How much is too much?

[Hemikiller]

Just for giggles, since I'm home bound for at least another week +, I pulled down the 351C-4V out of my dearly departed 71 XR-7 4 speed car. 

I bought the car out of NJ for the paltry sum of $500 back in 2003. A true M-code 4 speed XR-7, still running, but had a fairly loud knock. The guy I got it from bought it from a used car dealer in PA. Anyway, I did a quick thrash, replacing the bad shortblock with two spun mains, with one from a great running but wrecked 72 351-2V Cougar convertible that I parted out, so it still had the flat tops. I swapped the 4V top end, Comp 280H cam and lifters over, did valve seals and gaskets and had it running in a couple days. Gave the OE Autolite 4300 my best college try and after a couple weeks of no progress and 8mpg, pitched it on the shelf and ran a Holley 800DP with a thick spacer gasket. Thing ran damn good and other than the noisy fricking Crane Hi-Intensity lifters, it was a hoot to drive. I did a Duraspark swap, tossed the factory flex fan for a clutch setup and would consistently pull down 16~18 mpg. Fast forward to 2006, I got rear ended not 300ft from my house and totalled the car. She was a bit rusty, so the impact did a lot of damage. I did get a good insurance payout, but after getting screwed on a supposedly rust free car on eBay, I decided it was time and parted/liquidated all my Cougars. 

So, the engine's been sitting under my bench since then and with the "free" time on my hands, I figured I would do something with it. Did a quick degrease, wire wheel cleaning and blow off to make it a bit less disgusting and proceeded to take it apart. 



Ewwwww....



Everything looked as expected until I pulled the intake and found one bent pushrod on #6. At that time, it reminded me that there had been at least one bent pushrod when I tore the original engine down. 



one of these is not like the other....



Apparently it had been like that for a while. 



#1 intake and #5 exhaust lobes weren't giving full lift, neither was #4 intake. 





Like I said, this was a car that I drove daily and it was running great up to the accident.  Pretty much every lifter was showing signs of failure. 

 

[Hemikiller]

Next I yanked the heads and everything looked as I expected it to. Heads were grimy and I probably should have cleaned the sludge off them before plopping them onto the other shortblock, but eh, who knows. Oh, and these are 4 DOT closed chamber heads = D1AE-GA , cast in Dec 1970.



At this point I got a call from a friend in NC who I hadn't talked to in a long time, so we BSed while I pulled the pistons, so no pics there. She came apart fine, no drama, no broken stuff, but well worn. The new timing set I had put in when the engine went together was completely spent with about 1/2" play. I'm guessing it had 20k miles, so definitely don't use a link chain type stock replacement timing set on a Cleveland. IIRC it was an SA Gear unit, not an offshore cheapie.

Bearings on the pistons side did have some odd wear patterns on maybe 5 of 8. The cap side is fine, so I'm at a bit of a loss as to what would cause this. Thinking maybe it was a worn thrust bearing and the car was a stick, or maybe some taper on the journal from the crank grinder. Have to check journals and the clearance on the thrust surfaces to see. 





Pulled the crank next and the bearings there are worn, but again,m what I would expect to see. Clearly the guy who did the rear main seal when the 20/20 crank went in did not know what he was doing. 





Crank surfaces look really good, so it may just get a quick polish and a fresh set of bearings. 

The Cylinders however, show a whole different story. Clearly this is a very high mileage engine. The bore is standard, and the pistons are original FoMoCo. The rings I assume are original as well and completely wasted. I ran a dingle ball hone down the cylinder to clean the gunk and dropped a ring in at the bottom of the bore and squared it up with a piston. Pulled out the feeler gauges and got a big surprise. 

.039" gap, pulled it up to the top of the bore just below the ridge - .054". Factory spec is .010" ~ .020"  

:whistling:

Rings also were hammered into a self made Dykes ring with a .015" step.  :angel:



I don't know how many miles it takes to do that, but I'm guessing a lot.

 

[Hemikiller]

So after careful consideration, this engine has gone to the back burner and I have another that is getting the quick and dirty refresh.

The next victim is a '73 351CJ shortblock that came to me in a trade. More on that later.

 

[mjlan]

Sounds like fun!

I can never remember to take pictures when I get into something like this. I enjoy pulling engines apart, there's nothing like the smell of ancient engine oil...

I am trying to get an engine refreshed for my old Dodge truck, when I popped the heads off I had to laugh when I found a single 0.040" oversize piston while the other seven were 0.030". I don't know where to find a ring set now