Plug Gap?

mikesc

Registered User
I am in the process of putting my engine back into my ride ('90Bird) and was wondering what the plug gap should be. I've seen anything from .039 to .050 listed on this board I know it should be based on the mods that are present on the car, so here's a list.

Morana Stage Three Block & Heads (stock grind on cam)
1.8:1 Rollers
76mm MAF
75mm T/B
38# injectors
255 lph Fuel pump
MPII S/C, MP Inlet Plenum, 10% od pulley
OEM Plug wires & plugs (pp-34's)
Ported exhaust manifolds
DynoMax resonator, superturbos
EEC tuner (next week?)
No money in my bank account.

Anybody have any suggestions? I e-mailed Tom Morana but have yet to recieve an answer. I would like to find out before I put the motor in. (possibly today)

Thanks in advance,

Mike
 
Mike,

The wider you can keep the gap the better it is. Start with stock gap (.054 ) and if it doesn't miss under max boost, leave it alone. I have the same plugs in my car now gapped at .045.

BTW, why are you keeping the stock cam ?

David
 
Cam

It's on the advice of Tom M. According to him it's better for maintaining the proper amount of vacuum, and I can recoupe performance increases using the 1.8's.

Mike
 
I've been thinking about going to a step colder copper plugs, and gapping them at about .45 I've got the double plats right now gapped about .54 Any thoughts on that, or does it not really matter?

Thomas
 
Thomas,

Unless your getting detonation or missing under boost, gapping them tighter and going to a plug that is shorter to simulate a range colder, won't help and may hurt performance.

If you want a good plug try the NGK Iridiums #TR55-1IX standard length or TR55-IX short tip. Gap both at .045. I like the standard length.

David
 
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