DIY adjustable rockers

[Edub1]

Since I have a spare set, I think I'm going to go for broke and see if I can make a set of adjustable rockers for the SOHC.

I think they are mostly hollow so drilling a straight hole shouldn't be a problem. Then, it should be just a matter of tapping and fitting with a suitable screw & stop nut. I think for weight purposes, I will go with a bolt with a screw driver slot.

Anyway, I'm open to comments / suggestions.

[LEMHEAD16]

Along these Lines I think that the rockers from a Z24 nissan engine are Adjustable and would work. I need to go to the junk yard and pick up a set to check.

Anyone know what cars the Z24 came in?

[nvrplzd240]

that'd be pretty sweet

go for it

[Chezedik]

Nissan Pickup from the early 80's. It was the predecessor to the KA24E.

[wcbjr]

What size is needed? Would this place work?

http://www.alibaba.com/catalog....html

[wcbjr]

Or here.

http://www.cranecams.com/index...rt=23

Specifically, http://www.cranecams.com/?show...83-16

[WDRacing]

Good links dude.... Definitly somthing to work with.

[wcbjr]

Check the radius head type on the page.

http://www.indoschottle.com/ht....html#

I do have a question about lubrication. How would lubrication work with these new screws and locknuts?

[wcbjr]

A post from *gasp* ka-t.org.

Quote »f it ill help. ok the bore it has ull have to get a m10x1.5 helicoil set.this is wat i used.i used 2, 1/2" on each lifter you could probably use 1, 3/4" helicoil instead of what i did.

the screws i used http://www.mcmaster.com/ctlg/D...=1388

and the nuts i used http://www.mcmaster.com/ctlg/D...=1388

and if any one needs any help just ask[/quote]Two things I had a question on. Oiling, and the fact that the poster did not round the bottom of the screw. Here's the response:

Quote »on top of the valve u have to figure that out your self and play with valve adjustments i still havent got it to where i like the adjustments.oiling is my only concern but when i tapped into the lifter i made the oil gallery on the lifter itself a little bigger so oil can come out. but like i said i have been running this on my car for 4000mi now and did a full rebuild b4 that. but im not have any problems at all with this setup except for the annoying noise and my car is my dd and get taken to 7000rpm daily[/quote]

[Edub1]

Yah, I forgot about that thread.

That's probably why his are so noisy.

Anyway, do the rockers have to be replaced when changing a cam? If so, it would be worth the extra $100 to buy a set.

Ooohhh - just saw the Crane aluminum ones. Less mass seems like it would be quite desirable for high RPMs.

[LEMHEAD16]

KA And Z24 are not interchangable. compared 2 today

[Edub1]

I'm going to buy those bolts and give it a shot. I should probably have them drilled with a drill press though huh?

[LEMHEAD16]

I figured out how to do it.

First you have to remove the Hyd lifter and take the top of the rocker arm to a grinder (or cut off wheel) so that the RA has a hole in it.

Tap that whole for 10x1.25 thread and find a bolt to fit it. Cut the head off of the bolt and and grind both ends of the RA flush.

drill a hole through the center of the bolt you just cut off and tap it for whatever size adjuster you are using. Mine are 8x1.25

I have to do some more work on it to make sure that the Adjuster sits square in the valve stem. I am also going to drill a small hole in the oil galy of the RA to spray the top of the valve stem.

I'll post some pics when I am done.

[SSS]

Bolt within a bolt? You're certainly asking for trouble....

[wild_maxx]

yeah... I think thats why Gabe uses a helicoild inside the RA then uses the correct size stud to screw into the helicoil. I may be trying this as well pretty soon. High lift cam and stock 103k miles lifters don't work so well together.

[Edub1]

Definitly helicoil.

[deviousKA]

Its all in the jigs. Making one set is either going to be expensive and time consuming, or shoddy.

There are 4 different rocker orientations each requiring a set of 4 custom machined jigs for each main process with 16 different setups (preparation, rocker sizing, lifter cylinder sizing/tapping).

These jigs each have their own table setup components for each machine (slides, mill vices etc.), and a variety of machined lineup tools.

The adjuster screws themselves go through another set of machined setup jigs for sizing and notching.

I have deleted any errors in consistency this way, all dimensions are consistent to .005", and the lifter cylinders are bored and tapped perfectly straight, always. Lifter/valve offset contact is preserved over wide range of adjustment. The finished rocker is lighter than the oem hydraulic rocker, when both are dry, and sits at a lower profile with stock and smaller cam base circles.



Some things to remember when making a DIY set would to be prepared for the extreme hardness of the material (nissan steel forgings, strong as connecting rods). Also, the lifter adjuster screws themselves, depending, are extremely hardened. The tooling and equipment must be appropriate if you want good professional results. These have to be adjusted, smoothly, lock down hard, and have a longer lifetime than at least a couple engines.

Random tips:

Adjusting nuts must be hardened and lightweight.

Drill bits are a no no.

Oem type lifter adjuster screws are too soft of material for performance use.

;

Thats all your going to get from me! So dont ask

Oh, and btw, SSS knows what he is talking about when it comes to ka24e SLC! Same spec, different country.

[Edub1]

Are you still selling them? How much difference will those plus your turbo cam make?

[deviousKA]

zerothread/209181

Going from a hydraulic lifter to a solid adjustable lifter could probably be described best as a dynamic cam upgrade. Not only do you have more lift and more accurate duration throughout the full revolution of the cam lobe (for any given cam profile), but this affect presents itself at any valvetrain speed (RPM), with similar characteristics. The only thing that can cause deviation from the given valve lash spec discrepancy (typically .007") is valve float at high rpm. This would be caused (or compounded by) rocker and retainer weight, which is slightly reduced on these parts and right where it matters most.

The conversion is most noticable when going from hydro to solid on an aftermarket cam (which is possible in any situation, no matter cam tower dimension). Results vary, you can obtain up to ~.150" of lost lift and X amount of lost duration, depending on old hydro lifter condition, (which is quite a lot). The oem lifters do not necessarily make tons of noise when they are semi-collapsed.

[LEMHEAD16]

Wow Gabe, We haven't heard from you in a while.

After playing with the spare head I have in my garage. I came to the conclusion that this would take much more precision than what most of us can do at home.

I'm glad you chimed in and confirmed my fears.

How are things in N. Idaho?

[deviousKA]

Well, I dont mean to discourage any DIY efforts, Im just saying straight up.

If you have a shop with even just some basic equipment (mill, or really good drill press), and a decent amount of tooling including lots of facing, reaming bits, taper taps, you can pull it off.

You or whoever does it will need to come up with some jigs, a little experience, tools, and material is all it takes.

The jigs need to be solid when doing lifter cylinder operations, the power tap operation must be fluid else adjuster screws will be difficult to adjust once helicoiled. A standard quality tap will do maybe one set before it is worn, same with other tooling.

Things are going great here up north, although winter is looking not so mild this year,

I need an awd so was thinking maybe a 3 cyl justy with a sidepipe.

[Edub1]

What are these jig things and reamers and what not? Isn't it just a matter of putting it in a vice and drilling a straight hole and tapping it?

Please excuse my ignorance, I'm not real knoledgable about tool and die stuff and I don't understand what you are describing or why all that is necessary. I'm not contradicting what you are saying, it's just that all I see is a hole with a bolt though it.

[LEMHEAD16]

What are these jig things and reamers and what not? Isn't it just a matter of putting it in a vice and drilling a straight hole and tapping it?

Please excuse my ignorance, I'm not real knoledgable about tool and die stuff and I don't understand what you are describing or why all that is necessary. I'm not contradicting what you are saying, it's just that all I see is a hole with a bolt though it.

Technically yes, you could put it in a vise and drill a hole. The problem with that is getting it in the vise the sme way everytime and drilling that hole perfectly staight every time.

The process is not difficult but it does require some precision.

Think of how many times a valve opens in a minute @ 4000 RPM. I would not The RA only has a small area to contact the valve and if its not right it is going to wear parts prematurely.

BTW

Jig - a plate, box, or open frame for holding work and for guiding a machine tool to the work, used esp. for locating and spacing drilled holes; fixture.

REAMER - any of various rotary tools, with helical or straight flutes, for finishing or enlarging holes drilled in metal.