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Author Topic:   burnt pistons???
bigcitycowboy
Member
posted September 17, 2003 08:35 PM
i currently burned 2 pistons really bad on my new motor. the motor had less than 10 hrs on it. it burned #4 and #6 really bad, down by the spark plug. my question is, is it my timing or something else, or combination of things? and why only those 2 cylinders and so bad? any help greatly apperciated.


bettylewis70h
Member
posted September 17, 2003 09:20 PM
thx betty, just seems weird how only 2 on one side burned up, i dunno, but thx


way2fast
Member
posted September 18, 2003 12:38 AM
Jet the carb up, when the fuel is suspended in air in the intake,and when you are turning left, has a tendency to crowd to the right hand bank.


way2fast
Member
posted September 18, 2003 01:03 AM
Also, check and be certain there are no vacuum leaks that may have leaned those 2 cylinders. maybe open vac ports etc.


Raz_900
Member
posted September 18, 2003 12:08 PM
The 2 center cylinders on a SBC always run hotter than the others because of the side by side exhaust ports.

I'd check timing, spark plugs and fuel mixture. Too much timing with too hot of a plug and run lean will blow it to pieces in a hurry.

bigcitycowboy
Member
posted September 18, 2003 06:21 PM
what plugs should i be running?? any ideas will help alot. also there was no signs of any vaccum leaks. but why would only the right side burn up, and not the left two???


wermm
Member
posted September 18, 2003 11:01 PM
I had a problem burning plug wires on the right side. ended up going from r45ts plug to 43's and going up 2 sizes in jets. No more problems.


Raz_900
Member
posted September 19, 2003 02:09 PM
What heads are you using? I use Autolite AR72's in my 461 heads (gasketed plug) and AR133 or AR134's (tapered seat) in 041 heads. Both are around 10-10.5:1. I think both of those plugs compare to an AC R42 or R43. If you were running something comparable to an R44 or R45, you're lucky it didn't suffer a complete meltdown.

As for why just those 2, maybe the right side intake ports are 1% more restrictive than the rest and made it a bit leaner.

pandr
Member
posted September 23, 2003 09:06 PM
check your intake to see if your running and egr type intake. if not, sounds like a vacuum leak on the bottom side of the intake. it will smoke bad in the corners if it is. a cracked head or a blown head gasket could cause the same problem.

[This message has been edited by pandr (edited September 23, 2003).]

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