1979 SC Chewed a Valve - Total Rebuild

[Henry Schmidt]

Originally Posted by OsoMoore

I get the feeling there are 3 pump depths: SC pumps, Carrera pumps, and turbo pumps. The lesser curved ones probably are fine for Carreras, but not these.

This feeling is creative but not accurate. All pump pickup locations are the same.
That fact is true all the way back to 1964.
The pickup configurations have changed, (curved tube inserted into a screen, a curved tube inserted into a venturi attached to a screen, a venturi attached to the tube with a separate screen, venturi attach to the tube with a screen attached) but the pickup location has remained constant.

We actually have a jig to guarantee that consistent location, that we use when we rebuild pumps. Sometimes the early pickup tubes come loose so an alignment jig makes checking the location possible.

[mikedsilva]

Originally Posted by OsoMoore

I get the feeling there are 3 pump depths: SC pumps, Carrera pumps, and turbo pumps. The lesser curved ones probably are fine for Carreras, but not these.

yeah, I think I know what you mean....

SC pumps use a flat plate
Carrera 3.2 pumps can use the shallow domed stamped steel plate
3.6 pumps need the deeper aftermarket plates.

I've been through this, and posted my measurements in another thread a couple years ago. Same numbers as you.

The precision matters plates work.

But that Patrick Motorsports item looks sensational!

[OsoMoore]

Originally Posted by mikedsilva

yeah, I think I know what you mean....

SC pumps use a flat plate
Carrera 3.2 pumps can use the shallow domed stamped steel plate
3.6 pumps need the deeper aftermarket plates.

I've been through this, and posted my measurements in another thread a couple years ago. Same numbers as you.

The precision matters plates work.

But that Patrick Motorsports item looks sensational!

I almost bought one of the Precision ones, but thought I the other curved one worked just as well. Oh well. Now I'll have 4 plates. Maybe I can sell the "wrong" ones.

Here's the photos PM sent me when confirming my fit. Could be helpful to people in the future having oil sump plate fit issues.

[stownsen914]

Didn't realize the later pump screens could protrude more. Good to know, I'm planning to put a 3.6 pump into an early case for "future project" build.

[OsoMoore]

Picked up the newly powder-coated engine tin, cross bar, transmission mount, etc. today.
Today's mail should also include rockers/arms from Supertec, oil, spark plugs, and the new deeper oil sump plate.

Tomorrow I'm taking the day off work and planning to finish up the long block, put on exhaust, etc. Some friends will help me get the engine off the mount and we'll be targeting a weekend re-install of the engine.

Much excitement!

[silverlock]

Originally Posted by mikedsilva

yeah, I think I know what you mean....

SC pumps use a flat plate
Carrera 3.2 pumps can use the shallow domed stamped steel plate
3.6 pumps need the deeper aftermarket plates.

I've been through this, and posted my measurements in another thread a couple years ago. Same numbers as you.

The precision matters plates work.

But that Patrick Motorsports item looks sensational!

Related - Adapt has three different sump plate depths to accommodate for SC vs 3.2/Turbo/GT3 screen depth: https://adaptmotorsport.com/collections/current-products/products/porsche-911-engine-sump-cover-plate

(not a shill, just relevant to this convo!)

[stownsen914]

Looks like the Adapt plates are two depths to match the early and late factory style plates. Description for the third option mentions that it's the same depth as #2 but with two fittings for turbo drains.

[OsoMoore]

Big day - started early taking out all 8 old sump plate studs to put in the new longer studs. No issues, all came out clean!

What's the best way to put in the new ones? Just one of the old ones appeared to have loctite, should I do the same for the news? Just put them in snug via the allen wrench fitting?

[Jesse911]

I have the same cover. Here with my 993 pump. I used blue loctite on the studs. Snug yes.

[OsoMoore]

Looks good. Loctited and put new tensioner arms back in (thanks Henry).
Now warming up my RSR o-rings to put them on my barrels. They were 35 degrees from the garage, so I'm sitting on them for a few min before I stretch them out.

[OsoMoore]

Long day, got a lot done.
- Installed intake and exhaust rockers for 1 and 4. Checked cylinder/valve clearance, all good.
- Assembled the rest of the barrels, adjusting bolt, and locking nuts for other rockers.
- Installed but did not adjust all the rest of the rockers. All torqued, however.
- Installed new sump cover studs. Two of them seated too deep and had to be backed out a bit. Will keep an eye on them, maybe will need to replace.
- Installed new tensioner arms from Supertec
- Re-oiled-filled and installed tensioners
- Closed chain housings
- Placed valve covers on loosely with finger-tight bolts to keep area clean
- Installed spark plugs loosely to keep things clean. Did not set gaps yet.
- Began to install heat exchangers, discovered/remembered the stud length (as noted by earlier poster) was too long on all but the new head. A previous owner (probably Lee?) stacked a ton of washers in order to make the barrel nuts useable on the inner studs.

At that point, I decided to stop of the day. Dr. Pate is somewhere around here, so if someone wants to drag him to this thread he can explain himself.

Tomorrow there will be a ton of things, but one key one is to get the engine ready to take off its mount down onto the motorcycle lift. That requires some assistance from friends, and I can always do the CIS afterwards. That's what drove me towards the heat exchangers today.
The configuration of the engine stand mount prohibits installation of the cross-over pipe on the exhaust, so I think I won't be fully tightening the heat exchangers yet, as they'll need play to connect the cross-pipe. I'll figure that out later.

[OsoMoore]

Originally Posted by Flat6pac

For thin flange heat boxes, it looks like the new studs are too long, made for thick flange heat boxes.
Bruce

So this is a problem that I must address.
The studs on 5 of the cylinders are a good bit too long. A previous owner stacked a bunch of washers so they could still use the barrel nuts on the inner studs. Unsurprisingly, I found one stud had lost its nut (and presumably washers) somewhere along the way.

So... what's the best fix?
1) Pull the exhaust studs out and put in new shorter ones. Not sure how feasible this is, or how long it would take to get the new studs.
2) Shorten the studs in-place by cutting them with... something? Not sure if this is viable.
3) Find a way to put on normal nuts instead of barrel nuts. Doesn't look quite impossible to reach.
4) Use spacers or maybe even a stack of washers and repeat the rigging of my predecessor.

I'll do some looking into stud removal... not sure which way to go.

[draw]

Pull the studs and put in the correct ones. They come out pretty easy, just like the other ones you pulled out and replaced. It’s worth waiting a few days for the parts.

[Flat6pac]

The answer to the barrel nuts is 8mm JIS nuts with 12mm shoulders.
Use 1/4 drive and 12mm socket, you might have to grind the outside of the 12 socket if you don’t have snap on 12 which goes into the holes with clearance to tighten the nut.
Bruce

[mikedsilva]

Originally Posted by draw

Pull the studs and put in the correct ones. They come out pretty easy, just like the other ones you pulled out and replaced. It’s worth waiting a few days for the parts.

Unless I've misread your posts above, you are contemplating removing EXHAUST STUDS... Unless they've recently been changed, I've never found them to come out any other way but drilling them out.

Stomski sells a handy tool but you're in for a long painful task.

If you dont want to stack washers or spacers, do as bruce says and find some 12mm nuts.

[OsoMoore]

Originally Posted by mikedsilva

Unless I've misread your posts above, you are contemplating removing EXHAUST STUDS... Unless they've recently been changed, I've never found them to come out any other way but drilling them out.

Stomski sells a handy tool but you're in for a long painful task.

If you dont want to stack washers or spacers, do as bruce says and find some 12mm nuts.

Yes, exhaust stud. Drilling these out sounds awful!

[OsoMoore]

Originally Posted by OsoMoore

Yes, exhaust stud. Drilling these out sounds awful!

After more pondering, I think I can use a 1/2 spacer while I wait for JIS order. Will also need a new narrower socket that fits.