Hey all...

I have received some quotes for an engine rebuild (including parts) from some various vendors. Some numbers seem good while others seem inflated. What is the average cost for an engine rebuild. No performance upgrades other than forged rods and balancing the crank/piston assembly.

I have been searching everywhere for information. Nothing to be found. There is nothing that provides some solid numbers on what to expect. As a result the number have been all over the place.

Thanks,
C.

 

i spent about 5k five years ago, head cleaned up, five angle valve job i think, a few new valvesat $85 each, water pump etc, rod bearings, piston rings, gaskets, etc.

 

Did you do the reassembly? Looking closely at the motor, it seems VERY straight forward.

C.

 

I had SM Motorsports in NY do all the work. Not sure if the 5K also included things like motor mounts cap&rotor etc. that i supplied.

this is the car that was stolen shortly after the motor work was done.

i was getting oil in teh coolant. turns out the PO changed the headgasket and the monkey that did the job used a roloc on the head surface - a oil passage didnt seat right.

 

You need to be more specific.

Are you expecting to show up at a place and pick up your rebuilt engine?
Are you expecting to drop your car off and then go pick it up with a new rebuilt engine installed?
Are you expecting to do the assembly yourself and farm out some of the work to a machine shop?

I chose the third option. I don't have my spreadsheet with me, but it cost somewhere around $2k for parts and machine shop labor. I replaced everything. I never rebuilt a car engine before and I didn't think it was that hard. So far it has lasted 35k miles and about 10 track days. Knock on wood. If I can do it, anybody with common mechanical sense should be able to also. And it was kind of fun too. It all depends on how much time you have.

 

EXACTLY the info I was looking for. The third option is likely the route I will take as well. Machining for the 16v head is a bit more $$ due to its complexity. But overall, should not be too bad.

How many miles on yours when you rebuilt? How badly were the cylinder out of round? Tapered?

C.

 

Book time on an S2 to R&R the motor and rebuild is 44.5 hours. Obviously shop hourly rates are going to vary dramatically from shop to shop. Figure ball park parts around 3-3.5k which should include all your bearings, gaskets, waterpump/timing belt kit, clutch kit, motor mounts, 574, rings, spacer sleeves/oil pump drive gear, sensors, valve guides/seals,etc. On the S2 you want to replace the cam tensioner and chain, etc which will add a few hundred. Then add your associated machine work (head, block, crank, etc).

 

Fantastic. Thanks Doc.

C.

 

I got my donor engine from a car that had a broken odometer. But I estimated that it had around 150k on it. The crank was still well within specs and can easily go to 300k. I had it magnafluxed and polished. The cylinders were iffy (scratches), but I decided to leave them alone. But I went with new rings. All the other blocks I have in my house have beautiful bores. They should be good for 300k also if the engine was well cared for. The Alusil is pretty durable as long as you don't overheat it.

Yeah, with a 16V head, you're going to be spending more on that. I had new valve guides, seals, and 3 angle job done. I also had the head pressure tested and checked for warpage.

I also had to pay the machine shop a bit more to drill out bolts / studs that didn't make it through tear down. I left alone the head studs and lower crankcase studs, but got all new exhaust studs.

 

Great info folks. And thanks to all who have PM'd me as well. I am really getting excited to do this. If there is any more info out there keep it coming. I am sure I will not be the only 944 owner contemplating a rebuild in the future.

C.

 

Chad, I've been loving following your tear-down and rebuild threads.

 

Thanks bud. I will make a how-to thread as soon as I learn what I need to know about doing this properly.

C.

 

You might benefit from touching base w/ Erik Orhnberger... surprised he hasn't picked up on this thread yet, I'll mention it to him... we're just about to get started on putting his S2 motor back together... mild track build, mostly just clean it up, balance everything, new pistons from Diamond, and I think we got some mild lightening done...

I'm a little more interested than passing, now - seriously considering starting an S2 in another year or so for ITR...

 

Can you elaborate on the Diamond pistons? There are a few options out there, J&E, Mahle Motorsports, etc. How many miles on the motor? Did he have to get the block honed? Bored to oversize (104.5mm)?

I'd like to hope (based upon the info here) that the engine bores will be in some pretty good shape. So I am hoping that either new rings or new forged pistons. Here is the master list of parts that I am looking into:

Engine Parts / services needed:

Aftermarket Forged rods.........…………………………………….$1000.00
Engine rebuild kit: (Source Vertex Auto)……………..………..……$890.00

1 Rod Bearing Set (Standard) 92810314315
1 Main Bearing Set (Standard) 94410190100
1 Piston Ring Set 94410390260
1 Balance Shaft Belt 94410221902
1 Timing Belt 94410532302
16 Valve Guides 94410432700
1 Head Gasket Set (Upper) 94410090106
1 Case Gasket Set (Lower) 94410090103
8 Connecting Rod Nuts 92810317202
1 Front Engine Seal Kit 94410100000
1 Loctite 574 Sealant 50 ml Tube 00004301000

Balance shaft bearing (x4)…...94410112110…...………..…….….$65.00
Balance tensioner……………....94410202507…...………..…….….$25.00
Balance roller…………………....94410227706…...………..…….….$29.00
Timing belt roller…………….....94410524102…...………..…….….$29.00
Timing belt roller 46.2 ..……..94410524103…...………..…….….$29.00
Cam Hall Sensor ……………... 94460612500M14.…..…..…..…...$21.50
Block machining (local shop)...……………………………...………$1000.00

Refurb / Machine Head work…………………………………....…$1000.00
Timing chain tensioner……….94410504901…...………..………$359.00
Exhaust valve (x8)……………..92810564206…...………..………$272.00
Valve stem seal (x16)………..92810460107…...………..…..…...$47.84
Cam Hall Sensor ……………...94460617002M14.…..…..…..….$139.75


I think this is all of the parts I will need. I will be double checking the list to make sure I have covered all the components that should be replaced.

If any of you see anything missing and should be addressed, post it up. Hopefully, this list will also help those down the road looking to do this as well.

C.

 

The Diamond pistons, IIRC, were stock bore, stock CR. I don't remember what options he might have requested. Finished weights IIRC were within a gram, and I think maybe 25g lighter than stock. They were then balanced (whole rotating assy actually - with rods, rings, pins, etc) by a local machine shop.

His bores IIRC were just touched up by a 928 shop, don't remember which one. Think his mileage was around 160kmi? Not sure you'd want it done by a local shop, due to the special nature of the block/bore material. The crank journals were polished, too, no size change though.

I would expect the valve stem seals to be in with a headgasket set - they are for my 2.0L's. Unless you're talking about the heavy-duty Viton seals, which may be a very good idea for a track motor... wich I could get them for mine.

You oughtta add a crank scraper from crankscrapers.com (or from Paragon, FWIW) to your list! They rock.

You gonna have it balanced, too? It's pretty good stock, admittedly. Could compare before/after #'s with Erik, as well as cost.

I don't see any new springs there either... at a minimum, I'd check them all - for any signs of cracking, and for strength - before reusing. That's what brought Erik's motor to its knees, 3 snapped valve springs.

I'll keep thinking about options...