Intake manifold welding (on the car): Am I lazy doing it this way??

[69427]

I removed the plenum divider a few years ago to see if there was any resulting upper RPM power gain. According to my buttometer it may have helped. But, no pun intended, the idle quality really took a hit, probably from cylinders 5&7 interacting in the plenum. So, I want to weld a divider back into the plenum. Since I currently am out of ideas on how to remove more weight out of the car, I seem to have more time to be annoyed at noisy exhaust tubing and crappy idle quality.

I was getting ready to pull the intake off the engine, and then I got to thinking, can I just stuff rags in the runners, and tape off other internal surfaces to catch any weld spatter. The engine hasn't been started in months, so there shouldn't be any pooled gasoline in the ports. My biggest concern is just keeping the process crap-free, so I don't end up injesting some trash into the cylinders when I eventually start the engine again. I'm just looking for advice in case I'm neglecting something.

Thanks,
Mike

 

[Red77]

Mike,
If you have the ability to TIG weld in the divider, you could secure it with some small stitch welds and reduce the potential to get any mess into the engine. Make sure you ground as close as possible to your welds and maybe disconnect all the electrical around your distributor just in case some current tries to find a path through there. Disconnect the battery of course, but I'm sure you've done that already since it's been down for a few months. The big chicken in me would just pull the intake though to keep Murphy's Law at bay. I seem to have a hard time getting away with the short cuts...

 

[BBShark]

Matched the ports from my Ramjet intake to my heads doing what you describe. No welding but lots of aluminum shards from the burr. I used a urethane material that someone gave me that was super soft so you could use it like putty but you couldn't tear or shear it. Sort of like a really soft Stretch Armstrong (if you remember that). So i filled the intake port in the head with about 2" of the port entry exposed. It worked well. The shards of aluminum stuck to the urethane and I was able to pull it out as a unit when I was done.

What about making a piece and epoxying it in place? Maybe with some pins to hold in place?

 

[phantomjock]

JB Weld? There is also a Hi-Temp, but may not need that. Still fill the ports to keep drips out?

Cheers - Jim

 

[69427]

Thanks for the input, guys. I appreciate it. As much as I enjoy making performance/weight improvements to my car, I have an equal amount of dislike for spending time to repeat tasks or rectify my mistakes (given my track record of mistakes one would think I should be used to this by now). I have a TIG welder, and despite my being painfully slow when welding aluminum this way, this should be a small job.

And, thanks again. As much as I dread the gasket/sealant/coolant mess cleanup when pulling an intake, I suppose an upside would be the opportunity to look at the cam and lifters to see if everything is okay. I'm just trying to figure out what side of the fence I'm going to land on.

I also have to keep reminding myself that this is just a first world problem, and unimportant in the grand scheme of the universe.

 

[69427]

In the event that I happen to get a sudden burst of motivation and energy this spring, I thought it might be prudent to have a set of intake gaskets handy. I went on our favorite online auction site and I can't believe the price of the gaskets these days. Most are at least twice as expensive as I recall, and some are three times the old price. Thankfully I'm in no rush, so at least I can look around a bit before spending the money.