Engine restoration taboos?

[NV Stig]

OK, here's the situation:
It's a 69S, 2.0. Cylinders have to be honed which will bring it to a 2.2 liter, much cheaper than replacing with new cylinders all around, about $6K . Cost of heads is negligable and there is immediate availability on an MFI pump for a 2.2 which is a wash on cost for the rebuild of mine.
Is it considered taboo in the culture to expand to a 2.2 on these cars? I was told it was common practice since the 90's when parts started becoming scarce.
I appreciate the insight
Scott

[preS]

The other day I read on this board that some one (Tom?) sold an used 69S P&C set for $1000. If your set is still good you rather sell your set and get some 2.2 cores and have those honed unless you care for authentic look. 2.0L/80mm cylinders should be bored and honed to 84 mm and I don't know if that is possible or whether they are too thin for that.

just my $.02

Richard

[304065]

OK, here's the situation:
It's a 69S, 2.0. Cylinders have to be honed which will bring it to a 2.2 liter, much cheaper than replacing with new cylinders all around, about $6K . Cost of heads is negligable and there is immediate availability on an MFI pump for a 2.2 which is a wash on cost for the rebuild of mine.
Is it considered taboo in the culture to expand to a 2.2 on these cars? I was told it was common practice since the 90's when parts started becoming scarce.
I appreciate the insight
Scott

Scott,

It's not really TABOO, it's just a technical challenge and makes the 69S no longer original. If it's a REAL 69S, it is worth more in original condition if that makes any difference. Look even though the 69S has 170 HP, it's still not a rocket ship by any stretch, particularly around town with stock gears-- the displacement increase will help but not to the same extent as installing, for example, a 3,2 with MFI. Now THAT would be something.

But lets assume you want a basically original looking 69S with more pep. Ok, first challenge is the heads. 69S heads are the rarest most unobtainium heads you can find, and to utilize them with 84mm cylinders requires that they be cut. THAT is a TABOO-- even though you can find adapters to switch back to the old cylinders, it just doesn't make sense given the cheapness of 2,7 heads with bigger ports and bigger valves, so what if there's a CIS cutout in the intake port. Also, the 2,2 and later heads have a different casting number which is visible externally (not easily though) if you care about that sort of thing.

With a stock 66mm crank cutting the Birals 1mm to 81mm gets you to a 2,1.
You do the math- 81 x 81 x 66 x 3.1416 /4 * 6 / 1000 = 2141 cc. That's about the max cut you can do. So you would need some custom JE 81s (see my thread on Pelican, search for "jugs and slugs") or some ultra-rare Mahle 906 81mm pistons which are 10,3:1, impossible without twin plug.

If you are committed to bumping it up I would get some Biral 84s, some 84mm Mahle pistons and some 2,2 MFI heads. Some prefer to upgrade the rods to 2,2 although your 2,0 rods will work. Rebuilding a set of rods is about $500 not including the bolts (about $100).

Hope this helps.

[kenikh]

something is not right here. 80mm cylinders cannot be bored past 81mm. 84mm are a different beast altogether.

As far as all of the other points, 69S heads are a bad match to 84mm Mahle pistons due to valve angle.

Keeep the motor stock.

[NV Stig]

Thanks for the input guys.
I'm not to much interested in getting a bigger engine as I am getting the car on the road. I see where you are going with the math, I may go past the limits of the cylinder.
The current pistons are too worn, but cylinders are good. Bore increase will be increased 20 thousandths, and will have the J&E aftermarket pistons inserted, which are bigger racing grade pistons from my understanding. I'm stuck here if I want to keep the original cylinders. It's my understanding that the 2.2 heads are a simple bolt on from there.
The other lynch pin to the whole deal is the easy access to an already overhauled 2.2 liter MFI fuel pump, reducing the down time on the car. I'll get my old pump core back and deal with it at a later date. I'm told it is difficult to get a lold of the guy that does the work, and he works at his own speed. Very good at what he does, but again, is kind of casual with his effort.
I may have bit off more than I can chew with this little project. I'm sure you guys have put yourselves in the same boat at one point. I have the suspension pulled out, the transmission in a billion pieces along with the engine. I'll be saving for another year or so to get new 2.0 pistons at this point. I want to drive this thing again

[304065]

Can I ask a threshold question:

Why have you concluded that your cylinders need to be honed and pistons need to be replaced?

You should measure the piston bores to actually see if they are worn. Likewise, measure the pistons to see if they are undersize. Diameter at the ring lands, diameter at the skirt, ring groove width. This last part is pretty important, if the grooves are too worn then new rings will immediately break.

Looking at what you have I would tear it all the way down, clean everything and then start taking some measurements. Or if you prefer, have a local shop do it for you. Isn't EBS nearby?

Even if your cylinders are shot and pistons are good, a replacement set of Biral 80s is a lot less than new pistons.

[NV Stig]

Hello John,
The engine is pulled apart and cleaned presently. It is in a Porsche restoration shop in the bay area called PBR Restorations. The owner, Pete, has been doing these engines for 30+ years now. I believe he's on these forums. His shop is a living Porsche geneology museum with 5 or 6 cars in various points of repair.
It appears that the engine has never been overhauled, valves never done, and the engine has 174,000 miles on it and sat motionless for the last decade. It was my fathers car, purchased in 87, and he passed away several years ago. He wanted to get it up and running, and I'm working on it kind of as a tribute to him. It was also my Ferris Bueller car growing up. Besides routine maintenance, the only major work I know being done to this car were the 930 style chain tensioners and a new ignition system.
When we pulled the car apart, the hope was to recondition the pistons and hone out the cylinders and get away with new rings. When the pistons were sent out, the info came back that they were shot, and beyond repair. We are at plan B presently, which is the honing out the current cylinders and putting in the new larger cylinders, and incorporating the 2.2 heads
The MFI is also being overhauled, as mentioned before. We are currently trying to get a 2.2 liter MFI pump. It seems to be the least cost prohibitive at this point. Plan C is new cylinders, which is about a grand a jug. I'm hoping to avoid that at this point.
I'm deferring a lot to this guy, he know a lot, and answers my stupid questions. I like the additional opinions of the forum as well. You guys are a huge source of info as well. That's why I bounce this info back and forth between the two.

[kenikh]

New Mahles are $4200:
http://www.pelicanparts.com/cgi-bin/...2D%37%31%29%20

New JE/Nickies are $3899:
http://www.lnengineering.com/911.html

QSC Nikasil cylinders and JE pistons are less from Supertec, but can't recall the price.

Overboring your cyls to 85mm and using JEs is just the cost of the bore/hone and pistons at about $50/cyl + $1000 for all 6 pistons

[NV Stig]

Thanks Kenikh,
Just saw that in Excellence after you mentioned it. Appreciate the info. I'll make an inquiry.
All the Best,
Scott

[kenikh]

Thanks Kenikh,
Just saw that in Excellence after you mentioned it. Appreciate the info. I'll make an inquiry.
All the Best,
Scott

FWIW, I went JE/Nickie - they work so well together from a metallurgical perspective. Every bit as good as Mahle, IMO, when all factors are averaged in. JE pistons in Mahle cylinders are OK, but you have to be really careful when ordering the JEs to make sure you get the right alloy to ensure you get the right material expansion match. Same with Birals and JEs. Charles at LN can give you the nuts and bolts.