I did the same exact thing your doing right now 13 years ago. N/A 86 block, bought 1 used turbo pistons, one used rarest rod, reused the 3 ok pistons/rods, The most I spent was $400 for the crankshaft to be cross drill and rods turned down 1size, gathered the gaskets I needed pay check to pay check. It currently holds 18 psi without issues using k26-8 turbo. My block bores looked about the same if not more worn and scratched then yours. The only tolerances I checked were the piston ring gaps and used a plastic gauge for all the bearings. Highly doubt you'll have any issues. And I keep asking you if you would want turbo pistons because I have a set I'm not going to use. 3 turbo pistons and rods that came out of my 951 from the last engine that ate the #2 rod bearing, and I picked up another turbo piston and rod because I was thinking about converting my 86 NA but my plans changed. So I got these real cheap pistons...or not doesn't matter just trying to help. If you win the lotto I recomend you put a crank scraper with a screen in it and baffle the oil pan. Good luck with your biuld.

 

I appreciate the offer. Right now I am weighing my options. Are your 951 pistons tolerance group 1?

 

Ive done it like this if it is any help..

https://rennlist.com/forums/944-turb...it-look-4.html

 

What do you think is fair? $70 free shipping? Budget build right? You can even reuse three ring sets (not recommended).






Add edit: Voith that's awesome information!

 

I would advise against NA pistons. Piston rings are smaller IICR.

http://www.forgedpistonparts.com/por...rbo-all-years/

Not that expensive. Or get some turbo ones from lart.

 

I wouldn't run tall pistons in that hole with new rings. Broken combustion ring & blowby would be my main concerns. Theres a reason why you don't like the cylinder wall.

 

a scratch that small , with the pressure of new rings I think it would eventually wear smooth over time any how , like its been said a few times here before many of us including myself have put engines back together that were much worse off than that. In my opinion I don't think its worth the worry. and as far a spending money elsewhere you have a mega squirt system perhaps running an electric water pump might be a suitable up grade to look into . I've been looking into it myself for my new 924s and it seems pretty promising and will save money on maintenance over time like timing belt changes and the price of multiple shelled out water pumps. Best of luck to you I think your engine will be fine.

 

If your going to do a budget build, I would run it. I have 3 blocks all with similar wear with varying mileage from supposed 60k(used one I picked up last year), to 200k on the current money-pit. Only issue on the high mileage one is a bit of blow by, a blown HG, and 0 oil pressure

In all reality I wouldn't worry too much in your case, you know what your doing and the possibilities of quick failure from the current wear surely cant be any worse than most other DD cars with 100k+ original miles on them. Just my .02

 

I wonder what we would all think (or do) if we all got to take a look at our cylinder walls.

 

I'd prolly scrub em down with some marvel mystery oil clean the pistons up put new rings in and throw it back together , small scratch like that I don't think too much of. Of course that's me personally

 

I would guess the vast majority of running engines on here have bores at least as worn as mine. Seeing as how so many are so intent on following the WSM to the letter, most would "want" to do a full rebuild if they saw it. Even then, when the real world is taken into consideration, I bet most would elect to leave it alone. Ultimately, the way I see it is it can't possibly be worse than the blown motor its replacing that had horrible leakdown from a very tired head and so-so compression from worn rings. FWIW that 86 951 motor went the distance. It blew with over 200k miles on it and it lived nearly it's entire life under my ownership at 20+ psi; making tons of power and getting driven hard every day before finally breaking a rod bolt in vacuum while cruising at 70 on the highway.

All that being said, I'd be thrilled if the new motor makes the same power the old one did, doesnt leak or burn crazy amounts of oil, and lasts another 100k.

 

id run with it.

 

And run with it I will... Voith that's AMAZING info for a DIY AN30 lap job, but I think I'll pass on that procedure this time. I'll take the general advice and trust my own instincts which say "run the bitch; boost it hard and dont look back". The block will get new rings and bearings (and seals obviously) and go back together. Humboltgrin, are those pistons group 1? If so I'll probably end up taking them. They appear to be in decent shape, I'm sure I could clean them up with some work.

 

Yes they are. You can see the stamp on top of the piston in the photo I posted for verification. PM me you address and I'll send them. You need the rods too right?

 

200k at 20 psi , hell you cant complain with that at all. Ive seen engines running 8-10 that have blown long before that. best of luck with this build I don't think you will have a problem .. just remember to stagger the rings lol , Ive had a few friends in the past that made that mistake and couldn't figure out why they were getting gratuitous amounts of blow by.