1969 Imperial progress thread

bulldogchesty · Jul 28, 2014

They turned out fantastic. I need one of those Tornadoes.

70bigblockdodge · Jul 28, 2014

I had to click back on thread after I saw you posted bulldog just to have another look Lol

bulldogchesty · Jul 28, 2014

At the seats or my avatar?

70bigblockdodge · Jul 28, 2014

Avatar thanks again this could go on all night

bulldogchesty · Jul 28, 2014

You can borrow it and use it as your screen saver. What would they look like stretched out?

70bigblockdodge · Jul 28, 2014

No I'm going home.

tallhair · Jul 28, 2014

bulldogchesty said:
You can borrow it and use it as your screen saver. What would they look like stretched out?

I'd give it a shot

cm23uoc · Jul 28, 2014

I don't shoot that fast :laughing4:

commando1 · Jul 29, 2014

70bigblockdodge said:
I had to click back on thread after I saw you posted bulldog just to have another look Lol

#1 on my bucket list to do:

kmccabe56 · Jul 29, 2014

vdk2010 said:
Jep, there are notches on the pistons! Good sign!
View attachment 35394

The notch in the piston indicates which side of the piston needs to face the front of the engine. Why? Because the pin bore ISN'T in the middle of the piston ! Why? Piston slap. Having the wrist pin slightly off center to the center of the piston reduces the likelihood of the customer hearing piston slap before the engine warms up. The other thing that is unique to most of these pistons is that when cold, they aren't round. They're elliptical. There are steel struts cast into the pistons that you should be able to see from the bottom/inside. The portion of the piston that holds the rings, is round, the skirts are elliptical. As the engine heats up the struts control the rate of expansion of the aluminum and the piston actually "grows" into the bores.

Conversely if you don't give a rat's *** about piston slap and want to gain a few free horses, install all of the pistons with the notch facing toward the rear. This will bring the pin bores more into the center of the cylinder and reduce the friction created by the pin bore being offset. Purpose built racing pistons have the pin bore dead center for the same reason.

vdk2010 · Jul 29, 2014

Thanks! That's one hell of a description. I like to learn more about my car/engine. And I'm fine with no piston slap ;) Just yesterday I saw a video on youtube about forged pistons and their inclination to slap when cold.

(http://youtu.be/8VjJtW72QrM)

vdk2010 · Jul 29, 2014

commando1 said:
#1 on my bucket list to do:

Boob boob, I mean whoop whoop ;)

commando1 · Jul 29, 2014

Only I want to do it on a cross country race pursued by every law enforcement vehicle known to man including the NSA.
It ends with me leaping the Grand Canyon.

kmccabe56 · Jul 29, 2014

vdk2010 said:
Thanks! That's one hell of a description. I like to learn more about my car/engine. And I'm fine with no piston slap ;) Just yesterday I saw a video on youtube about forged pistons and their inclination to slap when cold.

(http://youtu.be/8VjJtW72QrM)

It took him a while to get going, but his explanations of the various types of pistons was pretty good. What I was disappointed he didn't talk about was the differences in the skirt designs. Run of the mill cast pistons used to just get a tin coating to help with friction in the bore (it eventually wore off) but these pistons also had a fairly big skirt, also to help with keeping the piston square in the bore. Up into the early 1990s, machining tolerances were usually measure in thousandths of an inch, but as the technology improved and the industry moved to metric, where clearances were measured in thousandths of inches, now they're measure in thousandths of millimeters, and in some cases microns, which is a ten-thousandth of a millimeter. The hyper-eutectic pistons he showed have basically a teflon coating on them to further reduce friction and along with that, the skirts are getting smaller, partly because the tolerances can be held much, much better than they were in the 80s and earlier, and also there's less chance of piston slap. The forged piston he showed has a really short skirt (not just appreciated on a tall well built example of the female side of the human race), partly because it's going into a stroker engine where space is at a premium, but also in production style engines, the clearances are such that the skirt isn't needed as much to keep the piston in the proper orientation in the bore. A lot of new engines have pistons that look like slightly tall tuna cans. Along with the improved clearances (actually decreased clearances), there's reduced mass, which allows smaller counterweights on the crankshaft and also higher operating speeds.

Haven't had a chance to look at any of the rest of those videos yet, but they look like they could be quite worthwhile.

vdk2010 · Jul 29, 2014

It's indeed impressive where the technology brought us today! I wish everything would be metric, that would make things much easier.

I love all his videos, he's a very knowledge guy who's good in explaining things. His whole story about the complete 289 Ford restauration is a goldmine of engine rebuild informations.

vdk2010 · Jul 31, 2014

I had not much time this week for Jacky but tonight I took a couple hours to inspect the engine a little more.

No surprises on the bottom side, i think. Just one small "rust trickle" on the crankshaft.