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Assume you have a component closer to an exhaust pipe than you would like. Still have a 3-4 inches of separation and air flow around but are concerned enough to want additional protection. You have a flexible wrap around high temp insulation material having a foil sheet on one side and the insulating substance on the other.

Would you wrap the exhaust pipe several inches before and after the component? If so, which side facing the pipe or ----
would you wrap the component instead and have the foil facing out to reflect the heat or ----
would you make some kind of sheet metal shield separating the two components as was done on fuel pumps. If that option, leave it plain or apply the insulation facing the exhaust.

Howard, it would be helpful to know exactly which component you're talking about, it might affect the answer.

In general, you want to get rid of the heat, not just 'Block' its transmission. So, a piece of sheet steel strategically placed between the two parts with air space between them is probably the best bet. For added protection, you can wrap the *Other*, mystery part.

I wouldn't wrap the exhaust pipe itself, the heat build up could cause problems in the pipe, or even a fire.

I don't know that I'd be too concerned about judicious exhaust header insulating causing the potential for a hazard or damage to pipes & mufflers; prewar senior cars (some with wooden floor boards) used several different exhaust pipe (NOT tail pipe) insulating methods, the primary intention of which was to minimize heat from getting to the passenger compartment. Depending on the year, the Eights & Super Eights used an exhaust header wrap of asbestos (we use an alternative today, see attached) between the manifold and the muffler, and the Twelves used a double-walled exhaust header filled with asbestos between the steel walls. Some models used heatshields between the muffler and floor board, and there were several service letters (around the 9th series) about tail pipe to gas tank clearances.

I'll dig up some pictures.

PS - looked to see if I had a good picture of the factory exhaust head insulation, but don't. I could take one if there is any interest.

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Master cylinder. The original Packard location for BTV had entire unit about 4-5 inches away from the L exhaust manifold it's entire length. The location I'm currently playing with for a modern setup has the end about 3-4 inches away from the exhaust pipe. The majority of the cylinder is actually farther away from heat than the original but If I keep this arrangement, still want to take heat into consideration.

EDIT: Thanks Dave. I looked into that type wrap from Restoration Supply and almost decided on it. Found a material from McMaster that looked a bit easier to work with so went with that instead.

Perhaps a piece of 1/16 or 1/8" aluminum sheet which you contour into a heat shield midway between the two parts.

I agree with bigkev about the aluminum heat shield. It should be shiny and spaced far enough away to allow air circulation.

Some years back I had a wood stove in an old farm house. The stove was about a foot from a wooden wainscot wall. I made a heat shield out of 1/16 aluminum sheet, unpainted. Spaced it 3" from the wall.

With the stove quite hot, too hot to hold your hand within 6" of it the wall behind the heat shield was ice cold.

I don't mean literally ice cold, but it felt that way in contrast to the stove side. I couldn't believe how well the aluminum reflected, absorbed and dissipated the heat.

If you can arrange your heat shield so it scoops up air while the car is moving so much the better. The shield should be big enough to shield an area several inches bigger than the master cylinder.

Howard, there's a loss of efficiency when brake fluid heats up, be careful here. I'd go with the sheet steel/aluminium as well as wrap the master itself.