Helpful ReplyHot!Turbo Engine Rebuild

Well she goes again! Ended up being the Bosch HFM-5 MAF unit that was goosed, thankfully I had a spare brand new one. It has either gone of its own free will or else it was tipped over the edge by the suspect wiring to it. We will never know!
 
Anyway, after waiting a week for Royal Fail to lose my new plug which should have been 24 hour delivery, I ventured to the scrappy today, how that brought back memories! I needed a 5 pin Bosch MAF plug so found a Golf and removed one. Slightly different looking, but 5 pins, and Bosch, of course it will fit! It didn't. So I then set about making it fit, and changing all the wires over, so I know I have 2 good ends on that harness now. Fired it up, same, starts and dies, also battery starting to go flat and Mrs about to leave for an overnight with the kids in her car with her ready 12v supply for jump starting. Asked her to wait 5 mins as I dug out the new MAF and did an F1 style change over, fired it up with all the hose clamps still loose and wires all over the place, and off she went! Joy! Then off she went, with the kids, and while it was still running I got all the wires in order, done up all the hose clips and refitted the snorkel.
 
Good old test drive and can report all beans are present. I have a slightly better idle AFR of 14.5 (low 14's before MAF swap) and WOT AFR of low 12's. This is the first time since the rebuild I've buried the throttle and kept it there, 4th gear, just under 20psi boost falling to 18psi as you do with an MBC, many leptons showing on the speedometer on my private road. No bangs or noises or fluids lost and all perfectly clear out the back of the tailpipe. Got to be happy with that. I'll probably change over that plug for the proper one when it finally arrives, but for now it should be fine and all the wiring is good.
 
Possibly the new MAF, or the wires now not being ropy, have led to the better idle AFR, who knows, but all is as it should be now! Time for beer!
 
Stuart

Congratulations, good job well done, and enjoy!

Thanks Dave - Yes Porsche polished it themselves!! Shiny is good.
 
As for the block, I cannot speak highly enough of AMAC engineering and the work they done, and for the price they done it. Granted it took a long time, but these things always do, and every "do it while your in there" was found and attended to.
 
What you can see is shiny (!) custom JE forged pistons in modified Westwood sleeves. And a replaced head stud (top of pic, 2nd from right). Someone had seen fit to attempt a JB weld repair on a stud many years ago, they fixed this with a proper stepped solution that is likely stronger than original.
 
What you can't see, well, is endless! Off the top of my head (and including head work), oil pick up pipe strengthened, crank measured, polished and balanced, new oil pump (v good 2nd hand one, as they found issues with old one), head tapped for steam vent kit and fitting installed, rods offset to reduce piston slap, new valve guides, cometic HG, every bearing and seal in the engine (inc. balance shaft bearings and seals), reface valves and seats, reface cylinder head, strip/decoke/rebuild cylinder head, block bored to suit liners, bore and hone block to suit JE pistons with torque plate fitted, reface block, remove and refit studs including the one needing fixed, check and measure con rods and housings, gap piston rings and rebuild it all! All this for £4.4k inc. vat. That is all parts and labour. Hopefully it lasts longer than me after all that!
 
On top of this there was £1,500 for labour at my mates garage, which was the full stripdown and then re-assembly and lots of other footering and fettling. These parts:
 
PORSCHE PARTS. Thermo valve. Plastic coolant elbow seal. Cam box washers. Oil filter housing/cooler gasket/seal kit. Both balance shaft housing seal kits. AOS seals. Dipstick tube seal. Clutch fork. Clutch fork bearings. £290.73 EUROCARPARTS. Water pump and thermostat. Cylinder head gasket kit. Spark plugs. 5 litres anti freeze. Oil and oil filter. £354.95
 
And, a new aluminium rad £150, a refurbed Bosch 1.7kw starter £80, a new turbo aux water pump £50, cup clutch disc £200, new old stock pressure plate £150, new release bearing £60, new brake reservoir cap £50, new heat shield for sump/oil sensor £50, new battery £100, re-charge AC system £20, steam vent kit £45, 2nd hand expansion tank £35, 8 x good used lifters FOC (one ticked before, now fixed), various new pipes, hoses and wiring fixes.
 
So all of that, engine work, new clutch, disassemble/reassemble it all, attend to all jobs that cropped up, came to £8k inc. vat. Got to be happy with that all in I think.
 
Stuart

Steam vent kit to head:
 

 
Steam vent kit to expansion tank and close up of wiring mods to enable use of £50 turbo aux water pump (and how to fix your TPS with a green tie wrap...........):
 

 
Stuart

Thanks Dan, be great to meet up at some point!
 
My car was about a year off the road, felt like forever, goodness knows what 5 years would be like! To be fair, you have a lot more going on. My goal was to do what was needed and provide a reliable 300BHP motor for daily use. As the build progressed, I was able to add a few nice upgrades on stock without breaking the bank and leaning on people's knowledge. The forged pistons, the offset idea, steam vent kit, strengthened oil pick up pipe, MLS HG, lightweight aluminium rad, uprated starter, turbo water pump fix, uprated clutch etc. all fell into place nicely. I got the cup clutch disc from the states, a new PP and release bearing here, all for less than a standard Sachs kit!
 
Stuart

blade7
What's the story with the TPS?

That tie wrap has been there a long time! IIRC one of the screw threads was a bit stripped, so I put the tie wrap on to keep it secure as it wasn't getting held together tight enough. Must be 10 years ago at least but it clearly worked and has been a lasting solution! Tie wraps are great things.

blade7
Ah right, I wondered if you'd opened it up, to investigate an idle issue.

No, didn't do that. On the subject of idle, I reported hot idle of 950 rpm, since reconnecting the vac pipe to blue/black valve, after my MAF issue, this has returned to the normal 850 rpm. So the vac pipe was the culprit. It is now fixed............with a tie wrap! 
 
Stuart

scam75
And one re-assembled engine bay:
 

 
Stuart

After all that work - please don‘t tell me that they are the original fuel lines? I’ve seen far too many 944s up in flames due to original lines being perished under the insulation.