Engine Rebuild DIY Project: 1976 Carrera 3.0

[Carrera 3.0]

I am located in Indianapolis, IN. Too bad it isn't a little closer!

[Carrera 3.0]

Finally got to work over the weekend. The engine is now mounted on a stand and I've removed injection, shroud, ignition, etc. Generally speaking, things are looking good so far. No overly rusty bolts/studs, oil on the thermostat looked very clean, etc.

There is a large chunk out of the alternator housing and the fan/alternator are missing altogether. I'm optimistically thinking that these may be issues for which the car was parked initially. Still wouldn't explain why it was removed from the donor car though.

It is a modest start... Next up will be removal of the rusty exhaust and checking on those pesky head studs: I'm putting the over/under at 4.5 broken.

[willcall]

Watching with interest!

I too have a Carrera 3.0 engine and have been doing research on modifications for this engine.
From what I can gather there are 3 routes to go down.
1. CIS
2. MFI
3. EFI

CIS is the cheapest by far and you already have it in your engine.
MFI will set you back around $6,000 on top of engine purchase price & standard rebuild items.
EFI will set you back about $8,000 on top of engine purchase price & standard rebuild items.
I would speak to Clewett Engineering re the EFI. They do a PMO ITB EFI setup which should produce around 260hp from the motor.

I personally am looking at the CIS route as its much cheaper for similar bang.

What i have found is this for a CIS.
9.8:1 mahle p's & c's.
webcam cams 21/30
Titanium spring retainers from Aase.
964 turbo oil restrictor.
'D' Ported and polished heads.
Adjusted distributor
SSi heat exchangers
Clewett park plug leads
MSD ignition & coil
This will set you back around 7-8k.
For either MFI or EFI add that 7-8k to the 5-8k for changing from CIS.
So you could be looking at around 20k to go to EFI or MFI with a fully rebuilt motor operating to its full potential. + the engine purchase price if course.

There are a few other things that I can't think of right now.

Basically all this costs much much less than going MFI it EFI and should give around 250hp.
Btw there is a 71T with a 76 carrera 3.0 fitted for sale on eBay atm.

W.

[Carrera 3.0]

Will - thanks for the reply. I don't think I'm all that interested in going to EFI or MFI, but those are intriguing options. With any of the options you've run through, there are a lot of engine changes being contemplated beyond injection. I'm not sure I want to venture out that far from stock.

Have you ruled out carbs? If so, why?

The yellow '70T is extremely interesting to me. I've actually located a '70T coupe body and am in the process of acquiring it for this engine. I am looking at doing some more extensive body and paint restoration, but I expect to end up with something roughly similar to the car at auction.

[willcall]

Originally Posted by Carrera 3.0

Will - thanks for the reply. I don't think I'm all that interested in going to EFI or MFI, but those are intriguing options. With any of the options you've run through, there are a lot of engine changes being contemplated beyond injection. I'm not sure I want to venture out that far from stock.

Have you ruled out carbs? If so, why?

The yellow '70T is extremely interesting to me. I've actually located a '70T coupe body and am in the process of acquiring it for this engine. I am looking at doing some more extensive body and paint restoration, but I expect to end up with something roughly similar to the car at auction.

No worries,
I have ruled out Carbs due to 3 reasons.
Tuning (ongoing)
Reliability
Fuel consumption

CIS is the most hands off so to speak (from what I can gather) & is also the cheapest to setup.
It looks the ugliest though.

With your stock motor you will probably want to replace the P's & C's while you are in there so it's a really good opportunity to go for higher compression like 9.8:1 or even combine that with a 98mm set so that it is a 3.2s.s. All this costs the same price as replacing the originals with new ones at the original 8.5:1CR. but gives better performance.

The cams, when you get them out may be good & you can keep them for sure. But going to a slightly lumpier cam will again give better performance.

You will just have to crunch the numbers on each part as you inspect it. Repairing the old bits is probably not worth it cost wise.

STAY away from twin plugging. Way too expensive!

Will

[jsveb]

EFI. Does not have to cost anywhere near to 8k. There are proven DIY solutions out there. Tbitz comes to mind as the cheapest by using your oem manifold. The DZUG buys have got an awesome itb setup, which is based on megasquirt efi like the tbitz.

I have a tbitz kit sitting on the shelf, but the CIS is doing just fine for now, so why bother.

Beware though, it doesn't take much CIS refurbishing before you get into DIY efi territory.

[willcall]

Jsveb:
Yeah I have seen it can be much cheaper than 8k.
8k is about how much clewett want for their state if the art EFI system. It looks like the ducks nuts and give excellent power. I would love that setup oneday.

[Carrera 3.0]

I finally have had some time to work on tear down and post some pictures. Everything looks pretty as expected with a whole bunch of broken head studs, and some oil sitting in one cylinder. Having torn into dozens of these engines in my experience, I have to say how pleasantly surprised I am with how easily everything is coming apart. The parts have required very little "encouragement" and I have yet to run into any real problem areas. To the naked eye, everything appears to be in good condition so far, save for a couple broken cooling fins on one of the heads (see picture, hoping this can be repaired).

The P&C's are MAHLE Nikasil, and look to be in excellent condition. This opens the idea of reusing this set up, which is perfect as I am going for a stock build.

Most of the case hardware has been removed, and I'll be finishing the tear down process this weekend. Then it's off to the machine shop! I'm still deciding exactly what I should have done.

[PilotFrog]

I'm about to do the same with a regular ol SC engine. I'm worried about the broken head studs though. How do you get the broken parts out? Love to see some pictures as you go along doing that, thanks.

[mreid]

Someone took good care of that engine. Upgraded hydraulic tensioners, turbo valve covers, pop off valve, and who knows what other gems. I think you got a good one. Good luck with the rebuild!

[Carrera 3.0]

[Carrera 3.0]

Mreid - I'm hoping (read: betting) that you're right. The upgrades were one of the reasons I was willing to take the leap of faith and buy this engine without any history. I still need to crack the crank, and inspect the internals before I'm going to sleep soundly.

PilotFrog - There are a lot of competing opinions on the best way to remove head studs from the engine, but most involve one of the many available stud removal tools and a blow torch. I've seen a hefty set of vice grips work pretty effectively too.

Aside from the fact that it makes shipping a lot easier, I'm inclined to let the machine shop handle this task. I am planning to send the case out anyway, so I think it's best to let the pros handle it.

[Carrera 3.0]

The case came apart without any issues over the weekend, and everything inside continues to look healthy. There is a small amount of corrosion near one of the mounting holes on the oil pump, but that is the only sign of wear that I've detected.

As you can see, everything is disassembled and ready to go to Ollie's. I spoke with them yesterday, and turnaround is expected to be 8-12 weeks! I'll be having them rebuild the oil pump, clean up the heads and insert new valve guides, and of course replace all of the missing/broken studs on the case.

After much internal debate, I have decided to make the following upgrades, but nothing further. As I've indicated from the beginning, this is to be a Sunday driver, not a race car or a daily commuter. I want aggressive and fun, but without being temperamental or obnoxious.

- S grind cams from WebCams
- PMO Carbs (not sure yet on exactly what setup)
- Aftermarket exhaust: Still looking for ideas here. I am not concerned with any emissions requirements, but I do want to keep noise level reasonable and retain functional heat in the car. Suggestions?

[MBEngineering]

HI Carrera 3.0

could you check before you send off your case, that some case mod's have been done, also check the exhaust guides and valve spring height's, check the inter-gear Ally gear for wear, check the head studs for the old Dilavar studs, as they need to be re-placed, could you send me you E-mail Add and I will send you over the re-call info on the engine as to what needs to be checked/modified , hope it turns out to look like this, or better



engine is 2.8 short stroke, 66X95, based on a 3.0lt turbo 1977 case, GT3 oil pump and GT3 inter-gear, Carrera 3.0 cylinders and heads, JE single plug pistons, (USA) SSI heat-exchangers, DC 62 cams, ARP rod bolts, TI retainers, early steel rockers, light flywheel and ally cover, P.M.O. manifolds (long) webber carbs.

regards mike

[Carrera 3.0]

Thanks Mike, PM sent. I really appreciate the info and hope my engine looks like that soon!

[Carrera 3.0]

Finally got at least a little bit more work done. Funny how life gets in the way of otherwise perfectly fulfilling hobbies. I got the head/cam assemblies and found some unfortunate news on the passenger side camshaft (some lobe damage). Hopefully this can all be resolved by the good folks at webcams.

I'm planning to go with PMO carbs and s grind cams. Anybody know how to tell if this will create a clearance issue with stock pistons and cylinders?

[Carrera 3.0]

More photos that show some of my cam issue. No takers on my clearance inquiry?

[Carrera 3.0]

Another stupid question: I know that I need to number punch/stamp heads, pistons, and cylinders, and that I need to avoid hitting any mating surfaces. Can anybody advise where it is best to mark each of these parts? Should I also be stamping the rods? They aren't going to the machine shop, so a piece of tape and a sharpie should suffice if stamping isn't advisable.

[Walt Fricke]

Rods have numbers on their sides - different numbers for each rod (statistically, because only three digits, so not like a serial number) - so you can keep rod and cap matched, and installed the right way around (cap to main part). Just write those down, although the only reason to keep rods in order is if their varying weights have been used as part of the balancing process. So just write down what goes where if you want. Or use tape.

Heads you can stamp in the middle of the top (valve spring side). The cam carrier doesn't touch the head there, and it stares you in the face when reinstalling. Although I don't think there is any downside to installing heads any old which way -- it is rockers which can potentially benefit from going back onto the cam lobes they are familiar with.

A head is a head is a head, unless you have jiggered with flycutting and cylinder base gaskets differentially to get things to line up - which is not a good way to go long term, though it can work. Best is all parts being of the same dimension.

Cylinders can be stamped on the base part which sticks out and you can see. Do it on the top or bottom. Top might be easier to spot while reassembling.

Pistons can usually be stamped on the crown, about in the middle. Again, you want it where you can see it during reassembly. Otherwise, you could etch a number easily lots of places on the underside. I recently purchased a tiny etcher, powered by one small (AAA?) battery, and its diamond encrusted tip (or is it carbide) works great for small marks. Cost insignificant, too.

[Carrera 3.0]

Thanks Walt!

Everything has been boxed up and safely shipped to Ollie's. My ego got a nice stroke from both Ollie's and WebCams as they commented on how very rare/special this motor is (A+ customer service - you get what you pay for). They even had to admit that they have no idea whether s grind cams will cause clearance issues with my pistons. Apparently the solution is to just do it and see what happens. Ollie's estimates 8-12 weeks for rebuilding the oil pump and heads, and machining the cases, crank, cams, etc. The waiting game begins! If only I could get my hands on the right car to drop this beast into... I'd have something to fiddle around with for the next few months.

For any DIYers out there thinking about tackling their first engine, I'll note that packing and shipping a case/crank with broken studs is a major PITA. This is especially true if you're like me and don't have lots of packing materials lying around or convenient Fedex pickups rolling up every day. I ended up spending around $90 in boxes and packing material, and just under $300 in freight with FedEx Ground, insured. These are costs to keep in mind.