Another Engine Rebuild Thread - 80 3.0L

[mca]

Originally Posted by Gunter

I suggest you save yourself a time cleaning by finding a shop with a large parts washer.
Case, cam towers, heads, nuts, bolts, etc go in there and come out pretty clean.

Cannot see why #3 had 0 compression.
Mahle P/C's are probably reusable; a shop can spec them.

If you use new chains, replace the chain sprockets on the I-shaft with new ones:

New chains without new sprockets? Read this!

Thanks for the tips. I heard about the chain sprocket issue and need to look into that. I imagine that I will use a new chain.

The pistons will stay on the shelf since I am going to purchase JE pistons with slightly higher compression.

About the cleaning ... I guess that my best bet is to find a local machine shop and see if they will do it. I tried calling some transmission clinics to see if they would run my stuff through ... no dice on that.

[mca]

More photos of everything shelved and in its proper place.

A little boring, but I thought it might show that 1/2 of a garage is plenty of space for a rebuild. Most of the parts fit nicely on the shelf next to the water heater. The case internals are still on the work table.

[Gunter]

Originally Posted by mca

Thanks for the tips. I heard about the chain sprocket issue and need to look into that. I imagine that I will use a new chain.

The pistons will stay on the shelf since I am going to purchase JE pistons with slightly higher compression.

About the cleaning ... I guess that my best bet is to find a local machine shop and see if they will do it. I tried calling some transmission clinics to see if they would run my stuff through ... no dice on that.

There are 3 sprockets in the whole train.
I suggest:
Chain sprocket (Drivers) new with new chain.
Cam sprockets (Driven) re-use
Idler sprockets (Tensioners) re-use.
The Carrera tensioners in the '82 engine may be an updated version over the ones in the '80 engine?

Crank is inspected and just polished if the journals are still good; measure to see if Standard/Standard bearings can be used.

Rods:
Usually, they are lightly machined/trued to get any oval out of the large bore.
A shop will need the old rod bolts and one wrist pin to fit new brass bushings.
Use ARP rod bolts when fitting the rods to the crank; ARP can be repeatedly opened, OEM bolts cannot!

I would keep the Mahle pistons if they are in spec; a US '80 SC 3.0 has 9.3 : 1 CR and you wouldn't gain much more with JE's for single plug.
Besides, you can increase the CR by shaving a few thou off the heads.

964-cam grind is good; I suggest 1.4 overlap with CIS.
Instead of JE pistons, spend the money on SSI's and a flow-through muffler to gain some horses (Aircare nothwithstanding?).

Find a good shop with Porsche-experience; they should be able to do the heads and rods for you and inspect/polish the crank.
Camgrinder can do the cams and refurbish the rockers.
Send the rocker shafts along to see if they're still good.
Some people replace all head studs with steel; some just do the exhaust ones.
Check/clean all oil ports in the case, cam towers, crank.

Oh, what fun.

[mca]

Originally Posted by Gunter

There are 3 sprockets in the whole train.
I suggest:
Chain sprocket (Drivers) new with new chain.
Cam sprockets (Driven) re-use
Idler sprockets (Tensioners) re-use.
The Carrera tensioners in the '82 engine may be an updated version over the ones in the '80 engine?

Crank is inspected and just polished if the journals are still good; measure to see if Standard/Standard bearings can be used.

Rods:
Usually, they are lightly machined/trued to get any oval out of the large bore.
A shop will need the old rod bolts and one wrist pin to fit new brass bushings.
Use ARP rod bolts when fitting the rods to the crank; ARP can be repeatedly opened, OEM bolts cannot!

I would keep the Mahle pistons if they are in spec; a US '80 SC 3.0 has 9.3 : 1 CR and you wouldn't gain much more with JE's for single plug.
Besides, you can increase the CR by shaving a few thou off the heads.

964-cam grind is good; I suggest 1.4 overlap with CIS.
Instead of JE pistons, spend the money on SSI's and a flow-through muffler to gain some horses (Aircare nothwithstanding?).

Find a good shop with Porsche-experience; they should be able to do the heads and rods for you and inspect/polish the crank.
Camgrinder can do the cams and refurbish the rockers.
Send the rocker shafts along to see if they're still good.
Some people replace all head studs with steel; some just do the exhaust ones.
Check/clean all oil ports in the case, cam towers, crank.

Oh, what fun.

Great info! Thanks!

I didn't know the Carrera tensioners went through some modifications. The tens on the 82 were done about 3 years ago ... not sure about the 80. Any specifics on this?

Also, the 80 engine has all steel head studs. It looks like it has been rebuilt already. Is it okay to keep the steel head studs or should I still replace the exhaust side?

The info regarding the JE pistons is great too. Currently my 82 has headers installed by PO. Do the SSIs really produce that much more HP compared to other headers on the market?

[sabeo.m]

mca, what size JE Piston's are you going to get? I want to use my Mahle cylinders as well but I would like to bore them out from 95mm to 98mm if possible. What set up are you going to use for your P&C ?

[Gunter]

Originally Posted by sabeo.m

mca, what size JE Piston's are you going to get? I want to use my Mahle cylinders as well but I would like to bore them out from 95mm to 98mm if possible. What set up are you going to use for your P&C ?

95mm cylinders from an SC 3.0 cannot be bored out to 98mm because of the gasket-groove on top.
EBS uses 95mm cylinders from Carrera 3.2 engines to bore/plate to 98mm because Carrera cylinders don't have the groove.

Stick with OEM Mahle P/C's if you have them.

If you want 98mm, find a set of Max-Moritz (Very expensive) or find a set of Carrera P/C's and send them to EBS for machining to 98mm (Not cheap either)

Either way, the 98mm conversion is not cheap and by itself is not a huge HP-gain; you'll need to do more to get to 230 horses.

I have a thread on building my SS 3.2.

It's fun but costly.

[mca]

Originally Posted by sabeo.m

mca, what size JE Piston's are you going to get? I want to use my Mahle cylinders as well but I would like to bore them out from 95mm to 98mm if possible. What set up are you going to use for your P&C ?

After further consideration, it looks like I am going to keep everything stock except for the cam regrind (964 style). I just can't justify spending 12-15k on a car that is only worth 15-17k. If I had ample amounts of $$, I would probably go the distance with engine improvements.

If, however, my pistons are determined to be worthless then I will go with the JEs.

[sabeo.m]

Yep I'm in the same situation, my OEM P&C look decent, so I'm afraid I will be sticking to stock. I would love to do the 3.2 conversion!

Thanks!!

[ToddM]

Everytime I see these kind of threads, I think about what my wife would do to me... and the lack of progress I would be making since I have two daughters, 5 and 1.

[mca]

I have some questions for you guys. See pics please.



1) What happened to the threads? It isn't gunk and can't be wiped off.



2) Should I replace the distrubutor gear on the crankshaft? Take a look at that rough spot.

[Gunter]

Studs:
Are they all like that?
Case-side or head-side?
Could be hardened thread sealer; use new steel studs anyway.
Do not use a regular tap to clean out the threads in the case, use a thread chaser; it doesn't cut more material out of the threads; it just cleans.

Distributor gear:
Just the little notch on top?
I would re-use it.
If you do remove it, make a mark on the outside! They have to go back on a certain way to ensure correct timing!

[mca]

Originally Posted by Gunter

Studs:
Are they all like that?
Case-side or head-side?
Could be hardened thread sealer; use new steel studs anyway.
Do not use a regular tap to clean out the threads in the case, use a thread chaser; it doesn't cut more material out of the threads; it just cleans.

Distributor gear:
Just the little notch on top?
I would re-use it.
If you do remove it, make a mark on the outside! They have to go back on a certain way to ensure correct timing!

That stud is the case-side. Two of them look like that. Looks like I will replace those.

[Gunter]

Originally Posted by mca

That stud is the case-side. Two of them look like that. Looks like I will replace those.

Not just two; replace all 12 on the exhaust side for sure with steel studs.
Some people do all 24.
Correct height: 135mm re Wayne's book page 137.

You can make a clean-out tap by using an old stud:
Cut a V-notch along the length of the thread with a Zip-cutter; all you want is to clean it out without making chips.

[mca]

Originally Posted by Gunter

Not just two; replace all 12 on the exhaust side for sure with steel studs.
Some people do all 24.
Correct height: 135mm re Wayne's book page 137.

You can make a clean-out tap by using an old stud:
Cut a V-notch along the length of the thread with a Zip-cutter; all you want is to clean it out without making chips.

All of the studs are steel. They have already been replaced in the past.

[mca]

Received some news today from EBS. They have my heads,rods,camshafts,pistons and cylinders.

Here is what is being done:

HEADS
Valve job
Resurface heads
12 valve guides
12 valve springs
6 exhaust valves
6 intake valves
6 time-serts

PISTONS
Piston rings worn beyond specs. Replacing with JE 9.5:1 pistons.

CYLINDERS
Ok (thank God)

ROCKERS
Ok

RODS
Reconditioning all of them.

CAMSHAFTS
Regrind to 964 specs

The total cost for this work will be in the neighborhood of $3k. It would have been nice if I could have re-used the pistons ... but so it goes. I am trying to keep this rebuild at or below $5k. I certainly think it is doable since I won't be messing with the exhaust or clutch. We shall see.

I took the case, crank, intermediate shaft and oil pump to Rennsport (Charleston,SC) for inspection. Everything is good except for the backlash. Seems that the aluminum gear on the intermediate shaft is worn ($200). Going to have to replace this - requires machine shop press so I will have local machine shop do this work.

That is all for now. Next step is to get my stuff cleaned up and start ordering from Pelican!

Cheers,
Craig

[stormin48061]

nice, i was going to do 2.7 rebuild but no time and sold it. question, how difficult was it to remove the exhaust? I'm trying to get mine off to replace with ssi. should i take the car to an exhaust guy and burn them out?

[mca]

Well, it depends ... if you have the tool that can reach through the heat exchangers to the exhuast nuts then that will greatly facilitate the process.

I didn't have the tool but had other approriate tools that did the job. I tore one exhaust stud up pretty bad though and must have damaged some others pretty good too. The machine shop has to replace 6 of my exhaust studs!

But to answer your question ... it was a pain.

[stormin48061]

I have the right tool. the ones from the 2.7 came off in a breeze. the 3.0 ones are a p.i.t.a... soaking in WD right now, for about.... 2 beers. haven't tried again.

[garmo]

subscribed - thanks for sharing

[mca]

Originally Posted by stormin48061

I have the right tool. the ones from the 2.7 came off in a breeze. the 3.0 ones are a p.i.t.a... soaking in WD right now, for about.... 2 beers. haven't tried again.

I pulled mine off when the engine was on a stand. Can't imagine trying to get them off from underneath the car. It was tough enough doing it standing up.

Try some of that PB Blaster stuff. It works pretty well - better than WD40 for sure.

Oh, and I had at least 3 studs back out of the cylinder heads. The nuts were so rusted / stuck that when the nut was turned it was actually turning the entire stud. Fun.