exhaust manifold studs (ARP part number and size info)

[Import_Ant]

I've been searching for the better part of this afternoon for exhaust studs for my car (Ka24E motor) because I'm going turbo soon and have 2 exhaust studs broken off in my head and 1 missing. I did a search on here, Googled it, and went through ARP's catalog and have finally found what I'm after.

Bolt size is M8 x 1.25 x 38mm

part number with ARP 400-8012 (total of 8)

I'm posting this mainly because I could only find 3 threads on here regarding exhaust manifold studs for the KA motor and none of them had any resolution and barely any information at that. I hope someone else can benefit from the time I killed at work if this ever comes up again :

I'll post a followup after I have recieved the studs if anyone is interested (I plan on going direct through ARP if I can so I'll be happy to post a price w/ shipping as well...)

Happy boosting-Aaron

[crzycav86]

I don't plan on using those studs, since all of mine are intact, but I didn't want your find to go unnoticed. So thank you.

Give us an update/review when you get them on. Someone will probably need them one day.

[Import_Ant]

Thanks for the kind words. I'll definitely get some pictures/info up but it will be a couple of weeks before I get a chance to do that (I've set a reminder up so I don't forget) I'm so broke from buying the turbo kit that I won't be able to order the studs for another 2 weeks but that's ok since there's a 2-week downtime for my kit while my turbo is being ordered and the kit made so I'll get back to this asap.

[onosqv]

Yes, we don't want this thread going unnoticed. It seems like 3 broken bolts run common w/ the KA's (at least mine has the same problem), hehe.

So, any updates, feelings on these studs?

[Import_Ant]

Yes, we don't want this thread going unnoticed. It seems like 3 broken bolts run common w/ the KA's (at least mine has the same problem), hehe.

So, any updates, feelings on these studs?

hehe... uh... I spent the 50$ on a new motor instead (had a blown head gasket but nothing else wrong and no stripped exhaust studs.)

gotta love the KA motor for that. descisions descisions; new motor or exhaust studs...

[onosqv]

HAHHAHAHAHAHAHHAA, new motor costs less than replacing exhaust studs, HAHAHHAHAA.

O man, sad... but true.

Good times.

[Titan]

Someone mind explaining why they must be ARP brand studs?

Local FACCA Fasteners Ltd.

M8 x 1.25 x 35mm Stud - Grade 10.9 (Equivalent to Grade 8 SAE - 150,000 psi tensile strength) was about $1.00 CDN each.

Also available in grade 12.9 (176,000 psi tensile strength).

Stock ones are grade 8.8 (120,000 psi tensile strength).

Why pay and wait more when these can be had locally?

[onosqv]

Because ARP is the JDM of exhaust studs

Well, I didn't know about FACCA Fasteners, thanks for bringing it up. We trust arp because many guys already run their stuff w/ great success - also, I suppose it markets to us better.

Only two options I even really knew of before were stock, nismo (which doesn't make exhaust studs anyway), & arp.

[Titan]

Because ARP is the JDM of exhaust studs

Well, I didn't know about FACCA Fasteners, thanks for bringing it up. We trust arp because many guys already run their stuff w/ great success - also, I suppose it markets to us better.

Only two options I even really knew of before were stock, nismo (which doesn't make exhaust studs anyway), & arp.

It doesn't have to be a FACCA, it can be any fastener shop in your area.

There is nothing special about ARP studs, bolts or otherwise. All are common commercial fasteners. Literally dozens of manufacturers.

[onosqv]

So all studs are made this way?:

GO BACK TO TOOL BOX HERE CYLINDER HEAD STUDS:“On the basis of superior material, a special heat treating process, and advanced manufacturing technology, ARP® Pro Series head studs are clearly the very finest on the market today!”

•VIEW APPLICATION CHARTS HERE

It is for good reason that virtually every top professional engine builder relies on ARP® Pro Series head studs for their all-out competition powerplants. Simply stated, there’s not a better stud setup on the market today.

For openers, ARP® uses a premium grade 8740 alloy that is rated far superior to “aircraft” quality. Then, each stud is placed vertically in special racks and precisely heat-treated to 190,000 psi. This procedure ensures complete heat penetration and the results are far superior to those lesser quality studs from other manufacturers who just dump pieces in a basket and hope for the best.

Following heat-treat, each stud is centerless ground to make it as close to perfectly concentric as possible. This procedure involves about ten very slight cuts and results in an exceptionally straight part. It’s important to note that lesser quality studs are not even centerless ground—the material is thread rolled in bar stock form (mostly before heat-treat, when the material is easier to machine). Because ARP® studs are manufactured to such exacting tolerances, you will note that gaskets and cylinder heads literally glide into position and are perfectly aligned—something that won’t happen with inferior quality head studs.

ARP® studs are thread rolled after heat-treat, which gives them about 1000% (that’s ten times) better fatigue strength than those studs that are threaded prior to heat-treat (a very common industry practice). It costs a lot more to do it this way, because it’s tough on tooling, but the results are well worth the extra effort.You will also note that ARP® offers specially undercut studs for several engines. This procedure (done only to the shorter studs) more equalizes the “stretch” of both studs, which makes for a more consistent clamping force—and one that compensates for head gasket compression when the cylinder heads are installed. This helps prevent blown head gaskets, and assures optimum engine sealing!

Premium quality heat-treated 8740 chrome moly steel head stud kits are available for most every domestic and import application. You won’t find a better quality stud on the market from any other source. Look for ARP® stamped on each stud as your assurance of quality.

ARP® head stud kits are available with your choice of conventional hex nuts or compact 12-point nuts. Premium quality parallel ground washers are also included with each kit. Clearly, they are the best on the market today, and the favorite of leading professional engine builders in all forms of racing.

I would think someone who finds above important would be willing to pay extra - peace of mind if you will. Others who don't, won't

[Import_Ant]

Someone mind explaining why they must be ARP brand studs?

Of course they don't have to be, that's why I listed stud size, length, and thread pitch as well. Alot of people like ARP bolts so I thought to list their part number as well since I had it available at the time of the post

[skatanic28]

thanks for the info:)

im surprised that none of mine have broken yet.

[Titan]

So all studs are made this way?:

I would think someone who finds above important would be willing to pay extra - peace of mind if you will. Others who don't, won't

That's the point, it's not important. The process described is far and beyond overkill. If you calculate the shear and tensile stress acting on the cross-section of the studs, even given the heftiest turbo/manifold setup, you will find the safety factor to be ridiculously in excess. More then likely, the studs will be one of the last components to fail.

Furthermore, having the studs centric to such a tight tolerance warrants no benefit, as the manifold is drilled for a clearance hole, not a dowel fit.

What I’m saying is, from a cost/benefit perspective, it makes absolutely no sense to pay for something you will never fully make use of. Especially when there is something locally available that will perform the job equally well for less.

This reminds me of people who buy fittings/hose/etc. from specialty shops (such as ATP Turbo), when the exact same product can be found at an industrial supplier (such as mcmaster.com) for much cheaper. I just don't understand it.

[Import_Ant]

This reminds me of people who buy fittings/hose/etc. from specialty shops (such as ATP Turbo), when the exact same product can be found at an industrial supplier (such as mcmaster.com) for much cheaper. I just don't understand it.

I am probably the most guilty of not practicing what I preach but...

It is a product of our society, slothfulness that is, to want everything 'pre drilled, polished, packaged, and shipped to our door' 2day UPS. I imagine they see it as ordering "head bolts for civic" not "M8 x1.75 x 80mm bolts". Alot of people get intimidated and, regardless of difference in price it is more comforting for them to pay extra for a part labeled as 'this part' for 'this car' that they feel they know will fit, instead of trying to research and get its generic counterpart and save the money it cost the manufacturer to print/stamp/etch their name into the same part. Sometimes it's cheaper if you order things as a kit for example, most of the time it isnt. It just comes across as a form of sloth to me.

[/rant]

[tiger]

I am probably the most guilty of not practicing what I preach but...

It is a product of our society, slothfulness that is, to want everything 'pre drilled, polished, packaged, and shipped to our door' 2day UPS. I imagine they see it as ordering "head bolts for civic" not "M8 x1.75 x 80mm bolts". Alot of people get intimidated and, regardless of difference in price it is more comforting for them to pay extra for a part labeled as 'this part' for 'this car' that they feel they know will fit, instead of trying to research and get its generic counterpart and save the money it cost the manufacturer to print/stamp/etch their name into the same part. Sometimes it's cheaper if you order things as a kit for example, most of the time it isnt. It just comes across as a form of sloth to me.

[/rant]

Dude, you're absolutely correct... I find myself just wanting to take the easy, no-headache way out. Especially when shopping for sizes.. i'm just afraid that I won't order the right part so I go pay more for a product that has already been figured out and labeled as "the right part" no guessing. I am not familiar with anything other than Milimeter.. that 1/16th and all that other just confuses me cause i'm not familiar with it. SOrry if this thread is really really old, I just had to chime in. I am not going to order ARP studs, i'm going to take those measurements and go to maybe Lowes or something and get the studs.. of course, making sure that they aren't made of cheap metal.. yes. people like the easy button.

[daconkiftador]

Good find, I needed to replace an exhaust stud before dropping my DE back in!

[Chezedik]

Ant, are you keeping the engine or just using the studs?

[WDRacing]

You do know this thread is Ancient Cheze??

[WDRacing]

I also added this to the sticky so its not lost forever.

[Chezedik]

No, I wasn't paying any attention. I was wondering why it said that Ant still wasn't turbo, hasn't he been running that T25 for a while?

Still I am in KC, and so I am about 20 min from him and would like to pick up a spare motor.

[C-Kwik]

Well since it was brought back from the dead, I suppose I'll add a bit of info.

I won't say not to do this, but if you are beaking stock studs, you should consider why before thinking a stronger stud is the solution. The stock studs are plenty strong for anything you can throw at it under normal use. Overtighteneing or perhaps breaking one free when siezed will probably be a couple of conditions that can cause this. But the ones that mysteriously break by themselves is likely attributed to a side load created by the expansion of the exhaust manifold (whether its the stock or a turbo mani). Generally, the holes for the studs in the manifold need to be bigger on the outer ends of the manifold or it can put stress on several studs. You'll probably find few aftermarket manifolds that are drilled out this way for you. This type of probalem will sheer just about any stud.

[eazye2000]

Yeah, while we're at it..I have a KA24DE block and the M8x1.25 studs don't fit in the exhaust side of the head for me. They just kinda dangle around in there. I DO however have some M10x1.50 bolts and they're the right diameter, but the thread pitch is wrong. So I'm thinking M10x1.25 maybe? The M10x1.50 bolts have a much more coarse thread than the stock bolts(studs, whatever) So either M10x1.25 or M10x1.75 (if there is such a size)

Just my $.02

*EDIT* The exhaust manifold side of the KA24DE head are M10x1.25 I really hope noone goes out and buys the M8's because they are too small. Unless it's for a SOHC, then I have no clue what thread size they are.
Modified by eazye2000 at 11:39 AM 1/26/2007

[GTR PrYdE]

Yes they fit!

Head to Exhaust Manifold: - Studs: Toyota Part# 90116-10017... MSRP: $2.06/ea... QTY: 8. - Nuts: Toyota Part# 94180-41000... MSRP: $1.49/ea... QTY: 8

http://www.trademotion.com/par...14074

I ordered 8 studs only and it costed me 20 bucks shipped, and they fit perfect. I got the nuts from autozone for like 4 bucks. Not bad at all!!!

thanks to IMperfection on ka-t.org

[tommypaton]

I have the SOHC and my 2 of my studs broke and I am already turbo. Does anyone know the right size for me? We are talking about the studs that stick out and a nut tightens down to them, not the bolts that just screw in the top holes right?

[kouki_hmongster]

i think the previous post already answered your question. studs are studs and bolts are bolts. so when they talk about stud its threaded only and maybe a plain spot in the middle. bolts have a nut at the end.

i think the kade and kae use the same exhaust manifold stud from the head to exhaust manifold. if you are afraid you can call up dealer and get a part number and compare it to previous post.

[JDS Performance]

Lets bring this back from the dead.

OK so for the KA24DE S13 and S14;

Exhaust manifold studs are M10 X 1.25 thread pitch - and the other end of the stud is whatever nut you want to use basically.

Ok so now what about the head bolts and main bolts - whats the size and thread pitch on them? Also what about the rod bolts/nuts?

I would love to get a cheaper alternative to ARP as the full kits will be around $275.00+ plus shipping and thats a bit steep for some fastners IMO.

If I had a bare block laying around I would find out and post it all up but I do not at the moment!

[Xise]

ressurrecting this thread again

when i searched for the size of the studs, at autozone and a few other places listed the size as M10 1.50 x 52 mm. I searched the cataologue of the manufacturer and they also listed both the ka24e and the ka24de as using these studs.

couldn't get the size of the studs from courtesyparts.com though they didn't list it.

I just ordered the studs from autozone, they come with the nuts and I am just going to get some generic bolts and some washers and i can bolt my headers on finally.

also does anyone know the wrench size for the ka24e egr port on the top of the exhaust manifold? some tell me 24mm wrench but i tried today and split my finger open, is it 23mm?

[C-Kwik]

I usually just went to the dealer for the stus. They usually had them in stock and weren't all that expensive (after you add shipping to a set of studs online, it probably gets pretty darn expensive).

While ARP studs are probably pretty good, there isn't any specific reason a OE stud should fail on its own. If you are running a turbo manifold, make sure the holes are drilled properly so that it allows for expansion. Not soing so can easily shear off a stud.

[Xise]

I usually just went to the dealer for the stus. They usually had them in stock and weren't all that expensive (after you add shipping to a set of studs online, it probably gets pretty darn expensive).

While ARP studs are probably pretty good, there isn't any specific reason a OE stud should fail on its own. If you are running a turbo manifold, make sure the holes are drilled properly so that it allows for expansion. Not soing so can easily shear off a stud.

Well I am keeping my KA NA, just wondering aboutt eh size of the bolts b/c what was origionally posted and what i found were different, can anyone confirm the actaul size of the bolts?

[WDRacing]

So you're switching from studs to bolts? Take a stud out, drive to Ace Hardware and tell them what you need. Done and Done