V2Rocket

if you decide to change engines to LS# or 951 i might buy your '68 motor.

95ONE

yes, they all (That i know of) pushed them beyond 400hp though and killed them in short order. AND no/yes.. Weston Dillard has been beating down a completely stock 3.0 bottom end with an 8v head for years. keeps power right around 350 @ wheels.

Am i going to do it with mine? Hell NO. Pistons / Rods are getting upgraded. Stock 968 variocam head. custom everything else..

CPR

Head gasket.


Abso-frickin-lutely.

ehall

Few will ever be THAT bad! lol

V2Rocket

you can put 951 rods in a 968 engine, no?

PorscheDude1

Don't think the 951 pistons fit the the 968 block without motorsport piston shims.....

67King

what are the respective rod lengths? With such a drastic stroke difference, rod length is usually changed.

different bore sizes mean different pistons. Are piston shims found with blinker fluid and muffler bearings?

gt37vgt

show the quote where it suggested 951 pistons in a 3.0 ??
the rods are the same length the pistons are different pin heights

Chris White

2mm of duct tape on each side will do the trick.

Chris White

OK – I’ll break it down a tad –

There are five distinct steps to building a good one off motor like a 16v turbo –

You need to know what configuration works (crank, rods, pistons, manifolds, turbos, wastegates….)
You need to know which aftermarket parts work well (you will need a lot of non Porsche parts, you need experience with the vendors to know what actually works and lists)
You need some decent machining abilities or a connection to a good machining shop
You need good engine building skills and tools (plastigage is not a ‘good’ building tool!)
You need the ability and knowledge to tune it

You can be an engineering genius but if you miss one of those steps your project will most likely fail like many have in the past. Finding all of those in one place is not easy….

BTW – ‘wormholes’ 16v turbo really sounded nice at Watkins Glen on Friday/Saturday – he was voted ‘best prepared’ by the corner workers!

95ONE

weird.. one of my posts are missing?

Rod lengths are the same, just make sure the crank end of the aftermarket rod clears the block. .. Pin heights are changed.. Not good for a turbo motor.. Leaves less meat, for the top ring land, and less design room for the top part of the piston, but not crippling in this case. The Piston is also larger for the 3.0. You will need to modify the 16V exhaust to to mate up to the turbo. The Stock intake takes up too much space where the turbo will go, so you will have to make/buy one.

Putting it all together. (bottom end only) Well, I'll just say that I have someone else I trust to do that. - I need someone else to bitch at for something!

odurandina

968 Turbo S pistons ?? a mint (woefully $$$$) ????


it seems from what i'm learning... (137 seconds before Krazy Karl's motor started losing power) and i barely know what i'm talking about, that there comes that moment when the engine should be pulled and the crank turned and bearings replaced, do a valve job and maybe some other stuff. but i'm wondering...


can partial rebuilds bear any fruit ?


what i'm saying is; if 2/3 of the wear is on the rings, why not just turn the crank install the new size bearings, oil pump, do a valve job, and new cams, belts, rollers etc right there, and put a set of oem sized rings right back in there ? or rings just slightly over ?

or if you go this far, you're stupid not to send the block out to be done too ?

gt37vgt

i don't understand the $1500 for new cams for what started as a modest build ..

Chris White

Don’t get your crank turned unless it is damaged.
The journals are heat treated at the factory and they are very hard, usually they are in great shape and a quick polish is all they need to be put back in to service.

ehall

I'll try to answer your one question. Based on your goals, I don't think a partial rebuild would bear much fruit.