fanstastic thread, thank you !

Only one question to the OP, why did you choose to run a GT35 (as you're replacing anyway) instead of a newer design turbo like a precision 6262, 6765 or a Garrett Turbo with HTA wheel ?
billet wheels spool faster and make more HP / lbs.

Just out of curiosity.

Good luck with the project.

Yep the 2 Bosch numbers on the unit are:

0 280 752 022 & 028907475BD

If you wanted one, let me know, I can send you the link to the UK guy on eBay (there aren't many of them if you search the listings)

Cheers
Spencer

Thanks!

Well, it's one of those projects that started off with "Spec n" and has gone down the slippery slope to "Spec n+10".

The original brief was for an engine that wasn't massively more hp than the stock car, just with EFI efficiency. I still need the engine to be a street engine, this isn't a track car, so I don't want a huge GT40, I still want it to be sensible (otherwise I would've gone for 993 GT Evo cams).

I'm very happy taking Chris's guidance on this, and it is something we discussed many times in the earlier days of the project, with things like A/R's...and IIRC we did also consider the billet wheels (remind me, are these the GTX units?), but the additional cost was yet another expense that was starting to run away, and probably wasn't justified at that time.

Chris also has a LOT of experience with Garrets and in particular the 35R; if you remember from one of the first posts, I really didn't want to be trying anything too left-field, I'm happy to follow the well trodden path, and I'm also happy to bow to Chris's knowledge and experience. You never know, once this is finished, maybe a few tweaks here and there may include fine tuning the turbo as Phase 2.

Cheers
Spencer.

Fair enough. Understood.
I just ask because I went thru the same thing with different cars, and from experience, the difference with modern turbos are really big, that being said, you could still use basically the same size turbo, as the HTA 3582 which is basically an upgraded Garrett.

link: Forced Performance Turbochargers: FP HTA GT3582R Ball Bearing Turbocharger

Yes the GTX are Garrett billet wheel, that came out a long time after the HTA and Precision turbos.

Keep up the great work !

Good luck and Merry Christmas.

Cheers, Merry Christmas to you too!

Sometimes spooling faster is not an advantage. Sometimes the compressor wheels produce more airflow at lower rpms than the engine can use, you get compressor surge. Anti-surge / ported-shroud compressor covers help, but do not fully eliminate the possibility of surge.

Agreed, that's true, It can happen, but you usually can minimize those problems with the covers like you said and also with tune / boost controller.

Do you often see this kind of problem with GT35s and the 964 3.3 or 3.6 engines ?

Unless the engine is modified to breathe a lot more -- intercooler, intake, heads, cams, exhaust -- then yes, it can be a problem on the 3.3L engines. We've seen surge on a few 3.3L engines with a plain GT35R.
3.6T -- sometimes. We just had a client do bolt-ons + EFI and hit 530rwhp at just 1.1bar on pump gas with a GTX.

530whp are very nice numbers specially on that kind of boost.

I miss my GT2, even though I had stock K24s, I spent quite some time on the dyno fine tuning the car, it came out pretty good, and very linear, if you ask me.
I'm looking for a late 911 or early 964 to start a project, unfortunately it must retain stock engine for the class I'm looking to run.

Chris, pm sent.

Finally an update!
 

Wow, long time since I last checked-in to write an update. Not a huge amount going on at the moment - everything's on hold until my garage extension project is finished. Basically, the garage will double in footprint, but the stuff that once occupied a couple of sheds has had to go into the original garage temporarily....meaning very little space to work on the engine.

But....I did have a free weekend a few days ago, so with some shuffling around of everything, I decided to continue on the blessed oil catch tank for the turbo. I swear, this part has given me the most aggro of the whole build!

Before Xmas, I was trying to be clever and upcycle (!) the OE tank, so that I could re-use the mountings and the space it occupied . Nice and out of the way between the turbo and the crankcase. So, we tried a number of times to graft on new -8 and -10AN fittings, but long story short, nothing worked out satisfactorily. Because this thing was so impregnated with oil over the last 20yrs it gave my welding guys a nightmare when trying to weld on the new fittings. I tried flushing it out in the cleaning tank, running brake cleaner through it, but it was still too "dirty" for a clean weld. Porosity on both the -10 feed from the turbo and also from the -8 breather tube. It was looking a dogs dinner, so I decided to start from scratch and fab a custom tank from ally that fits in the same space.

By re-using some of the 3" diameter ally from the intercooler charge pipes, I made the unit below, which has worked out really nicely with a 45deg bend, insomuch that I've been able to feed from the turbo with a 90deg -10 bend, a straight -8 breather that will go to the air intake near the filter, and a -8 outlet that's presented at the right angle for the aux scavenge pump to draw from. Happy days!

http://img.photobucket.com/albums/v2...2CD7F64AB4.jpg

http://img.photobucket.com/albums/v2...2CDE4CF3D2.jpg

Nice strong bracket to mount it onto the same M8 studs on the crankcase that the original tank hung from. I'm paranoid about this being mounted securely. No offense to anyone who has one, but I'm really not too keen on the style of tanks that dangle directly from under the turbo oil outlet...perhaps a little overcautious, but to me it looks like a fracture waiting to happen, with the vibration and extreme heat. Anyway, collected mine at lunchtime, and quickly offering it up into position, it clears everything nicely!

This is literally as I've collected it, so tonights job is to clean and prep the surface finish ready for it to be anodized black (I think...or I may get it done silver...not sure yet). I can also now finish off making the Aeroquip lines between the tank and the turbo and from the tank to the pump.

I'll post some more pics later, with the tank in place with a couple of the hoses attached.

Ok, some more pics from last nights work....

I "ovalised" the 3" tubing, which gained me about 15mm additional ground clearance. It's now not the lowest point on the engine....

http://img.photobucket.com/albums/v2...32773D53CC.jpg

The -8AN breather pipe will be a straight coupling, going up through the rear tinware section, and across to the air filter/intake pipe assy....

http://img.photobucket.com/albums/v2...327D7AB99D.jpg

The tank fits just nicely between the myriad of pipes for the heat take-offs, wastegates, primaries, etc...

http://img.photobucket.com/albums/v2...3283E57A7A.jpg

A chunk -10AN hose between the turbo outlet and the input to the catch tank. Probably overkill in size, but the I.D. matches the turbo's outlet diameter...

http://img.photobucket.com/albums/v2...3289EC0811.jpg

http://img.photobucket.com/albums/v2...328FA0394A.jpg

A 90deg -8AN elbow works perfectly for the coupling to the pump. The I.D. of the -8AN is near enough identical the I.D of the original scavenge pipe, so the suction should be as before....

http://img.photobucket.com/albums/v2...32973F44BB.jpg

A neat run along the top of the exhaust valve cover...

http://img.photobucket.com/albums/v2...329CF3AAA1.jpg

This is where the auxiliary pump will pull the oil from - I guessed that I'd need a 45deg fitting, but a straight coupling will work better. Easy to swap next time I go up to Think Auto....

http://img.photobucket.com/albums/v2...32A23B5BE6.jpg

And after some initial polishing. Not quite as I want it yet - needs to be more polished for the anodizing to look ok, but it's starting to look tidier....

http://img.photobucket.com/albums/v2...32A7EF8813.jpg

Looking good! How about some photos of the new shed? :)

Hello mate!....haha, I may well be in a position to take some snaps this weekend - time to insulate the workshop and fit the interior panels, run some electrics through, etc. At the moment, it just looks like a giant mess, full of piled up garage stuff that moves between the garage and the workshop, depending on what needs doing. The pit is now finished in the main garage, pit boards all cut to size, so we're moving along gradually ;)

Sorry for the tardy response, been extremely busy at work - its like 4Q all over again!

You and the family well I trust?

Cheers!
S

Amazing build!

Thanks Simon.....work will hopefully recommence on the engine again soon. Still sorting out the new workshop and doing a light-refurb on the new (old) lathe.

From this, tired, filthy neglected unit -->

http://img.photobucket.com/albums/v2...2FC76A5FFE.jpg

http://img.photobucket.com/albums/v2...2FB1611686.jpg

To this --->

http://img.photobucket.com/albums/v2...9E20456A95.jpg

http://img.photobucket.com/albums/v2...9E191EEE3C.jpg

http://img.photobucket.com/albums/v2...9E40039222.jpg

http://img.photobucket.com/albums/v2...9E517E70B8.jpg

http://img.photobucket.com/albums/v2...327102E5F4.jpg

http://img.photobucket.com/albums/v2...327A8C146A.jpg

http://img.photobucket.com/albums/v2...3280F0C54F.jpg

Lots and lots of hours with degreasers, abrasive papers and tins of the original Colchester shades of paint.

No teardown of anything apart from removing the tailstock and the cross-slide. Not yet checked the alignment, but if it does need adjustment, at least it's all clean again.

The original Colchester suds pump kicked into life yesterday, so tonights job is to wire in the new 3ph digital inverter that I'm now going to use instead of a static converter that I've got.

Great lathe, should have everyone who's sick like me (or you):)

Thanks Roland, yes, it's just about the perfect size for what I need; smaller than a Colchester Student that I (and many of thousands of others!) learnt with as apprentices, but it's big enough to cope with anything I'm likely to want to turn. Beautifully built, geared head, gearbox for screwcutting, the spindle bearings are the Gamut ones (apparently well known for their precision and durability)...lifting the cover on the headstock gearbox, there looks to be no wear on the gear teeth...chances are that this was just used by apprentices (there is evidence on the bed of the occasionally dropped tool and/or chuck!) for them to make their test pieces on, nothing too heavy duty. Even the gib strips look to be adjusted somewhere near perfect ;)

Nice job on the lathe! They sure look dismal when they are old and grungy but you end up having these things for years/decades/lifetime so it's worth the time for a clean up and lube/adjustment. I certainly appreciate a clean machine.

Absolutely Jim, this'll be good for another 40+ years - was tinkering again today, now got the coolant pump wired up so that it only switches on with the main motor (due to me having a 1ph > 3ph converter, and it only being something like a 0.25hp pump)....being super-careful to ensure its electricallly dead each time...you don't get back up from 415v!! Also fixed the wobbly apron fwd/rev lever. Another clean up of the machined faces to remove a few errant bits of paint, now ready to fit a DRO sometime during the week, then set-to checking alignments and moving it into position.

Apologies - going a little off topic here, just posting in reply to a few folk asking why there's no engine progress at the moment ;)