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This thread is to serve as collected documentation and knowledge-seeking for my recently started engine rebuild. The donor engine is from a 1974 spider, and will find a new home in my 1978 spider soon enough. The engine shop is a 10x10ft shed in my back yard. Pictures of the engine in transit (for your amusement) and set up on the engine stand in the shop (a "before" picture of the engine) are attached. My goal is to build the engine to stock spec, with the addition of improved gaskets and oil rings, high lift valve springs, and other miscellany. I aim to build a competent, reliable street engine. I will add a 123ignition and am also considering an MSD box, though I fail to see how the MSD system is better given it still works with the same single ignition coil. Anyway, I'm looking at overhaul kits from Spruell Motorsport and already before touching the engine have some questions:

  • Are oil passage restrictors to increase oil pressure recommended / are they always a good idea?
  • What is the purpose of crankshaft oil gallery plugs offered by Spruell Motorsport?
  • I expect this engine has 9.1:1 compression as does my 78 spider. The options I see available for rebuild are 10:1 motronic or 10.5:1 (shape unknown). Greater compression options are available though I assume they are for performance applications which I'm not ready to attempt on my first engine. Do these (10:1, 10.5:1) compression ratios still allow the use of 87 octane fuel? Is the performance improvement to 10.5:1 worth it in anyone's opinion? If possible I would prefer to stick with 87 octane as I run now as I daily drive the car in the summer and do a lot of road tripping. I don't want to spend more on fuel to gain 5HP.
Engine teardown will commence Saturday and more updates will follow.
 

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Why is it black?
Pete
 

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Discussion Starter #4
Just a bad picture, was late and I was tired. It's actually pretty clean looking for its age. I don't think the car was driven much past the 80s. Condition looks like it sat for decades unloved. The body was ruined but interior and chrome trim looks new. Anyway, this engine had the carb conversion block off plate, but when I got the car, the carbs and intake manifold were torn off. My 78 has SPICA and I plan to move the SPICA over to this engine.
 

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I will add a 123ignition and am also considering an MSD box, though I fail to see how the MSD system is better given it still works with the same single ignition coil.

Bad idea. I did that, ignoring the advice from 123 and it caused the electronics to fry. The inductive ignition from a 123 with a suitable matched coil makes better sparks than an MSD and it puts much less stress on the cap, rotor, HT wires and surrounding electronics, including the 123 distributor.
 

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Do these (10:1, 10.5:1) compression ratios still allow the use of 87 octane fuel?
No. You will need premium.
Higher compresion ratio pistons work well with longer duration cams. Some knowledgeable people reckon that flat topped, so called 10:1 pistons make more power than the so called 10.5's and flat topped with a head shaved to bring the CR into the 10's is the best plan if you do not want to shell out for forged racing pistons.
I measured the CR of "10 to 1" Motronics on a stock head and they were 9.7.
 

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Discussion Starter #7
I will add a 123ignition and am also considering an MSD box, though I fail to see how the MSD system is better given it still works with the same single ignition coil.

Bad idea. I did that, ignoring the advice from 123 and it caused the electronics to fry. The inductive ignition from a 123 with a suitable matched coil makes better sparks than an MSD and it puts much less stress on the cap, rotor, HT wires and surrounding electronics, including the 123 distributor.
Aha! Had a feeling I was missing something. I'll stick with the 123 which I have ready, actually been sitting a good 5 years as it was supposed to go in the old Alfa before it became a parts car. No MSD in my future.

No. You will need premium.
Higher compresion ratio pistons work well with longer duration cams. Some knowledgeable people reckon that flat topped, so called 10:1 pistons make more power than the so called 10.5's and flat topped with a head shaved to bring the CR into the 10's is the best plan if you do not want to shell out for forged racing pistons.
I measured the CR of "10 to 1" Motronics on a stock head and they were 9.7.
If the pistons in the engine are within spec when I get them out and measure them, is it acceptable practice to re-use them? I would still replace the liners of course. If we optimistically suppose my 78 spider with the cat removed makes 115 horsepower, CR increase by 1 point would provide theoretical 4% power increase or 4.6 horsepower. To me this is not enough to justify moving from 87 to 93 and spending an added $0.70-1.00 a gallon at fill up.
 

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Inspect your pistons and post pictures if you need advice about reusing them. The liners may be OK with a re-hone. It depends upon how much wear you find. Buy new rings from Hastings and gap them for your new bore diameter.
IMO, the best change to make if you do not have to pass emissions is to replace the stock exhaust manifold with either a 2 piece type or a set of tubular headers. You should pick up close to 10 HP.
Are you using SPICA or Webers?
 

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Here's a few thoughts, mostly in the order you refer to them above.

-If you haven't done so, search for and read as many of the engine rebuild threads as you can.

-Consider your camshaft options and decide what you want. If you are just rebuilding to stock specs using the existing cams, there is no need for valve springs for high lift cams. Besides, you can replace cams and valve springs without removing the head in the future if you desire. However, if you intend to use high lift cams, you may need to have the follower bores relieved for lobe clearance.

-Ignition options are fairly straightforward and can be considered in the future or separately from the engine overhaul.

-I would use restrictors in the six oil galleries to the head. In addition to helping to maintain oil pressure in the bottom end, they help keep the o-ring seals from collapsing.

-Oil gallery plugs in the crankshaft seal the drill holes. As part of an overhaul, the plugs are removed and the oil galleries in the crank are flushed to remove debris. New plugs are then driven into the holes to reseal the galleries. A better approach is to have a machine shop tap the holes and use set screws and Loctite to reseal them.

-Ditto Ed's comments regarding compression and using the nominal 10:1 "Motronic" pistons. I have them in my '88 Spider with a head milled 0.020" and use 89 octane fuel. With better cams and the two piece cast iron exhaust manifold, engine power and characteristics have noticeably improved. I drive the car 130 miles a week.

-You can reuse pistons and liners if the dimensions are within specs. I would probably do that from a cost standpoint but not on the basis of the estimated, individual contribution to performance. The performance gains from a 10+:1 CR and a good set of cams are likely more than the sum of the gain from a higher compression ratio or better cams individually. Improvements work together as a system.

I am slow posting this so somewhat redundant with Ed's advice...
 

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Did anyone respond re oil passage restrictors? If not here's my take. On a stock engine in normal use, I don't think it's going to matter much. I have 70,000 miles on a used 1750 I got from APE 20 years ago and oil pressure has not changed on the gauge at all. I use 20W/50, change it and filter every 3000 miles, and drive moderately.

That said, the more oil and pressure you can keep at the crankshaft the better. And the half-shaft sprocket and cam bearings get more oil that then really need, so restricting those doesn't hurt them and keeps more pressure at the crank. The race engines I've built I put Norman Racing brass o-ring retainers in the head gasket, and you can solder those up further and redrill to any size you want. And they make a little kit to put a jet, basically, in the base of the half-shaft sprocket to reduce its oil flow. On a race or other high performance engine, sure. On a street engine I don't worry about it.

Same with drilling #2 and 4 main bearings to get oil directly from the gallery. On a race engine I'd do it, on a street engine I wouldn't worry about it. I just tore down my Giulietta Veloce engine, 108,000 miles on it, last inspected in 1986 and driven regularly since, and all the main bearings were essentially perfect. So the oiling in non-extreme use seems plenty adequate. To me the biggest thing is good oil and regular changes.

Andrew
 

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Same with drilling #2 and 4 main bearings to get oil directly from the gallery. On a race engine I'd do it, on a street engine I wouldn't worry about it. I just tore down my Giulietta Veloce engine, 108,000 miles on it, last inspected in 1986 and driven regularly since, and all the main bearings were essentially perfect. So the oiling in non-extreme use seems plenty adequate. To me the biggest thing is good oil and regular changes.
Agree. I faced that decision when I decided to build a high output road motor. I discussed it with A number of people including Jim Steck and Richard Jemison, two people who could have done the modification for me and I left the crankshaft stock. I very often spin the motor up to 7000 rpm but no more than that and I don't hold it at those engine speeds. I cannot imagine a situation when I would want to do that with a street car.

I agree with my friend Rich Hanning on most things but not on pulling the plugs from the crankshaft. I once used a crankshaft of unknown pedigree from a junk car. I flushed the oil galleries in the shaft by setting it in a big bowl of kerosene which I circulated through the holes with a fuel pump and then blew it out with compressed air. Usually when I have rebuilt a motor it has been one that has had regular oil changes and the oil has been clean and I do not clean out the galleries. I know a couple of people who had plugs fall out after they had replaced them.
 

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2000 cranks are hardened and it's tough to get replacement plugs to stay in. Earlier cranks you can tap and use a hex plug. Norman Racing makes a plug that drives in, then tack welds with tiny blobs of TIG to keep in place.

The last crank I had the plugs out of, boy am I glad I did. One or two passages were about 75% blocked with sludge.

Andrew
 

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Discussion Starter #13
Did anyone respond re oil passage restrictors? If not here's my take. On a stock engine in normal use, I don't think it's going to matter much. I have 70,000 miles on a used 1750 I got from APE 20 years ago and oil pressure has not changed on the gauge at all. I use 20W/50, change it and filter every 3000 miles, and drive moderately.

That said, the more oil and pressure you can keep at the crankshaft the better. And the half-shaft sprocket and cam bearings get more oil that then really need, so restricting those doesn't hurt them and keeps more pressure at the crank. The race engines I've built I put Norman Racing brass o-ring retainers in the head gasket, and you can solder those up further and redrill to any size you want. And they make a little kit to put a jet, basically, in the base of the half-shaft sprocket to reduce its oil flow. On a race or other high performance engine, sure. On a street engine I don't worry about it.
If I'm understanding this, the oil passage restrictors increase oil pressure, and decrease oil delivery to the camshafts - thereby increasing oil available at the crankshaft. And after I typed that, I re-read 65Sprint's post above and noticed he said this verbatim. I will plan to use these restrictors. Regarding the crank, I'll see if I can get an engine shop to tap the plug holes and install set screws. Not quite there yet, but planning ahead. Regarding crank bearings, I have yet to read anything about drilling them - but since this is a street car, I will not consider any such modifications.
 

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The point of the restrictors isn't to increase pressure at the cam bearing and halfshaft sprocket, but merely to limit flow to them, which don't need a lot. It thus increases remaining pressure at the crank.

1, 3, 5 mains get oiled directly by passages from the oil gallery. 2 and 4 aren't drilled directly, get their pressure through the crankshaft internal passages, just as the rod bearings do. So that mod gives all the main bearings the same direct oiling from the oil gallery.

Andrew
 

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Last night I prepared the engine for Saturday's teardown - I removed the gearbox and some of the annoying exterior items. Boy, the second time around is much easier. The crank pulley was no trouble for me now that I have identified the process (in my first teardown, a learning experience, it took a week of frustration - last night it was a couple of hours' soak in PB blaster and my "crankshaft pulley breaker bar" AKA a 6ft piece of iron pipe. First pic attached is the flywheel (right) from my 1974 spider, next to the flywheel (left) pulled from an engine the seller gave me with the car. I believe the engine is from 1976 but don't know what car it came from. It was also definitely overhauled in the past, albeit poorly (all bearing surfaces severely damaged). I was surprised to find a different style flywheel and I don't know what to make of this. Anyway, the clutch was stuck hard and only came off after a coat of penetrating oil and 5-10 minutes of careful prying. A bit of history, I had the clutch replaced in the car the engine came from when it was an operational restoration-in-progress because it was stuck after presumably 10+ years in storage - it got stuck again after a month sitting in the garage. Could this point to a problem with the flywheel surface? Should any work be done to the flywheel before being re-installed?

I also included pictures of one camshaft. Both show some unusual scratches near the cam gears, and one has a small scratch - not sure what to make of this. Picture is also attached of top of the engine after removing the cam cover. I was a foolish young man when playing with this particular car years ago, and I cannot recall if I changed the oil or not before running it - it was at most 20 miles of travel and a few hours of engine time between my getting it running and abandoning the project, so I remain hopeful the camshaft and crank journals are in good condition. Time will tell.

Before I begin disassembly - how should one mark the position and orientation of the camshaft and crankshaft caps? In engine rebuilding class I was taught to use a set of number punches. I have done some reading which suggests this is discouraged and can damage the parts due to the force of action of the punch.
 

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The thing about the oil passages in the crankshaft is Alfa are the only manufacturer that to my knowledge uses plugs that can be removed. Others drill somehow so plugging is not required ... and there are literally millions of other manufacturer engines pounding around public roads and race tracks after rebuilds where these passages were cleaned by squirting kerosene down the holes ... so why remove the plugs?
Pete
 

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You needn't really worry about it; it's pre-marked. If you get the crank to #1/4 TDC, #1 cam lobes pointing horizontally outward (away from each other), marks lined up, and dist rotor pointing to #1, it should run. There are pre-marked timing marks on the cams (two per cam) and one on the front cap, rear side. Note there is a specific orientation of how to insert the oil pump to get the drive dog lined up.
If you don't understand this stuff yet you should keep reading and/or asking questions til you do. And you can set the cams at other than the factory timing marks (small amounts) or time with a degree wheel but I'm guessing you aren't planning to do that.
Anderw
 

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Pete, stuff gets into places in the passages that a normal physical or chemical cleaner won't remove, at least in my experience. Maybe ultrasonic would.
Andrew
 

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The scratches on the camshaft are from a vise grip wrench that was used to turn it. No big deal.
 

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I'm actually doing a 1300 and 1750 for friends of mine. The crank plugs MUST be removed, drilled, tapped and slide hammered out works for me. You would not believe the amount of sludge that is behind them, it is mind boggling. Brake parts cleaner and nylon rifle brushes work well. Not all machine shops are keen on drilling a nitrided crank and tapping threads, the fear of breaking a tap is always on my mind but I have a process and all my cranks are done that way, hardened or standard. For a street motor, a standard build is fine and will last for many years. If a higher HP motor is desired many of the tricks stated above should be applied. Have fun with your build and pay attention to the cleanliness of the parts going back in. If you think its clean, wash it again! Better in the long run. Clean, clean, clean.
 
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