What would cause a piston to do this??
- Thread starter manlye
- Start date
The intake is also the exhaust side of the engine on the M7.
Thats is the #1 reason to use Wiseco's.. forgings will errode , stock or any cast piston would have sent the dome edge out the port in large pieces as it shattered and killed the head, and turbo..more so if it has one of those pinball flipper turbos,, all the flippers would be bent up and torn up..
no evidence of any siezcoe ing .. thank your stars the other owner didn't listen to the old wives tales..
Gus
no evidence of any siezcoe ing .. thank your stars the other owner didn't listen to the old wives tales..
Gus
M
mike_s
Well-known member
I should rephrase that to transfer side then, i suppose. The incoming fuel from the transfer ports generally cool the piston, hence the reason this usually occures on the exhaust side of the piston.
My guess is too much boost and running pump fuel instead of higher octane required. Lower the boost and/or increase the octane used.
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What are you running for boost Shawn?
Is this the same piston that looks more torn up on FB, or is this the other side?
Definitely looks like det to me... but that other piston looks WAY worse!!
Is this the same piston that looks more torn up on FB, or is this the other side?
Definitely looks like det to me... but that other piston looks WAY worse!!
Here is the other side, and yes Kaleb this side is fully roached To make a long story show I bought a turbo m7 for next to nothing, from a friend that owns a car dealership who got it in on trade.(have no idea who the orig owner is) It was backfiring when I inspected it and suspected a blown top end. It does has an oil delete on it so my first thought was someone didn't mix the ratio right, but after I pulled the other piston with wear the wear and not the grenade, I thought it must me something else, i.e. no race gas. I want to hunt down the cause so it is not repeated 
Thanks for the help!
To make a long story show I bought a turbo m7 for next to nothing, from a friend that owns a car dealership who got it in on trade.(have no idea who the orig owner is) It was backfiring when I inspected it and suspected a blown top end. It does has an oil delete on it so my first thought was someone didn't mix the ratio right, but after I pulled the other piston with wear the wear and not the grenade, I thought it must me something else, i.e. no race gas. I want to hunt down the cause so it is not repeated Thanks for the help! She was rattled hard and for a long time.. someone cheaped out on octane .
Go thru the old girl, check the box settings, recheck the squish and compression ratio. then make sure its not overboosting..
be cool
Gus
Go thru the old girl, check the box settings, recheck the squish and compression ratio. then make sure its not overboosting..
be cool
Gus
lots of oil on those pistons though.
like gus said... go through it, and enjoy boost this winter!
like gus said... go through it, and enjoy boost this winter!
Most of the M7...
turbos that were built back in the day were race gas only kits. You got extremely lucky that the "good" piston didn't catch the exhaust port like the "bad" piston did. IT WOULD have, VERY soon. Pump gas is out of the question at anything over 7-9 lbs. boost depending on elevation. those M7's will rip if set up right. But on pump gas there only "ok" at best.
turbos that were built back in the day were race gas only kits. You got extremely lucky that the "good" piston didn't catch the exhaust port like the "bad" piston did. IT WOULD have, VERY soon. Pump gas is out of the question at anything over 7-9 lbs. boost depending on elevation. those M7's will rip if set up right. But on pump gas there only "ok" at best.
