what spark plugs are you guys using?

[32valvZ]

are the NGK BKR5EIX the plugs of choice on a stock engine?:icon_scra

[Jeffvette]

Yep, I run the iridium plugs on my car and customer cars. Plug # 6341 for your car.

[Aurora40]

I believe I'm using the BKR7EIX. Keep in mind the '90-92 plugs have a different seat than the '93-95 plugs when comparing part numbers.

[Polo-1]

NGK # R5671A-10 for the 125 shot.

[flyin ryan]

NGK # R5671A-10 for the 125 shot.with that cold of a plug you could run a 400 sniff without worry you'll lose a plug. wow that's cold:jawdrop:

[flyin ryan]

Yep, I run the iridium plugs on my car and customer cars. Plug # 6341 for your car.:iamwithst Jeff's 100%. 90-92's NGK stock no: 6341=BKR5EIX. on 93-95 NGK stock no: 7164=TR55IX. these would be more for stock or close to stock applications. on 90-92's in a pinch you could use NGK FR5's too.

[Jeffvette]

NGK # R5671A-10 for the 125 shot.

Why are you running them when you haven't sprayed yet..... Has the bottle even been filled yet ? :icon_scra

[Polo-1]

OOPPS
NGK #FR5's for the 125 shot and 10's for the 150 pill.
Just what others are running.
From the NGK web the 10's are only 2 sets colder. Plug are not fouled, must be ok to run. I dont need a hot plug for smog.

[tomtom72]

Noobie Q.

Does it really make a difference which plug in a stock LT5? I use the ac delco replacement for the FR2LS plugs that came in my 90.

TIA
:cheers:
Tom

[32valvZ]

Ok, cool. I already spent the $70. on them!! Gapping at .050...correct?

[Bob G]

Autolite 3933 Gapped At .032

[Polo-1]

Why are you running them when you haven't sprayed yet..... Has the bottle even been filled yet ? :icon_scra

It's on it's second bottle with the small jet;)

[ZR1Vette]

Ok, cool. I already spent the $70. on them!! Gapping at .050...correct?

Gap...depends on which plug:

NGK IX iridium (javascript:glos('Iridium','0','1')) 6341 BKR5EIX .050"ZR-1 Submodel

or

ACDelco 41-602 (standard plug) .042"

This site has excellent prices and you can see the variety of plugs for the ZR-1 (chart is for MY90)
http://www.sparkplugs.com/results_app.asp?productTypeID=1&AAIA=1041275

Michael

[bldavis11]

I just used the regular NGKs (like every other vehicle). I will want to change the plugs before the irridium's service life is up, so I figured I would just be wasting money. I like tinkering with the car, so it's one more thing for me to do. All of 10 bucks or so for the plugs. JMO.

[Zr1 Destroyer]

Autolite 3933 Gapped At .032Yep...that's all i've ever used with NO issues and they're cheap too!:dancing

[karterdon]

I do believe that the stock gap is .035 - why would you run a larger gap then that. The ignition system was not designed for that large of a gap. It makes no difference whether you run iridium, platinum or stock. I still would suggest the stock gap unless you have boosted the ignition system.
:)

[Jeffvette]

I do believe that the stock gap is .035 - why would you run a larger gap then that. The ignition system was not designed for that large of a gap. It makes no difference whether you run iridium, platinum or stock. I still would suggest the stock gap unless you have boosted the ignition system.
:)

The '90-'92 LT5's use the FR2LS (now replaced by #41-602) plug and were factory gapped at .035. The '93-'95 LT5's had some changes done to boost the HP to 405 used a tapered platinum plug, Bosch #41-913 and was gapped from the factory at .050. Some owners claim that re-gapping the '90-'92 plugs to .050 gives them better performance. The draw back is that the plugs don't last as long and should be replaced every 10,000 miles. An alternative is to purchase platinum plugs which will give you longer spark plug life for your '90-'92 ZR-1 and gapped them at .050

[32valvZ]

Ok, so....whats a better gap for me to go with on my 92 with Iridium plugs? Will I get a better burn if I go back to the .035....or somewhere in between, say, .040-.045 :icon_scra

[Jeffvette]

Go for whatever you feel comfortable with. But I will suggest a .040 gap.

Be very careful with the iridium tip.

[32valvZ]

I think I'll do that. Heres a pic of the "goods" you sent Jeff! :cheers:

http://i32.photobucket.com/albums/d45/Johnny-Mo/DSCF4520.jpg

[Jeffvette]

What happened to the nifty plug wire number collars I put on?

[bldavis11]

I can't tell if those are the stock plug wires or not. I think I see some of the LT-5 lettering though. If they are stock, I would replace them while you have the plenum off. If they aren't new, then I would consider the same. Otherwise I'll just go back to my little hole. :)

[Jeffvette]

I can't tell if those are the stock plug wires or not. I think I see some of the LT-5 lettering though. If they are stock, I would replace them while you have the plenum off. If they aren't new, then I would consider the same. Otherwise I'll just go back to my little hole. :)

They are stock replacements. The lettering says AC-Delco.

[ZR1Vette]

The picture reminds me of a question I have had.. I always see the coolant hoses being replaced (Samco or otherwise) that are forward of the engine... have there been any issues with the two hoses buried under the plenum and seen in this pic amidships of the plenum area? Just asking so when the time to replace the injectors and I have plenum off I can replace or not.

Thanks
Michael

[32valvZ]

What happened to the nifty plug wire number collars I put on?

I think you got me mixed up with someone else....I didnt buy the wires from you......Previous owner replaced them last May 07, so I kept them. He only put a couple thousand miles on the car since replacement.

[32valvZ]

The picture reminds me of a question I have had.. I always see the coolant hoses being replaced (Samco or otherwise) that are forward of the engine... have there been any issues with the two hoses buried under the plenum and seen in this pic amidships of the plenum area? Just asking so when the time to replace the injectors and I have plenum off I can replace or not.

Thanks
Michael

Hey Michael, the two hoses under the plenum are the breather box hoses. They only have air moving through them. Its part of the PCV system. As far as problems, I only dicovered that mine seemed a little hard. I asked about them here & was told I could get new ones at a pretty tidy price....or just reuse them. I elected to do the latter. They will be fine considering thier function.

The box that they are protruding from is called the breather box. It has a gasket between it & the valley floor. I found all of the bolts finger tight & a leaking gasket. In turn that had a good amount of oil on the valley floor. I replaced the gasket & loctited the bolts as advised from a member here.

[4DSZR1]

... They only have air moving through them. Its part of the PCV system. ......new ones at a pretty tidy price....or just reuse them. I elected to do the latter. They will be fine considering thier function...

I haven't removed my plenum but have seen a couple and have always wanted to ask. Could you find a couple radiator hoses with correct diameter that has a 90 degree bend and then cut it to fit? Somebody has had to of tried this.

[32valvZ]

I haven't removed my plenum but have seen a couple and have always wanted to ask. Could you find a couple radiator hoses with correct diameter that has a 90 degree bend and then cut it to fit? Somebody has had to of tried this.


I imagine you could....but the passenger side hose has a slight jog in it in addition to the 90* angle....so that one may be harder to match up.

[ZR1Vette]

Thanks guy... there you have it... newbie learns something new already again. Now I will concern myself less about those two hoses being cooling fluid carriers ;)
Michael

[bradslt5]

I haven't removed my plenum but have seen a couple and have always wanted to ask. Could you find a couple radiator hoses with correct diameter that has a 90 degree bend and then cut it to fit? Somebody has had to of tried this.yes i have done this both hose s for A TOTAL OF 12 DOLLARS i wish i kept the napa number . you could do a search of my past posts or on my other name that i used previously jonszr1 . it gives the napa number that makes both vent hoses out of one hose . its really rude that someone would charge42 dollars each for these . i also have posted a hose replacement for the bottem water pump hose for 20 . just reuse the spring . sure beats 85 dollars . i am sorry i havent kept the numbers (OLD GUY THAT HAS c.r.s). I KNOW THEY ARE IN MY PAST POSTS .

[32valvZ]

Ok, I tried the plugs gapped at .040 :thumbsdo: Not good. The first thing I noticed was a much rougher cold idle.....next, when I blipped the throttle, it had a dead spot. Drove onto dinner & came home, put them back at .050 much better throttle respose when it was hot. Tomorrow, I'll check it when its cold again, but I suspect it will be good like it was before when I had them at .050.

Maybe the thin air up at this altitude contributed to this????

[Jeffvette]

Interesting, I'd be playing around with the altitude issues.

[kenthompson]

I think I'll do that. Heres a pic of the "goods" you sent Jeff! :cheers:

http://i32.photobucket.com/albums/d45/Johnny-Mo/DSCF4520.jpg

For some reason, this just makes me want to go do a plenum pull.

[Paul Workman]

I just used the regular NGKs (like every other vehicle). I will want to change the plugs before the irridium's service life is up, so I figured I would just be wasting money. I like tinkering with the car, so it's one more thing for me to do. All of 10 bucks or so for the plugs. JMO.
Yep, according to who's doing the spec quoting, the platinum (P) plugs will last 3 times longer for a given set of conditions than standard plugs. And, the irridium coated plugs will run a little longer still. But, I think of plugs in three phases of life: New, OKay, and the "borrowed time" phase. I respect what Jeffvette recommends - I figure he knows what he's talking about. However, it occurs to me that if one's LT5 spends most of it's life on the highway, it would take a lot longer to burn out a set of Ps, and, as you pointed out, one would have to suffer plugs running in the "borrowed time" phase of their life a lot longer to take advantage of their added initial cost.

Considering all this, and the fact that at 5k miles or less a year it would take me 6 years before I even got close to burning a set of Ps out, and a tank of gas is as much (or more?) than a new set of Ps...what the heck???

Although I fully appreciate your position, I bought the AC/Delco 41-800 platinum plugs anyway (they were available, a little cheaper, and I was impatient). Like you I love to tinker anyway and 4-5 years down the road I hope to be able to save up enough :wink: for a new set and prolly never break out of that "NEW" phase of the plugs.

http://198.208.187.182/internet/VehiclePartDescription.jsp?selectedfld=&application=Car%2FLight+Duty+Truck&year=1990&make=CHEVROLET&model=CORVETTE+ZR-1&engine=V8+5.7L+350cid+GAS+FI+N+Engine+VIN+%3D+J+++ +++&productline=25&part=7212

P.

[72ZR1]

Yep, I run the iridium plugs on my car and customer cars. Plug # 6341 for your car.
i went to parts store and ngk.com said to use plug #5464 BKR5EIX-11 not #6341 for my 90. what ones should i use?:dontknow:

[XfireZ51]

I settled on the NGK BKR6, a step colder than the stock plug. The BKR7s were a bit too cold. They're gapped at .040". Looking at the ground strap and after some plug cuts, the 6s were just about right. BTW, I'm with bldavis on using regular NGKs.:dancing