Allcoupedup

Plasticman,
The AC45's above had at least 500 miles (they were in it before I got it) and the AC43's got the next 500 miles or so. No other changes except a clean air tube on the motor and an oil change. There is no smoke upon firing it up cold.

Thanks
allcoupedup

SWCDuke

Hmmm. I now realize that the plugs are from the same engine. When I made those comments in my original post I didn't pick that up. Plug heat range will not affect oil consumption, but will affect whether the oil deposits remain on the insulator or burn off. The R43 was not operating hot enough to burn off the deposits, but the R45 is. The metal shell temperature remains about the same regardless of plug heat range, which primarily impacts the insulator temperture, so I'm surprised at the difference between the deposits on the two shells. Maybe the original poster can tell up his oil consumption and how many miles those plugs accumulated before he took the photos. Short trips can also lead to black deposit buildup due to the rich mixture from cold operation, but carbon deposits from rich mixtures are usually dry looking, not wet.

Prior to replacing the valve guides and seals on my Cosworth Vega last year it was consuming a quart of oil every 100-200 miles, but it didn't foul the NGK TR5 plugs nor the Denso T22EP-U (two heat ranges colder) that I use for hot-lapping. After the head refresh with modern nickel-bronze guides and positive viton seals the oil consumption dropped to so little I can hardly measure it because of low mileage accumulation- maybe a quart every 4000 to 5000 miles.

Duke

Plasticman

Duke,

Agree with you, except that if the engine is misfiring due to the oil fouling, then the metal shell would remain oily black, whereas when the plug is firing properly (and burning off the deposits), then the metal shell will look dry & black).

Allcoupedup,

Still maintain that what you are seeing is the result of valve guide oil drip. Oil does not suddenly appear and then disappear in a combustion chamber. Your choices are rings or guides (or a poorly sealed intake manifold, but you have not indicated anything to make me think that is the "problem"), and like I said before, have seen a lot of Chevy guides that wear enough for this to occur. It could be rings, but Chevy guides wear quicker under normal circumstances than do the rings. Since you have gone back to the 45 heat range, the problem is moot at this point, but if and when you do tear down the engine, don't be surprised to see a caked up mess on the back of the intake valves (that is robbing the engine of power).

Have you ever done a compression test, or perferably a leakdown test to determine engine "seal" condition?

Plasticman


[Modified by Plasticman, 12:10 AM 3/18/2003]

Cris

I posted earlier, my 43's looked exactly the same as allcoupedup's plugs. If I have an oil problem, it isn't obvious. The car blows no smoke at start-up, even if it has been sitting for two weeks, and no smoke under any acceleration/deceleration conditions. Seems I should see something if there is that much oil on the plugs. I even had my ferrari-owning neighbor come over and comment how he nevers sees any blue smoke appear when I fire the Vette up after a long hiatus (I think he's jealous).

This stuff on the plugs isn't really oily, it has the consistency of WD-40. But there is no gas smell. When I first looked at my plugs I thought it must be oil, but I just can't find evidence of a problem. I won't rule out an oil problem (I did find some loose intake manifold bolts), but could it be anything else??

Allcoupedup

Plasticman,
here's the results of the compression test
1: 165
3: 170
5: 170
7: 152 (170 w/oil)
2: 174
4: 176
6: 170
8: 175

(plasticman - we discussed results similar to this a few months back - I think you even offered some assistance in nailing down that low cylinder - its getting warm out I may take you up on that offer! I'd love to be an understudy. :D )

I have NO history on this car and the carb needs a rebuild (have a rebuilt one waiting to go on).

The AC 43 plugs got just over 900 miles - 850 of them were highway @ 3000 RPM and the last 50 were put putting around town and the last six starts or so were 10 minute warm-ups in the garage - the last few times it was difficult to start and missed on at least one cylinder. I attribute most of the wetness to my stinking carb but for the oil?... I dunno - I'm going to cross my fingers and hope my new set of AC 45's looks like the set I removed earlier.

Thanks
Allcoupedup

Plasticman

Allcoupedup,

Remember the discussion and offer well. Just needed to be reminded what the results were (and if you had done a leakdown test). I have a leakdown tester, so bring it on over and we will start from there. That should identify the problem with the one low cylinder, and if there are any valve problems.

My previous experiance is that the valves don't seal all that well when the guides are really worn, and sometimes read good/sometimes leak due to the guide wear (valve stem wears as well, and the guide wear is not linear, but tapered with more at the top and bottom of the guide, hence the valve will rock back and forth with the seat/valve interface becoming somewhat rounded). At any rate, head repair is a lot easier than rings. We will see what we see and go from there. As for using the 45's, I agree completely that is the best way to go right now, and we will hope for the best.

Send me an E-Mail, and I'll supply directions + phone number. Although next few days look kind of wet! Timing is pretty much open for the next few months at any rate.

Maybe we can start up an Illinois chapter of the CCC!

Plasticman


[Modified by Plasticman, 5:11 PM 3/18/2003]

tuxedo

Hey plasticman' I have never had a leak down test done to my car. I will drive up from Texas to take advantage of your services see ya soon. Seriously you and allcoupedup have fun. Good Luck

Plasticman

Tux,

Come on up! Just bring some of that Lone Star with you!

Plasticman

Frank.luvstingrays

Hello I was surprised when I replaced my spark plugs..
I first got (7) R45S in a R43S labeled box's yeah and (1) was the in the correct box really flip me out.. then I notice it's a AC R44S in the car my 69 book said R44 anyway..
not sure but i think the plugs are about 15 yrs old or so...and dame they look really good! I thought it was running rich too.
I brought back the R45S plugs i'm thinking I shouldn't have...time will tell.
Anyway in the stock manual you get from GM when you buy a new car..says R44 are std - R45 highway driving and R43 for heavy duty..
does anybody know when AC changed to ACDelco??
Peace
Frank

Steve439

It'S BAAAAACK!!!!!

I'd start a new thread...

vettsplit 63

I actually have more friends ask for Ziggy

MiguelsC2

Who dug this corpse up?

Chuck Gongloff

Unbelievable.

Yet ANOTHER 2003 thread dug up. This is the 2nd or 3rd that I'm aware of over the past 2 weeks or so.

I proposed it before, and I'll say it again....


Mr. Moderator.

these old threads should be locked and archived.

Chuck

Mike Ward

Looks like it's one of those d*mn C3 guys. You know what they're like.

tuxnharley

I'm not sure I understand your concern. People are ALWAYS being told to "use the search function" instead of starting a new thread. In this case that's exactly what Frank.luvstingrays did, and now he's getting slammed for it? What's the problem?

abe g

I have a 63swc with 340 hp, 4 speed manual. Presently have 45R plugs with enough mileage to consider plug change. Question: Some time ago Corvette America filled an order for this car with 43R plugs. Can My short haul driving (no long trips) replace the 45s with those 43s? I want to avoid pulling present plug if not necessary. Your comments appreciated. Regards, Abe G

Chuck Gongloff

I think that it's wonderful that folks use the search function for research. It's great to read up on things that had been previously discussed. It's great to see how problems have been solved in the past.

BUT....to resurrect an 8 year old thread to me is a bit over the top. Although I didn't check this thread's participants, I wonder how many of them are still here?

I'll grant you a year or two, but IMHO, 8 years is WAY too long.

As is done on some other forums, old threads should be "archived". They can be read and researched, but they cannot be posted to.

Chuck

MikeM

Send the 43's back to whereever they came from and don't take your current plugs out as long as the engine runs smooth and doesn't misfire at the speeds you drive it at.

tuxnharley

OK, got it, I understand your position. One thing's for sure - you are right about the participants! SWCDuke is no longer here by his own choice - sadly for the rest of us!

MiguelsC2

Couldn't hurt to clean and gap them though.