engine clearance

Ive had my chassis & body made, mounted. what is a good clearance measurement of engine to firewall for a glass body. as mine is real close! 4mm on left side head. how much heat can glass take?

 

That is pretty tight, but I only have about a half inch between the back header tube and the firewall on my 27 and the paint has never burned or discolored. My body is fiberglass too. A head doesn't get over 180 degrees or so and a header tube gets a lot hotter, so you should be ok.

Don

You can sort of see how close the rear tube is in this picture.

 

You could use either polished SS plate or the chrome tape (even thinner!) to reflect the heat away from the closest region.

 

thanks, that's good to know!

 

Heat is not the only issue here. The engine shouldn't move fore and aft very far on its mountings, nowhere near as much as laterally or rotationally about the crank axis, but 4mm might still be cutting it a bit fine. I wouldn't be quite comfortable with 4mm of clearance between an engine-driven fan and a radiator, for instance. And then, of course, things flex with road contours and expand and contract with heat. I'd expect the engine to touch the firewall sooner or later.

 

that's what I think, ill be speeking to the shop who I paid $$$ to have this not my issue. Im going to have to fix it as im not having it that close. at this stage I think its easier to move engine & gearbox mounts.

 

Safe operating temperature for fiberglass is around 1000* F (540*C) if either your engine or engine compartment is reaching those temperatures then you have bigger problems to solve.

 

should be easy to notch---what is an mm ?

 

maybe for the raw glass. Not the cheap resin used to make car bodies. If they used polyester resin and a room temp cure you maybe have 200F before damage begins

 

I made a plenum box for the top of a Holley double pumper out of polyester resin and woving/cloth. It was for my '64 XKE coupe that had a Ford 302. There was little room for a conventional air cleaner. I mounted a remote K&N filter. The plenum box held up fine...even on a trip to LA and back (800 miles). Sometimes the water temp reached 210, especiall going up the grapevine into the LA basin.