new or used. They could have been misrepresented if purchased used.

Offset roller rockers can also have the roller off center as well, but I am not sure why we are talking about them.

Supposed to be new.

Ethyl I agree
also I'm by far not a engine builder and was confused as the word offset came into play early (not by me) I believe and agree these trunions were made to work or they are not for this application

My definition of offset is on the other side of the roller rocker the pushrod cup is offset from center line

I wanted to see the other side OP only showed top side


My whole point I guess is the stud is closer to the pushrod side which is where the bind is (see mark on roller rocker) "push rod side " because the hole in the trunion is not centered it's off centerline by maybe .05/.08 thousandths

I'm willing to bet that's all the OP took off the Poly lock diameter was .05-.08 thousands
Which is already a thin walled tubing to begin with (not really thick ) it's hollow with threads I can't see much meat your able to take off


Anyhow, I'm certain you've been in more motors than I have Ethyl and all the info I gave was more less visual things that would concern me I'm not saying the fix is inadequate and I seriously wish them the best of luck that cam must have some serious spring pressures and the thinner you make that poly lock nut the risk factor goes up with opposing forces and add RPM and heat there's a lot riding on that little dinky nut


I'm very glad to hear they were able to look at it again more closely and in depth so my fingers are crossed for you guys for a successful build
Best of luck

Here is a pic Zap posted comparing poly locks...see the circled part? This little ledge is what was hitting the rocker...we simply machined this up a bit - this, along with the proper pushrod gives us plenty of clearance. The part of the poly lock that holds down the rocker wasn't touched...



You can see it hitting in the pic below...