Exhaust Manifold Washers

[GTR_JOEY]

Quick question, hopefully someone can answer this quickly for me as I wanna put the engine back in.

I've just bolted up my exhaust manifold and the bolts don't thread 100% of the way into the stud

The reason for this is that is the washers I'm using are like 8mm thick. Is it necessary to use such a thick washer or can I use something thinner like a stainless spring washer?

Cheers

[89CAL]

The genuine washers are quite thick so im assuming you are using them. And from your description it sounds like the nuts arent going on far enough for some of the thread to protrude out of the nut?

Honestly, a decent stainless washer will do. The nuts (if genuine) are lock nuts so wont require a spring washer.

[Dobz]

As 89CAL said a decent stainless washer will do. If you don't have factory lock nuts you can just go to the bolt shop and ask for prevailing torque lock nuts. These have the three press marks on one tapered side to form the lock.

[GTR_JOEY]

Sweet cheers lads, I just used a steel spring washer in front of a steel flat washer.

Used the flat because the stud hole in the manifold is a large diameter and I wasn't happy with how it sat with just the spring.

Regardless I still managed to get an extra thread or two with this method. Those standard washers are thick as!

[kingtube69]

Sweet cheers lads, I just used a steel spring washer in front of a steel flat washer.

Used the flat because the stud hole in the manifold is a large diameter and I wasn't happy with how it sat with just the spring.

Regardless I still managed to get an extra thread or two with this method. Those standard washers are thick as!

Also about 90 bucks for replacements (with studs and nuts though) which I think is silly.

[GTR_JOEY]

Yep,

I noticed that kudos also supplies a longer after market stud for a few extra bucks..

Still a bit pricy though

[MozzMann]

As a general rule you can use any washer to spread the load of the nut on the stud, the reason they are thick is to help them cupping and thus the manifold loosening from the heating and cooling cycles in normal operation.

I'd replace the studs in the head with a sleeved bush on the outter ends for locating and use stainless cap screws for manifold retention, and decent thick spreader.s , this will give you the best adherence to the manifold gasket preventing leaks.

The reason I like Socket head Cap screws is you don't tend to over tighten them and this in turn helps longevity .