I'm on the final assembly of my 403 motor and
all was going good until I looked at the valve
tip pattern using the comp cams Magnum
"Roller tip" rocker kit including pushrods.
I have included a photo of the valve tip after
assembly and turning the motor a few times.
This was done on the engine stand with no oil
in the motor or hydraulic lifters. As the pattern
is not centered, I am under the impression that this will
cause a big side load on the valves. Have you
ever ran into this? As these roller tip rockers
are not really "adjustable", I'm kind of
confused as what to do !
Can I use a stock rocker/push rod set up with
a cam lift of .510/.512 ?

what have you done in the past with these
higher lift cams without resorting to full roller
rockers.

ps:
And the pattern shows more toward the exhaust
ports.


Thanks in advance,
Gary

 

I run the Magnum roller rockers on my 355 with no problems with .512 .517 lift on the cam. I did replace the pushrods for Trickflow chromemoly cause the ones that came in the kit started to bend and tips looked worn after cam break in and driving 300 miles.

From what I read here you shouldn't run stock valvetrain with anything over .500, but I am sure somebody with more knowledge will chime in.

 

Looks to me like the pushrods are too long. Get yourself a measuring tool like this:

http://streetperformanceusa.com/i-89...Fcd_QgoduG4ANw


And then get the correct length pushrods. Don't guess our you WILL have premature parts failure.

 

This is were my confusion lies:
Since these Magnum roller tip rocker are not really "adjustable"
like full roller adjustable rockers, won't getting shorter pushrods
throw the valve lift efficiency off since these Magnum rockers call
for a "set" length?

I guess I am under the impression that you can only change pushrod
length using a full roller adjustable rocker set up.

Gary

 

What do you mean not adjustable??

 

According to what I can find they are a ball and nut type adjustable and not a pedistal mount which is not adjustable.
http://www.summitracing.com/parts/cc...ake/oldsmobile
What makes you think they are non-adjustable?

EDIT:
This is from the PDF instructions for the Magnum tip roller rockers.

Quote:

OLDSMOBILE

 

I guess I thought since the Magnum set has a
fixed pivot point that is not adjustable "up or down"
the shaft and they are secured via zero lash + half turn, I
figured they needed the "set" length push rod
that came with the kit.

So, a slightly shorter push rod should fit?

I also just ordered a comp cams length checker.


Gary

 

Get the checker and figure out length you need and order them. Don't guess on the length before you check it.

 

It must be that I also dont understand the Difference between the Magnum roller tip set and a set of full roller rockers then. I thought i understood that full roller rockers had an adjustable pivot point "up or down" the mounting shaft where the comp cam magnums were a fixed pivot point. Hopefully using the length checker will help show me where I misunderstood.

Gary

 

I see your confusion.

The roller tip rocker use a pivot ball instead of a pedistal and bridge like the factory rocker set up does. A full roller rocker arm uses a trunnion at the pivot point with needle bearings to reduce drag on the rocker arm and free up horsepower.

Both the roller tip and the full roller rocker arms are adjustable where the pedistal type rocekr arm assmebly is not and gets torqued down.

Factory type:

or

Roller tip:


Full roller:

This:


Or this:


There are also shaft mounted rockers, but that's a whole different ball of wax.

 

Thanks for the replies! I will get the length checker and go from there.
Should I get a solid lifter also for checking as the hydraulic ones seem to depress and throw off my measurement. Or can I take apart an old one and make it so it doesnt depress?

Gary

 

the kit is adjustable you need to replace the nuts in the kit with poly locks.
If you can get the short ones to clear a stock valve cover.
If not, I double gasket the covers to clear.

Gene

 

Thanks for the reply, I had been thinking about using polylocks
and looking for some but the ones I have been finding to use on this
kits are all long ones? Any idea who might sell "short" ones?

The nuts that come with this kit are crap !

Gary

 

Ok, I got the comp cams "HI Tech" PR checker and a light weight valve spring checker and attempted to find the right length PR needed.

The comp cams KIT provided 8.500 pushrods and as the photo in the opening post showed them as to long.

Using the spring checker and adjustable pushrod, I adjusted back to a pushrod length of 8.400 by going 2 full turns and turned the motor over several times. There was really no change in the valve tip pattern.

then I adjusted the the Pushrod checker one more full turn back to a pushrod length of 8.350. There still was no change to the pattern.

The photo below shows the pattern at 8.350 down from 8.500.

Also at the 8.350 length, my tightening nut is just about at total bind on the rocker post.

Not sure if I'm doing this wrong or should I just trash the comp cams KIT and go with something else?


Gary

 

Where the heads machined for the guide plates. It has been mentioned to me. I'm not 100 percent if it's neccessary the machine shop set everything up for what I was going to run and my pattern checked out.

 

No, the #6 heads are pretty much stock except for putting in the larger
403 sized valves and slight pocket porting.

Do I have to have them machined for the guide plates? To make them lower?

Again, I am at a loss of where to go. This happens quite often it seems


Gary

 

Try going longer just to see what happens, just for the heck of it.
Black felt pen the stems and see what happens.

Gene

 

Thanks for the reply 64Rocket.

"Just for fun" I just tried going to a longer length on the pushrod checker and funny
thing is that the pattern got thinner but didnt change location.

I have included the new "thinner" pattern. I also noticed something that may
help.

I started looking at the side view of the assembly earlier and noticed that when the assembly is at zero lash and resting, the rocker tip centerline is nowhere near the center of the valve tip. With all of the sizes I have tried, the rocker tip centerline allways stays on the exhaust side. It's like the rocker tip arm is slightly over long.

Any ideas would be GREATLY appreciated!!

Gary

 

That actually is moved out a bit from the original posting. You need to go shorter for sure.
I was under the impression that these kits didn't require machining for the guideplates? Maybe?

 

Fwiw worth what kit do you have. In the instructions that where posted it say's 67-84 1442 260-455 but then it say's for 455 kit 1442 then kit 1441 350-403. I'm assuming the diffrence maybe in the pushrods but why would they generalize the kit by ranging it's use from 260-455 then specifying kit 1442 for the 455 if there is possibly difrent components probably being the pushrods.

 

I have the 1441 kit for the 403. Im not convinced that this kit is all what its advertised to be using it on anything but a stock 403. I may just look into getting full rockers and going from there as im kind of at a loss now. Not sure yet.

Gary

 

The pushrods are only good for stock configuration, and even then are questionable. The rest of the parts are just fine.
I'd suggest re=checking your setup. You may need to go drastically shorter.
For reference, I'm using a Lunati hyd cam, full roller rockers and 0.040" head gasket. Pushrod length was 8.28".
The Comp roller tips are not bad, and you should be able to find a good configuration. That cam is not wild...

Running out of thread on the stud is certainly a problem. For poly locks, just dig through the Comp catalog for the appropriate size and height. IIRC, normal ones are 1.25" tall, "short" ones are 1" tall.

Just for grins, the pivot is installed in the rocker correctly, right? I also check with a pumped up lifter, but I doubt that particularly matters.

Where are you located? This might need someone to lay eyes on the setup.

 

Thanks for the reply,
Im not sure I really trust this kit any longer.
So I ordered a set of comps alum full rollers.
Which I should done to begin with !!
http://www.jegs.com/i/COMP+Cams/249/17043-16/10002/-1

I have a local speed shop here in Dayton, Ohio that can look at my
set up geometry if I cant get it together.

Will update when I find out more.

Thanks,
Gary

 

Switching to full rollers should not change any of the geometry problems you're looking at, unless this rocker is a different application than the magnum.

As noted, those are actually Ford arms that are "close enough" to Olds spec. You may want to consider throwing those back and getting the Harland Sharp 5016 set. Those are actually Olds configuration, but are quite a bit more expensive.

 

I see your point, I allways wanted roller rockers but saw that full comp kit and thought it will save me headache and time putting all the pieces together myself. I really shoulda went the full roller route to begin with.
I looked at the harland sharp ones originaly but those are way too pricey for me at this point especially considering I would also need new 7/16 studs machined for or coverter studs for another 100 bucks.

I am going to try these for fittment and have my speed shop do the final geometry adjustment.

The only thing I can think of that is throwing the set off I have now is me putting the 350 #6 heads on my 403 or the wrong valve length somehow.

Gary

 

I also shoulda mentioned in my very first post that I have the #6 350 heads on the 403. Not sure if that would have made a difference. Sorry bout that.
is there any geometry difference between the #4 and #6 heads?
I was under the impression there was not.

Gary

Gary

 

Aren't you gonna need 5/16" to 3/8" studs since the roller rockers use a 3/8 stud?

 

I have 3/8" studs in the heads now.
They came with the comp cams 403 kit I had purchased originaly.

Gary

 

Not entirely true.
The 5016 and 5017 are really for Olds/Edelbrock heads. They have a .050 longer arm on the valve side due to the taller valve length on the Edelbrock head (.100).
The HS 5003 I think is the regular Ford/Olds rocker.

Talk to HS themselves and they'll tell you the same. Olds, Ford, AMC and Pontiac all share similar rocker geometry, apples to apples.

 

ok ic

 

Just wanted to update with what I found so far.
I got the comp alum full rollers today and tried
them out. The photo shows after just setting the
rockers on with a 8.500 push rod. As you can see,
the rockers roller is spot on in the centerline !!
Without the PR in the block, I can raise and
lower the rocker arm to "sweep" both before and
past center. I didnt have time to fully adjust for
correct PR length. So I think I am where I need
to be.

Not sure what is up with the Comp 1441 kit rocker
arms. Any ideas what I should do with them?

Gary

 

Glad you got it sorted out.