SpinMonster

As always, before getting into this write-up, I would like to ask each person reading to know a big part of my motivation is the St. Jude’s fundraising effort on this board. I don’t think its much of a reach to understand why this cause is so important but unless you suffer such a painful loss as a result of a childhood destroyed by various illnesses I don’t think you could see it from the point of view of it happening to your world. The loss of a child changes you forever and I will never be able to relay the pain associated with it. Take a moment and send 20 bucks to this charity. We have the means to send robots to mars so I believe we can beat cancer, sudden infant death, and form new medications.
I have a dream.....that one day it will say St Jude's Donor under everyone's name.

---------------Make a difference TODAY------------------
How to donate:

1) Personal checks, cashier checks, or money orders, made out to: St. Jude Children's Hospital and mailed to "pewter99,":

Robert Briggs
P.O. Box 17083
Clearwater Fl 33762

Please put your forum name on the memo line of the check

2) paypal: corvettes4stjude@aol.com

3) Go to:
https://waystohelp.stjude.org/sjVPor...9&programId=51
Follow promts, we get credit for this method.

Okie...to the issue at hand:

Long ago in the land of LS2edit (another tuning platform), many tuners trying their best to tame a big cam didnt know that HPtuners was available with base running minimum airflow tables that could take care of idle surging. To remedy the problem he promises you that everyone is drilling holes in the TB blade to get more air in. He lied. Tar and feather him later.

The holes that did in fact help would be something like 3/16" and not the mouse-hole sized thing he puts on it that you can pass a Jelly-bean through. In my porting days, I had to reject such TB's that were sent to me as a core. I told the potential customer that all is not lost because i could send him a ported TB and take his as a core but the core he got from me would be a repaired hole. I did this repair long ago and it withstands lots of boost, nitrous, fuel, and meth blowing past it.

IS THIS ANOTHER GOOP PLUG?

Heck no! I learned my lesson and stepped up to the plate covering that rediculous recall losing lots of money to shipping costs.

This time around the epoxy of choice is none other than JB Kwik. It is a faster curing version of JB Weld and has about 1/2 of its tensile strength (only 2000lbs instead of 4000lbs) and most of the other properties as per the JB website are the same. It is resistant to fuel, meth, oil, ect.

This is what it looks like in the package at 4 bucks from your local Walmart...aka Slavemart:


BUT WAIT SPIN, I DONT NEED A TUTORIAL ON GLUING THINGS

In my middle age, I dont take anything at face value and I never assume anyone is up to the task just because he has bravery with or without common sense.

A few pointers:

In order to keep the plug from popping out and getting eaten by your engine, you should first make the hole flared quite a big more than the original opening. This gives the plug a sort of rivet shape so it has more surface to bite the TB plate.

You flare it out to about 1/2 inch like this:


Other side:


You then mix up some JB....about this much:


Then you put it on the hole overlapping the opening by a bit like this:


With it about 1/32" tall and not pushing down as you apply it, put some masking tape over the protruding JB like this (you want some thickness here so it will have good strength and we will sand it down later to be perfectly level with the blade:


Now flip 'er over and you see this:


Add more JB to this side and smooth it outbut leave some height to it for strength like this. We will sand this side too later:


It cures in about 5 minutes but wait a few hours before you sand it for best results. This is what the side that had the tape looks like after its cured and the tape is removed:


Using a pad sander and going slow so it doesnt dig in it will go level like this. Now as you cuss me out, be aware that this stuff dries really hard and the sanding will not be a few seconds. It moves material away slow and is rock/metal hard.


this plug cant come out because its flared on both sides and the plug holds itself in, unable to come out because it doesnt fit through the smaller hole that is at its center.

When you replace the TB blade in the TB, place the blade in and dont tighten the little screws down until you press on the blade at the extreme closed position to center it. Then with red locktite, tighten them until snug and dont strip them.

OK all better and no more hole. You can then tune properly and not be ashamed to send the unit in for porting or whatever.

If anyone needs help, I'd be glad to do this for free. Just pop in a few bucks to cover the JB and return shipping.

BlackC6LS3

Good tip

JB is awesome stuff. I ported an intake for a friend about 5 years ago and ended up taking off too much meat in one area. I JB Kwiked the spot and it has help up the 5 years, 50K miles and 15lbs of boost without issue.

Robls6

Why not just weld it up instead? I don't think I would want to chance that filler falling out and getting into the engine.

sxeC7

I think the problem with welding would be distorsion from the heat required, since the plate has have a close fit. Cold joining is the way to go, as most of the Vette is put together that way.

PowerLabs

I am sure this works fine, but JB is mostly intended as an adhesive and not really a filler. Which is why you need the tape on the other side, for example...
Although this is not a high stress application let me point out that using a metal-filled putty always ends up much stronger when you have to fill in voids like that.
Here is a good example of one:


Also don't forget to clean the surface to be bonded with Isopropyl alcohol / denatured alcohol or acetone in order to remove any traces of oils from your hand. A single fingerprint can remove almost all the bond strength of an adhesive

Mez

Epoxy will work fine if the hole is tapered from both sides and the surface is rough and free of oil & dust.

Since I don't have a mig/tig welder, I've been playing around with brazing aluminum. There are aluminum brazing rods that melt at low temp using a propane torch. Very tough stuff and sticks very well to aluminum.

Just do a search on YouTube "brazing aluminum" for a demo. >>>
BRAZING ALUMINUM

The issue of heat distortion is a real one but the throttle plate is pretty thick so it may not be a problem if its tig welded. But I have not tried it so I don't have any first hand experience here.

knkali

nice write up Spin. Thanks

Robls6

you could easilly TIG that hole up without worry of warping the part.

SpinMonster

Most guys dont have a tig welder.

drivinfast

Even if you have a tig welder, do YOU want to weld your TB blade, if you mess up just a little bit, where are you gonna get a new blade. no place i know of...

SpinMonster

My fix as listed in this thread is time tested and works. No need to keep trying to improve on what doenst need it.