Need help choosing the right spark plug
Thread Starter
Instructor
Joined: Mar 2009
Posts: 190
Likes: 0
From: Langhorne PA
Need help choosing the right spark plug
Hey guys, I need some help choosing the right spark plug for my 1981 Corvette. I wanted to get your opinions on what to use. Here is a little information on my motor.
Stock 1981 Corvette motor and transmission, the motor was just rebuilt only reusing the stock block, intake, carb, valve covers, pulleys, fan and oil pan, still has the erg (if i should put an erg block off please let me know) is there advantage to this? smog pump and manifolds removed, and has long tube headers with 2.5 inch pipe back.
Motor rebuild:
1968 350, 350HP cam with matching lifters and pushrods from compcam
1.5 roller rockers
STD bore flat top pistons (sightly higher compression I think it went from 8.2:1 to 9.2:1) might be wrong though, not exactly sure how much more flat top pistons add, its been a while but remember the builder telling something along those lines.
eagle crank
high volume oil pump
dart replacement heads 200cc doms
new gaskets, timing chain excetra
advanced timing to 12 degrees
Stock 1981 Corvette motor and transmission, the motor was just rebuilt only reusing the stock block, intake, carb, valve covers, pulleys, fan and oil pan, still has the erg (if i should put an erg block off please let me know) is there advantage to this? smog pump and manifolds removed, and has long tube headers with 2.5 inch pipe back.
Motor rebuild:
1968 350, 350HP cam with matching lifters and pushrods from compcam
1.5 roller rockers
STD bore flat top pistons (sightly higher compression I think it went from 8.2:1 to 9.2:1) might be wrong though, not exactly sure how much more flat top pistons add, its been a while but remember the builder telling something along those lines.
eagle crank
high volume oil pump
dart replacement heads 200cc doms
new gaskets, timing chain excetra
advanced timing to 12 degrees
Melting Slicks
Joined: May 2002
Posts: 2,431
Likes: 52
From: Florida
I
http://www.dartheads.com/dartboard/s...ead.php?t=2674
http://www.chevytalk.org/fusionbb/sh...php?tid/20477/
Hey guys, I need some help choosing the right spark plug for my 1981 Corvette. I wanted to get your opinions on what to use. Here is a little information on my motor.
Stock 1981 Corvette motor and transmission, the motor was just rebuilt only reusing the stock block, intake, carb, valve covers, pulleys, fan and oil pan, still has the erg (if i should put an erg block off please let me know) is there advantage to this? smog pump and manifolds removed, and has long tube headers with 2.5 inch pipe back.
Motor rebuild:
1968 350, 350HP cam with matching lifters and pushrods from compcam
1.5 roller rockers
STD bore flat top pistons (sightly higher compression I think it went from 8.2:1 to 9.2:1) might be wrong though, not exactly sure how much more flat top pistons add, its been a while but remember the builder telling something along those lines.
eagle crank
high volume oil pump
dart replacement heads 200cc doms
new gaskets, timing chain excetra
advanced timing to 12 degrees
Stock 1981 Corvette motor and transmission, the motor was just rebuilt only reusing the stock block, intake, carb, valve covers, pulleys, fan and oil pan, still has the erg (if i should put an erg block off please let me know) is there advantage to this? smog pump and manifolds removed, and has long tube headers with 2.5 inch pipe back.
Motor rebuild:
1968 350, 350HP cam with matching lifters and pushrods from compcam
1.5 roller rockers
STD bore flat top pistons (sightly higher compression I think it went from 8.2:1 to 9.2:1) might be wrong though, not exactly sure how much more flat top pistons add, its been a while but remember the builder telling something along those lines.
eagle crank
high volume oil pump
dart replacement heads 200cc doms
new gaskets, timing chain excetra
advanced timing to 12 degrees
http://www.chevytalk.org/fusionbb/sh...php?tid/20477/
Last edited by jimvette999; May 4, 2015 at 04:43 PM. Reason: post invalid, misunderstood head type, posting links to other sources
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
NGK 5 or 6 heat range. I use 6 in some of the hotter cylinders, 7 and 8 mainly. Higher the number the colder the plug for NGK.
Here is a chart to decode an NGK plug.
http://www.ngksparkplugs.com/techinf...tnumberkey.pdf
I run BKR5E or 6E. running a .045 gap with HEI recently. Seems to work.
Here is a chart to decode an NGK plug.
http://www.ngksparkplugs.com/techinf...tnumberkey.pdf
I run BKR5E or 6E. running a .045 gap with HEI recently. Seems to work.
Thread Starter
Instructor
Joined: Mar 2009
Posts: 190
Likes: 0
From: Langhorne PA
Ended up going with the NGK UR5IX Iridium Plug. I found out that the dart head I have uses a 460 reach taper seat plug so I couldn't use the BKR5E. It was too long of a plug for the head. I ended up using the stock AC Delco R45TS plug and cross referencing it to the NGK BPR4FS plug, then talked to a tech at NGK who got me the part number for a plug one degree cooler with the 460 reach taper seat specs.
Thank you everyone for the help.
Thank you everyone for the help.
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Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
Ended up going with the NGK UR5IX Iridium Plug. I found out that the dart head I have uses a 460 reach taper seat plug so I couldn't use the BKR5E. It was too long of a plug for the head. I ended up using the stock AC Delco R45TS plug and cross referencing it to the NGK BPR4FS plug, then talked to a tech at NGK who got me the part number for a plug one degree cooler with the 460 reach taper seat specs.
Thank you everyone for the help.
Thank you everyone for the help.
I think that is a fine wire electrode, might be good for flame propagation, should be interesting to see how long it lasts.
Thread Starter
Instructor
Joined: Mar 2009
Posts: 190
Likes: 0
From: Langhorne PA
will definitely keep you guys posted. they had the iridium one and the standard one, read reviews on both as far as longevity, and performance and decided to go with iridium. hopefully it doesn't go on me too fast. only put 400 and some miles on the car last year and have owned t for 7 years and only put a total of 800 miles on her. hardly drive it, usually sits and gets started every now and then only.