1979 SC Chewed a Valve - Total Rebuild

[OsoMoore]

I did do fuel lines a few years ago (Spring surprise). I'll take a look at those bushings. Some suspension work was done ~20 years ago, but I'm not sure exactly what.

[OsoMoore]

Just got back from the rebuild shop here in Milwaukee. He's done engines for many years, including rebuilds for some friends of mine.

We talked for a little over an hour and went through the parts. My plan is to use his shop as a base for getting major parts hot-tanked, source new parts, and farm out the work like heads etc that I can't do at home via his contacts.
I'll handle all the manual stuff that's doable in a garage, cleaning, assembly, etc.

Ballpark is looking in ~$10K for cylinders, pistons, head work (one totally replace), rod balancing (one totally replaced), new oil pump, cam grinding, rocker arm grinding (one totally replaced), one new tensioner, new chains, new worm gear, and some other stuff.

A rebuild on his time (with a some cosmetic extras) would run $25K, so I'm looking to save a fair penny with my work. But I'll have his support and backup to get it done a lot cheaper. I won't get things zinc-plated or professionally repainted, but I'll come out the end with a solid engine that should run another 25 years.

[Cairo94507]

Man, that failure sucks. Have you considered just swapping in a running replacement engine? Maybe a 3.2? Might be a lot cheaper in the long run and get you back in your car. Good luck.

[OsoMoore]

Originally Posted by Cairo94507

Man, that failure sucks. Have you considered just swapping in a running replacement engine? Maybe a 3.2? Might be a lot cheaper in the long run and get you back in your car. Good luck.

I did, but a rebuilt engine looks likely to cost $30K, considering mine wouldn't be considered a useable core due to the destroyed cylinder, piston, and head. And damaged chain tensioner etc.

Final worst-case parts plus shop work now tallies to just under $18K.

[OsoMoore]

Heads are out to a shop, as are cams and oil cooler. Will take a bit for new/repaired parts to start rolling back in. For now, just waiting and cleaning the bits that aren't traveling.

[OsoMoore]

Parts are starting to come back from machine shops - heads should be in this week.

I need a replacement connecting rod for the one that impacted and was gouged and twisted. The number on my bent one reads 930.103.105.0R, although I think 911.103.105 works as well. A full new set is $$$$ so I'm hoping to find a used one that can be matched with the other 5.

Can anyone confirm if these match? Sierra Madre Collection: "Porsche Connecting Rod - 911 2.4/2.7 72-77 911-103-105-0R"

[Henry Schmidt]

Originally Posted by OsoMoore

Parts are starting to come back from machine shops - heads should be in this week.

I need a replacement connecting rod for the one that impacted and was gouged and twisted. The number on my bent one reads 930.103.105.0R, although I think 911.103.105 works as well. A full new set is $$$$ so I'm hoping to find a used one that can be matched with the other 5.

Can anyone confirm if these match? Sierra Madre Collection: "Porsche Connecting Rod - 911 2.4/2.7 72-77 911-103-105-0R"

First, 2.7 and 3.0 SC rods are not the same. Next, you can't believe how many weights groups there are in Porsche connecting rods. They can very 12 grams in the same part number and even rods that have the same overall weight can very over 10 grams from end to end.
Your best best is to buy a new set of rods, I like Carrillo.
The next best bet is to source a matched set of used rods. They are available for pennies on the dollar compared to new.
Then have that replacement set rebuilt.
Trying to source one matching rods could take 100 hrs of your life and you may never succeed. Spend 10 minutes on PP classified or EBay and you win.

[Flat6pac]

Part number and complete weight with nuts and bolts, weigh it against one of the good ones, or maybe the best of three to assure your grams are equal.
Bruce

[OsoMoore]

Originally Posted by Henry Schmidt

First, 2.7 and 3.0 SC rods are not the same. Next, you can't believe how many weights groups there are in Porsche connecting rods. They can very 12 grams in the same part number and even rods that have the same overall weight can very over 10 grams from end to end.
Your best best is to buy a new set of rods, I like Carrillo.
The next best bet is to source a matched set of used rods. They are available for pennies on the dollar compared to new.
Then have that replacement set rebuilt.
Trying to source one matching rods could take 100 hrs of your life and you may never succeed. Spend 10 minutes on PP classified or EBay and you win.

Originally Posted by Flat6pac

Part number and complete weight with nuts and bolts, weigh it against one of the good ones, or maybe the best of three to assure your grams are equal.
Bruce

Thanks guys, good to know that's a fool's errand.
Got a lead on a Pelican (2K+ post history) with a full set for $120 + S/H. Also swatting off scammers left and right.

[snbush67]

I had a bad experience with original rods. Your highest probability for success is to skip the used rods and buy carillo, or pauter, etc.

[mikedsilva]

Originally Posted by snbush67

I had a bad experience with original rods. Your highest probability for success is to skip the used rods and buy carillo, or pauter, etc.

Really?
Most of the feedback I've had, is that the 3.0SC rod is quite a strong rod.

[snbush67]

Originally Posted by mikedsilva

Really?
Most of the feedback I've had, is that the 3.0SC rod is quite a strong rod.

Not the strength of the rod but reusing could be problematic, remember you commented on my spun rod bearing. Probably wasn’t the rod but the bore dimensions after machining. And by the time you pay for shipping, machining, new bolts etc. you’re probably not that far off from buying new higher performance parts with exact specs.

[OsoMoore]

All parts are accounted for and should be arriving this week. Some are new (RIP my oil pump), some are reworked by the machine shop (heads, rods, etc), and some have stayed here in my garage (engine tin, heat exchangers, etc.)

I've read that I should clean all of these very carefully, even the brand new or hot-tanked stuff. I ordered a bunch of lint-free cloths, but I need to figure out what is the best solvent to use for cleaning these various parts.

Also, I need to figure out how I should be protecting the new steel parts from rust while I work through assembly. My garage is not temp or climate controlled, and I don't want rust while I'm working through it.

I'm excited to finally start putting things back together!

[hanieid123]

good luck!

[targa72e]

I need to figure out what is the best solvent to use for cleaning these various parts

I recently was cleaning some body panels for paint where the recommendation was clean with solvent based cleaner and then water based. After cleaning the panels until the chem wipes came back clean with solvent cleaner I was surprised when the first wipe with water based came back black. Different contaminants have different polarities to solvents. Example gasoline does a bad job of cleaning mud but water works very well. So switch it up with something like brake cleaner and something like Dawn dish soap in water.

john

[OsoMoore]

Originally Posted by targa72e

I need to figure out what is the best solvent to use for cleaning these various parts

I recently was cleaning some body panels for paint where the recommendation was clean with solvent based cleaner and then water based. After cleaning the panels until the chem wipes came back clean with solvent cleaner I was surprised when the first wipe with water based came back black. Different contaminants have different polarities to solvents. Example gasoline does a bad job of cleaning mud but water works very well. So switch it up with something like brake cleaner and something like Dawn dish soap in water.

john

Good idea, I'll have that on hand.

I have been studying the first assembly step (titled Section 2) in Wayne's rebuild book, and the complexity of the step is astonishing.
Hot oil bath to get the gears on, Plastigage checking each rod clearance before final bolts, a crazy circlip that doesn't have holes for a circlip tool... I'm in for a ride.

I thought the transmission was a lot, but this is far more.

[OsoMoore]

Looking for input on if the Harbor Freight measurement tools are sufficient quality and precision for the engine tolerance measuring I need to do.

I'm seeing measurements specified to 0.0xx level. Will these be good enough? Also, is an Aluminum Oxide pad right for gentle scrubbing? Or do I need one that is more plastic to fill the "Scotchbrite Pad" role?

[Henry Schmidt]

I inherited a bunch of Harbor tools after buying a bankrupt engine shop and the quality was atrocious. We literally tossed them in the waste bin.
The snap gages are probably OK but if you're looking to hold .0005" why not spend a little more and enjoy the quality.

Most of our tools are Brown & Sharpe, Mitutoyo and Starrett.

Edit: As I'm writing this my machinist just told me even telescoping gages should be high quality. Apparently, the locking mechanism can move when tightened on cheap tools.

[OsoMoore]

Originally Posted by Henry Schmidt

I inherited a bunch of Harbor tools after buying a bankrupt engine shop and the quality was atrocious. We literally tossed them in the waste bin.
The snap gages are probably OK but if you're looking to hold .0005" why not spend a little more and enjoy the quality.

Most of our tools are Brown & Sharpe, Mitutoyo and Starrett.

Edit: As I'm writing this my machinist just told me even telescoping gages should be high quality. Apparently, the locking mechanism can move when tightened on cheap tools.

That's what I was afraid of. I carefully kept the receipt.

[CNB]

Originally Posted by OsoMoore

I ordered a bunch of lint-free cloths, but I need to figure out what is the best solvent to use for cleaning these various parts.

Also, I need to figure out how I should be protecting the new steel parts from rust while I work through assembly. My garage is not temp or climate controlled, and I don't want rust while I'm working through it.

Good quality brake clean works fine for cleaning.

Regarding rust, a light coat of WD40 should do the trick. There is always the corrosion inhibiting "wax" paper which you can wrap the parts in. Hit of WD, wrap in the corrosion inhibiting paper, seal in a bag.