dime1622

This is such a bummer

For you guys - are those valve indents on the pistons cast there, or were they caused by the valves? I know on some motors the pistons were cast like that, but I don't know for sure on this one.

Jay W

The indents are cast into the tops of the pistons. I only see minimal marks where the valves hit. I have done 3 engines with valve contact and damage with pistons that bad or worse and had zero problems related to the tops of the pistons having had contact. Just make sure to clean all of the metal shavings and debris from the cylinders so it does not scratch the cylinder bores.

dime1622

That's what I was thinking. Thanks for the clarification

thirdgenbird

back to pulling the engine. is it 100% impossible to remove it from above? the car is outside but i can get an engine hoist to it.

the car will need trailered els ware as well is there any harm in rolling the chassis without and engine?

krystar

it's possible yes.

remove the hood. cam box and head comes off. get the weight of the engine on the hoist, then unbolt the motor mount from the crossmember. remove the steering rack from the cross member (also undo the steering shaft, remember to center your steering wheel first). engine can then tilt up and slide forward and out. u do have a hoist balancer right?

thirdgenbird

are you sure they were cast there? they look awful crude, uneven, and shinny:
#1

#2

#3

#4

thirdgenbird

does the rack get in the way?, im 50 miles from the car so cant go out and look...

krystar

those two little half moons are cast there... "damage" wouldn't be so uniform.

...yea it gets in the way. i wish i didn't have to remove it...but u can't get the oil pan forward w/o removing the rack

thirdgenbird

if this is the case, how do i safely clean up the mess?

are you saying there is no damage?

Jay W

The half moons that were already on your piston tops are modified by the valves hitting them, therefore making them look crude and shiny from what amounts to a hammer slamming into them at high speed. 16 valve cars have 4 smaller indents in their tops.

krystar

i didn't say there was no damage. but there's nothing u can do with ordinary tools. sure if u had a mill or some precise way to shave the piston surface flat....

krystar

yea that's a better explanation. the valve hitting the piston just basically took off the carbon deposits that were caked on already. that's why they're so shiny

Jay W

If you move the piston to the top, you may be able to knock some of the edge of the damage off with the end of a file, doing it very carefully. I filed on one of mine a small amount because there was a thin sliver of the top of the piston sticking up where the valve gouged it. I was afraid that sliver would break off and score the cylinder wall when it was running so I filed it off. It in no way was perfect but I felt better about it. I have had no ill effects from any of my bent up pistons, some say the damage can cause detonation problems. Just make sure none of them are cracked.

thirdgenbird

i also had "issues" getting out one of the allen head bolts on the front of the head.

im not sure tapping it will correct it. is heli coil my only option?

will i want/need new hardware when i bolt the head back on?

thirdgenbird

thanks. i am still leaning to a full rebuild. i found an encouraging thread about boring/stroking these motors (even with the stock afm/montronic)

https://rennlist.com/forums/924-931-...ter-maybe.html