2013年5月2日 · I do not have a personal experience with UR4, but I think UR4 is the hottest plug that NGK makes. I have used 44's with good results, but now I use Brisk HOR17YTE-1 which is an extra projected tip plug. They have little more projection and therefore the plug is less likely to foul during idle and cruising. I am very happy with them. Hope this ...

2006年5月14日 · New NA 496 BBC 10.1 .675 lift solid roller Victor intake Demon 825 carb 781 heads. Low tension rings MSD 6 Recurved HEI intal timing 16 DEG. What NGK plug would be better UR4 or UR5? What are you using with same combo? I know the UR4 is hotter and the UR5 is like AC Delco R43TS plug which is...

2017年8月21日 · Im building a 454 9.5:1 in comp 241 oval port heads hyd roller 224 234@050 .558 .576 RPM intake with a holle 3310 750 cfm. Shall I start with ngk ur4 or ur5?

2009年5月25日 · Right now i'm running the ngk r5673-6. Is the UR4 a shorter style plug as well? The shorter plugs are great for header clearance. The UR4 is 2 steps hotter compaired to my current plug, and I would hate to make a just like that. I may try the same plug i have currently but in a projected tip and see how that goes before making a hotter plug change.

2008年9月2日 · Just bought new plugs there r45ts a/c delco's and they're to long. I was wondering what would be a good set of plugs that are shorter. I have the ngk s UR4's in there and they fit good but i just don't care for them. I have a 355 with a pro billet dist and msd box. thanks

2006年5月9日 · Is anyone using an NGK UR4 or any other 4? I was running the YR5 but due to my choppy cam and lots of idling with city driving,these things got pretty fouled. I'm considering going to a hotter plug. I know there are lots of other factors; timing, fuel mixture and things like that. You input would be great. Thanks

2013年10月16日 · 1972 402 asks for a NGK YR5 stock number 7052 1971 402 asks for a NGK UR4 #6630 I've run a lot of UR4s with my 781 head engines, like 'em. I never looked at the 1970 heads I bought a few weeks back to see what the spark plug size was

2023年9月9日 · Yes, NGK UR4 is similar to AC R45. The reason I went NGK was that I could not find short AC's. The threading matched the AC 43 I took to compare. My current motor is 69' 327 bored 30 over. It was fresh in 2002 as were the heads. Since then has continued to be seasonal/weekend driven. The cam is Comp XE274H.

2019年1月7日 · Accel 8199 seems to be a shorty plug that comes up as an alternative for the R45TS. OR NKG UR4 6630

2007年7月14日 · Ngk Ur4 . 1966 Chevelle 300 Deluxe Post, 327cu AFR180CC Street Eliminator, Voodoo, Harland Sharp 1.6 RR ...