Jay Wellwood

This thread will help chronical the above topic hopefully for those interested to follow. When I first started this project, there was little information to be found other than a few notes here and there.

As such, I will attempt to capture all of the WTF's as well as no NS's in this project...including any Technical aspects that I can include.

Feel free to ask and point out problems as this gets going. My goal is to complete this project by the end of this year.

Up front I would like to thank Raj forhis support as well as insight to this topic...the others that contribute along the way will be recognized as they should be.

If you have constructive criticism...by all means let me know. If you just want to make a point...please use the PM feature.

Oh yeah...there will be a few pics added when I can - and there may be days at a time with no update...if you want to track the progress, may I suggest using the 'subscribe to this thread' function.

Thanks for reading the boring introduction...let the journey begin!

RajDatta

Jay, to start, how is the head coming along? Did you get my PM about the splitters getting here?
Raj

User 41221

Any chance a KC guy might get an invite to check out your progress and spin wrenches with you from time to time? I'd love to check it out, if I get the time available to get away from work.

Regards,

RajDatta

Jay, take him up on it before he changes his mind, lol. I think it would be a great experience for both you DIY'ers. I wish we all lived closer. It was really tough installing the turbo S torque tube in last week!
I am getting a lift in my next house, thats it!
Raj

Jay Wellwood

All....

Raj...yeah I got the email and inadvertaqntrly deleted it in an email cleaning frenzy...I'll call you in the morning to straighten this out.

Scott...you bet you're always welcome to come down.

Jay Wellwood

Okay....here we go...

92 968 that has been Turbo charged...but with the Stock Compression Ratio. This we have to fix.

First...we need an 89 NA head (enter Mr. Raj Datta) - got said head as it will match up from a bore stand point...but may need some work in the water jacket area - jury is still out on this part.

You'll need better exhaust valves that the 89 NA Head can provide...as it turns out, the 951 turbo valves are EXACTLY the same size (same diameter, length is 0.5 mm longer which can be shimmed I'm told - anyone have conflicting info here?). Springs are different - but hey, if it were easy....

Ordered springs, exhaust valves and valve seals from Vertex...best deal for the exhasut valves - only $65 each ( a bargain by any means!). Also needed 951 springs and seats which were ordered as well.

Talked with Dave @ Lindsey Racing...apparently I may have to have a bit of machine work done to accomodate the water passages...I'll will let you know how this turns out.

Compression will be lowered using custom pistons from Andial...designed for the 8V head. In hand cost ~$1400 for the set.

I'll update again in the near future.

RajDatta

[QUOTE=Jay Wellwood]...but may need some work in the water jacket area - jury is still out on this part.
QUOTE]
Jay, this is the reason to use a 2.7 head on a 3.0 block. When I spoke to Dave as well, he was not aware of this. I hold Dave in high regards but a few things he assumed about the 2.7 head were incorrect.
You don't need any work on the water passage. Trust me on this one. They mate perfectly as the 2.7 has the same bore as the 968 block.
Raj

Jason Judd

We used the 2.7 head, too.

We didn't have to do any work on the water passage, to my knowledge.

Are you talking about adding water cooling to the turbo?

Jason

Jay Wellwood

Thanks for the updated info Raj....got too damn busy at work today...another 'emergency' so I couldn't break away to chat. Promise to hide in a Closet Friday.

For those just joining....or seeking more info...Here's the deal. To be able to fully boost a 968 engine, you'll have to lower the compression to do (or limit your boost accordingly). To raise the boost - you'll need to lower the Compression Ratio - this helps to save the motor (or limit activation of the knock sensors) - and also helps to reap full advantage of the boost. That being said - follow below. Sorry for the confusion if it seems like I bounce back and forth...

For the 89 NA head...in as far as the head and water passage is concerned (or lack thereof)...sounds even more believable based on the PET info that I have. There is no difference on the part numbers between the the 89 NA and the 3.0l head gaskets...which tells me we're 'in the groove'. All I gotta do is match it up in the field to confirm...but I feel 100% confident that this is a non-issue.

What about the head studs...talkin' with Dave led me to believe that I'll need a custom length set...not a problem...but an unforeseen...anyone know for certain? If I have to go with different studs...Dave will sell 'em for a measely $370/set. Just need info to confirm. (another helpful note here).

Next...Pistons...or Rods...or how to lower the Compression ratio? I've got a line on both...but I also have a preference....

fast951

Jay, It all depends on what you want out of your engine. When you swap the 16v head and use the 2.7l head, the CR drops.. This is not the BEST setup, but works. The ideal approach is to find pistons that Andial offered (I think they sold out). Of course you will need stronger rods, 968 rods may not be up to the task. 951 rods work well or aftermarket rods.

The 2.7l bolts up to the 3.0l block, of course you need different exhaust valves (951) as well as 951 springs... You must figure out which intake runner to use as the 2.7 intake ports are oval...

As far as the head studs, what type of "special" studs do you need. Custom length?? How do the compare to 951 head studs? I would think you can get the 2.7L head studs, after all it's a 2.7l head and 2.7/3.0l block... I guess more investigation is needed.

One important task is the tuning? Do you plan on keeping the 968 DME or convert to 951 DME/KLR?

Graham CS

Raj,

Lifts are great I strongly would advise it - time saving!!!! and less stress.
The only problem is that on mine being a two post you have to take the side skirts off every time.

Anyway, does the 2.7 head really just fit straight on? I thought as much due to the spec.

Which heads did the Turbo S and RS use, were they differant?

I know that the turbo S cam is still available from Porsche Germany (or was last year when I was looking for cams for the clubsport)

One day.....

Graham

RajDatta

The turbo S and RS heads were similar to the 2.7 head with a few differences. The intake port was round instead of oval and there were ceramic liners on the exhaust port. The ports are much smaller than a 2.7 head.
Jon Milledge ( a very well known tuner) scraps the turbo heads just for this reason. An NA head allows him to do some bench flow, port and polish work. Chris Cervalli, whom I bought my current setup from scrapped the turbo S head for the same reason and was was able to pick 30hp just by swapping the head alone on a dyno.
Jay, I have the old studs that came off my old block if you need them for reference. I would recommend going ARP though. I can find out from Chris what to use. He can answer most of your questions.
You have to be very very careful where you get your info from. All the vendors have a vested interest in giving you advise so be very careful. I had a well known tuner tell me a Garrett GT30 would not be the best application for my setup. Well guess what, I couldn't be happier with the setup. Just goes to show.
My setup is as such. Milledge cam, lifters, valve springs, valve retainers and minimal port/polish. This gives me 7500rpm redline even though I never take it past 6500rpm. The setup is more race car and has been proven bulletproof on other cars. The intake manifold was ported to match the oval ports of the head. Seems to work just fine, no need for a custom intake manifold.
I would be interested to compare the lift and duration on a turbo RS cam and a Milledge cam. Too bad, I had a turbo RS cam, but I sold it to my buddy with the real turtbo S. Atleast I know its in good hands .
Get Carrillo rods, don't go any other brand. These are the best! I know you enough to know that you only want to do this once.
Raj

User 41221

Here's a plug for John (aka fast951)... Jay, see if you get him to do your chips for you, if he will, I will all but guarranty you'll be impressed.

Welcome back, John!

Regards,

fast951

Hi Scott...

The 2.7l head has larger intake valves and flows much better than the 951head..

dynatech

Raj,
As i have discussed with you before the GT-30 will be my choice of turbo ( if i ever get any money to do so) do you run both oil and coolant to your GT-30 or just oil. i know a lot of guys that are running them with just oil alone what are your thoughts on this.

Thanks, Scott