Pulled the Heads off today...everything looks really good, only worry is the amount of movement the pistons have.....normal?
http://www.youtube.com/watch?v=PGx2GKQ7uio
http://www.youtube.com/watch?v=PGx2GKQ7uio
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Is this much Piston Clearance too much!
- Thread starter fast400
- Start date
WS6
Stay thirsty my friends
#1 It appears it's your birthday,so happy birthday!
#2 I think they are too sloppy, but if you can get a skinny feeler set down there and get a measurement I think there is a spec range for tolerance.
We know that a stock TTA piston bore is 3.800 so maybe run a piston down to the bottom and put a bore gauge in there and see what the clearance is with a little math.
Are you opposed to re-ringing them?
#2 I think they are too sloppy, but if you can get a skinny feeler set down there and get a measurement I think there is a spec range for tolerance.
We know that a stock TTA piston bore is 3.800 so maybe run a piston down to the bottom and put a bore gauge in there and see what the clearance is with a little math.
Are you opposed to re-ringing them?
WS6
Stay thirsty my friends
Acceptable tolerance would be .003-.004, but that's measured further down the piston as the crown is smaller diameter.
I don't know how far into this you are,with respect if the engine is on a stand or in the car.Or how far you are willing to go.
You run the risk of turning this from a mole hill into a mountain of work. I suppose if the car ran good and a compression test yielded decent numbers I'd leave it alone and button it up.
But if it's on the stand and it were me, I'd pull the crank and get a set of mics around the skirts and do the math vs. the cylinder bore. Which then could lead to complete disassembly, a ball hone,new rings and then fit new road and main bearings on the crank and any work that needed done to get the crank cleaned up. This also would include a complete block tear down and cleaning.
I'm guessing your into this for a head gasket change in which case I would still pull a rod bearing to look at it and I would pull #2 and #3 main and look at them,especially the thrust surface. If they all look good then I'd button it up.Especially if it's street driven and not raced at the track.
I don't know how far into this you are,with respect if the engine is on a stand or in the car.Or how far you are willing to go.
You run the risk of turning this from a mole hill into a mountain of work. I suppose if the car ran good and a compression test yielded decent numbers I'd leave it alone and button it up.
But if it's on the stand and it were me, I'd pull the crank and get a set of mics around the skirts and do the math vs. the cylinder bore. Which then could lead to complete disassembly, a ball hone,new rings and then fit new road and main bearings on the crank and any work that needed done to get the crank cleaned up. This also would include a complete block tear down and cleaning.
I'm guessing your into this for a head gasket change in which case I would still pull a rod bearing to look at it and I would pull #2 and #3 main and look at them,especially the thrust surface. If they all look good then I'd button it up.Especially if it's street driven and not raced at the track.
WS6,
I spec'd a few cylinder bores....this is odd to me...at the widest points in the cylinders I got no more the 96.2mm (3.78").:boxed: I thought they started at 3.8"?? I need to get a larger outside micrometer to mic the pistons...ebay here I come.
I think you're right as far as the mole theory goes. Everything looks pretty good, simply started tearing down because it was leaking pretty bad at the back corners between heads and intake and oil seals.
Since I'm here now, I'll probably go with a roller cam, pistons, timing chain, head work, etc.
I spec'd a few cylinder bores....this is odd to me...at the widest points in the cylinders I got no more the 96.2mm (3.78").:boxed: I thought they started at 3.8"?? I need to get a larger outside micrometer to mic the pistons...ebay here I come.
I think you're right as far as the mole theory goes. Everything looks pretty good, simply started tearing down because it was leaking pretty bad at the back corners between heads and intake and oil seals.
Since I'm here now, I'll probably go with a roller cam, pistons, timing chain, head work, etc.
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WS6
Stay thirsty my friends
3.78 is probably as close as I would come using a bore gauge, as those instruments are hard to use and gauge error is also a factor when were talking about .02 and a metric conversion.But maybe it was 3.789 which makes it .019. I would check my bore gauge with a standard ring to be sure it was accurate.
The problem I see with your plan(and maybe it's not a problem if you don't mind) is that pistons will need the rods pressed,which will need them re sized,which leads to bearings,which leads to crank turning,which leads to line boring and you might as well get it decked.....so..a complete rebuild. And if done with your labor will still be around $3K or more.
When buying a mic. I always look for one with a spindle lock and I'm pretty hip on Starrett brand. you might as well buy a 2-3" and 3-4" set.
I also take all my measuring instruments to a tool and die shop and have them calibrated.New and used.
The problem I see with your plan(and maybe it's not a problem if you don't mind) is that pistons will need the rods pressed,which will need them re sized,which leads to bearings,which leads to crank turning,which leads to line boring and you might as well get it decked.....so..a complete rebuild. And if done with your labor will still be around $3K or more.
When buying a mic. I always look for one with a spindle lock and I'm pretty hip on Starrett brand. you might as well buy a 2-3" and 3-4" set.
I also take all my measuring instruments to a tool and die shop and have them calibrated.New and used.
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WS6
Stay thirsty my friends
Okay...so I'm gonna take an educated guess at an oiling issue with some metal passing through a few of them and some embedding in #3.
Enlarging the rod bearing picture I think I see some copper beginning to appear.
All in all they look like you caught this in time, but you're going to probably have the crank polished at best and turned .010 at worst. Polishing you should be able to get away with standard size bearings, but maybe .001 bearings at worst.
Ultimately I'd spec that oil pump out and put a new pump cover on with new standard depth gears. Then I'd do the Earl Brown timing cover/pump mods.
That will make the oil pump work better and provide more volume and better idle pressure.
Enlarging the rod bearing picture I think I see some copper beginning to appear.
All in all they look like you caught this in time, but you're going to probably have the crank polished at best and turned .010 at worst. Polishing you should be able to get away with standard size bearings, but maybe .001 bearings at worst.
Ultimately I'd spec that oil pump out and put a new pump cover on with new standard depth gears. Then I'd do the Earl Brown timing cover/pump mods.
That will make the oil pump work better and provide more volume and better idle pressure.
WS6
Stay thirsty my friends
couple more things...I don't see any signs of crank flex either. Looks pretty even wear.
Secondly I was going through my measuring tools and I forgot that I also seem to buy alot of Fowler brand mics and my bore gauge is also a Fowler but I need a new dial indicator for it.
My smaller mics and calipers are starrett brand.
Secondly I was going through my measuring tools and I forgot that I also seem to buy alot of Fowler brand mics and my bore gauge is also a Fowler but I need a new dial indicator for it.
My smaller mics and calipers are starrett brand.
