4AGE 20V Head Studs?

[KARNAGE]

I have seen a brand new one fail i think it was more a dodge head stud than anything as its the first time i have seen them fail and as ke25 racer said high horse powere engines have handled them fine. i went down the stock head stud road and have a 212kw 20valve and never had a problem

[RT40Corona4AGTE]

Got a message back from ARP.

"The studs in the 4AGE kit are 4.250 and 5.000 long, 5 each. I don't know of a special kit that we make for the 20 valve. If we do it's probably proprietary for someone and you would have to buy it from them. Or someone called here with dimensions and ordered that way. If you want me to see what I may have in open stock that could work for your application fill out the attached calculation sheet."

Will try to give them a call next week and arrange a custom head stud kit for the 20V using their calculation sheet. I am staying well away from stock head bolts as I want my head to be very secure under 30PSI. ;-)

[Sam_Q]

I am hopefully going to end this topic once and for all:



The 20v bolts as they are fitted to my spare engine with the right washers




20V bolts in the middle and the arp 16V studs on the outer




Many have said that you need the two longer 16V studs on the 20V, well this picture shows the longer stud installed in the low side of the 20v head, as you can see I have no idea what they are talking about





Here is the 16V studs installed exactly the same way as what you would for a 16V, at first they seem too short but looking closely you will see that thats the start of the thread near the face of the head so no more thread can be put into the block. While the 20v bolts on the exhuats side normally thread further into the block this is the same block as the 16V and it uses the same amount of thread as the 16V head. So in conclusion I see no reason why the 20V head should be any different.




This is the top on the high side, as some have sujested there might be clearence issues luckily its very far from the case. Pictured is a 1/2 inch drive 12mm socket on the head of the ARP nut and even with such a bulky socket it doesnt touch.




The low side is the same story, clears with ease and that with a socket much larger than what you would normally use I would think.


Final verdict = 20V is the same as 16V in studs

I am happy to make inidvidual measurements of stud shank and thread lengths for anyone who wants to know.

[pryorshazam]

the 20 valve head needs the longer bolts on both sides of the head as previously mentioned. i bought the 16 valve arp stud kit not knowing this and worked out a way around using it (i know alot of you arnt going to like this but im running standard 4agze bottom end and 20 valve head making 207 rwks @ 16psi [jem] and it seems to hold together)

on the exhaust side of the block the thread starts about 30mm deep into the block and on the inlet side it starts relatively flush. i got some high tensile m14 bolts cut to length and drilled and tapped them metric fine10mm (making my own heavy duty helicoil). then drilled and tapped the exhust side of the block m14. screwed them flush into the block then drilled a 3mm hole down the side of the thread and locked the insert in with a pin.
then just used the standard 16 valve studs all round

[too_quick]

You must spread some Reputation around before giving it to Sam_Q again.

Good work mate.

[Sam_Q]

oh ok... I thought it was odd that it seemed to fit well but everyone else said otherwise.

Your idea is quite resourcefull and I like it, what your basicly saying is you drilled the block out and put an insert in to have an extended threaded section.

Oh and also I like your combination of parts, a bit off topic but what compressor are you running?

[Sam_Q]

I had a look at the block today and indeed your right, now surely with all of us we could somehow convince arp to sell just the long studs off the 16V kit

[pryorshazam]

gt28rs............

[blacktop]

Maybe a of group buy?

[Sam_Q]

you know what you might be right about that, If you guys go to ARP and say we want just the long bolts and we want 10 sets of them then I think thats a bit of bargaining power.

[-GT-]

I'd be in that.

[Esteban]

Me too! .

[Bazooka]

I'd be interested also.
If we can get enough numbers then I would say do an order straight from the USA.

[DX20VT]

i did mention before that i sent a head bolt to ARP and they couldnt match anything.....

so, every high HP 20v i have supplied parts for has used the stock bolts and not one has had a failure that can be blamed on the bolts. and that includes some rather serious engines....
and they are cheap too. so i recommend you use the stock ones

I still run standard toyota head studs and run over 400hp out of my 20v head.

Just fit new one every time the head comes off,
and they are cheap anyway.

[Sam_Q]

how cheap?