ADA Girdled Head BR8HS Spark Plugs?

[joshp]

Through searching the forums it looks like ADA girdled heads call for an ES rather than the shorther HS thread. Has ADA ever made a head that requires HS plug (shorter shaft)? Is there any reason why HS would be used rather than ES? Is there any harm in running HS plugs?

 

[augustaf]

No serious harm, just 20 psi lower compression.......

 

[joshp]

No serious harm, just 20 psi lower compression.......

Thanks. Would 20 psi make the difference between pump gas and racing fuel? PSI I think was 150 when I did compression test.

My question maybe be an oversimplication based on other threads I've read but figured might as well ask.

 

[Big Kahuna]

Run ES

 

[DAG]

Are you really not going to spend $2.50 for the correct spark plugs. C'mon man!

 

[TheBuzzard]

i got cases of HS plugs and just started running those instead of ES on the advice of senor. been using HS the last 2 days with my 2mm over 701 ported motor and ada head 190 psi . I notice no difference and it rips like always. short reach plug will lose you a couple CCs in the dome and that will lower compression a few lbs.