Catalytic converter and heat shields

[pagrunt]

When I first did true duals with cats (2.25", Catco universals with their own shields) I didn't have a heat shield on the drivers side & I never felt the floor get hot. But with this thread it has me thinking if I don't gut the universal Ebay (the spun type with the 4" body) should I bother witha drivers side heat shield.

 

[MrSony]

My 85 regal has a heatshield on the passenger side footwell.

 

[olds307 and 403]

I have to think it may have been a cost or less weight? My 81 Delta 88 had a pellet converter and a shield.

 

[kustomkyle]

From my experience, a heat shield on the floor is very necessary. Catalytic converters are going to have one on them, but you need something on the chassis side of the floor as well.

Carpeting is going to insulate to a certain extent, but not as much as you'll need. Working on my car, the carpet was out, the factory shield was gone, and catalytic converter was installed. I had a rubber floor mat on the passenger foot well, and after 5-10 minutes of driving, the rubber was cooking. Not melting/smoking, but giving off the smell. The floor (by touch) was well over 100 degrees. This was a later model reproduction catalytic converter, not plugged, no issues.

Something like Dynomat on the interior side might help, but keep in mind the factory heat shield is mounted on (4) pedestal type brackets with an air gap. I've been thinking about how to add a second one for dual exhaust, if I'm not mistaken the V8 cars had the exhaust on the right, V6 on the left, so maybe a V6 setup could be added to the driver side footwell (?).

 

[pagrunt]

I've been thinking about how to add a second one for dual exhaust, if I'm not mistaken the V8 cars had the exhaust on the right, V6 on the left, so maybe a V6 setup could be added to the driver side footwell (?).

All cars had the cat on the passenger side.

 

[DoubleV]

...keep in mind the factory heat shield is mounted on (4) pedestal type brackets with an air gap.

Yes that's what I find weird. I don't have those pedestals which means my car never came with a heat shield. My Gbody specialist friend of mine says all of his gbodys ( mostly 78-79's ) have a factory heat shield. Strange.

I was just going to use the heat shield from my 85 ( no cat on that car ) but I can't because the 78 doesn't have the factory mounts for it. Yes, I can cobble something up but I'm not going to do any sort cobbling, hacking, butchery on this car since its a very nice, unmolested car and I wanted to keep it that way.

 

[565bbchevy]

If it was me I would just make some steel stand offs that mimic the factory mounts and weld them on and it wouldn't look out of place.
Or cut the ones off your 85' and use those.

 

[tc1959]

The new Cat I put on my El Camino came with a shield on top of it.

 

[pagrunt]

Heres what you might want to keep in mind is what cat you'll be using. Most if not all direct replacement cats have shielding on both sides, universals may have the either one or both sides, spun type has none (not sure what kind of heat they make but personnally like to know.) The chemical reaction inside will create heat but with the improved catalyst the new may convert cooler than what was originally installed (I will make that comment as a theroy not fact) so the floor won't be getting as hot. Then again the shields may be fail safe incase the cat got too hot/failed & it was to protect the car floor. As I posted eailer I did not have a shield on the drivers side after going with true duals but the cats had shields until they rotted off (still never noticed heat.) For the shield, look at Summit, Jegs & the like for under car sheild that might just need a good spray adhesive to be put strait on the floor.

 

[motorheadmike]

Air is your friend as an insulator. Air is also your friend for dissipation of heat when moving. Creating a physical reflective barrier with an air pocket will work wonders for keeping the interior temps down, and not risk lighting your carpet on fire.

That said I have Catco cats on the wagon and they have lots of integral shielding - I added a lot more under the passenger's feet because I love my wife.