It's been so long that people probably don't remember that my Aero blew its head gasket at Goodwood a couple of months ago (yes, it's been that long!).

Having removed the cylinder head a while ago, today I finally got cracking on the crankshaft pulley and the timing cover to replace the timing chain and guides and to remove the balance chain completely for both reliability and performance.

Around 5pm, Aerohead arrived, complete with lovely white Aero and lovely young lady. We got stuck into the reassembly.

Everything went far too smoothly and well before 10pm, I turned the key and started it up. Then we noticed what I hope will be our only mistake. We'd forgotten to tighten up the turbo-to-manifold nuts, resulting in a lot of smoke around the engine compartment. These were very first thing we had (half-)done after dropping the head on http://www.saabscene.com/forum/images/smilies/rolleyes.gif

A quick tighten and it runs smoothly, despite some initial confusion over which camshaft was which http://www.saabscene.com/forum/images/smilies/eek.gif
Sounds like we got that bit right in the end.

And all finished in plenty of time to grab a couple of well-earned pints.

I'll get the adjustable fuel pressure regulator on tomorrow to address the fuelling problems (starts to run out of fuel at around 300hp) and hopefully cure the detonation that was evident with the head off. Top up the coolant and change the oil and it should be ready for the road.

Many thanks to Aerohead. I owe you one and I'll be first in line to help with any jobs on your own Aero.

Was the electric impact wrench any good for the job on the crank pulley? I bought the one in Costco which claimed on the packaging 332Nm but looks exactly like the other cheap ones.

The gadget didn't arrive and I finally got the bolt loose with the 2 foot breaker bar. As soon as I did, I contacted Machine Mart to cancel it. I'll probably buy one some day but I really felt I should make some protest against them taking so long to deliver.

It turned out to be a matter of bracing myself well with the flywheel locked and pulling from underneath where there was a bit more room to swing it. Pulling was also easier than pushing, which was what I would have had to do from above. A bigger bar certainly wasn't an option from below, though, as the end of the 2 foot bar just scraped the ground.

Good work Bill- and Aerohead http://www.saabscene.com/forum/images/smilies/thumbsup.gif Nice to hear it went back together OK.

Which FPR did you go for BTW? I've been looking around for one but haven't had much joy.

Originally posted by Mark E:
Which FPR did you go for BTW?[/b]Part number AIR004 listed here (http://www.fuelsystem.co.uk/regulators.htm). As far as I can see, this is a fixed-rate regulator. I did some calculations and realised that with 1.6 bar, a rising-rate regulator set at 3 bar at atmospheric would whack the pressure up to around 8 bar http://www.saabscene.com/forum/images/smilies/eek.gif , which is well beyond the working limit of the standard fuel pump.

They also do a pressure gauge that can fit directly on the regulator, or they also sell an adapter to mount it inline.

Along with the FPR adapter I got from Trent, some hose and a bit of metalwork to fabricate a mounting, I should be all set. There's every chance it will arrive today. Then I'll book into a rolling road somewhere to get it set up. The idea of the gauge is that once I have it set up properly I can note the reading and if the regulator ever shows signs of drift I can re-adjust it.

Originally posted by Mark E:
Nice to hear it went back together OK.[/b]It went so smoothly that I'm worried we must have made a big mistake somewhere... http://www.saabscene.com/forum/images/smilies/rolleyes.gif

Bill, I hope I'm wrong on this but I talked to Demon Tweeks the other day about adjustable FPRs and sure enough AIR004 was "on the list" but we decided it wasn't suitable on the grounds that it didn't appear to have a vac hose connection and thus was only suitable for N/A cars http://www.saabscene.com/forum/images/smilies/eek.gif

I'm pretty sure even N/A cars need a vacuum hose. The job of the regulator is to maintain a set pressure difference between the fuel rail and the manifold. I'll find out shortly, though.

Having said all that, there doesn't appear to be a vacuum pipe in the photo! http://www.saabscene.com/forum/images/smilies/rolleyes.gif

Looking again at the photo on the Glencoe site, there appears to be a vertical pipe directly in line with the adjuster on the top. As I say, I'll find out when it arrives.

Yes, I think you're probably right about N/A cars needing a vac hose- certainly there was one on the BMW 635CSi FPR I was trying to nurture back in to life at the weekend. I suppose the vac hose stub could be hidden in the picture. Let's hope so...

Originally posted by Mark E:
I suppose the vac hose stub could be hidden in the picture[/b]It is, and not that well hidden once you know where to look. It's directly between the adjusting nuts and the camera.


Originally posted by Mark E:
the BMW 635CSi FPR I was trying to nurture back in to life at the weekend[/b]Would that be the car your neighbour used to own? Does he no longer own it or were you just helping him out?

Bill - should I expect a blown head gasket with Maptun Stage 3.....?!

Zip

Zip, I really don't think it was down to the Stage 3 (-and-a-bit). I'm fairly convinced that the tension in the head bolts lessened over time - the engine has covered about 140K miles. The bolts were surprisingly easy to remove. Especially in contrast with the enormous force required to tighten down the new ones through the last stage (90 degree angle), with a two-foot breaker bar http://www.saabscene.com/forum/images/smilies/eek.gif

I have had the Maptun upgrade in place for 50-60K miles with no problems other than driveshaft traumas which are directly attributable to my specifying no boost limit in 2nd gear, fitting an LSD and driving really badly. With this arrangement, I can get silly amounts of torque pushed down one driveshaft under certain conditions. Doh!

I would certainly consider having the head bolts re-torqued. In fact, I planned to do this on my CSE (unmodified 2.0LPT) which is showing signs of oil weeping from the corners of the head gasket. However, events have overtaken me on that score.

you mean like this for +90 degress

http://www.ashill.org/saab/chg/carlyhg18.jpg

Andrew

Originally posted by Mark E:
AIR004 was "on the list" but we decided it wasn't suitable on the grounds that it didn't appear to have a vac hose connection and thus was only suitable for N/A cars * http://www.saabscene.com/forum/images/smilies/eek.gif *[/b]Having received one this afternoon, I can assure you that it has the required vacuum connection. It is exactly where I identified it on the photograph.

One thing I had to ring and check was that it really is a fixed-rate regulator. The box it came in is the same as all the rest of the FSE regulators and mentions the 1:1.7 rate all over the box. It seems they all come in the same box and the AIR004 is definitely a fixed-rate regulator.. The box did have a label saying "AIR004".

It should be in place tomorrow morning so I'll let you know how I get on.

Originally posted by Scaero (Maptun stg3):
you mean like this[/b]Well... my engine bay is not quite so filthy

Originally posted by BillJ:
*QUOTE
Originally posted by Scaero (Maptun stg3):
you mean like this[/b]Well... my engine bay is not quite so filthy [/b][/quote]You know me, if it's not filthy you're not using it enough

Originally posted by Scaero (Maptun stg3):
You know me, if it's not filthy you're not using it enough * * * [/b]So that explains it - my Aero's not on the road often enough to get filthy

Originally posted by BillJ:
*QUOTE
Originally posted by Scaero (Maptun stg3):
You know me, if it's not filthy you're not using it enough * * * * *[/b]So that explains it - my Aero's not on the road often enough to get filthy [/b][/quote]Maybe the word I should have used was Abused rather than used.

Talking of which, I've killed the synchro on 2nd on the carly over the last week /500 miles

3 gearboxes in 3 years.

Andrew

Originally posted by Scaero (Maptun stg3):
3 gearboxes in 3 years.[/b]Not bad, but until you manage 3 gearboxes in roughly 4 months, all on the same car, I'll remain relatively unimpressed

On the head bolts, I don't see how I can retorque without loosening them off as the current torque is an unknown.
Or - can I torque to spec and then add the 90deg? - The only issue here is that they may still be at say 45deg. worth of torque so I still won't know what my starting point is?
If you get my drift.....

Originally posted by faero:
On the head bolts, I don't see how I can retorque without loosening them off as the current torque is an unknown.
Or - can I torque to spec and then add the 90deg? - The only issue here is that they may still be at say 45deg. worth of torque so I still won't know what my starting point is?
If you get my drift..... * * *[/b]I get your drift! I had exactly the same dilemma when I thought about doing this some time ago. I found that the bolts were all torqed to spec, so had to ask myself can I safely add any extra degrees?Probably not the full 90, but maybe an extra 20 degress or so would be okay.... who knows?!
In the end I did nowt.

The head bolts are stretch bolts so there is no need for any re-torquing unlike the old head bolts of years gone by where you only had a torque setting, basically if the torque wrench settings designate an angular torque then they are stretch bolts and are a tighten once only. Hope this helps

hmm - so to do it right I need to fit new head bolts as the curent are already stretched? Makes sense.

The information I do have, though, is that the bolts must be at least the basic torque setting (pre 90deg). If they are not, then I can retorque to spec (and add the 90?), but if they are then I should leave them as I don't know.

In the Haynes it says "Saab do not recommend replacing the head bolts, although they should be replaced if they are damaged or corroded." I've heard people say you can somehow measure them (presumably the length) and replace them if they are out of spec. The OEM Elring head gasket I bought had a symbol table that basically said new head bolts should be used.

I ended up re-using the head bolts this time (I figured this is only their second tightening - or third, since I removed the head again did it again), but I do wonder if that was correct.

When I did the heads on my Sierra V6 you had to replace the stretch bolts every time. 12 bolts came to quite a lot of money!

I'll side-step the re-torquing question for the moment, although the theory is that they loosen a bit with time (not by design, but in practice) so you loosen them all off a bit and redo the torquing stages. The Aero's engine had covered at least 140K miles, on the original gasket, I think. The CSE has covered nearly 160K miles. Again, I think it's on the original gasket.
Anyway, the fuel pressure regulator is fitted and appears to be working (car runs fine). I'll have it set up on a rolling road to get the A/F ratio nice and safe at maximum power (if it can be done without going to bigger injectors).

Hi Bill,

Glad to hear that things are continuing to go smoothly on getting your beast back up to full boost. Hope the new fpr sorts out the lean running problems, and keeps the detonation at bay.

Now try not to break it for a while...

Originally posted by Aerohead:
Now try not to break it for a while... [/b]But you enjoyed helping me fix it so much. You don't fancy doing it again next week?

Seriously, though, you were a great help. I'd certainly never have got it all back in one evening on my own and it was great after all that work to hear it fire up. http://www.saabscene.com/forum/images/smilies/thumbsup.gif

Having played with the fuel pressure, it still felt a little bit flatter than it did before so I checked base boost and it was about 6psi where it used to be around 8 (like yours). No idea why it dropped but after setting it back as it was it picks up a lot better. A few adaptation runs and it's going pretty well, despite the warm weather and a tank full of Optimax that's months old. Can't wait to get her filled up with fresh stuff and get some cooler weather to drive in. http://www.saabscene.com/forum/images/smilies/fawlty.gif

good job
glad to see another member of the 300+ club back in action..


*get some cooler weather to drive in.[/b]come up to Scotland ...its at least 10 degrees cooler up here
just back from a trip to Salisbury ...could not believe how hot it was....

Originally posted by ylee coyote:
come up to Scotland ...its at least 10 degrees cooler up here
just back from a trip to Salisbury ...could not believe how hot it was.... [/b]Should have let us know you were down here! We could have seen the car then... or did you not bring it?

Should have let us know you were down here! We could have seen the car then... or did you not bring it? * *[/b]It was just a day trip....
and yes I did bring it
did the earth not move for you ??

Originally posted by ylee coyote:
come up to Scotland ...its at least 10 degrees cooler up here[/b]Well, I'll be up at the Lakes this weekend, which is a lot closer to Scotland than I am at the moment.

Originally posted by ylee coyote:
It was just a day trip.... * [/b]That says a lot about the car in itself!



did the earth not move for you ?? * * * * * * * [/b]I did notice some Jurassic-Park-style ripples in my tea at about lunchtime now that mention it...