Exhaust manifold stud upgrade

[bigaaron]

Another thorn in the 7m's side is the exhaust studs. Most of you know that this is a big problem when you go to replace a manifold and the studs strip before you get even close to 29ft/lbs. Some people have them start to back out on their own creating a big exhaust leak. I have seen engines where a stud is just completely missing :nono: So I came up with a fix/upgrade. I go up to a 7/16 stud with coarse thread on the head side and fine on the manifold side with a 7/16 helicoil in the head. The coarse side has larger diameter threads that will not strip out of the head. The fine side lets you get accurate torque like stock. I use metal locknuts like stock too. I have had helicoils of the origional stud size pull out because the aluminum gets brittle and weak after all those years of heat cycles. The stock studs are too small for the weight of the manifold and turbo imho. There are manifold brackets for bracing but when you lower the car and put a aftermarket exhaust and it scrapes the ground it really stresses those studs reguardless. I can do this job in car with a right angle drill adaptor. I have tested this on several engines and had great success. Make sure to use thread cutting fluid when tapping for any size helicoil. So here are a few pics of my setup:






What do you think?

 

[turbo]

Very nice, I might retry helicoiling to stock size again due to one pulling out but if that fails I might give your 7/16 a try. I definately agree with the stock studs being way too small.
Geoff

 

[rakkasan]

Very nice. Why not make a few bucks by putting together a kit with everything needed?

 

[supra90turbo]

I think that looks HOT! I love new bolts... does that make me sick?

 

[jmcboost]

Ya, I like it and I would buy a kit so I wouldn't have to go try to figure out where to get all the parts.

 

[aye mate]

I just tapped new, standard threads into my head and used bolts with lock washers. Its been over a year and they've never come loose. I don't remember what size the tap was, it was the next size up and was in between the stock size and the next metric size up. I'm thinking 5/8 course. That install looks really good though Aaron.

 

[rakkasan]

Ya, I like it and I would buy a kit so I wouldn't have to go try to figure out where to get all the parts.

For me, the time saved from not having to run all over the county to find the misc pieces justifies paying more for them.....

 

[bigaaron]

Sure, you can put in new stock studs with helicoils and you will be fine 90% of the time. I did a bunch of heads with oem metric studs and helicoils and they worked fine. It depends on the condition of the head. Then I had two heads that were a little older higher milage and I had a helicoil strip out in each. I hate that feeling when you are trying to get the required torque and you can feel that you went about 1/4 turn farther then you should but not hit the torque spec yet. The problem is that once you have it going back together and one strips it is a real pain in the ass! I said to myself, f-it, i'm gonna fix this once and for all! LOL

On the tap subject, you have to use a helicoil tap. It is not a standard size and some brands vary. The helicoil tap has the same tpi as the stud, but larger diameter to account for the size of the helicoil. It is not a specific size metric or standard tap, it's a helicoil tap.

I can put together a kit to install stock or 7/16 studs if you guys think it would sell.

 

[GrimJack]

Great idea.

 

[rakkasan]

I can put together a kit to install stock or 7/16 studs if you guys think it would sell.

I recommend making everything needed available to be purchased. I'd rather buy the taps, drill bit, ect from you in addition to the inserts & studs at a higher price because I literally don't have the time to get out & hope to find them locally.

 

[bigaaron]

Ok I got a call into my hardware supplier and I will hopefully have a kit price put together by tomorrow.

7/16 is the biggest diameter that will fit all the manifold holes without drilling. The gasket is tight on the two smaller holes but it will fit. You could dremel it a little to fit easier.

 

[cnewingham]

sent you an eamil Aaron

 

[bigaaron]

Prices updated with shipping now included!

Three kits, in car or out of car install, metric or upgraded 7/16!
Shipping included is for US only. Please contact me first if you are not in the US!
Paypal fees are now included in the price!

out of car 7/16: $67 SHIPPED!
1) 7/16 helicoil kit
8) helicoils (one extra just in case: murphy's law)
7) studs
7) metal lock nuts
1) 29/64 drill bit (standard length)
1) tap holder tool
1) cutting fluid
1) antiseize

out of car 10mm: $67 SHIPPED
1) 10mm x 1.25 helicoil kit
8) helicoils (one extra just in case: murphy's law)
7) 10mm Toyota oem studs
7) 10mm Toyota oem metal lock nuts
1) 13/32 drill bit (standard length)
1) tap holder tool
1) cutting fluid
1) antiseize

in car 10mm: $87 SHIPPED
1) 10mm x 1.25 helicoil kit (tap, insertion tool)
8) helicoils (one extra just in case: murphy's law)
7) 10mm Toyota oem studs
7) 10mm Toyota oem metal lock nuts
1) 13/32 drill bit, shorty (machine length) fits purfect in right angle drill attachment because it goes a hair over 3/8"
1) right angle drill adaptor (pictured below)
1) tap holder tool
1) cutting fluid
1) antiseize

The shorty drill bits are so you can get that last hole without hitting the firewall.

Shipping included is for US only. Please contact me first if you are not in the US!
Paypal fees are now included in the price!

 

[bigaaron]

Here are some of the items, everything in my kits for sale would be brand new. I don't have the custom drill bit to show you quite yet but it will work nice. The right angle drill attachment and tap holder are good tools for other projects also if you don't already have them.

 

[IJ.]

Aaron: Well done filling a need !

 

[supra87t/t4]

What material/finish are your 7/16" studs?

 

[suprageezer]

Great Upgrade. I have done this on the mopar engines I have rebuilt. One thing I would add is Always use Nickle Anti-Seize on everything Exhaust. you know dang good and well your gonna work on it again. I also try and use a copper gasket if available and have never sprung a leak with one.
Rick

 

[rakkasan]

Cool, paypal address?

 

[bigaaron]

What material/finish are your 7/16" studs?

These are I think grade 10, black finish but I can get plated ones for a few more dollars. Antiseize would be a great idea Suprageezer, I will include that in the kit too. aaron@driftmotion.com for the paypal. It will only take a few days to get everything together.

 

[bigaaron]

bump