S52: Cost for stock rebuild?

[funcrew]

Sadly, my much-abused S52 is suffering from bad compression in several cylinders. Mileage is less than 80K. Assuming that I go to an E30-friendly shop in Socal, what kind of "turnkey" budget am I looking at for:

1. Head rebuild including R&R, if the bottom end is good shape
2. Full rebuild including bottom end, with overbore and new pistons

I don't want to upgrade/hot rod the cams or anything else. Any other thoughts are also welcome - Thanks

[FredK]

This is really an unenviable task.

The most economically feasible way to skin this cat is to get a known-good S52 and install it, and part your S52 out. Even if you don't part your S52 out, selling it as a "core" will partially defray the cost of the engine R&R.

Otherwise, a mostly full refresh will cost around $2500 in machine shop and parts cost (bearings, head refresh, timing parts), assuming you can re-ring the stock pistons and just hone the block.

[funcrew]

This is really an unenviable task.

The most economically feasible way to skin this cat is to get a known-good S52 and install it, and part your S52 out. Even if you don't part your S52 out, selling it as a "core" will partially defray the cost of the engine R&R.

Otherwise, a mostly full refresh will cost around $2500 in machine shop and parts cost (bearings, head refresh, timing parts), assuming you can re-ring the stock pistons and just hone the block.

The "known good" is the problem. I replaced a blown S50 with a "known good" S52, 80K, perfect compression, and it failed within 10K miles. While I didn't baby it, there was zero track or autocross time.

[VinniE30]

The "known good" is the problem. I replaced a blown S50 with a "known good" S52, 80K, perfect compression, and it failed within 10K miles. While I didn't baby it, there was zero track or autocross time.

Any possibility that they lied to you about that mileage?

[Pudmunkie]

I'm at ~2grand. All new bearing, bolts, timing components, rings, sensors, etc. Full rebuild on an 84mm bore 3 liter.

Call Blunt, he can hook you up.

[Wanganstyle]

Sadly, my much-abused S52 is suffering from bad compression in several cylinders. Mileage is less than 80K. Assuming that I go to an E30-friendly shop in Socal, what kind of "turnkey" budget am I looking at for:

1. Head rebuild including R&R, if the bottom end is good shape
2. Full rebuild including bottom end, with overbore and new pistons

I don't want to upgrade/hot rod the cams or anything else. Any other thoughts are also welcome - Thanks

I'd say a little more than 2k.

if the s52 only has 80k and had bad compression, there may be some foul play inside. It's still running and does not have a blown head gasket??

My last s52 burnt crazy oil from bad rings, it had close to 2x the milage. Compression was still within 3% across all 6 CYL.

Have you preformed a leakdown test?

[funcrew]

Any possibility that they lied to you about that mileage?

Methinks you may be right. I bought the lump from Zionville Motorsports.

I'm at ~2grand. All new bearing, bolts, timing components, rings, sensors, etc. Full rebuild on an 84mm bore 3 liter.

Call Blunt, he can hook you up.

Might do that, but I'm going to farm out the rebuild. I expect labor cost to be substantial.

I'd say a little more than 2k.

if the s52 only has 80k and had bad compression, there may be some foul play inside. It's still running and does not have a blown head gasket??

My last s52 burnt crazy oil from bad rings, it had close to 2x the milage. Compression was still within 3% across all 6 CYL.

Have you preformed a leakdown test?

Can I do that with my plain-vanilla compression tester?

[Wanganstyle]

you need compressed air and a leakdown tester, it pumps air into the cylinder and tells you also a constant air pressure. the difference is what you are looking for, you have to close the valves manually and hold the crankshaft in position. This would let you see if any cylinder has a bent valve, also will have pressure in the oil if you have a bad oil ring.

I had stuck/failed/worn/burnt oil rings on my s52, perfect compression within 5%. (210-203 psi). engine burned insane amounts of oil but would take track abuse all day and not consume on WOT. Leakdown test would let you pinpoint this issue.

[funcrew]

you need compressed air and a leakdown tester, it pumps air into the cylinder and tells you also a constant air pressure. the difference is what you are looking for, you have to close the valves manually and hold the crankshaft in position. This would let you see if any cylinder has a bent valve, also will have pressure in the oil if you have a bad oil ring.

I had stuck/failed/worn/burnt oil rings on my s52, perfect compression within 5%. (210-203 psi). engine burned insane amounts of oil but would take track abuse all day and not consume on WOT. Leakdown test would let you pinpoint this issue.

I'm down 50% on a couple cylinders, so probably not a candidate for that, eh? I didn't see any cross-contamination of fluids, and the engine spun smooth, so I'm thinking bad HG at a minimum, plus whatever condition caused that.

[jrdeamicis]

Down 50% compression or leak down?

[funcrew]

Down 50% compression or leak down?

Plain compression. 80PSI in the worst cylinder, cranking for 5 seconds. 180 in the best 3.

[jrdeamicis]

Dry and wet leak down tests are now required. Post the results.

[funcrew]

Q1: I only have a cheap-ass $60 compressor with a tiny tank. Would that be adequate?

Q2: Harbor Freight's leakdown tester gets terrible reviews. What would be a decent model/supplier, considering I'll probably only use it once?

[328ijunkie]

The harbor freight leakdown tester is a POS. I had to buy a snap on one :(