3.4 QV Crowndog's Adventure

This is better than a mystery novel.

 

Had no idea the frame was originally red.

Paul, I don't see a pressure washer in any of your pics. What do you use to clean off all the greasy stuff?

 

Paul, in that first pic of the piston damage, wouldn't "dings" like that cause hot spots and possible detonation issues? Just curious.

 

I used my pressure washer, straight hot water no chemicals.

The raised sharp edges can cause hot spots. They should have at least deburred the piston when the head was off but judging by the gouges you'll see from when they removed the head it makes sense why the tech didnt.

 

The rear head was off in the past, who ever took it off used a pry bar of some sort under the water manifold to pry the head up so the block is chewed up along the top edge.

Block degreased quickly, it'll get cleaned at least 2 more times. Rear deck covered in sanding pad swirls, the front deck is untouched because its never been off.
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So this engine has been pretty much worn out & had more than its fair share of abuse (and then had a gorilla work on it too) !!

Seems like you've got to it just in time - any clues as to the state of the transmission & diff? Do you think that's going to need a rebuild too?

 

Liners showing wear at the top as well as pitting in the coating.
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That about sums it up.

1st and 2nd are difficult to engage cold, better warm. Monday ill have a report on the gearbox. No gear whine.

 

Are the QV liners Nikasil?

 

Newman, what is the cost of of the pitting? Also, is that the cross hatch from the original honing?

 

Why were the bottom of the intake manifold and the heads sanded?

 

I thought 308 engine used hemispherical pistons. These don't look hemi to me. Maybe it's the way the light hits or maybe it's a QV engine or maybe I'm just wrong.

 

Yes, aluminum sleeve with a nickel ceramic coating as I understand it. Not a fan of it.

Thats the original cross hatching. Cost of pitting?

Hack mechanic.

Not a hemi on a QV, pent roof design with a dish piston.

 

So new liners, pistons & valves ( + guides ) on top of the crank & bearings? What cams are going to go in this thing, has that been decided yet?

 

The rebuild calls for a 360 crank, that is how the displacement becomes as the title of the thread 3.4 liters. Larger valves, custom pistons,custom cams. The crank and new liners we have ready to go.

And fortunately I got this engine to Paul just in time, it was on it's last leg. Perfect time to do this.

 

Not at all intending to nit-pick nor to be critical, but assuming that you are keeping the 308's stock 81 mm bore and then adding the 360's 79 mm crank, you may want to double check your math.

Cheers - DM

 

79mm stroke &
81mm bore = 3.256L ---> 308
82mm bore = 3.337L
83mm bore = 3.419L ---> 328

 

I get that but what was he/she trying to accomplish by sanding and what damage does that cause? I'm only asking because, at the risk of sounding like a moron, it seems like it would clean up poor machining edges and maybe a bad finish. But obviously I don't know anything about this.

 

A 308 is really 2.9L. The 3.4 John did is roughly 3.4L, the other two I did were 1mm smaller in bore than Johns because 1mm OS is my comfort level. Now we have new liners, should I bore them or leave them alone? We discussed the options and were tossing around the idea of boring 1mm over but no further.

 

They were looking for a quick way to clean off the gasket's remains and corrosion and get it back together. Carefully cleaning take time and doesnt hurt the factory machined surface. It was nice to see when I split the engine from the box that the machined surfaces didnt look like they were cleaned with an air chisel. Perfect smooth cutter marks from the factory. Its not a silly question either!

 

Robert, how are Maryland emissions? Are you going to have to worry about those?


Paul, what's your deal with the liners? Are you going to have a set of iron liners made or will you have these bored, then replated and honed?

 

I bought new steel 308 liners and measured them and test fit them. All the critical dimensions are the same as the aluminum ones that came out. There are other checks ill make but so far they pass with flying colors.

 

Going historic so it becomes moot.

 

The original cross hatching on the cylinder lining wall is still visible, that's amazing.

 

So no more Nikasil, just plain steel?