2.8SS build on 3.0 turbo engine - questions

[rennzeit]

Hi,
I am the lucky new owner of a 77 3.0 turbo engine on which I plan to build a 2.8SS. The engine sat for a while, but it turns over by hand. Assuming components are usable once torn down, what should I use from this engine for my build, and what should I sell?
Things I know I should keep...
- Case (I'm pretty sure on this one
- 4 bearing cam towers
- 95mm Nikasil cylinders (replated if necessary)

Things I'm not sure about...
- Heads ??
Turbo heads have small intakes (32mm) , but that means more meat to port a custom shape, no? Exhausts are already 36mm, but could get bumped to 38 or more, also with custom shape. Does the "special" turbo alloy help in anyway on an NA engine? Would I be better off finding a set of large port SC heads? Are these turbo heads valuable to anyone?
- Oil pump ??
I'm not sure from BA which pump came in this engine.
- Cams ??
Can these be welded and reground or am I better off with fresh blanks?

Things I will definitely be selling...
- Crank
- Rods
- Pistons

Did I forget anything?

thanks,
dug

[Walt Fricke]

3.2 heads might be better - big enough ports from the get-go. Don't know if you'd come out ahead or behind with a swap.

Some cam grinders much prefer to use new blanks rather than welding and regrinding, so maybe no cost savings there?

The one thing I can tell you is that you will need to clearance some of the bearing webs, because the throws of the 66mm crank will interfere here or there. Or perhaps you can knife edge the crank some to avoid this, but that's going to have to be done before balancing. So a trial fitting, with crank and bearings in place to see what needs to be done here is in order. I had the whole case together before finding this out. At least this allowed me to sort of scribe the areas where I had to use the die grinder a bit. Not much, but you don't want a running crank to do your machining for you.

[rennzeit]

Thanks for the tips Walt. I hadn't heard about the interference with the crank before.
Cheers,
dug

[fred cook]

I second Walt about swapping for a set of 3.2 Carrera heads. You will get nice big fat ports and slightly newer parts. If you can find a set that someone is selling off a hot street or track engine that has been dual plugged, more the better! Especially if they come with comp springs and titanium retainers (typically used on perf heads). Good luck on your project!

[rennzeit]

That makes sense to me too, and would likely be cheaper than sending them out for porting. The 3.2 port sizes match what Henry said he used in "The best engine Porsche never built" 2.8SS parts list. I also will probably use the DC80 102 lobe center cams.

Another question that keeps coming to mind... is shuffle pinning necessary or just an extra precautionary measure?

In his thread Henry mentions that "The SSI and mufflers offer a bit of a tuning challenge. With a proper size header these engines will produce close to 300hp on street gas."

This engine will be in a 914-6, so I'm not stuck with the SSIs (or I'm stuck without, which ever way you want to look at it.) What would be the "proper size header" to achieve that 300hp figure?

I plan to use EFI with a unique ITB setup. More on that when I have supporting photos of my setup.

thanks,
dug

[KTL]

Since a 2.8SS loves to rev, I would recommend the shuffle pinning. Even on stock-like engines, you find the bearing web mating surfaces "fretted" and they look like they have been machined that way

My 3.2SS (SC crank, 98mm pistons) engine case has been used for racing for a number of years. It was used at tracks that see high rpms for a good while like Road Atlanta. When I opened it up last year, the bearing webs show a good bit of fretting and that bugs me because that means there is considerable movement. I'm having mine sleeved thru the thru-bolt holes this coming weekend. Going to drop it off at cgarr's place (G2 Performance) in Michigan.

[Walt Fricke]

I second using the method cgarr is using. I would have to, because I sort of put him up to it. He had been using a junk case to index inserting bushings where the through bolts go and the webs meet. I figured out how a machinist had done this for me. Clamp case together, bore through case through bolt holes from one side to depth needed on other, insert bushings (care needed so as not to block any oiling holes, which are nearby) then shrink or otherwise fit an aluminum piece by where the bolt heads are to get that part back to size. Better mousetrap to be sure the bushings are spot on.

Better than inserting pins in one half, and holes in the other, seems to me. Locating bushings are used for the #1 main bearing. Why not everywhere?. I've never seen any fretting on my cases (three) done this way. No extra problems getting the case halves apart on the inevitably more frequent race motor rebuilds. Though traditional shuffle pinning seems to work fine also.

[KTL]

Yah i'm looking forward to the case sleeving. Should make the case rock solid for sure. Looking forward to hanging out with Craig & Denny for a day. Haven't seen those sons a biyatches in over a year!

https://www.youtube.com/watch?v=gJz-gmy8YOc

Here's a picture of the fretting from my bearing saddle mating surfaces. Ignore the ugly bearings. That's a whole 'nother story not worth getting into in this thread with you bastards!

[Henry Schmidt]

The turbo heads are made of a better material so stick with them.
Valve sizes are the same and ports can be modified to flow better than stock 3.2.
If your building a street engine, smaller ports can produce better port velocity / volumetric efficiency.
The issue with the short stork engine is cylinder filling to produce compression so they need all the help they can get.
Think towards aggressive cams if you want to make power.
One of our street 2.8SS engines runs RSR sprint cams and believe it or not, it is very driveable.

[rennzeit]

Henry, thanks for the affirmation on the better turbo head material. The information about it is vague at best. You listed 40/38 ports on the 2.8 with the RSR Sprint cams. How much smaller are you talking? 38/36?

This engine will probably share time between my historic IMSA 914 and your (Henry's) old 914-6 race car. No street time for this one, but drivability is a good thing on the track too.

Walt: I looked up cgarr's threads but couldn't find any info on his shuffle pinning alternative, except a photo of his rescue 2.7 case where you could see them. All the west coast shops list shuffle pinning on their price lists. Is the bushing method cheaper or measurably better in some way?

cheers,
dug

[KTL]

Saving an old 2.7 case

[rennzeit]

Yeah, that's the thread with the photo, and it has lots of cool info on checking clearances and other tweaks, but there's no actual discussion of using the case bolt bushings vs shuffle pins that I could see.

[KTL]

Sorry, I thought the process was described in the thread. Here's a short description:

First make accurate plugs for the mains to hold it square bolted together and use a ½ inch reamer thru the case thru bolt holes into the other case half. This creates a ½ counter sunk bore to install the sleeve which is ½ od .35 wall and 1 inch long. Then make sizing plugs for the case half was reamed all the way thru to bring the thru bolt hole back to size. This method is using the case as the jig to line up everything, it can’t be off and works very well.

The caveat is you must notch out 3 of the sleeves to allow oil to pass thru for the piston squirters, but only in 3 locations.

This gives you a very sturdy case. Pretty much the whole case looks like #1 main bearing.

[Henry Schmidt]

Originally Posted by dug@project914

Henry, thanks for the affirmation on the better turbo head material. The information about it is vague at best. You listed 40/38 ports on the 2.8 with the RSR Sprint cams. How much smaller are you talking? 38/36?

This engine will probably share time between my historic IMSA 914 and your (Henry's) old 914-6 race car. No street time for this one, but drivability is a good thing on the track too.

Walt: I looked up cgarr's threads but couldn't find any info on his shuffle pinning alternative, except a photo of his rescue 2.7 case where you could see them. All the west coast shops list shuffle pinning on their price lists. Is the bushing method cheaper or measurably better in some way?

cheers,
dug

39-40 on the intake part 37mm exhaust.
DC 80 cams.

Which 914-6 race car do you have? I've had a few. Pictures!!!

[rennzeit]

It's the one with the 956 rear wing on it. At the moment it pretty much looks as delivered. Slowly been making my plan.

[Henry Schmidt]

Originally Posted by dug@project914

It's the one with the 956 rear wing on it. At the moment it pretty much looks as delivered. Slowly been making my plan.

You mean the "914 from Hell"?
Here's how it developed.

Phoenix



Willow Springs




During the build

[rennzeit]

I was originally going to canabalize it for parts for my IMSA car, but it has so many cool tweeks, I couldn't break it up. My favorite part is how you widened the rear tail lights and raised the trunk floor.

I'm going to tie the cage to the rear suspension and add door bars. And now a 2.8SS

[PFM]

Henry,

What year was this? I recognize Martin's car but cannot place your 914. Mid 1990s?

[Henry Schmidt]

Originally Posted by PFM

Henry,

What year was this? I recognize Martin's car but cannot place your 914. Mid 1990s?

That was 1995 or 6 Tribute To Lemans 3 hr enduro. That little 914 ran a 1:28 (the track was 2 seconds a lap slower than it is now) in the dark to qualify on the outside of the poll against some pretty fast cars. That weekend we were running a 280 hp MFI 3.0.

If memory serves, from front to rear:
Martin 575 HP turbo
Me 280HP na
Angel Nardi 500+ turbo
Jim Bazagalu 300 hp RS
Mark Manda 650 hp 935 factory flat fan turbo
Guy from Phoenix (David?) 3.8 RSR 360 + hp
Baddich ? 505+ twin turbo
Randy Beck carburetor 3.6 liter 914-6

[Henry Schmidt]

Originally Posted by dug@project914

I was originally going to canabalize it for parts for my IMSA car, but it has so many cool tweeks, I couldn't break it up. My favorite part is how you widened the rear tail lights and raised the trunk floor.

I'm going to tie the cage to the rear suspension and add door bars. And now a 2.8SS

Want to sell it back?