Budget SC top-end ?

[dandrews64]

So, I change the oil on the '82 SC today and the crankcase drain plug has the usual flakes of metal stuck to it. Not a lot, but some. Something is wearing away. There's 165K on the clock, never been opened up. So while I don't have the cash or stable employment right now (and frankly, who really does in this economy???) I'm wondering what would a bare-bones top-end run? I'm talking a roughly speaking, no surprises, DIY kind of deal. I'm bleeding oil all over, so sure would be nice to freshen things up. Maybe even the CIS would work better after new seals and stuff.

So....is it even possible to just hone cylinders and replace rings, or is it pretty much always a bore and pistons? I realize there's no guarantees until you open it up but I'm just wondering..... In my fantasy place I'm dreaming of a hone, rings, head and valve refinishing, cam chains, gaskets, and a bunch of seals and rubber stuff to freshen the intake system. Are valves also a "always replace" thing? I always hoped to got to 964 cams if I did a top end but I worry about passing smog and adding pop to the top end w/o doing the bottom with 165K on it, so think there would be zero upgrades.

Of course, after all this, I may still have junk on my plug which then the means the motor comes out again and a bottom end would need to be done but I'm just spit balling here..... Wondering what "best case" looks like.

Thanks PP BBS.

[CMDR Perry]

Subscribed to your thread Doug. I need to do the same with only 70,000 miles (headstuds) plus freshen trans or sell car next spring.

[Gunter]

Oil plug will usually show a small amount of fine residue but not flakes.
If you plan to rebuild, get Wayne's book on Engine Rebuild!

P/C's should be o.k. with just a light hone and a re-ring but...........................if the P/C's are Alusil instead of Nikasil, it's a different story and you don't know what is in there until you have the engine out and partially dismantled.

Valves could still be good and may just need a grind; a good valve job is ~$6-800 ?
Head studs should be replaced, at least the lower exhaust ones.

New chains/ramps and new chain sprockets (The ones on the I-shaft) meaning: Split the case.
Unless you intend to use new chain sprockets, re-use the old chains.
Gasket set and seals for the block.
Some new rubber boots for the CIS intakes.
Special tools needed: Engine stand, Adapter ring, Cam tools, Dial indicator and Z-block, Good-quality 3/8"-drive Torque wrench.......
If you split the case, new bearings on crank and I-shaft (Recommended)
Rods need new bearings and bolts (Recommend ARP bolts)
The big bearing bore on the rods may need to be trued by a machine shop and the small bushings replaced.
The crank may just need to be polished if you're lucky; same with the cams.
Once the engine is dismantled, a parts washer is highly recommended, most shops have them. Cleaning by hand sucks.

Overall cost: Somewhere between $5-10k ??

You could also take a chance and keep running and maybe just take the engine out to fix the oil leaks. Usual suspects are Oil breather gasket, Oil Thermostate O-ring, breather hose, Oil cooler seals, Oil return tube seals.
And definitely check the head studs; torque is 24 ft-lbs.

[mca]

Are there other clues that lead you to believe you need a rebuild? Using a lot of oil?

Like Gunter said: "You could also take a chance and keep running and maybe just take the engine out to fix the oil leaks."

You could get a compression and leak down test. If those numbers are good you could drop the engine and replace the various seals to stop the leaks.

[porschenut]

Maybe you'll get lucky and they'll be Nikasil. Unlike Alusil, those can be honed and ringed.

At 165k, I think you'd regret not doing the bottom end while you've got the top end off. Very few SCs or Carreras reach the ultra-high mileage we sometimes hear about.

[JMH82SC]

Alusil is not the end of the world. I just did the top end on my 82 SC and used the in spec Alusil cylinders. I used a hone with FELT PADS and Sunnen AN-30 past to prep cylinders for new rings. I was lucky and all of the valves were good so the heads only needs guides and seals and new springs. The heads with machine work and parts worked out to be just over $1000. The parts ( w/ rings ) list to reassemble was just over $700 and specialty tools $250. I did all the work myself except the heads. I'm happy to report with over 1500 miles no smoke and using very little oil in fact oil consumption is on the low low side of spec.

[911st]

First I would check to see if there is really any clues to real issues. Check compression, leak down, send a sample of oil out for analysis. Put a stethoscope on different parts of the motor and listen for unusual noise or have someone do it that knows these motors. Check head nut torque. Cut the oil filter open and look at what is it it (do not use a saw).

I do not think a motor will usally chew its self up unless it is pounding out a bearing. If that is the case you will know real soon. Also, you should be able to hear it.

Another failure it a chain tensioner failure. That is typically an all at once failure. It least it was for me.

Then, sell the motor with full disclosure and buy another used motor that is in good shape. 3.2?.

If you have metal floating around in your motor I would think you would have to look at a full rebuild.

I am not an expert, just my two cents worth.

[afterburn 549]

I would count on one thing...under estimating what cost is and needs....
I would break it into two parts of thinking and hope for the best....
1 being complete top end
2 the whole meal...
In reality it seems silly with that amount of time (mil age) not to knock the bottom a part and see whats what....very little left once the cylinders are off..

[RideShoot&Drink]

What are the rebuilt SC engines going for theese days? Perhaps find a healthy engine and sell yours?

[afterburn 549]

The cost of a rebuilt would be the same as yours to rebuild ?? except, maybe some uknowns will be involved.......