Sealing Firewall

[Mark]

Took a drive this AM and discovered a massive amount of exhaust gases entering the cockpit through the seam between firewall and the frame.

What are the best ways to keep the gases out yet ensure the firewall is easily removealbe (ie, no sealants)? Same for the tunnel where the ZF calbles and the coolant pipes run.

Am in process of covering engine with lexan and sealing off carbs. That's going to make a lot more gases available to leak into the cockpit so want ot fix problem now.

With Webers, what is best way to rounte valve cover gases (most of the gases leaking into cockpit) back into motor versus just filtering and venting?

Thanx
Mark

 

[Seymour Snerd]

What are the best ways to keep the gases out yet ensure the firewall is easily removealbe (ie, no sealants)? Same for the tunnel where the ZF calbles and the coolant pipes run.

For access panels I like adhesive closed-cell window-sealing foam (the grey stuff you can get at home depot). Same for the rear window. Where the cables run through the frame I've used plain old black RTV. The coolant pipes shouldn't be a problem since they just run through the tunnel. But each of the two smaller (~6" x 8") sheet metal panels at the bottom of the seat back need to be sealed, and I made panels to seal at the far right and left (eg where the shifter rod goes through on a sill-shifter car).

 

[Kevin L]

Don't forget the round holes in the cross beam. Those are open to the cockpit and need to be sealed using closed cell foam.

 

[Grady]

DON'T use a can of expanding foam. I saw two cars at Olthoffs on Friday that someone had tried to seal using this method. When you have to go back in to work in those areas it is a mess to remove.

 

[mark b.]

might be able to find something here

Raw Materials from Aircraft Spruce

 

[Seymour Snerd]

Don't forget the round holes in the cross beam. Those are open to the cockpit and need to be sealed using closed cell foam.

Good catch; I'd forgotten about those. Kevin how did you do that on yours, exactly; just stuff the ~1.5" holes with foam? Has anyone found a good plug for those holes? I found a mediocre plastic one at McMaster, but it doesn't fit tightly.

 

[Doug S.]

You might check with Rick Muck (MKIV) and see if his company offers a sealing kit for this purpose. They stock quite a few items of that nature.

Cheers!

Doug

 

[Seymour Snerd]

You might check with Rick Muck (MKIV) and see if his company offers a sealing kit for this purpose. They stock quite a few items of that nature.

Good suggestion, but being a Rick Muck acolyte I own everything (almost) he sells. But let's turn that into a suggestion: Hey Rick, feel like making up some plugs or some other method for sealing off the shoulder belt bar?

 

[Kevin L]

Good catch; I'd forgotten about those. Kevin how did you do that on yours, exactly; just stuff the ~1.5" holes with foam? Has anyone found a good plug for those holes? I found a mediocre plastic one at McMaster, but it doesn't fit tightly.

I used (after following Olthoff's lead) exactly as you said, 1.5" foam cut in a circle, stuffed it down there. Seems to work pretty well to keep it sealed up. Used something similar to this:

Minicel closed cell kayak foam

 

[Doug S.]

Same stuff I use for fitting my kayaks...makes a world of difference in how the boat responds to paddle strokes. I can attest that it is incredibly tough and durable. I have some kayaks that are 15 years old and they still have the same minicell foam pillars they came with, and I use and abuse them!

Cheers!

Doug

 

[Seymour Snerd]

Minicel closed cell kayak foam

Cool looking stuff; Thanks! I just ordered a 2" x 12" x 48" piece. Also might make good insulation for my Olthoff deeper firewall, in case my crazy spray-in foam idea doesn't work out (more on that later, I hope :lipsrsealed. I also ordered some 1-7/8" metal plugs from McMaster that might work better than my last attempt. Will report back.

 

[Grady]

CAPLUG Company makes plastic plugs the will fill the holes nicely.

 

[Seymour Snerd]

CAPLUG Company makes plastic plugs the will fill the holes nicely.

Just ordered 20 of BP-1-78 from Anson Industries in TX, 713-271-2344 for a whole $5 (their minimum)

Thank you, Grady! :thumbsup:

 

[Seymour Snerd]

Just ordered 20 of BP-1-78 from *************** in TX, 713-271-2344 for a whole $5 (their minimum)

Sorry, the company name is STAR SALES phone number as stated.

Anson Industries is also a Caplug distributor, but they have not called me back yet. Their number is 817-226-3044

Both are in Texas.

 

[Doug S.]

713 is a Houston area code. I drive through Houston on a regular basis. I'll have to look them up sometime!

Cheers!

Doug