Replacing plenum bolts w/ studs...

[GrndNatnl]

Could anyone fill me in on replacing the plenum bolts with studs?

Some exact stud and nut numbers would be nice to head to the hardware store with. And how many are needed.

I'm not sure, but I think theres already studs along with bolts? Which ones do I replace, and what should I lock them down into place in the intake with? Threadlocker or epoxy?

Asking because I'd like to do this to avoid future stripping horror stories. I'm going to test a Power Plate out for myself that I recently ordered and awaiting arrival. Any info is appreciated, so I can stop at Sears Hardware on the way home.

 

[87 WE2]

Matt, ask banning I am pretty sure he did this to his car, he would know all the info you need haveing already done this....Ed

 

[slipstick]

In order to achieve maximum thread engagement in the intake I screwed a long bolt to the bottom of the threaded hole then measured and marked the bolt with the length required for the total thickness of attaching nut, plenum flange, gaskets, power plate, and bracket for throttle cable (if applicable). Remove and cut the bolt to the required length. Clean and grind a chamfer on the new stud's cut end. This method will yield a "non-standard" stud that is just the right length for this specific application

 

[GrndNatnl]

Thanks Slipstick, I like that idea. Thats probably the most "mechanically correct" way to do it.

 

[Be4u]

Middle back-35mm (no washer, wouldnt fit)
Driver back -50mm with an extra nut for a spacer between the
TV bracket and the intake, just like the stock stud,
only longer.
driver front -35mm
pass back -45mm plus an extra nut...again, like the stock stud.
pass front -35mm

PartNumber 94000A039- metric 18-8 Stainless steel acorn nut, M8 1.25 pitch $7.12 box of 10

Call http://www.mcmaster.com/. Tell the girl that you need "metric 18-8 Stainless steel full thread stud,
M8 1.25 pitch." She will also need to know the length.

If your going to do a perfect job I'd get 1X50mm, 3X35mm, 1X40mm, 1X45mm, 1X30mm, a box of acorn nuts, 2 regular nuts and stainless steel washers. You'll have extra studs...I was talking with someone and they said sometimes the holes are a little shallower.

I bought 5 of each size....from 25mm-50mm. This method is tried and tested.

One last thing, on the passanger side back bolt (the one that everyone strips) is a bitch to get off. You have to be very careful not only to strip the hole but also bending the vacuum line. The nut freezes to the little bracket sticking off the lines. Get some
PB Blaster and let it soak...it's still a bitch...shock the nut, tap, tighten, loosen...take your time!

I hope you find this useful. I wish I had a pic to send you of the outcome. It looks great with the acorn nuts. Real clean looking.
Robert

 

[J Banning]

Originally posted by Grand Nash
Matt, ask banning I am pretty sure he did this to his car, he would know all the info you need haveing already done this....Ed

Matt,
Did you see the ones we did on Scott's car today? He can get you the pat numbers for the studs. I did a trial fit, marked them, then cut to length.

Each car is different, so make sure you do this before the final install. (My car has a stock upper plenum, he has accufab. I have plenum spacer & power plate, he has power plate, etc. etc.)

-Banning.

 

[GrndNatnl]

Gruff... Thank you for the hardware specs!

I just installed the powerplate earlier tonight. And interesting that you mention the passenger side back stud being the difficult one, because thats exactly what I had trouble with. Getting it off, and back in. Had to use a thin open-end wrench around the lower nut to hold it, while turning the upper one with a socket. Did the trick without messing up the vac line.

In fact, when I was torquing them down, I did them all to 20 ft-lbs, then another 1 or 2 ft-lbs to top them off, that passenger side rear stud started to get a little easier to turn, so I just left it alone right then and there. No problems under boost, so its sealed up. Took it for a few WOT blasts afterwards. I'm hoping if I pull the plenum back off again to put in studs, that all I'll need to do is just put a bolt/stud in there, and that it should just thread right back through and bottom out perfectly.


Banning, did Scott find exact length studs or did he cut bolts to proper length? Didnt catch that when lookin at his motor the other day.

 

[Be4u]

Originally posted by GrndNatnl
Had to use a thin open-end wrench around the lower nut to hold it, while turning the upper one with a socket. Did the trick without messing up the vac line.

I didnt even think of that. It took me 30 minutes to get it off. I really babied it though.

 

[J Banning]

Originally posted by GrndNatnl
...Banning, did Scott find exact length studs or did he cut bolts to proper length? Didnt catch that when lookin at his motor the other day.

We cut to length. Only took a few minutes with the cutoff wheel and bench grinder.

 

[GrndNatnl]

I'll see what I can find as far as hardware. If I go the bolt cutting route, maybe one of you guys can give me a hand?