Technical Full roller rocker contact on valve

Friend called me last night to come look at his 327. He had the shortblock done by a shop 7-8 years ago, after he got it back he put a set of ProComp Al heads and 1.5 full rollers rocker on it. My concern is it had been sitting for 7 or so years, I wanted to see what the cam lube looked like, so pulled the intake and a few lifters, all was good and gooey.

So I got to looking at the rockers and them sitting on the valve tips, many of them were "skewed: and only had 75% coverage on the roller to the tip. Some were right on it with full coverage of the roller on the tip.

He has adjustable guide plates, but even to get the roller on the rocker fully on the valve stem, we'd have to pull the heads and do a little die grinder work for clearance for the push rod.

So...please without talking about ProComp stuff...should the rollers be in 100% contact (I think they should) with the valve tip?

Or?

Thanks.

 

Yes.

 

The center of the roller should be centered on the tip, not fore or aft. If the guide plate is holding up the pushrod, i'de start there first... Do we have the correct push rods though?.........Sounds like the guide plates might be the culprit....

 

Yes from me too.
To be honest,,,that should hav3 been double checked at assembly.
But,,,a lot of people miss it,,,it isn’t too hard to fix .
Is the pushrods hitting the head casting,,,?
It can be ground with the heads still on,,,,,just cover the lifter valley with rags and mask it off .
Sounds like only a few need attention.
Got any pics,,,,,you probably don’t have to remove much at all .

Tommy

 

Google pushrod length checker, then Smith Brothers Pushrods.

 

Pushrod length brother. That is if I'm reading this correct. But I've had enough issues with roller rockers that i stick with stock on my SBC street engines.

 

The guide plates are adjustable...not to my liking, but I pulled one off and to center the roller on the valve, the PR would be rubbing on the head.

Could be the heads are not made right, rockers (ProComp as well) are not made right...they do (rockers) look like they are thicker on one side vs the other.

I been trying to get pics from my phone up, but am failing miserably...I'm sure there is enough meat in the heads next to the intake runner to open it up some.

Engine is on a stand, so we'll pull the heads and do it, gaskets and time are cheap

I just needed affirmation, having never had roller rockers before, but it just didn't look right to me.

 

They're a two piece guide plate (not to my liking), and when you move one to get the roller centered, the PR wants to rub on the head...very hard in fact. I told the guy we should go with standard guide plates, and work the head a bit if needed.

 

So the roller is setting to the side of the valve tip?

 

I'm not a stranger to pushrod length. the geometry with the 7.9 PR's he has is really nice, It's not an over the tip/under the tip, but side to side that I see as a possible issue, Hope that makes sense?

 

See above/below...lol...it's not a length issue (IMO) it's the roller being to the back or front of the valve (looking at the engine), or side to side when staring at the head.

 

Yes, not as a PR is too long or short. As if the stud was placed off of the mark to the left or right in the head (as viewing the head from the side...I/e like looking at it from a fender, not from the radiator.

 

If the tip is centered, then go for a lil clearance side to side. Yes- total sense.......

 

When using guide plates isn't drilling head a requirement?

 

Yeah after i read your other post i realized what you was saying. I'd say the rockers are the culprit.

 

I eventually get all the information out...lol

Ya just gotta keep asking me!

 

Sell all of it and buy a set of T & D’s. They make a sportsman set. Eliminates guide plates and when check a complete season of dirt track racing all are still set where we started.

 

I know this is gonna sound dumb as hell, but if some are right and some are wrong, can you move them around? Kinda like they are position specific?

 

I don't know. The guide plates are under the studs, what would there be to drill? Regardless, if located where need be, it still looks like the head needs me be massaged some, unless there is some kind of offset rocker?

 

Not dumb at all, I didn't look everything over enough to put that thought in my mind...might be possible..Might save a lot of fucking time too!

 

You drill the guide hole in the head so "adjustable" guide plate can be positioned correctly.

 

I hear ya, but it's not mine and I don't know my buddies expendable income to step up and do it all over again. I'm just trying to see if we can work with what he has...I think it's do-able, based on the replies before.

I don't like the two-piece guide plates though, I'll have him get "regular" ones, and we'll do some work on the heads to line things up.

 

t

If I could post up a pic, you would know what I mean...so the guide plate(s) for each cylinder are two piece, each pice is under an adjacent stud.. There's a male/female slot that they sit in to each other. I'll see if I can find a link to them. Not my best idea, IMO

 

Similar, but not what he has:

https://www.summitracing.com/parts/...ogdqJFx-5JrYK-U7TI5d1lTuhhk184vRoCqFgQAvD_BwE

 

It is very common to have to do a little grinding on the push rod passage in aluminum heads to get the roller centered on the valve tip. The last 2 sets I have done required some grinding. One of those sets was Procomp. You definitely need to keep the roller on the valve. The 2 piece guide plates will probably be required to get them centered. That is what I use.
Those heads probably have .100" longer valves in them, requiring longer than stock pushrods.
. This is the best explanation I have seen. Good geometry does not necessarily put the roller sweep in the center of the valve tip.

 

You're absolutely correct, the PR's were Comps and 7.9, vs 7.8? Geometry looked fine for the quick check I didm just the side to side, which I see you mentioned you had to do some work on the heads before..

Now that is affirmation!

Thanks!

 

Exactly where is the push rod/rods rubbing on the head? Also, have push rods been up graded to larger diameter over stock?

 

The PR's would rub on the head, onto the side of the intake ports, I didn't measure the diameter of the PR's, just noticed they were CompCams at 7.900. That was etched into them. It really looks like some die grinder on the heads off the outside of the intake ports will get things lined up where they should be. As @jaw22w mentioned he has had to do this before on the ProComp heads.

 

Also had to grind on a set of Dart 200's. My new 210 Profilers did not require grinding.

 

Here is a couple of pics of my brand new Brodix heads (as shipped) with non adjustable guide plates. I found out the hard way, that you have to use adjustable guide plates (one for each pushrod) and make sure the pushrods do NOT hit the casting in the pushrod slot. If it hits, grind it out for clearance.

Sorry, I don't have any pictures of the adjustable guide plates installed.

Plus, the rocker moves all around side to side and finds it's own center. You have to find that center and adjust the guide plate to it, on all of them. You might have to run it after adjusting the guide plates and see if they are still in the center and if not, adjust it again until it's right.

It's an easy fix, but makes it a pita to get the guide plates adjusted correctly, but it can be done. It must be in the center of the valve tip (side to side) or you'll have troubles. Patience my Boy, patience!