How long does it idle before fouling a plug? Assuming (correct me if I'm wrong) it starts to run on seven cylinders, will the plug clean up if you run the engine at high revs (Italian tune-up) for a while?

9 hours ago, Mark Maras said:

it starts to run on seven cylinders

YES! We drive V8's... He means 5... oohh...😀

 Brain fade. I've spent the last week working on my brother's 31 Model A Hot Rod with a 350 Chevy in it.

On 3/17/2024 at 6:55 PM, Mark Maras said:

How long does it idle before fouling a plug? Assuming (correct me if I'm wrong) it starts to run on seven cylinders, will the plug clean up if you run the engine at high revs (Italian tune-up) for a while?

4th plug from right to left still fouls. Im ready to open this engine. Idle gets rough during traffic and clears up once accelerating. Any other thing to consider before breaking the engine?

 

Refresh my memory. What were the compression readings the last time you did a compression test? Was #4 lower than the others?

Time to pull that head off where you can see what is going on IMHO.

10 minutes ago, Mark Maras said:

Refresh my memory. What were the compression readings the last time you did a compression test? Was #4 lower than the others?

All were almost equal. 

2 hours ago, Yarb said:

Time to pull that head off where you can see what is going on IMHO.

Any gaskets i should purchase in advance prior to opening the head?

I would pull the head first have it evaluated at a machine shop and go from there.

At least ill need the parts and gaskets before opening the head. Most of these parts are not available in Panama so i think its smarter to have them ready.

Yeah, get the parts you need and pull that engine apart.. very interesting to see what the problem is..  Although the compression looks good it could be some broken rings on your No: 4 piston or something like that..
Can't wait for the pictures!  I would have taken it apart years ago.. just start to do it, you learn A LOT!  And... ASK if you don't know exactly how to do something like opening up a engine!  And remember, pictures can tell more than a 1000 words so put a pic with your questions!

I ones had to open up a 300zx engine, it was a non turbo z32.. my dealer told me YOU CAN'T DO THAT!  I told him "you don't know what i CAN!  I brought it to the dealer because i had an accident at work and was very ill..  then the dealer wrecked the engine by making a "testride" It had a timingbeld problem..

I took it apart AT THE DEALER and repaired it all,It costed me 1600-2000 guilders. (Then about 1000 dollars..)  This was in 2001... the car is still on the road today!! 

Is there any other test that i should perform before i open it? 

One of the mechanics i used has dealt with MG su carbs and has always told me there is a problem inside the engine. He told me he could help me open the head and take it to a local machine shop here for rectifying. He asked me to get a full overhaul gasket kit. 

https://zcardepot.com/products/cylinder-head-gasket-kit-set-240z-260z-280z

Any other thing i shall consider? Any additional tests prior to this?