ARP Hardware

Are you serious about the 4agz studs?! If so, then I have already screwed up my block! Guess I will find out later tonight but I thought I compared the bolt and stud a few months ago and they looked good.

Just to clarify, the 4AGZ studs are for the main bearing caps, not the head. I hope you misunderstood this...(sad1)
 
before everyone freaks....

the 10mm will work... as the thread is the same and the reason for the enlarged thread on the stock unit is as i said the fact that they stock head bolts are made with rolling dyes.......

hope this helps
 
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ok everyone well the engine is back together with the main studs sitting in there nicely... sadly as for time reasons the engine had to go back toegether with haste meaning new stock items took up the role of head studs for the next 2 weeks until the ARP replacement items arrive.... no biggy no big boost until the 1000km run period is done with anyway... and a replacement gasket is not ig dollars so what the heck... with the boost we are planning on running with the thing it won't be the first or last time we pull it apart but thats the name of the game...

i have been in clsoe contact with a few high up members of the ARP community and have informed them of all part numbers for our car and that the 4AGZE amins are the same and they are doing a quick test on a local car and putting the code out internationally as a kit for our cars.... great feeling it is to take part in the forward movement of our cause... =p

i was also wondeirng if anyone had stopped.... scratched their heads.... then had a ciggy while thinking about how our so called "cam belt tensioner" in translation "the spring holding the wheel on" will hold up to big amounts of boost... i have looked at our factory manual and there is no spec on the actual "tension" held by such and item and therefore it makes me think that for big boosters a replacement part will need to be sourced....

there is a hoe in the tensioner itself for a dowel to e drilled and fitted to the block to hold it fast and this looks like the route we will be following... as total valve train failure infront of a crowd at the local dragway at 30psi would not be the impression we would be trying to leave on the onlookers...(of either my inteligence... or that of the workshop employees advertised on the side of my car)
if anyone is interestedin knowing the exact details of our fix then just pm me and i'll explain more indepth... although any of you who have replaced the item in question along with the timing belt at a DIY service should know what im talking about...

...breath....
so at the end of it all, if none of the above made any sense ask questions and they shall be answered... :p
</long post>
 
The Head studs are indeed 11mm threaded. Wiredone, I don't think it's a good idea at all to use 10mm threaded studs. I am interested in your tensioner idea, please PM me the details.
 
why would the tensioner be an issue??? why would that be more of an issue with very powerful engines over stock? it only holds the cam belt in place. all that changes is the accelaration of the belt...
 
the faster the accelleration the more tension being put on the spring...

why do all skylines, 300zx's etc... sell upgraded cam belt tensioners.... all it takes is a loss of the tension for that split second and it all breaks loose... the spring is made for a set tension... i am not going to rest the thousands i've spent on internals and machine work on the sole hope that the spring will take large amount of boost..

ddog: are you 100% sure... the stock head stud is a rolled thread therefore you need to actually measure the thread diameter not the bolt diameter... as the ARP items are not made using dies....

with the tensioner we have stock if you take it off and look at the inside of the tensioner there is a hole for what would normally be a dowel coming out of the block.... but in our case we use the same part but without the dowel... if you drilled a hole exactly the same in the block and put a dowel in the tensioner would be held rock hard...
 
Wiredone, I took the headbold to a copperstate bolt and nut and it was 11mm x 1.5mm pitch. They actually screwed it onto a nut and it went on smooth. With rolled threads this is to be expected, that is the thread diameter being the next step up above the bolt diameter. I was talking to a rep at ARP and he thinks the Miata headstud set will work because it is 11mm and 5,400" long. He asked me to get a few specs to verify.

Regarding the tensioner, I haven't looked at it in months but my understanding is that is used to take up slack. If you are going to use a dowel you are going to have to preload it so that it would never slack up more than the acceleration would cause. This will put a tremendous strain on the timing belt. I hope you have an aftermarket belt; but then if you had that you wouldn't need the dowel, just a stiffer spring so it takes up the slack faster.
 
thats the other solution... but do you know anyone who makes a stronger spring...? cause i sure as hell dont...

it would be impossible to even try until we knew the exact speck of the tension on the stock item...
 
you could always take it out, put 500grams on one end and measure how much it expands. that'll allow you to work out what spring rate (or whatever) it is. then just get a spring that's double or even tripple the rate.
 
OR you could just use the dowel and save yourself 3 months of experimentation...
the tensioner is adjustable once you have the dowel in... using the hex key you can spin the bearing to tension it... so it is still adjustale... just rock hard...
 
so these are the wrong size studs? we should be using 11mm instead?

wtf maybe thats why me headgasket is no more.....

-B
 
Damn guys, this sux! I still have the stock head bolts in. Guess I will upgrade sooner or later.
 
Wiredone, I would like to know if you used your dowel method and what results you might have had...
 
we decided to watch it very closely for now... but everyone i have spoken too agrees that the acceleration at big boost will create heaps more slack and the spring rate may not be good enough to pull it in quick enough
 
So how do we get a new spring made? What are the stock rates? Where's THEMAN when you need him?
 
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