May Day !! Down a cylinder
 

Alright class racer mechanics. I need some help. I am down a cylinder. Nber 7 keeps fouling plug. I have changed plugs wire cap dist. I did a leak down got about 1 percent leakage. Compression is 165lbs all cylinders I pulled the intake and fitted it last night.
I connected a plug to wire and it is firing at the cylinder.
The cam loves and lifters are fine.

Any idea?? There is several of us scratching our heads on this one.

I put 170 lbs air straight to cylinder it ha no leakage out valves

Re: May Day !! Down a cylinder
 

Intake valve guide or seal on that cylinder. Sounds like a properly sealed engine. If the intake or heads were very mismatched, it would have affected other cylinders as well.

Re: May Day !! Down a cylinder
 

Sounds like a leaky valve guide, you could put a little hotter spark plug in that cylinder to burn off the oil.

Re: May Day !! Down a cylinder
 

Chuck we changed plugs and wires several times. I am thinking guide but if guide was wore it would show in leak down?
This is the new head we did fix. I busted one at gators.
Mb is gonna post up pic of plugs for me. I sent him pic of 1 and 7 plug so y'all could see

Re: May Day !! Down a cylinder
 

Running with a temp gun number 7 never gets within 200 degrees of other cylinders.

Re: May Day !! Down a cylinder
 

Posting for Phil:
https://fbcdn-sphotos-d-a.akamaihd.n...85858693_n.jpg

Re: May Day !! Down a cylinder
 

Thanks Michael. That is 1 and 7 plug I changed number 7 that is one run on that plug.

Re: May Day !! Down a cylinder
 

Does your cam have any of the cylinders swapped? I had two plug wires swapped on the dyno and the engine sounded decent but kept fouling out a plug. Also, what kind of top piston ring are you running? My plugs looked like that all the time when I ran a gapless top.

Re: May Day !! Down a cylinder
 

Cam is norm firing order. All plugs look like 1 except 7. 7 doesn't never get hot like the rest. Head scratcher I have wore bald spots in my head since Friday.

Re: May Day !! Down a cylinder
 

Give me your phone number so we can talk about it, PM or otherwise! Rick Brown

Re: May Day !! Down a cylinder
 

Hey Sparkie, check to make sure that you didn't suck an intake gasket into the port!

Re: May Day !! Down a cylinder
 

Jeff Taylor Is gonna dyno it and figure it for me if I can't get it. He treats me like family. I always feel like I am bugging him. I can't get there till thurs so I am trying to fix it myself. I have sent him all the info I gathered yesterday I will see what he thinks. He takes time out if his business to teach me things over the phone.

Mike T another class racer engine guy has spent countless hours with me giving me info.

I appreciate all you guys do for me. I love turning wrenches. It's something I really don't mind.
Frustrating sometimes but I wouldn't trade this stuff for nuttin!!

Re: May Day !! Down a cylinder
 

Billy I changed intake gaskets Friday night when I took heads off to check all gaskets!! I am like literally 5 minutes away from pulling the heads off. An just checking valves.

This is a new old head. When I left Florida I had a busted casting.

Re: May Day !! Down a cylinder
 

try another new pug in 7 u might have a bad plug---- or swap 7 plug with another cylinder see if it moves---you just might have a cracked plug tho--FED 387

Re: May Day !! Down a cylinder
 

859 743 1859.

Re: May Day !! Down a cylinder
 

We tried 17 different plugs we sapped wires around we put new in wire cap everything. I worked all night Friday at Indy changing ing everything even carbs.

Only thing I didn't swap is the head from one side to the other. That might happen today.

Re: May Day !! Down a cylinder
 

Collapsed sealed power/speed pro style oil ring expander will do that and still show good leak . Just a thought ------

Re: May Day !! Down a cylinder
 

I can't take it lol. He's is off we are headed to peel son valves check some guides. Number 7 piston looks like it did when it came out of box clean as a pin. Other cyl have little black carbon on them from where they have fired.

Re: May Day !! Down a cylinder
 

What does the intake port look like on that cylinder. It could be a small crack or sand pit in the head casting allowing oil to be pulled in to that cylinder. You could do a vacuum check on that port if your machine shop has that type of equipment. You could have a problem with the oil ring in that hole too. It will leak check good even if the oil ring is not sealed. The expander could be lapped over.

Re: May Day !! Down a cylinder
 

Phil, is the plug gas fouled (stinks of gas) or oil fouled (you may smell some gas residue but no stronger smell than the other 7 cylinders)? My guess is an overlapped oil ring expander ( especially if it uses those damned Hastings Rings type of expander). Ron.

Re: May Day !! Down a cylinder
 

I believe it oil. It doesn't smell much like gas. I am headed to pressure check some things. Let u know Results shortly.

Re: May Day !! Down a cylinder
 

Just a question, How would a loose guide or bad valve seal show up in a leak down test?

Re: May Day !! Down a cylinder
 

I wouldn't think it would beings it's above the seat. Wouldn't the spring hold the valve in the seat good.
If I knew the answer I wouldn't be on here. I am going to tear into the head I don't find nothing obvious I will have the pistons on the bench before I sleep I promise.

Re: May Day !! Down a cylinder
 

agree with the oil ring problem

Re: May Day !! Down a cylinder
 

I think that is right next step,call me you need anything
Mike Taylor 3601

Re: May Day !! Down a cylinder
 

I had a broken expander on the oil ring and it pumped oil like crazy. Pull the piston and you will find the problem. Dyno

Re: May Day !! Down a cylinder
 

Did you say Speed Pro/ Sealed Power rings?
If they are:
Second ring installed upside down. Reverse twist is pushing oil up the cylinder.
Second choice would be the oil ring expander overlapped.
Have you rotated the firing order on the cap to be sure that there is one firing
cycle that is dead? I had a HEI kick my butt like that!!

Re: May Day !! Down a cylinder
 

What distributor do you have in it?

Re: May Day !! Down a cylinder
 

Check valve springs on that cylinder.

Re: May Day !! Down a cylinder
 

I have total seal rings. i have msd ignition I have changed every piece of it. I have done everything most has named twice. the piston is clean as a pin guys. there is no oil ,if a ring was bad enough to foul my plugs wouldnt you think there would be oil on top of piston.


i really appreciate all the advise but I am throwing in the towel for a couple days. I have some concrete to get poured now the rain is over.

hopefully be back in action by norwalk!

Re: May Day !! Down a cylinder
 

Don't give up!!!! Put that thing back together and run it on 7 cylinders. I've seen you do more drastic things than that!!!

Re: May Day !! Down a cylinder
 

Phil,
Probaly dial the same on 7 or 8 cylinders LOL
Mike Taylor 3601

Re: May Day !! Down a cylinder
 

Just a thought. The PCV isn't hooked to a vac. port on that runner is it ?

Re: May Day !! Down a cylinder
 

That picture on my phone looks more rich than oil.

Re: May Day !! Down a cylinder
 

I got rained out today so i decided to do some more work. I glued the crap out of intake and put it back like it was. i fired it and was pretty much the same. I loosened the rockers ran it withem loose for a few and then adjusted on them while running. Somehow someway My cylinders are burning the plug looks great now. I beat it up and down the road for a bit and seemed to be running good.

Re: May Day !! Down a cylinder
 

Where's the "Hell Yeah" button?

Re: May Day !! Down a cylinder
 

x2 !!!

Re: May Day !! Down a cylinder
 

maybe a stuck lifter. Glad its fixed, Good luck in Columbus

Re: May Day !! Down a cylinder
 

So, what did you find? How did you have such a great cylinder leakage percentage with a valve hanging open? Was the lifter bottomed out to the point where the valve only closed with room temperature non-expanded parts,( i.e valve stem and pushrod) and was held off its seat when things hit operating temperature? If loosening the lash did this, that must have been the case. Hope your concrete project turns out as nice.

Re: May Day !! Down a cylinder
 

Good Luck, Phil! I'll try and look you up tomorrow.