Clearance questions on Cylinderhead

[frederick]

I have finally got the time to start working on the car again.
After checking out several things I hope you don't mind me asking some questions.

1. The tops of the valve stems aren't all at the same height.
Difference between highest and lowest is 0.010"
Is this going to be a problem?

2. Some of the rocker(OE stamped) are touching the retainer, or valve spring.
I believe there are two options, buy new adjustable rockers, or get smaller valve springs and retainers.
Which would you recommend?

Adjustable rockers would solve the problem with the valve stem heights, but might still need smaller valve springs.

The heads are 440 source, with comp cams 10degrees retainers and locks, 440 source valve springs.

Cheers,

Frederick

[Chatt69chgr]

Hmmmm!   I'am real interested in hearing the answers to these questions too.

[firefighter3931]

I guess the big question that needs to be asked is : has the installed height of the valvesprings been altered with the addition of the new retainers/locks ?

That's the only scenerio i can see causing the problems you're describing....


Ron

[frederick]

Thanks for the replies,

Yes, installed height had increased slightly with the new retainers and locks, so I put a spacer under the spring to correct this.
Measured from cylinderhead to top of the valve retainer:
was: 2.022"
with new retainer: 2.055"
I made a sketch below to make this clearer.

440 Source retainer:


Comp cams 10 degree retainer:


I noticed another thing too, the rockers are very loose on the rockershaft.
I'll try taking a picture.

Oh, for reference I have the folowing retainers and locks:
CCA-613-16
CCA-748-16
(Summit numbers)

Frederick

[frederick]

Here is a pic of the clearance between the rocker and arm.
Sorry it is so blurry, I took a few but this is the best I can do with one hand.

[Tilar]

Are these all new?  As far as the stems being .010 off from one to another, hydraulic lifters will compensate for that, but they won't fix hitting the retainer or spring. It almost sounds like they may have the groove for the keepers machined a little off or the seats may be ground a little too deep in the heads.

[Tilar]

I'm not sure which engine you're working on, but some rockers are angled for intake and different for exhaust, and if they are not put on the rocker shafts correctly they will hit the retainers.

[frederick]

No it is all new, never run.
Seats weren't machined, only thing I had done was to mill the head, but that won't change the stem height.

The engine is a +0.030 383 Big block.
Heads are 440source.

Do you mean left and right rockers?
Yes they are in the correct position.

[firefighter3931]

Yes, installed height had increased slightly with the new retainers and locks, so I put a spacer under the spring to correct this.

Bingo !   

Try reinstalling a 440 source retainer & lock to see if yu have the same interferance issues. 



Ron

[frederick]

Just reinstalled a 440source retainer and lock on a valve, like you said Ron.
With the comp cams retainer the rocker was touching, with the 440 source retainer there was about 0.040"clearence.

So what should I do?
I don't want to run the source retainers.

Frederick

[frederick]

I think I have found a solution:

Beehive springs: CCA-26918-16
http://store.summitracing.com/partdetail.asp?autofilter=1&part=CCA%2D26918%2D16&N=700+115&autoview=sku
Retainers: CCA-787-16
http://store.summitracing.com/partdetail.asp?autofilter=1&part=CCA%2D787%2D16&N=700+115&autoview=sku
Locks CCA-648-16
http://store.summitracing.com/partdetail.asp?autofilter=1&part=CCA%2D648%2D16&N=700+115&autoview=sku

The small OD of the retainer would mean. lots of clearance.
These springs come close to the springs fitted to the source heads regarding pressures.


Frederick

[firefighter3931]

Just reinstalled a 440source retainer and lock on a valve, like you said Ron.
With the comp cams retainer the rocker was touching, with the 440 source retainer there was about 0.040"clearence.

So what should I do?
I don't want to run the source retainers.

Frederick

The 10* parts i recommended to Mike (MFR426) for his Stealth headed stroker are the Comp Cams #741 retainer & #613 lock. Both were installed successfully on Mike's heads and he is using the stock stamped rockers with a .530 lift hydraulic cam. 


Ron

[Chatt69chgr]

I am wondering if the stamped rockers and shafts are new or used?  Too much play in used rockers/shafts might account for the problem.  O/W, might have to go to the Crane ductile iron rocker.  I heard that they had been discontinued and then that the company was still in business.  Another choice might be the Hughes rockers and shaft.  They have a tech section about their offering in this area on their website.  Might need to deal with stock valve covers not being tall enough then.  Hughes has a taller one (they get from Indy) and 440 Source has a nice welded sheet metal one. 

[frederick]

When looking at they compcam site, I don't see any difference between the 748 and 741 retainer, regarding the outer diameter.
http://www.compcams.com/technical/Catalogs/106-07/308.pdf
So I don't think that is the solution to be honest.

The rockers are a mix old and new, shafts are new.
Is there supposed to be a lot(>0.080) clearance between the top of the shaft and the rocker, like I am trying to show in the photo?

Maybe another possibility would be to use a -0.050 valve lock.
That would raise the spring pressure however, even when I loose the 0.020" shim I added.

Cheers,

Frederick

[frederick]

I finally bit the bullet and ordered the beehive springs.

Ordered these today:
Beehive springs: CCA-26918-16
Retainers: CCA-787-16
Locks: CCA-648-16

I'll let you guys know how it works out.

Frederick

[Chatt69chgr]

There is a good article on the beehive springs in one of the current car magazines.  I don't think it was a Mopar specific magazine.  Maybe Muscle Machines or something like that.  The article said "sourced from Hughes Engines".  They may have it on their website.  But it sure looks like the beehives would solve any problems with clearance between the rockers and the valve spring retainer.  In fact, the way the article said, the beehives would be superior to a standard type spring.  Has anyone read this and what's everyones take on this?

[frederick]

Thanks for the reply Chatt69chgr,
I'm sure these springs will solve any clearance problems, but it is extra $$ I had not counted on, plus I now have a 10 degree retainers and locks I can't use.

Comp cams as a number of articles on the beehive springs, although other cam manufacturers also make beehives of course.
http://www.compcams.com/Community/Articles/

Apparently there are a number of benefits using beehives.:
-Beehive springs don't have a resonance frequency
-Use a smaller lighter retainer + spring is lighter
These two facts mean the valve motion is controlled better; less chance of valve float and bounce, permitting higher rpm's
-Permit lower seat and nose pressure
-Don't have circular wire but "ovate" which distributes the loads better giving and permits higher lifts.

Cons
-It is not possible to use 2 beehives on on valve
-More expensive

Frederick

[Chatt69chgr]

I'am kind of in the same boat as you.  I already bought the comp cams retainers and locks.  Not knowing about the beehives, I decided I just didn't want to risk having the retainers hit the stamped rockers so I bought the Hughes roller tip rockers.  But knowing about the beehives now, I would have elected to go with them and use the stamped rockers.  You indicated that the folks at Comp Cams have the beehives.  If they have one that will fit, maybe they would allow you to return the locks and retainers you have for credit since I don't think you have run them.  But you may not have the original packaging which they would probably want.  Or you may have got them from another source.  Please let us know, via pictures, etc. how the beehives work out.  I'd like that info for future builds.