Dyi heat shield

[david lo pan]

Had a buddy bend up some aluminum.

 

[Draker]

Does it flop around? Seems like it might be worth adding a support somewhere.

[david lo pan]

Well see, it's pretty stiff, my buddy said it's stiffer than 6061 al.

[racerx]

The only way to know if it holds up is install engine and take it for a spin and also at high speeds and bumps.  Other than that looks good.

[2wheel-lee]

Now you'll have to make sure the undersides of the carbs are clean, too!

 

Seriously, though, how are you going to test if that actually makes an improvement?

[HOGIE]

I like how it makes it possible to look beneath the carbs, keep that shit polished up

 

 

 

Do It YOurself    DIY change your title

[Stoffregen Motorsports]

Seriously, though, how are you going to test if that actually makes an improvement?

They work.

 

They help protect the fuel and air from radiant exhaust heat.

[david lo pan]

Yes diy.

[2wheel-lee]

They work.

 

They help protect the fuel and air from radiant exhaust heat.

 

How do you measure the effectiveness beyond just the theoretical benefits?

 

I'm curious because I'm considering using a heat shield in a similar applications, but I'm curious as to the best way to measure effectiveness. 

[mttam510]

Gold Foil FTW....great choice of heat shield, that shit is SOLID, have sold loads to raceteams over the years.  Make sure you keep that -10 line off the edge of the rear of your shield....that shit will saw a nice relief if you don't. 

[mttam510]

How do you measure the effectiveness beyond just the theoretical benefits?

 

I'm curious because I'm considering using a heat shield in a similar applications, but I'm curious as to the best way to measure effectiveness. 

put a temp probe under the carbs with and without the shield......see for yourself.  I imagine it will be a big Delta.

[david lo pan]

 

Already fixed

[Stoffregen Motorsports]

How do you measure the effectiveness beyond just the theoretical benefits?

 

I'm curious because I'm considering using a heat shield in a similar applications, but I'm curious as to the best way to measure effectiveness. 

Dyno with and without heat shield.

 

It's tough to replicate the under hood scenario, but you can get pretty close if you know what you're doing.

[KoHeartsGPA]

How do you measure the effectiveness beyond just the theoretical benefits?

 

I'm curious because I'm considering using a heat shield in a similar applications, but I'm curious as to the best way to measure effectiveness.

 

Stick your hand beneath the carbs while the engine hot and running....then do it with the heatshield on.

 

I made this one myself....$10...it works.

 

 

You're welcome.

[2wheel-lee]

Dyno with and without heat shield.

 

It's tough to replicate the under hood scenario, but you can get pretty close if you know what you're doing.

 

How much of a difference have you seen on a dyno with and without this kind of heat shield?

[shacks510]

I was having bad heat soak issues with my Mikunis. It was even worse once I took the stock mechanical fan off, due to the lack of constant moving air. Before, I would only have issues if I was sitting for a long period. Once the fan came off, the fuel would start to percolate within 10 minutes, even while driving. Fuel percolation = going nowhere. I had a electric pusher fan on the manifold side, so it was probably blocking some airflow through the radiator.

 

Having a short Mikuni manifold, it puts the carbs right over the exhaust. I made a shield out of some galvanized steel and aluminum band I had laying around. Mikuni manifold has two threaded bosses on the underside, so that's what the shield mounts to. The aluminum band reinforces the shield; it's rock solid. The shield has no extra heat barrier material. The steel itself does the job. Under the shield and the shield itself will be hot, above the shield is cold. I can touch the bottom of the carburetors and they are not even warm. Heat shields do work!!

 

Notice the dimples for the accelerator pump rods.

 

Mounting bolts

 

[Stoffregen Motorsports]

How much of a difference have you seen on a dyno with and without this kind of heat shield?

It depends on the engine, but it's noticeable. 5hp on a race KA24 with an air box completely isolating the air to the outside is one number that comes to mind.

[Stoffregen Motorsports]

I have seen tons of different mounting options. Using the 6mm screws on the intake only, usually results in broken screws. You need to hang them out at the edge near the opening of the carbs too, but when doing this, you need to mount it in a manner that doesn't add rigidity to the carbs, especially when using soft mounts.

 

One way to mount the heat shield, is to use an air cleaner backing plate (ITG) and mount it to that alone. The backing plate ties the carbs together too which is important when using soft mounts and a centerpull linkage.

[david lo pan]

Modified my redline centerpull for da mikuni's