Best spark plugs for a stock ZR-1 - ZR-1 Net Registry Forums

voxdeidave · 10-12-2010

Ok....I'm new to the whole LT5 thing, and I've heard alot of differing opinions. So I'll put it out to the forums.....what are your favorite plugs for a stock ZR-1?
(I'm working on a bone stock '91)
Thanks,
Dave

scholtmj · 10-12-2010

Whatever plugs you get, make sure they are the correct style. 93+ heads used tapered seat spark plugs instead of flat ones. There is a one time 'over-torque' you can perform on the early heads to create the taper, but I don't have that number handy.

Aurora40 · 10-12-2010

For a '91 with the flat seat, I used this NGK iridium plug:

BKR7EIX-11

if I had it to do over again, I'd go with BKR6EIX-11 which is not as cold of a plug. I think it's too cold for the daily driving I do, sometimes the low throttle action gets a bit rough. Some will say "open her up more", but I can't always do that.

NGK recommends the BKR5EIX-11, but I've heard some of the stock recommendations are too warm of a plug and can cause knock when driving aggressively.

White Bullet · 10-12-2010

Call me old fashioned but I prefer the stock plug with the stock motor (ac delco).

10-12-2010	#1
voxdeidave Join Date: Sep 2010 Location: Saylorsburg, PA Posts: 50	Best spark plugs for a stock ZR-1 Ok....I'm new to the whole LT5 thing, and I've heard alot of differing opinions. So I'll put it out to the forums.....what are your favorite plugs for a stock ZR-1? (I'm working on a bone stock '91) Thanks, Dave __________________ [B][I][SIZE=3]Dave Macbeth[/SIZE][/I][/B] 1991 ZR-1 #384 1969 MGB OD, Pertronix, Monza 1972 MGB project Life should be filled with classy music and fast cars!

10-12-2010	#2
scholtmj Join Date: Nov 2008 Location: Grand Rapids, MI Posts: 384	Re: Best spark plugs for a stock ZR-1 Whatever plugs you get, make sure they are the correct style. 93+ heads used tapered seat spark plugs instead of flat ones. There is a one time 'over-torque' you can perform on the early heads to create the taper, but I don't have that number handy.

10-12-2010	#3
Aurora40 Join Date: May 2005 Location: Leesburg, VA Posts: 2,713	Re: Best spark plugs for a stock ZR-1 For a '91 with the flat seat, I used this NGK iridium plug: BKR7EIX-11 if I had it to do over again, I'd go with BKR6EIX-11 which is not as cold of a plug. I think it's too cold for the daily driving I do, sometimes the low throttle action gets a bit rough. Some will say "open her up more", but I can't always do that. NGK recommends the BKR5EIX-11, but I've heard some of the stock recommendations are too warm of a plug and can cause knock when driving aggressively. __________________ Bob Saveland Former owner of #2517 [IMG]http://a.random-image.net/aurora40/vette.jpg[/img]

10-12-2010	#4
White Bullet Join Date: Apr 2008 Location: Gainesville GA Posts: 232	Re: Best spark plugs for a stock ZR-1 Call me old fashioned but I prefer the stock plug with the stock motor (ac delco). __________________ 1991 ZR1, White/Red.