How do you modify the dizzy to clear ARP head bolts:4AGZE?

[benjamin]

I have a 4agz with arp head studs and unfortunately the CAS strikes the protruding head stud quite hard. I tried grinding the CAS back a little so that it is clear but it has now damaged the gear part on the cam and a little on the CAS gear. Because I had to grind the gear back a little this meant the trailing edge of the cam cog wasn't able to turn the CAS cog far enough to cleanly accept the leading edge of the following gear.

So now my question is how do I need to modify the assembly so that the gears still mesh correctly and completely. Do I need to grind the head stud down?

I think the easiest solution may be to take that one stud out and put the standard head bolt in...

[30psi 4agte]

Hmmmm not sure whats going on here ????? You should have no such probs using arp studs.

I use them and did not have to mod anything.

Are you sure the stud is wound all the way in to the block ????

The studd will only stick out alittle over the thickness of the nut.

[benjamin]

well unless they gave me the wrong studs... but they were the box marked for 4ag.

They are all the way home into the block. Plus the CAS would foul a little on the nut anyway

I have also heard of other people having the same issue. I think it was Joshstix who I originally heard it from but I am unsure.

Edit I just checked the inlet side and the studs protrude through the nuts the same amount as on the exhaust side so I didn't put them in the wrong side either... I can't inderstand why I am having issues with my set and you aren't. Are you using a smallport head or bigport?

I have a bigport (on a smallport block) and I am still using the Smallport CAS which is interchangeable (as far as I am aware)

[1JZ-Rolla]

Benjamin, yes, you will have problems with the 1st stud on the exhaust side as you found. The extension of the CAS shaft (beyond the gear) does foul the top of the stud and needs approx 4mm removed CAREFULLY, but it definately should not interfere with the nut unless you have used washers other than those supplied with the ARP kit.

How did you manage to damage the gear on the CAS? It should be well back from the stud itself... only the end of the shaft touches usually.

CHeers
Phil

[benjamin]

Benjamin, yes, you will have problems with the 1st stud on the exhaust side as you found. The extension of the CAS shaft (beyond the gear) does foul the top of the stud and needs approx 4mm removed CAREFULLY, but it definately should not interfere with the nut unless you have used washers other than those supplied with the ARP kit.

How did you manage to damage the gear on the CAS? It should be well back from the stud itself... only the end of the shaft touches usually.

CHeers
Phil

The only fasteners I used were what was supplied with the ARP studs.

Maybe I shouldn't have put the smallport dizzy on the bigport head... are they different?

[30psi 4agte]

Im basicly using the same setup you are. Big port head small port GZE block.

I never had to grind anything.

I guess you could have probs if the head has been machiened a bit causing the stud to come through further.

This is the first i have herd of this prob.

[benjamin]

and the reason why the gear is now damaged is because I needed to grind about 1-1.5mm off the gear to clear the stud and nut. That causes it to under rotate and the ends of the teeth collide instead of neatly intermeshing.

[slide86]

wow. i have a gze bigport engine with ARP studs and i havent come across this problem either.......

my CAS went in easy as pie. im going to pull the rocker cover off and check it out tho.

[kingmick]

Im unsure without looking, what the problem is! i have studs and bigport and there is no clearance prob at all and ive never come across on ever!
Got me stuffed, are they way over size studs? is the dizzy tunnel flogged?

["Z" UTE]

My ARP Stud kit for 4AGE, came with instructions, which state " You will have to shorten 1 stud, the one adjacent to the CAS/Dizzy, shorten the stud at the base, not at the top, or you will lose the hex drive"

cheers Chuck.

[kingmick]

I always chase mine so there is no need to shorten!
I cant imagine anyone putting studs in and not chasing it properly??

[Cruiser97_80]

I always chase mine so there is no need to shorten!
I cant imagine anyone putting studs in and not chasing it properly??

What do you mean by chasing it ?

Duck duck goose

[30psi 4agte]

He means runing a thread chaser through the thread to clean up any crud or stary threads esp at the bpttom of the hole. This is essential to ensure that the studd will reach the bottom of the hole.

A thread chaser is basicly a thread tap but slightly different and is designed to clean a pre existing thread not create a new one. As 9/10 people dont have one of these or have access to one you will be able to use a thread tap(10x1.25) without any probs. ----- Make sure you blow out the thread holes afterwards !

Like i said this is the first i have herd of this prob. The instructions that came with my ARP bolts mentioned no such thing of shortening a studd. You would think that a company like ARP would supply one studd 4mm shorter rather than having people shorten them thereself .

[1JZ-Rolla]

As 9/10 people dont have one of these or have access to one you will be able to use a thread tap(10x1.25) without any probs.

if you do use a thread tap, make sure its a bottoming tap (ie: does not taper down at the end to make it easier to start) otherwise your time will be wasted

[takai]

I didnt have any issues putting mine in. Although i have heard of people having issues by putting the exhaust studs in the intake and vice-versa.

Sure i chased mine down, but that has absolutely no relevance to the need to shorten a stud. My ARP studs were used with a 100kw dizzy and a GZE CAS as well. It is possible that ARP have fixed this problem in recent times (post 2004) but you still have some of the old stock.

In either way, if you need to shorten a stud, i would highly reccomend doing it on a lathe so you can shorten it accurately without destroying any of the thread.