Any of you guys that are running Edlebrock Performer RPM heads on your big block, I am curious what plugs you are running and what gap.

I'm running Autolite 3926 with a .042 gap
10.2/1 compression, Isky rr620 solid roller, Holley 950 HP

Gaz

3924s with GM alums. FR3LS are the best I've found so far. Don't rightly know whether the 3924s are hotter or colder than the 3926s.

Thanks 427L88, anyone else ? No one running Performer RPM's on your BBC's ?

Originally posted by Gazzer:
Thanks 427L88, anyone else ? No one running Performer RPM's on your BBC's ? =

The 496 I just took off the dyno with Ede "rovals" has Champion RC12YC's which is a 5/8" hex smaller plug.
I use them in a lot of aftermarket street SB & BB applications with no problems.
And they are cheap :D

Mike,
Is that the 496 your building for a certain magazine? If so, can you tell the dyno results?

Mitch

I'm running the high compression version of those heads. Champion RC12YC or NGK FR45 is a good plug at a low cost. For the Champion you can also use the RC12YC-5 which is a wider gap version.

If you want a fancy plug there's the NGK BKR4EIX (hot) or BKR5EIX (a little colder) that's a $7/ea Iridium plug. Probably won't run any different than the regular copper plug though.

/Markus

Gazzer,
According to the GMPP catalog they use #4 Rapid Fire Gap .045 , R43XLS Gap .045 on thier ZZ502.

The ZZ454 uses MR43T Gap.045 , #10 Rapid Fire Gap .045.

Both engines use the same "390" head.

GM heads are identical to Eddy's but have bigger valves. I believe Edelbrock actually casts the heads for GM (?).
Mitch

Originally posted by hamrdown:
Mike,
Is that the 496 your building for a certain magazine? If so, can you tell the dyno results?

Mitch =

Pretty simple basic bolt together deal, 489, Ede 60459 roval heads, Ede 5062 cam .527/.553, 224/232, 114 lsa, 109 icl. I believe it's called the Torker Plus, RPM intake, 1413 800cfm Ede carb, Probe rotating assembly.
Carb was great at part throttle like hi 13's, low 14's & pig rich under power like 10.5 - 11.4 (AFR)
Timing was 36 degrees, 10.8 compression
numbers were:
2800 - 267 - 501
3000 - 306 - 519
3500 - 359 - 538
4000 - 427 - 547
4500 - 460 - 538
5000 - 480 - 514
5500 - 478 - 456

The compression was higher than planned but the parts were as supplied & I just supplied the machine work & dyno time along with profiling the cam & flowing the heads etc.
Cam was advertised as 302/304 but measured a surprising 285/288 at .006. The rest of the numbers were right on.

Heads were 315 on the good "port" & 307 on the "bad" port. Heres the 'bad" port, I don't have the "good" one in front of me.
050 - 38/ 31
.100 - 74/ 64
.200 - 146/119
.300 - 218/150
.400 - 260/179
.500 - 291/207
.600 - 307/229
.700 - 302/245

Mike, what are chances of dynoing that combo with Edelbrock 's 2261 hyd. roller cam ?

Originally posted by jay:
Mike, what are chances of dynoing that combo with Edelbrock 's 2261 hyd. roller cam ? Slim to none :D

BTW, what the hell is a 2261?? Post the specs with the cam so we don't have to go look it up ;)

If I can talk the powers that be into it I wouldn't mind doing a Brodix RR head test at some time but I ain't holdin my breath,,

Thanks All,
I'm not really seeing any issues with the 3926's that I'm running, but I am always certainly open
to trying different ones.

Gaz