924Board.org

[Arvidw]

[Grenadiers]

[Carrera RSR]

[WEASEL149]

Small update.

New turbo. Holset HY35 with 10cm exhaust housing.

The log manifold won't be going back on. Turbo position will change.

Side by side with K27:-


T3 exhaust manifold flange:-



2.5" V-band turbine outlet:-


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1979 UK 932

[Raceboy]

Looks very good! I would spend some time finding some Garrett/Schwitzer etc twin-scroll turbine houging what would be suitable for fitting onto the HY35 after some machining as this would greatly help in terms of spoolup and power.
It would make more sense moneywise to source a toasted turbocharger than to buy a housing.
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'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold
'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche

[WEASEL149]

[Raceboy]

He uses dual chamber wastegate control, but as he stated, those rpm points are where the boost starts to build, not full boost.
Would be interesting to know where the torque really kicks in in SR20 engine as those are known not being a very good spoolers.
On 931 the fun would be max when full boost would be reachable ~3000-3300 rpm and according to my calculations etc it is with HY35 and decent boost control.

HX40 is 600hp turbo so it would be wise not to expect it to have full boost below 3000 rpm
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'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold
'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche

[WEASEL149]

Bottom end is built now.







I resurfaced the oil pump endplate to bring clearance back in tolerance. It's now measuring 0.002" clearance with plastigauge. Later it will be coated with Molybdenum Disulfide which should bring clearance to less than 0.001".

Here's a pic of 2 worn endplates and the resurfaced one:-



I also took pics of my modified/lightened S1 flywheel and a standard one, then weighed them both. Standard S1 weighs 16lb. Modified weighed just under 11lb, so over 31% saving and most of that on the outside where it counts.



As you can see in next pic, it's been machined and a 60-2 trigger wheel fitted.


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1979 UK 932

[WEASEL149]

Next job is to increase combustion chamber volume.

Static CR currently works out at ~9.0:1 which is too high for the kind of boost I plan to run.

I'll feel a whole lot better running less than 8.5:1

Rings have all been gapped for high boost and bearing clearances all checked at the loose end of tolerances.

ARP rod bolts were all taken to 0.0085" stretch.

After the head work is finished, work on the inlet manifold is likely to start.
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1979 UK 932

[GeorgeV]

Nice to see your rebuild is progressing well.
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1981 932 with mods:
http://www.924board.org/viewtopic.php?t=37921

[WEASEL149]

Work has been progressing slowly on the cylinder head.

After a lot of work I now have the head combustion chambers roughed out to 27.3cc, so once they've been finished and smoothed they should measure ~27.5cc.

Using the Ideola's Garage CR Calculator (which has been very useful) I get 8.3:1 static CR which should now allow me to run a nice level of boost whilst giving a welcome improvement in off-boost response.

I will post some photos up of the work.

I am waiting for some aluminium to arrive and then I can start on the new inlet manifold.

I'm going to drop a spare head/block assembly in the engine bay so everything can be worked out for fabrication.
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1979 UK 932

[WEASEL149]

This is where I'm currently at with the head chambers at ~27cc. They're not quite finished yet but getting there.

Once the chambers are done the valve guides are coming out so I can port the head.


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1979 UK 932

[Power Tryp]

Your car is the ROW twin to mine. Same interior and paint although I wish I had your bumpers and lack of fender lights.
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Melanie - 1980 931
NoName - 1980 931 (seeking rebuild)

Green tartan interior, you don't see that on a Civic.

[WEASEL149]

**Blows dust off the thread**

In reality very little has happened with my build since last time as I've been busy with my house and garden again. Very little will happen until next year I fear as I've got a holiday coming up and then a bathroom to knock to pieces and renovate.

My plans have changed considerably. With the inlet almost complete I'll be sourcing some 304 stainless next for a new exhaust manifold.

I have a stock S1 engine to install. This will be my test bed for the gazillion new/custom parts I have and hopefully allow me to get to grips with the engine management without worrying about running-in the newly built unit.




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1979 UK 932

[GeorgeV]

**Waves dust away from face**

Doesn't life have a habit of getting in the way of rebuilding cars? Better late than never, though.
G
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1981 932 with mods:
http://www.924board.org/viewtopic.php?t=37921