BeachinVette

The other day I hammered on the car hard...
It immediately let me know it did not like that. We limped home 4-5 blocks away. The car definately had a miss to it. I pulled plug wires till I found one that made no differance and replaced it. The end of the plug had no gapthe end was touching the center. (they were cheap Delco plugs) I bought some Bosch Platinums and put them in today. (slow at work) 3 more plugs were bent,,, but not closed very close though. I gapped these plugs before I put them in about a month ago when I was still putting the car together. The previous owner said this engine had been rebuilt 40,000 miles before it was wrecked and parked in storage. Do I have some wrist pins or bearings that have play enough to hit the end of the plugs??? or can to much fuel in the cylinders do this??? I did have a problem with a stuck secondary float when I put the Holley on it the otherday it flooded bad. Actually caught the car on fire.. Could the pressure of raw fuel do this to plugs???

Thanks for your help
Bob

Matt Gruber

i've never had this happen.
Are you sure they are the correct plugs for the heads?
I've never seen a "cheap Delco plug" either. Are they dupes made in China?

BeachinVette

Drives61
I got them at the auto parts store and had the guy look them up. By cheap I meant $1.19 a plug compared to the $2.45 per plug for the Platinums. I compared them with the new plugs and they are the same length. a different parts guy looked these up and handed them to me. The car is running great. very smooth very powerful. no knocks no hessitation(PS). I am very affraid to put my foot in it. :cry I cannot afford to have to rebuilt the engine I am trying to get all the bugs out so I can paint it. I have never seen plugs do that..
The numbers on the ACdelco=R45TS
Bosch Platinums =4208

Thanks Bob

MasterDave

Sounds to me like the heads may have been changed and you've put the long threaded plugs in where they should be the shorter ones. If this is not the case it's possible that the head was shaved too much. Put an extra flat washer under the plug; uh, if they're not the tapered 'peanut' plugs that is. It would be an interesting job making 8 little tapered spacers for your plugs. I did have a spacer once for my dirt bike, just in case I got stuck in the desert and the only one I could get was the long threaded one. Just slipped it over the spacer and plugged it in. :yesnod:

BeachinVette

MasterDave
These are short plugs.. I do not know if head work was done on the car But I will get some of the plug washers to put on them. I hope to rebuild the engine in the fall so I hope this will help preserve my piston tops. I would think that someone would have to have been drunk to shave the heads that much to hit the plugs :eek:
Thanks
Bob

MasterDave

I agree Red, but it's the ONLY thing I can think of. The only thing that would bend a plug end would be the piston. Hey!! Use the gapless plugs, there is no ground end on those......stroke of genius here..... :lol:

BeachinVette

I have never heard of those.. I`ll just cut the ends off mine :cheers:

Bob

Paul L

The "S" in the R45TS indicates a plug with the extended tip. So you do not have the short plugs. But that still does not explain your problem.

robert kirk

had this problem on a dirt car. motor was a 350 30 over about 12 to 1 comp.we ended up having to index all the plugs. it is easier to do this with the heads off but can be done with the heads on. high comp with a rich mixture will cause this at high rpm. set the plug where the last thread lines up with the last thread in the head when tight. also we set the curve in the electrode straight up on all plugs. this cured the prob. we turned that motor to 8200 and never had a prob again. just my 02 hope it helps you robert

427V8

OOOOo Very very bad. I would NOT drive the car till I knew whay it was happening!

Also if it IS hitting the piston ( and it is) why is it only happening on three clyinders and only when you 'hammer on it' !! :eek:

Bad rod bearing?
Bad wrist pin?

BeachinVette

427V8
I was`nt looking for that kind of reply!!!! :nonod: :nonod: :nonod: :sad:

I know I`m going to keep my foot out of it. but I need to drive it for a couple of months. I will just baby it.

Tnks
Bob

427V8

Is this a stock engine? or has it been worked on?

If it is not stock you should not be using stock plugs!:boxing

Higher compression pistons, different heads or head milling will change plug requirements...

MasterDave

Too funny dude, no really, there are plugs called 'surface gap' that are flat with a ceramic spacer btwn the electrode and the outer rim. Use 'em on outboards all the time. I've used them on my dirt bike and they are great and foul less than the std's.

BeachinVette

It is stock as far as I know. it was well taken care of by the first owner the second owner only drove it for 4 months then totaled it. It sat in a storage building for four years till I found it. Nothing looked modified at all. I did some dress up on it when I had it out that is all, I plan to put some HP in this fall. I just don`t have the funds now. Plus my wife would kill me it has been taking garage space all of it for 8 months while I replaced the frame and front clip bushings ect.. Long list. I just put a plate on it last week so I can drive it to work.

Bob

Chuck Harmon

If the car had been driven too slowly, it may have formed large carbon deposits on the piston tops which could be banging your plugs. Carbon is loosened up by making a few hard passes with a car aka "blowing the carbon out" which sounds like what you did. The plugs may even have been bent by loose pieces caught between the piston and plug before they were blown out of the motor. Try spraying some Dupont #7 carb cleaner, or similar, into the motor while the engine is running. It really gets the crud out.

I can't imagine your stock engine closing plugs due to any combustion situation. The plugs are hitting something!

If you have a loose wrist pin or bearings, you should be able to hear knock with a stethoscope from the pan side of the engine. (A long screw driver or wooden hammer handle work just as well)
Good luck to you. This is the kind of stuff that causes one's stomach to more than churn!

Chuck




[Modified by Chuck Harmon, 11:08 PM 2/10/2002]

utahrookie

Compression will not change your plug gap. Have you looked down the spark plug hole and inspected your pistons for damage? I'd keep it parked until I got the correct size plugs installed. Other wise you could be looking at another rebuild. :cry
good luck

vert2go89

I would suggest pulling the pan and checking the rod bearings and crank for wear and damage.I would think if it was rod bearings then you would have a knock sound.Rod bearings are not that expensive and checking and replacing is a lot better than having an engine destroyed.I had slight tapping sound and not all the time on m/c I had.I sold it and guy was romping on it hard.Pistons hit the heads and blew the bottom case apart.Rod and crank bearings were bad and caused the damage.

paso

BoB, Chuck Harmons answer about the carbon is very good. I have seen it many times. Even a piece of carbon breaking off almost always finds it's way to the spark plug. Bends the tip. :)

redvetracr

76Red,
"If" you really need them Mr Gasket sells "index washers" for peanut plugs. .....redvetracr

john's '81 mouse

Agree that it's probably carbon or the wrong/too long of a spark plug.........No way could this be bad wrist pins, or rod bearings, not without a very noticeable knock/noise from engine.

If carbon, start engine up, let it warm up, remove air cleaner, then use a spray water bottle and spray water / mist into carb. while reviing engine, this will blow the carbon out. Just don't spray so much that you kill the engine.