Guru stud kit sealing?
 

i have heard of people having problems with the guru oversized stud kit leaking water out the back of the block. i will be building my engine in a couple days and want to ensure the that i dont have a coolant leak. any tips?

There are other studs out there that do not have this problem.

Get rid of the kit and dowell the engine.

yeah i heard that the oversized studs can actually decrease the strength of the engine.

I"m still curious as to why the Guru Kit specifically has issues, haven't gotten any response on it yet either.

It is a spiral cut thread onto which a rubber O-Ring is asked to provide a positive seal *that will never ever happen* you need to use copious amounts of ghetto silicone sealant and pray you do not get a leak.

A proper bolt *as Mazda designed it* has an elevated shoulder that is 100% smooth (no thread cut on it like on a stud/nut) and thus the sealing washer with integral rubber seats tight against a perfect surface (seat in housing chamfer and flat surface on tension bolt) thus you have no leakage path and a reliable seal.

O-ring and the like DO NOT seal on leakage paths that interlink one element to another (such as is the case with a spiral thread interlinking the water jacket to the atmosphere) the only way you can hope to stop it is by drowning it in silicone sealant and that is not only ghetto but will ALWAYS leak.

Proper design is a BOLT! not a threaded stud and nut as it will NEVER seal correctly or the odds of it being right are similar to winning the lottery :)

Good thread, I was going to buy a set of Guru oversized studs. My buddy bought the standard sized studs he now has 300 miles on the engine no problems yet.

I got the 12.7 mm kit in my engine ,no leaks. Make sure you do a coolant pressure test up to 30psi, let it sit for a while and see if it leaks .
I did not use any silicone with my o rings and have no problems at all. Lube the o rings up good and see how she does under pressure. The question is whom did you r machining for your stud kit. If Rohan did it? I don't think you will have a problem.

That is an awesome response to a question nobody asked. I understand the issues many people have with the concept of using a stud. What I want to know is why people seem to believe the Guru stud kit is inferior to other manufacturers' stud kits.

200 miles on mine and hasn't leaked so far.

the stud kit as a whole to me is rubbish.
bolt is better.

Do you believe that a stud kit can give any more rigidity to an engine compared to a stock tension bolt?

i did not start this thread to hear whether or not you like the stud kit, so stop with that shit. i just want to know how to ensure the back of my engine is not going to piss water. a-spec is doing the machine work.

Good luck with the down grade. if aspec are doing the machining why dont you let them tell you if its going to leak or not.

In my experience the O rings supplied with the GURU 12.7 kit are too thick. They tear when the nuts are torqued up.

guys guys guys

For those of you who have never used the kit, be quiet and don't say anything please.

Ive used both kits' the 10mm kit and the 12.7mm kit and have not had any issue.

When u open up for the 12.7mm studs u can't use the stock sealing washers between the block and the nut that comes with the kit.

Now what u hafto do is use a washer that is quite tight against the studs and also use a o-ring that fits down into the machined grove that the person that is drilling the 12.7mm holes need to make.

If u look on the stock hole there is a machined grove where the rubber gasket on the stock washer will go into to seal between the stock stud and the block. This works fine with the 10mm stud kit as well.

So when i make the hole bigger u will need to make a similar groove to get a new o ring to fit with a washer. And also the person opening up the holes do also need to do a good jobb. If the holes is too big u will ofc get sealing issues.

It works fine, you just need to do it correct. It is a aftermarket mod that involves precice machining work to be done. And should not be done by everyone, and you do need to know what you are doing.

Jan-Tore

Better yet ask my customers, if my studs kits leak ;) I've done dowels and studs both on 900hp 13B's I like my studs :) Though I have done a sleeve type setup I'm going to try and I think that may prove a good plan we'll see.

I didnt say your stud kits leak. the possibly dont.
So i hope you didnt misunderstand me.

I have USED a few times guru stud kits and been extremely disappointed and the water leaking out was the last of my worries.
How about some awesome cracked plates.
But anyways this thread isnt about how shit they are. Its about to stop them leaking.

I started making mine because I got sick off the guru's leaking, cracked plates happened on dowelled engines as well, It's not a stud issue when your cracking plates.

well for me. Same engine. Same computer. Same tune.
front plate broke in to 3/4 pieces twice
New engine dowelled.
No more falling apart.

so what ive gathered from this is im going to need to find some properly sized o-rings for the studs. then what about the copper crush washers?

Does anyone know the exact length of the 13b studs in the kits?

i already built my engine, otherwise i would measure them for you. lol

-masin

I installed the pieces as Guru recommends, and I slathered everything with Hylomar. No leaks after 5K miles.

BTW -- I think the washers are gold anodized aluminum.

GRRR... I guess I'll have to figure out the length the old fashion way!

what do you need to know the length for?