Planning budget for rebuild....

[mtrotter]

Hi, I have an 80 SC with a totally stock 3.0 and 174,000 miles on it.
It still runs great but I found 4 broken head studs, Im thinking I am just going to rebuild it completely.
So, for planning reasons I have a few questions for those of you that have done it recently. First off, I plan to replace bearings (main, rod, intermediate), timing chain and guides, tensioner with carrera tensioner, cams with 964, valve springs with AASCO racing springs, head studs with ARP steal bolts and have the crank knife edged, the cylinders half mooned, the case boat tailed and have shudder pins installed.
The heads will go to a machine shop as well and be checked, repaired, cams installed and get a good valve job.

(any comments on these things?)

So, im guessing after researching, without needing to replace cylinders or pistons (hopefully) parts are going to cost me about $3000 maybe a little less.

How much can I expect in machine work?
$1000-2000?

Has anyone used the ARP head studs? or should I just go with Dilivar?

Is boat tailing and shudder pins worth it for a stock motor that will only see autox once a month and 2 track days per year?

I live in southern California so there are quite a few good shops people have recommended, perhaps Ollie's in Santa Ana.

Thanks in advance.

I plan to start the rebuild later this year, maybe early December. I just need to know how much more money I need to set aside. I saved up $4000 for the job, but thats when I planned to drop in a stock 3.2 that was used. I now want to rebuild the 3.0 and have it last another 175,000! and run smoother!

Morgan

[Steve@Rennsport]

Morgan,

A few thoughts,......

1) Don't waste your hard-earned money with boattailing, shuffle-pinning, and crank knife-edging on a stock cammed engine. That stuff is great for race motors that see 7.5K+ RPM and its well worthwhile for those things.

2) Use the late Dilavars as they do a much better job of holding head torque from cold to hot. ARP's are very durable but they do not work as well as the 993TT Dilavars and by not wasting money on unnecessary machining operations, you can afford to do this right.

3) If you want the engine to last another 170K miles, budget for new P/C's, intermediate shaft/gears, and all new chain sprockets.

[mtrotter]

ok. cool. thanks for the information on the dilivar studs. I was torn. I know the dilivar can be quite brittle and after time tend to break. I hear good things about the ARP studs though also, so your insight was well recieved.
As for machining, because I would like to see increased performance out of a mostly stock engine... 964 cams and SSI heat exchangers. I thought that knife edging the crank would give noticable throttle response and smooth power delivery. I know it does with the BMW and VW motors I have rebuilt in the past.

Any thoughts on that?

So, no need to boattail, stick with dilivar studs. Ill probably use the old pistons and Cylinders if the machine shop says they are good to go.

Thanks Steve,


Morgan

[Steve@Rennsport]

Originally Posted by mtrotter

ok. cool. thanks for the information on the dilivar studs. I was torn. I know the dilivar can be quite brittle and after time tend to break. I hear good things about the ARP studs though also, so your insight was well recieved.

Dilavor is not brittle at all,.....its very elasticity with temperature are some of its valuable qualities. The older ones were prone to corrosion that would cause failure.

As for machining, because I would like to see increased performance out of a mostly stock engine... 964 cams and SSI heat exchangers. I thought that knife edging the crank would give noticable throttle response and smooth power delivery. I know it does with the BMW and VW motors I have rebuilt in the past.

Such things yield no gains until the engine is over 7K RPM and 964 cams won't make any power or torque up there,....

So, no need to boattail, stick with dilivar studs. Ill probably use the old pistons and Cylinders if the machine shop says they are good to go.

Yessir, thats correct,.. .
Remember, if your engine longevity expectations reach to another 100K-150K, reusing your current P/C's runs counterproductive toward that goal.

[robmog]

get wayne's rebuild book, it will answer all your questions.
even if you don't rebuild yourself,
acquiring this info will make you an educated customer.
the best $25 i ever spent, AND a great read at that!

[euro911sc]

+ 1 on getting the book.

Ollies does good work and have an amazing case cleaning tumbling machine. Looks like new after.

I ditched the dillavar for all steel head studs on my recent re-build. I had one broken stud.

While the others are correct in their comments on the P&Cs, they have gone for 25+ years... if they measure in spec, that's a big if, I'm sure you could drop them back in for at least another 5-10 years of use depending. You have a bunch of other cars so its not like you'll be daily driving it 100mi./day. However, if you had 4 broken studs, be sure to review the cyl to head sealing surface for marks from broken seal rings. I had that and needed 2 new C's.

Alternatives are finding another good used set w/ less miles on them. Re-plating the C's and finding good P's. Swapping to the Euro 9.8:1 P's (hard to find and not cheap). Or buying aftermarket P&C's (the most expensive).

A good full head job will be $600-1200 all in, but not including a spring change as you are also planning.

Plan on $500-1000 in special tooling for your re-build. Buy the Pelican HW kit and chemical kit. Budget another $250-500 for powder coating and sand blasting... if you plan on making the engine shine...

Lastly, add another $750-1000 for wires, hoses, seals, and sensors you feel might let you down in the near future.

Have fun!! I am!

-Michael

[mtrotter]

Thanks for the info Euro911SC

I havent had a chance to call Ollies and ask about pricing on stuff. Unfortunatly I do have a budget on this, I just dont know quite what it is yet. Im thinking less than 7k for sure. and that will include freshing up the tranny.


I found a place (EBS Racing) that sells replated Nikasil cylinders for 125 +100 core. so thats $225 per for me. Not bad. about half price.
And Im guessing Ill just pay full price for the pistons.

Now the heads, Ill be interested what Ollies wants to charge for port, polish, valve job and installing my cams and valve springs.

I got some conflicting information today, maybe someone could fill me in based on personal expirence. I was told that the 964 cams would seriously decrease the low end power and only show slight signs of improvement in the top end.

any one know first hand?

I still plan to at least ask about knife edging the crank, at a minimum ill have the crank magnafluxed, micro polished and ballenced. Along with the rods and pistons being ballenced. The case cleaned and checked

Im guessing all in all about $2300 in machining Think thats a low guess?
I need to call and see. My expirence with machinists is this... if you have to ask, you cant afford it. But I tend to ask anyways.

*This guess is based on the heads not being cracked and the crank not needing to be replaced or welded.*

Now, other than replace motor mounts, powder coat and shine metal. ruber hoses will be inspected and replaced. injectors will be cleaned and flow tested.
Should I waste the money having the intake manifold ported and polished? Is that remotely worth it in these cars? I know it is in other applications but how about this one? Remember Im a BMW guy of 15 years.

The jury is still out as to what head studs Ill go with. I probably trust Ollies recomendation on that one. So Ill let you know when the time comes.

[euro911sc]

Originally Posted by mtrotter

Thanks for the info Euro911SC

I haven't had a chance to call Ollies and ask about pricing on stuff. Unfortunately I do have a budget on this, I just don't know quite what it is yet. Im thinking less than 7k for sure. and that will include freshing up the tranny.

I did my engine only rebuild on less than 3k ($1200 was heads)... but I took 3 years to do it. If you can wait for the right parts to come up in the classifieds or flee-bay you can save decent bucks. But it takes time. The market is soft now, however, so I bet if you put a WTB out there for a good used set of P&C's you could get the deal you need if you choose to go that route. Steve is right though, if you intend to go another 175k miles you need new or near new parts.

Originally Posted by mtrotter

I found a place (EBS Racing) that sells replated Nikasil cylinders for 125 +100 core. so that's $225 per for me. Not bad. about half price.
And I'm guessing Ill just pay full price for the pistons.

EBS is good or CN Engineering nickies (they may supply EBS ) check the pistons out first. hell check everything 1st. Then go buy stuff. Slower, but smarter And CHECK all your NEW parts. Some venders have a rep for actually sending you the wrong stuff... ie:You order 10:1 and you get 11:1 and trusted the box... "Wow! this engine really whails!.... ... ... boom!" Happened to a friend. *shrug* now he triple checks everything.

Originally Posted by mtrotter

Now the heads, Ill be interested what Ollies wants to charge for port, polish, valve job and installing my cams and valve springs.

I got some conflicting information today, maybe someone could fill me in based on personal experience. I was told that the 964 cams would seriously decrease the low end power and only show slight signs of improvement in the top end.

any one know first hand?

If you are assembling your engine yourself you will be putting in the cams. You send all 6 heads off and then they come back. If they are assembled you still need to check the spring height just in case. Then when you put on the cam carries to the heads you put in the cams and make sure they spin freely after you torque the whole thing down.

Originally Posted by mtrotter

I still plan to at least ask about knife edging the crank, at a minimum ill have the crank magnafluxed, micro polished and balanced. Along with the rods and pistons being balanced. The case cleaned and checked

Yes to all above. Though, Porsche cranks are very well balanced from the factory so I would expect, if no crank work is done, it will not need a balance. YMMV.

Originally Posted by mtrotter

Now, other than replace motor mounts, powder coat and shine metal. rubber hoses will be inspected and replaced. injectors will be cleaned and flow tested.
Should I waste the money having the intake manifold ported and polished? Is that remotely worth it in these cars? I know it is in other applications but how about this one? Remember I'm a BMW guy of 15 years.

As far as having a lot of the more exotic machining, honing, balancing, porting, etc.. done you will really be chasing the last few single digit HP gains on your engine. You may wish to simply save the money and put it toward a good header/SSI & muffler combo that will get you a fairly good HP ++ results. To get more out of it you need to drop the CIS and change cams, pistons, induction... $$$ While you are in there just go to 98mm or 100 mm bore for a little more grunt...

... oh... did you just fall down that slippery slope? Or did I push you

-Michael