TR2/3/3A TR3 Intake Exhaust Manifold Studs

[MGTF1250Dave]

Aloha All,

A quick question about threads on the studs mounted in the TR3 cylinder head to attach the intake/exhaust manifolds. are the threads on the end that goes into the head course or fine? My son has one that is damaged but he hasn't removed it yet. I was going to look for a replacement today for him.

 

[martx-5]

They are coarse on both side...3/8"-16. I just removed one from an engine sitting here to check. The lengths on the bottom are longer then on the top.

Edit: If you want me to measure the lengths on either or both let me know.

 

[TR3driver]

Coarse threads, both ends. 3/8-16 as I recall. Note that there are 3 different lengths.

 

[martx-5]

There are THREE different lengths???

I'm going to go out and check. Visually, it looked like two.

 

[MGTF1250Dave]

Thanks for the quick responses. I have the approximate length I need. What a great resource the forum is, I'm sitting in my office, the car is twenty miles away, I ask a question and get an answer in less than twenty minutes. Isn't technology grand?

Thanks again!

 

[TR3driver]

There are THREE different lengths???

I double checked ... yup, three different lengths. The 4 studs on top all take the short bridge pieces, so they are medium length (2-1/16"). The 2 center studs on the bottom take the long bridge pieces, which are also taller, and so the studs are longer than the 4 upper studs (2-3/8"). And the 2 outermost studs on the bottom take no bridge piece at all, so they are the shortest ones (1-11/16").

On later engines, there was even a 4th length, to accomodate the engine lifting eye on the bottom rear stud (1-15/16"). Not sure when that change happened, maybe at TS60K (but it's listed in the TR4A SPC).

 

[martx-5]

I checked the length on the studs on my engine. There are three different lengths as TR3driver says, but the two outermost studs on the bottom are only an 1/8" (1-15/16") shorter then the top studs...the "fourth" length. I have no "third" (shortest) length. My engine is TS 247xxE. Maybe something was changed along the way on my engine. /bcforum/images/%%GRAEMLIN_URL%%/crazy.gif

 

[TR3driver]

Should be no problem, as long as you use some sort of spacer to keep the nut from bottoming on the threads on the front stud. That's not a bad idea anyway, I have thick flat washers in there that seem to help keep the joint tight.

Or, TRF has the short studs listed, P/N 58688.

 

[martx-5]

The two washers that are on those studs are thick. I didn't measure them, but they appear to be about 3/16". That's what was on there when the car was running.

 

[TR3driver]

Sounds perfect to me. I also find that the lockwashers need replacement almost every time I have the manifolds off; they seem to lose their spring quickly when exposed to exhaust heat.