Jim Devine

The Corvette restorers are fanatical- I know of a '64 fuelie coupe than when it was being restored the owner searched everywhere for a proper pair of unmolested heads. The heads on the car, although original to the car had been ported and even though no one would see that, he would know.

mark kibort

cant you cut them back to fit? i know they are pretty long, but is that a possibility?

JWise

??? My COA contains VIN, engine and transmission serial numbers. Am I missing something here? Thanks!

Imo000

Even though the engine was fixed in a somewhat unussual way, it is worth more than a S4 replacement. I this was a good financial decision.

Rob Edwards

D'oh! No, _I'm_ missing something- I was knee-jerking based on the fake COA generator template that exists here somewhere. I have to confess that I've never ordered a real COA, so I will somewhat sheepishly retract my statement.....

That's actually a good thing that the COA has them, 'cause for ~$100 you have factory validation of matching numbers if that matters in a given transaction.

JWise

I agree. Not cheap, but I think the documentation is worth the money when it comes time to sell. Thanks for the clarification!

Rob Edwards

Compared to what Ferrari charges for Classiche certification, a Porsche COA is a frickin' steal. (though the process is much more involved for classic F-cars, and the stakes are just a little higher...)

http://www.ferrarichat.com/forum/att...mentid=1837743

Bill Ball

Nice to see the recent updates. This thread is getting close to a happy ending. Oh, still much to be done, but it appears all doable after the woeful impressions 6 years ago. Keep those rod nuts in the glovebox.

FredR

Erkka,

Can you describe the differences? I have wondered what it may take to get my S4 motor back up to GTS spec but if I were to go this route eventually it would have to be with a system that worked/resolved the apparent GTS flaws.

Originality is not my concern- more a question of recovering original performance [or better] without compromising anything.

I understand the GTS has some reliefs in the casting to give more clearance from the rotating assembly although exactly where no clue- presumably close to the rod nuts?

Rgds

Fred

Vilhuer

Physical differencees in shape and function is another matter. I meant about numbering differencees between blocks. Besided obvious number on top there is upper and lower part pairing number which need to be in certain range for block to be believable GTS block. Casting week in parts must be within reasonable range and also cast part number must be correct etc. And then there are obvious design differencees which are easy to see at least when engine is in stand.

All design differencees between S4/GT and GTS block have been talked about years ago in few threads. There are pictures of them in archives.

Strosek Ultra

The GTS block has some extra bay to bay pressure equalization holes. Thanks to Erkka for one of the pictures.
Åke

FredR

Thanks chaps- not particularly interested in the paper work trail as the only person I intend to fool is myself [I am pretty good at that!].

A better way of expressing myself would be "what needs to be done to fit a GTS rotating assembly [or stroker crank] to the S4 block and make it work correctly".

I know there is some difference in the inter bay breathing and this has been challenged as to its effectiveness of operation. Indeed the entire GTS crank design has been challenged and some strokers have a crank more in line with the S4 configuration [or so I understand].

That Porsche tried to stroke their original design and arguably failed as they changed rod design and never got the breather system right suggests that doing so is a major challenge for others like Greg to take this on board and achieve success speaks volumes not to mention what you chaps in Finland have also achieved.

I was following this thread with interest as Rob's mission to get his original motor back to stock form in perfect condition is quite a challenge in itself given the rod that let go and subsequent damage. That fitting a wet sleeve is not viable according to Greg is also interesting- presumably because of the lack of "meat" in the casing design. Clearly a design that was at or near to its limits.

Rgds

Fred

Strosek Ultra

Fred, I was going to put a GTS crank into a S4 block but as you remember I sold the crank to Houssam in Saudi Arabia. Now it will be a 3.75" stroker crank with 104mm pistons under some special ported 2V heads. I have not checked very carefully but if there is an interference between the the rotating assembly and the block it cannot be very much, not more than it can be cleaned out using the die grinder.
The major design fault with the 928 engine block is that the oil drains also have to act as pressure equalizer between the crankcase and the heads. Best is to add some chimneys inside the V for the pressure equalization making the oil drains to work as they are intended to do. Check out the Ford Modular engine block which is very well designed in this respect.
Åke
http://www.drivingenthusiast.net/sec-blog/?p=4024

William A

As an aside and since it was mentioned in this thread, the dirty little secret with the Ferrari Classiche program is that Ferrari really doesn't know the original info in most cases. So the client answers a questionnaire citing all the original info, stampings present and documentation the client may have, and then build a book with the information the client provided in a book that the client is charged for.

On top of that, I know of hard data where a client had a car restored to "factory" through Classiche and showed the car in a reputable concours and didn't even garner a Silver because so much was incorrect. In one specific case that I know personally, the clients spent many hundreds of thousands precisely so he would "ace" the concours test. Disappointed is an understatement.

Rob is doing this the right way for long term value of his GTS, in my opinion. Glad he is preserving most of it and cosmetically it will be indistinguishable.

mark kibort

been racing a pretty stock 85 block with it bore out to 104mm and using 968 sized pistons and a much larger stroke crank than the S4 with no issues... I dont know the details of why the GTS has the oiliing issues, but i would think with the S4 block or 85 block, there should be no issues if you use custom pistons and Nicasil or find the coating and make GTS copy pistons. if you have the pistons and rods, i would just bore that out to use 968 pistons and make it a GTS over bore engine.
i think that still would be near 6 liter.