SC Engine Rebuild Sticker Shock

[chuckw951]

Originally posted by Lindy

My local Porsche (independent) shop is quoting $8,700 for a rebuild using the existing pistons and cylinders, which seems rather high. I would send any machining work out to a reputable shop.

It seems like a very thorough rebuild would include new P&Cs. I'm on my second rebuild (different engines) 3.0 project. The first top end job cost me $3K including a new clutch. This time the motor required new studs, P&Cs, exhaust valve guides, a couple of valves/springs, split case, and reseal. Not everything needed to be machined, much of the bottom end was within spec. The motor I'm rebuilding had Aulicil (sp?) cylinders rather than Nikasil cylinders. I think that is a good question to ask about your motor. I bought as used low mileage set for good price. I figure the whole rebuild will cost around $4K. My builder gave me a rough estimate but could not give me an exact number for sure until the motor was opened up. $8700 seems quite high to me, but then again not everyone has the same overhead. If you want to ship your motor to be rebuilt I think you would have more options that are less expensive and maintain the same quality.

[widebody911]

Here's the receipt for the rebuild of my 3.6L. Not included here are the RaceWare fasteners and some other bling bits I had him put on.

Click to enlarge

[Superman]

I still have not made a rebuild report that I promised but my rebuild cost me about $2500. I could say $2000, but cams and incidental expenses really made it about $2500. I reused the P&Cs since they were in excellent shape (at 182K miles by the way). I did the work myself except for rebuilding the heads. This included all new valves, guides and seals. JW really gave me a good deal, on top of the priceless advice he continues to provide.

As for the earlier question, Wayne knows better than I, but magnesium case engines required more expensive machining because there is more machining to do. All the 'business surfaces" need to be machined. The case needs to be align-bored, for example, which means bolting the case halves together and re-boring the main bearing saddles. Perhaps the case mating surfaces are shaved first, which means that the cylinder spigots then need attention. In any case, they probably should be decked for proper height. With SC cases, you get to pretty much ignore any case issues unless you think there is a problem. In fact, SC bottom-end rebuilds tend to be so straightforward that you can pretty much split them, clean them, drop new bearings in and bolt them back together. I recommend measuring everything, and it's smart to have the crank and rods examined and magnafluxed for possible cracks.

But hey, SC engines are about as reliable as the Sun, so I frankly did not spend a lot of time looking for bottom end problems I knew were not there. Very few people have even heard of an SC bottom-end failure.

[john walker's workshop]

thom, that's not a rebuild, just a minor repair, in spite of the price.

[ChrisBennet]

While we are on the subject of "rebuilds" I have a question.
I'm doing some work on an SC motor for a friend who will be selling the car. I want to represent what was done to the motor accurately.

This is what was done:
Replaced lower head studs.
Welded up leak behind the oil cooler
Replaced all bearings and seals.
Replaced rings.
Had the heads done with new valves
Resurface flywheel
Measured crank and P&C's (well within spec)
Tested oil cooler, piston squirters and cam spray bars
Clean and repaint engine tin
Beadblasted and powder coated fan and housing.
(Edit: forgot this stuff: )
New chain sprockets and chains
Like new intermediate shaft gear
Pressure fed tensioners
New starter ring gear

According to Jim Pasha's article in Excellence magazine, this would be termed an "overhaul" because there wasn't all the machining done that you'd do for a "rebuild". Do you think it would be fair to represent this work as an "engine overhaul" or is there a better way to decribe it?
-Chris

[john walker's workshop]

there's rebuilds and there's rebuilds. you can ring, bearing, touch up the valves, and reseal an engine, or you can go the whole route and replace all the things that wear and machine all surfaces that are out of spec. full rebuilds include, but are not limited to: new P+Cs, oil pump, intermediate shaft, all bearings, chains, tensioners, all sprockets, idler supports and pins, ramps, all new valves, springs, guides, rockers, rocker shafts, rod bolts and nuts, rebush rods, recondition rod big ends, gaskets and seals, etc. cranks and cams usually have no particular wear and can be used as is in most cases. a balance job and magnaflux is optional, but recommended.
either one will potentially run about the same in the end, but which one will last longer?

[Bill Verburg]

Originally posted by Nostatic
But then you might have to rebuild that engine sooner rather than later, so you're in for quite a bit of money. While it is a solution for more power, I don't think it really is a solution for "getting around" a rebuild. Unless the engine you're buying has a recent well documented rebuild, you're still in a crapshoot.

Even if the 3.6 needed rebuilding(which can be avoided by careful shopping), you would be ahead of the game w/ a transplant. Look what you get w/ a 3.6, high compression, chip tuning, twin plug, ceramic, inserts in the ports which aid cyl. head cooling, one of the best oil pumps available, big displacement, most modern design and materials. In addition should a rebuild be necessary there is far more room for additional streetable mods at no more expense than for a smaller displacement rebuild. I would like to remind everyone that a 3 liter that gets its 300 hp from revs may not be a particularly streetable power plant compared to a 3.6/3.8 that gets its 300 hop fom revs and displacement.

All in all the main downside of a transplant is the legal issues presented by smog inspections.

[speeder]

"What constitutes a rebuild"?, is a good and legitimate question. Here in the good old U.S., there is a legal definition of "rebuild". It is determined by one of the automotive sanctioning bodies, maybe ASC(?). JW will know. This is valuable info when "rebuilt" is so common in "for sale" ads, I have seen it refer to a minor tune-up. Some people, (sellers), are not even scamming. They literally have no idea what the term means. Many people who think that they are car people also have no clue.

My only question for JW would be, Do all of those machining operations need to be carried out to meet the standard, or parts just measured and checked for tolerance limits? TIA.