Jump to content
HybridZ

What is an angled plug?


Guest nwzeeman

Recommended Posts

Guest nwzeeman

Fairly new to chevy v8's and I've got the stock SBC heads (casting number 462624) onr my 350. I'm ready to buy headers but I've got to ask this stupid question...how do I know if the heads are for angled or straight plugs? The headers I've been looking at say they are either set up for angled or straight plugs, and I've never really figured out what the difference is or how to distinguish between the two. Thanks for any clarification. -Rod

Link to comment
Share on other sites

They are exactly what they are called. Straight plugs are perpedicular to the head. Angled plugs are about 20 degrees left or right of being perpedicular to the head. I'm not sure why there is such a thing as angled head plugs. I think they are for exhaust clearance on certain cars where the engine bay is really tight, like corvettes. If you see a picture of the two styles it becomes obvious. You can try looking at different head manufacturers and they may have a picture.

Link to comment
Share on other sites

When the first angle plug heads were introduced by Chevrolet, there was no real difference. Then, engineers moved the location of the plug towards the exhaust valve, which improved flame propagation. By moving the position of the

spark plug in “straight†heads, similar gains were realized. It was easier to move the spark plug closer to the exhaust valve via an angled plug, than by a straight plug.

Link to comment
Share on other sites

Yes, angle plugs can make more power, as long as they are moving the plug's firing tip closer to the exhaust valve, and yes, they can cause fitment issues with some styles of headers

 

Like anything else, it can be give and take. On most of my engines, the angled plugs make it easier to get to the plugs for changes etc.... with block-hugger headers, you normally have to ensure that they will fit properly ahead of time, depending on the design of the tubes for the end cylinders 1,7,2 and 8.

 

for the center cylinders, it make it easier because the plug is angled away from the primary tubes..... all a matter of preference really...

 

If a straight-plug head has the plugs moved closer to the exhaust valve, then it will realize the same performance benefit as an angled plug, but then you are getting the plugs closer to the center tubes which can make plug changes more interesting as well as increasing the likelihood that you may barbecue a wire boot.... Also keep in mind that if you are wanting to run larger tube headers, especially block-hugger style, the angle plug design will do a better job of keeping the plugs on the center cylinders clear of the header tubes, but may increase the likelihood that you will have interference on the end cylinders.....

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...