92blue

iTrader: (1)

I am going to be pinning the rocker studs on a set of heads I am porting right now. Basically what I need to know is what size pins to use (as far as the pin's diameter), and how far down to drill the hole for the pin. I need to assemble one valve and see in which direction it would be best to install it. Does anyone that has done it before have any pictures they can post? I don't want to drill and install pins and then realize that they interfere with something.

AJ_92RS

https://www.thirdgen.org/techbb2/sho...=pinning+studs

F-BIRD'88

The roll pins I used to pin my heads and all the others are .095" thick.
The drill bit used is .092".

Has stood to numberous 7000rpm+ blasts and .550" lift.

I would not use a pin any thicker than .125" (1/8")

That would weaken the stud boss.

AJ_92RS

Whoa!!!

You typed that word for word just like in the other post.

You're like phsyco or psycic or something like that.

F-BIRD'88

...

88IROC350TPI

Maybe a dumb question but why not just get screw-in studs installed? Especially since they are off the car.

8Mike9

Dollars.

demonchild

exaclty how hard is it to tap 16 holes. someone with a good tap set can do it thierselves...

kfoley

Converting to screw in studs is cheap. $23 for colarless studs (Mr. Gasket pn: 1076) and a few hours of your time. You'll also need a 7/16-14 tap (IIRC).

F-BIRD'88

Costs me about $15 to pin the studs on two heads.
The parts are readily available at most hardware stores.

8Mike9

I should have explained further.

IMO, just pulling the studs (which is a lot of work) and just tapping the holes and using shoulderless studs, is not the way to set up a valve train. The guide bosses should be machined down and a stud with a shoulder should be used so the stud can be properly torqued..most people would/will have to take the heads to a shop to be machined down.

I guess you could get away with using a stud that has a thin nut in it and cross your fingers that the valve guide boss is flat enough to distribute torque evenly, but I wouldn't.

kfoley

Well I wouldn't use colarless studs in a race motor, but for a daily driver they work fine. You will have to double-nut them to torque them to the proper 35 ft-lbs. As far as pulling the studs go, it's pretty easy. Stack of washers and some 3/8-24 nuts and an impact gun. Had mine out in about 1/2 hour. Now granted tapping takes a while, that took me about 2 hours.

8Mike9

You used an impact gun? No kidding, I tried an impact gun before, about the 3rd or fourth stud I pulled, I broke off a side of the boss and never used an impact gun again.

Anyone else use an impact gun?

kfoley

I used one, but I set it down pretty low. I think it was on 2 out of 4... I didn't have a problem with any of mine...

a73camaro

Just used an impact at full setting, no probs but the nuts got hot real quick.

Seen other use an impact gun with no problems. You may have had a defective boss to begine with and the impacting action did it in.

1991tealRSt-topGuy

my question is:

how do you keep the drill straight when drilling for the pins?

not knocking, i am curious myself

89RsPower!

i've done em with an impact gun before.. if they dont come out real quick to begin with i normally lower the setting and givem a chance to cool out of fear of having on break on me but never actually had one break..

kfoley

Almost forgot, if you pull them use a new nut for each stud. I made the mistake of using the same nut for a few studs and ended up screwing up some threads. Nothing a die couldn't fix, but it could have been avoided if I used my head... lol

Twilightoptics

Just a quick FWIW....

I pulled two studs on my 416 heads. Decided I'd put in collarless studs all the way around... well while pulling one of the studs OUT, I broke the stud boss... how you ask? I used the block to tap stud holes/remove studs. And I was only turning the nut atop the block with a 3/8 drive ratchet

Machine shop said sometimes when they are installed by the factory the stud can literally weld itself to the head from the force/friction.

Ruined a head.



BTW F-BIRD'88..... do you need a special long drill bit for this? And does it have to be perfectly perpendicular to the top of the stud boss, or can it be at somewhat of an angle say if your drill wont fit in there right?

F-BIRD'88

No and No. Eyeball straight is good enough.

There is nothing really technical in doing this.

The trick is to use moderate pressure and speed on the drill and sharpen the bits as needed.

AJ_92RS

For those wanting to tap the holes for screw in studs, get this. It'll make life much easier.

http://www.jegs.com/cgi-bin/ncommerc...11&prmenbr=361

Twilightoptics

DO NOT GET THAT TOOL!

I bought one and the tap the factory used when making it was so off, that my tap wouldn't even go through and I broke off 3 taps just trying to tap that damn block. I had to take it back

I had a machinest make me one out of aluminum.

BTW that's how I broke off my stud boss: You can see that the stud is not a true cylinder. At the right end it flares out a bit from the installed friction I was talking about.

Twilightoptics

Broke Stud Boss:

kfoley

Ouch...

I didn't use that tool, I didn't want to spend $16 on it when washers work just as well, and I have plenty of those.

92blue

iTrader: (1)

Where do you buy your roll pins at? Do you know where I can order them online? The closest place to where I live that carries them is Harbor Freight, and its a long drive to the nearest one. As far as using a .092 drill bit and .095 roll pins, what sizes are those exactly? The closest drill bit I have seen to that size is 3/32. But that comes out to .9375.

I've been busy porting my heads, and so I have put pinning the studs off to one side for the moment. If I get a chance, I'll post pics of my progress with the heads this weekend.

F-BIRD'88

Was wondering why you were having such a problem.

Well I went back and measured the left over roll pins and drill bits I used and the bits are indeed 3/32"
The roll pins are not exactly perfectly round. Range from .097" to .104" as you roll it in the dial caliper.

Most well stocked hardware stores have 'em.

I got mine at the lil mom and pop hardware store at the
top of my street.
Sorry for the inaccurate size info. Hope this helps.

Any simularly sized roll pin and drill bit size that would allow a slight press fit to compress the roll pin will do I guess.

This is what worked well for me.

92blue

iTrader: (1)

Thanks for your help. I am waiting for some new carbide bits to come in. The ones I have are starting to chatter and vibrate.... seems like they are bent. I need to finish porting, pin the studs, and them I am going to trim the valve guides a bit. Its not difficult work, its just time consuming. Not to mention messy.

xpndbl3

iTrader: (5)

what are the benefits to pinning studs compared to just getting screw in studs besides saving money?? does it do the same thing essentially? etc etc

Twilightoptics

Pinning studs is the safe way to keep your studs from pulling, when you don't want to remove the cylinder head.

If you run a lift around .480 or higher, or stiffer than stock springs, there is a chance of pulling studs.

To stop this from happening you can do one of two things:

Pin them

or

Pull all the studs and tap for screw ins.



When you pull the old ones, you have a chance of breaking the stud boss and ruining a head. When you pin them, you drill through and put a roll pin into the drilled hole.

The pinning method is good for mild applications/cams. If you have a beefy cam and very high lift, it's not recommended.


The BEST way is to pull the head and have the bosses machined down for TRUE screw in studs.

TheMysticWizard

iTrader: (1)

How much lift would it be able to handle.. I'm looking at .510"... will the pinned studs handle that without pulling out?

kfoley

Pinning would probably work for .510 lift, but if it were me, I'd spend a little more money and get screw-ins.

ljnowell

i would just say screw it and get screw in studs anyway. just my .02

CCHembree

I'm also wanting to pin 487 heads ported polised myself need to know length of pin and how far to drill down on boss thanks