Pfc. Parts

BC, thanks to your clarification (alusil instead of nikasil) I found an excellent reference on the subject of reconditioning a 928S block:

http://www.w124performance.com/docs/...nditioning.pdf

Sometimes just knowing the right key words can make all the difference.

brutus

You could not be more mistaken. ."I'm pretty sure PCA requires stock " they have many ,many classes from stock to slightly modified to race car to ....all that MUST be Porsche is the engine block, transmission case and floor pan from axle to axle. Everything else is only limited by the budget. Good news is they do have stock street classes or slightly modified with race tires. Serious PCA racers have pro support teams , stacker trailer semi haulers, and burn up 2-3 sets of $2000 race rubber in a weekend.
But there is something for everyone just get familiar with the rules and what people are racing. The Spec racer classes are popular because of all the limitations which make it a drivers challenge not a check book challenge although it does challenge the checkbook anyway

danglerb

I've got a 85 block sitting waiting to be project motor, I've kept the rings on the pistons because the bores look fine, and if the rings measure "ok" very good chance they are going back in. I don't think I was careful and saved the bearings, so new bearings. Money is going into the heads, mostly lifters and fancy springs for the cams I plan to use. Otherwise normal set of seals and gaskets.

BTW if the block etc have been sitting that long, gotta pull the heads to check for damage related to coolant.

Podguy

If you are considering building a race engine then there are many more considerations. If you do not need smog then a lot of things come off the engine. First off the 85 motor is probably the worst choice. If you are going to go that route then I would get rid of the 32 valve stuff and build up a Euro Hybrid. You will get more horse power and better throttle response. With a 5.0 block and Euro Heads you will be damn close to a S4 without any of the pesky expensive electronics. I will also assume you can put a stroker crank in this hibrid to give a longer stroke and add some torque. After that boring the block and using bigger pistons. A bit of porting and polishing can help. The key here is each thing you do gets incrementaly more expensive with diminishing returns.

Then there are things like cross drilling the crank, adding a sump and a few others. I would not consider using used rod bearing that is for sure. All this depends on how intense a racing campaign you are planning. If you race all the time then you know. If not then the 5.0 hybrid is the cheapest way to get in game and find out what you want. The best person to ask in this case is Mark Kibot.

Hope this help.

Pfc. Parts

Oh, you have no idea. I've been much more mistaken than that. There was this time I was training for my IANTD level 1 deep air certification. We were doing a decompression dive, 90 minutes at 130 feet. I was of course wearing doubles with redundant regulators. At the 90 foot stop my primary reg quit. Since I was hanging on the line with another guy, when I stopped breathing I instinctively grabbed his backup regulator and stuck it in my mouth.

I didn't grab my backup.

I never heard the end of that one. Dumbest thing I ever did in my life. On the upside, I lived through it.

Then there was the time I tried turning towards a cliff face while I was soaring a hang glider ...

Never underestimate my ability to be mistaken. It goes with the territory. You've probably heard the old adage "If you build something foolproof, they'll just build a better fool". Well, I'm the better fool.

danglerb

Mistakes you live through are the best kind.

namasgt

For a S4 32 valve engine a complete rebuilt with machine work to the heads cost about $10,000, you doing the labor. The price includes changing every possible thing while the engine is out and apart.

Pfc. Parts

Excellent. A ballpark figure is what I was looking for. TV suggested just buying another car but I've sort of already done that. I like working on these cars, which is why I bought the parts car. $10K is something I can work with. Now I need to figure out the "must replace" list since I'm one of those people that likes to have all the parts lined up and in stock before the project starts. Obviously all the bearings, I'm going to research all of Dan's suggestions too.

I think I'm going to try to stay close to stock (no super/turbo charger). I haven't heard any arguments in favor of them yet.

Pfc. Parts

Very much, thanks.

brutus

You might want to consider building a stroker motor. Then it gets interesting and it solves the crank oiling issues of the stock crank (search 2-6 rod bearing failure). Sure you need 104 mm pistons and custom rods but bumping it to 6.5 liters makes a world of difference.

These stock engines often run well 200,000-300,000 miles rebuilding one at 140,000 is probably long before it needs it and will net you little or no improvement in performance.

Speedtoys

Most race classes, engine wise, are stock or OEM replacement spec.

The Unlimited classes...then you can screw with the OEM powerplant by form & function.

I'll pull hardware from a head that even LOOKS non-oem SPEC at Nationals and leave it to the manufacturer to tell me if its OEM replacement or not.

Locally...who cares, but with $$$$$ on the line..the entire national class and it's nationwide competitors care.

Clean classes are fun classes.


Then there's Spec Miata...

Podguy

I just pulled a head apart on my 85 today and measured the valve guides. They measured less than 50% of the factory factory. The intake valves were more like 30%. I could have some expensive machining done on the head which I am sure most machine shops in this area would automatically recommend without even meauring.

As a result with four new valves and a touch up on the surfaces of the valves and seats and install new seals the head is good to go. That is a lot cheaper than the $500 the machine shop quoted. I am temped to take the head around for estimates just to see what I kind of BS I get.

$32 for new seals and maybe $20 a valve for used exhaust valves and the head is done for around $100.

Not all situations call for all new parts. The estimated mileage on this engine is over 100K miles.

Pictures to follow.

Pfc. Parts

Dan, you give me a great deal of hope. I can't wait to see the pictures. I also got in touch with Jim Morehouse ( <jim928@ptd.net> ) and found out he has a full set of Factory Training videos for the 928. He apologized for the fact that all the videos were based on the '85 S type. I all most fell off my chair

Needless to say, I'll be in further contact with Mr. Morehouse as my project develops. This forum is a great resource, I really wish I had it around back in 78 when I was doing the 914 and 87 when I was doing the 931. See? Somethings really have gotten better. We need to celebrate them sometimes, it seems lately all I do is talk about the bad stuff that's happened over the past 30 years. Makes you crazy.