Spark plug heat shields - worth doing?
 

I have an L31 engine with Ram style exhaust that Im am putting into my 66 and as I was looking at videos on how to install intake and exhaust manifolds on a 350 I saw this and I wondered if its worth doing? I had headers on an older 350 I had before and it was just plain old plug wires arranged in there with nothing fancy going on.

Re: Spark plug heat shields - worth doing?
 

I don't have the shields on mine and have no issues that I know of. Wonder what the idea behind them are?

Re: Spark plug heat shields - worth doing?
 

It;s been shown that the heat shields reduce the temperature of the surrounding area the plugs and wires are placed in from exhaust manifolds and reduced temperatures equate to longer life of the part since heat related breakdown of the material they are made from is reduced.
Paul Jr @ GMCPauls

Re: Spark plug heat shields - worth doing?
 

Heat shields were standard OEM on V8's from the factory.

Make sure you get the style that will fit the RAM horn manifolds...

They are not all the same...

:chevy::chevy::chevy:

Re: Spark plug heat shields - worth doing?
 

Yes.
Anything that keeps the heat away from your plug wires is a good thing.
GM wouldn't have bothered putting them on if they weren't necessary. Why would they waste the money?
If you don"t care about looking stock, you could always use plug wire boots.
https://image.crov.com/pd8-DVqZvSFNm...-454-black.jpg
Either way, protecting your wires from the intense heat of those manifolds is a great idea.
Just my opinion
-Russ

Re: Spark plug heat shields - worth doing?
 

I would like to find the oem looking ones that I assume are in the photos I posted. It does look a little cramped to work with the plug though with that there. But if it prolongs the life of the wires I will start shopping and see what the price difference is in boots vs the ram style shields..if I can find them.

Re: Spark plug heat shields - worth doing?
 

I made the mistake of pulling mine off when one broke. Ran for miles until I had a miss.

Turns out melt my Accel Super stock wires in a couple spots. They are inexpensive and worth it.

Re: Spark plug heat shields - worth doing?
 

I remembered reading once that there is even a performance benefit to shielding the wires and plugs. I googled that thought and came up with this article by a vendor. They mention it around the fourth paragraph. https://www.heatshieldproducts.com/b...boot-protector

Re: Spark plug heat shields - worth doing?
 

Thanks AcampoDave! This is the part they mentioned that helped explain its not a melting concern only..

"Complete burn-through is not the only problem to consider when looking at spark plug wire heat shields. Whenever a wire that conducts electrical energy is exposed to high heat, the resistance of that wire increases. That means it takes more time for the energy to travel through the wire, and a certain amount of the energy is restricted and never actually reaches the spark plug."

I'm looking around now for a set of the oem type that will work with my set up.

Re: Spark plug heat shields - worth doing?
 

There’s a bunch of different styles but it all depends on how you’ll bolt them to the block.
Does your motor have the drilled bosses in the right locations?
Being a newer motor there might not be any.

Re: Spark plug heat shields - worth doing?
 

I saw these from another member

http://forum.ih8mud.com/attachments/...ds-jpg.124440/


and it looks like my block has the bolt holes for it, I think they look close to lining up right. Here is mine.

Re: Spark plug heat shields - worth doing?
 

Well heck, since you got the the whole topic back in my brain again...I guess I'm looking for some for my ramhorns too.

Re: Spark plug heat shields - worth doing?
 

Lot’s of ideas and links here.


https://www.google.com/search?tbm=is...bADBQMQ4dUDCAY

Re: Spark plug heat shields - worth doing?
 

Thanks Geezer.
I found these for 25 bucks at classic parts. I've had good transactions with them before.
https://www.classicparts.com/1957-72...ctinfo/83-389/

Re: Spark plug heat shields - worth doing?
 

Thanks guys, Ive got these on my list at Classic too. Hoping for a labor day coupon code so Ill hold out a bit. The style in the first pic I posted I think are for a corvette. I dont know if that upward point helps any more with heat absorption. Probably not enough to worry about.

Off topic but I needed to order a door felt kit too and Im thinking to give Classic a try

https://www.classicparts.com/1964-66...tinfo/03-636/#

I called and they did say the bead on the window felt was stainless. Hoping for a good fit.

Re: Spark plug heat shields - worth doing?
 

The uptilted one is to provide for the temp sender. Mine is in the inake manifold so I don't forsee any problems.

Re: Spark plug heat shields - worth doing?
 

What size thread is that boss supposed to be? I can't find anything that fits, but it could just be because of paint. I thought I'd chase the threads with my 1/4-20 tap, but since you're all here, I thought I'd ask first.

Re: Spark plug heat shields - worth doing?
 

I tried a 1/4-20 x 1/2 and it threaded well. If any can say it's any different please chime in.

Re: Spark plug heat shields - worth doing?
 

I did it, I got those things installed without removing the manfolds. I did it mostly by feel and It was only a bit of a bear. I used a 1/4 inch drive palm ratchet to snug the bolts and then torqued them with a ratcheting dogbone wrench. For my bolts I just used some old timing cover bolts with a captive lockwasher

Re: Spark plug heat shields - worth doing?
 

Good deal, were they from Classic Parts? They look like they will be a good fit.

Re: Spark plug heat shields - worth doing?
 

When I actually placed the order, I mistakenly bought them from Classic Industries. An unrelated company with a very similar looking website. They were the same as the ones I assumed I was ordering from Classic Parts and the order went withiut a hitch. Quality was decent.

Re: Spark plug heat shields - worth doing?
 

The passenger side rear heat shield cutout doesn't line up with the oil dipstick tube on my roller cam vortec head engine. Sure wanted to use all four of these
Maybe I will use the front left on a corvette, be better than nothing. Might have to trim it just a bit.
https://www.zip-corvette.com/media/c...i/s/is-319.jpg

Here is my Engine and dipstick passenger side.

Re: Spark plug heat shields - worth doing?
 

Can you do a little trimming and make it work?
BTW, it looks like a nice price. What is the year and application for this one?

Re: Spark plug heat shields - worth doing?
 

Yes it is a "68-75 Left Front Spark Plug Inner Heat Shield". That's shown in post #1 of this thread. To my door Zip Corvette was the best price I found.
My plan is to dremel out the slot needed for the dip-stick tube, shouldn't look too bad.
The real PITA is keeping the dual wire bracket from moving on the front two cylinder heat shields when tightening down. ;)

Re: Spark plug heat shields - worth doing?
 

Well it doesn't fit. The mount bracket and hole sit a good 3/4 to one inch too far forward. In fact the stock units don't fit that particular (right rear) hole either. :(