JohnStra

I'm trying to figure out if ARP makes head studs that I can use in my 3vze. I'm thinking of use ARP instead of DOA because they are keyed on the end for a wrench and can be removed. I an email to an ARP dealer and they say they don't have an application match for the 3vze. If I give them the bolt length, thread length, thread pitch, and diamether, they'll tell me if they have studs that will work.

Can someone post these specs or let me know if they've used ARP head studs.

Thanks,
-john

amusement

Really good question. I tried to look it up on internet, mitchell's and haynes manuals with no success.

Bump

CTB

I know guys have talked about using ARP studs on here before (when they talk about changing out the head gaskets). Sorry, I can't give you much more info than that, but I do know it has been discussed quite a few times. Have you tried a search on here for it?

MTL_4runner

Just take a head bolt and measure it (from the tip of the threads to the underside of the hex head) then add about 1" for the nut to fully thread with some leftover and for the threads to fully penetrate the block. Also be sure all the head bolts are the same length. Some engines have different lengths but I am not sure what the case is with the 3VZ-FE.

JohnStra

I can measure them next time I tear things apart, but that won't be until August or so. I'm collecting parts for my overhaul now.

JohnStra

I'm just going to go with DOA. I got this email from Tim (from DOA) today...

"I'm having all my studs slotted for this very reason. A screwdriver is all that would be needed to remove them after install."

I had asked him if I was going to have trouble removing the studs to get the heads out.

-john

radrex

I'm sorry - but I just can't see 250.00 for 8 studs.

I'm going to use some aftermarkets for about 50.00 and takes my chances.

I'm a cheapo

JohnStra

$250 for 16 studs... still high but worth it for the peace of mind for me.

amusement

I will be honest. $250 equats to 13% total cost of a rebuilt 3.0 @ $1,800.
If DOA machines each of hte 16 bolts using a CNC machine the cost might run around $86. Material maybe $40. So, in general terms about $126 to make all 16 of them. Since there the only one making them ... there's a markup price of over $100 bucks.

What's the guarantee? And who's going to pay to have the bolts removed?

The minimum warentee of a rebuilt 3.0 engine is a year. Most have three year guarantee.

If you're building a racing engine then this debate is all mute. But, if it's your daily driver then, review the economics and re-think the purchase (IMHO).

JohnStra

Compelling post, but as I say... I'm willing to pay that amount for peace of mind. Given your comment, though, I will do some more research. If I cannot be convinced of the superiority of going with studs - and with DOA studs at that - then I won't buy them. My goal is to overhaul the top end this summer, put it back together, and not worry about it again - ever. Naive? Maybe, but that's what I'm shooting for.

amusement

Naive? Maybe, but that's what I'm shooting for. - JohnStra

Doesn't sound naive. Perhaps your learning experience might accidently under cover
some new source of 3VZE head bolts. Keep moving forward. I hope for the best. Please share your finders with the rest of Yotatech.

Firefyter-Emt

You know.. I have never replaced then ones on my motor. They have been out twice. I have also never ever had a head gasket problem. 1st time I pulled the heads back off after about 5k The second time they have not come out yet (1st time to change heads, 2nd time to change them again) I know it is a big piece of mind, but I have never broken a head bolt in my life re-installing them..

JohnStra

I guess one thing that would help me understand whether studs are worth the cost is knowing what causes head gaskets to fail on the 3vze. I see lots of posts on HG failures, but I rarely see comments concerning how/why they failed. Is it the head/block interface, water jacket design, the bolts, the gaskets themselves, or something else? DOA claims the torque variance you get using the OEM bolts contributes to the problem. That seems logical to me, and that a more even torquing of the bolts/studs would result in a better seal. That also could account for why some 3vze engines never have HG issues... their bolts are torqued more uniformly than those that do have problems.

Thoughts?

-john

Dan_90SR5

Stock head bolts are 3.75".......not sure about the thread pitch because the box doesn't say.

MTL_4runner

I would bet the problem lies in the yield strength on the OEM headbolts. The DOA and ARP bolts use very high yield strength bolts and thus can be torqued to a higher level that the stock ones. This means that even if one does begin to yield a bit and lose some sealing pressure, you are still in the clear. The stongest bolts I have seen yet come from Unbrako (I don't think they make studs too but you could check). They are very expensive (we used them alot in critical areas in aerospace design) but the strength is amazing.

amusement

It was my belief that the head bolts were only a part of the problem. The second part was the result of poor gasketing material from a Toyota vendor.

Further, I was under the impression that having a copper ring compressed around the cylinder top would help resolve the issue. To install this type of hard head gasket there would need to be some material removed from the head to allow the copper ring to seat flush.

MTL_4runner

Jim, your completely correct, but I thought the new headgaskets address this issue?
Maybe my wires are crossed and they didn't fix it.
I thought that was what the recall was all about.

The highest pressures should be inside the cylinder so you want that copper ring to crush pretty well so I don't think you would want to remove any material from the head except to correct flatness. The trouble is that with the stock headbolts, they don't provide enough clamping pressure so even with the new gasket, you may still have problems. The aftermarket studs or high strength bolts allow almost double the clamping pressure and thus the chance of displacing the gasket are much slimmer. Incidentally, the gasket tends to be pushed outward towards the coolant passage because of unequal pressures (very high in the cylinder vs maybe 15 psi in the coolant passage).

amusement

Thanks Jamie for the enlightment.

I think some of those replacement head gaskets just aren't up to task. Maybe a higher level performance gasket from Felpro would work better.

MTL_4runner

Could be? Do they make one?

JohnStra

Yes, Felpro does make an entire gasket set of the 3vze. In fact, that's what I put on recently when I cleaned my top end - the entire set cost $197. My understanding is that the gasket design was changed as part of the recall. If you go look at various head gasket offerings on the web for our engine, they all have a note that says there is a recall on the engine and that the gaskets you're purchasing are the 'fixed' ones. But... there are a significant number of folks who do have follow-up HG failures after they've been serviced by a dealer (or by someone else). Surely, the new gaskets they are getting following the failure are the 'fixed' ones. So the 'fixed' gaskets alone must not entirely resolve the problem. Which is what has encouraged me to go with studs.

-john