Flapper mod project

[hjtrbo]

Hope this might help someone avoid the die grinder butchery than can be achieved as demonstrated here with the quality workmanship on display from a 'Big Name' Melbourne workshop. First time I've ever ported a turbo so have taken some happy pics of the journey.

 

Pulsar GTX3584RS. Default 32mm port with 38mm flapper. Not having that. CGC squeeze in a 38mm port with a 42mm flapper in that same(ish) housing. Challenge accepted. 

 

Carefully remove the wastegate actuator arm. Just plugged enough to break the welds. Need to save this piece to weld back on at the end of the job.

 

With the actuator arm out of the way, the flap and shaft just slide out.

 

Getting the roll pin out is a pain in the arse. I used a bit of heat to anneal it and then had at it with the drill bit. It eventually caught the drill bit and spun. Just used the vice grips to pry it up from there. 

 

Measure the sleeve height before it gets pressed out

 

Now, getting that sleeve pressed out is a pain. That farker is in there tight. Heat is needed to get it to move. Only need to push it back enough to provide clearance to the port area. Crank it up in the vice as hard as you can with a couple of sockets, then heat around it evenly until the farker cracks loose and makes you need a new pair of undies.

 

Centre the port up in the mill.

 

Then realise you don’t have the right tool to continue. Farken c@nt. To be continued…

[hjtrbo]

Whilst I wait for my boring head to turn up I got stuck into the flapper itself. Before I started, I removed the old flapper from the actuator arm to get some base measurements. Bunnings nail pincer to the rescue to remove the press fit lock collar. 

 

Started out with a bit of 63mm 316 that I had laying around. Heap of rough turning to get it to shape.

 

And the finished 42mm flapper. Plenty of room. Could even go bigger if I bored the housing out a few mm more. I reckon a 42mm hole with 46mm flapper is easily possible. Would take the housing clearance out to 48mm to give 1mm clearance each side of the flapper. 

 

Shed is cleaned up. Thristy now, time for a beer. 

[Tom Tucker]

Let me guess. Maxx or Dyno-Mite?

[hjtrbo]

No comment. 

[Tom Tucker]

I see.

[Puffwagon]

Scaramouch, Scaramouch, will you do the Fandango!

[hjtrbo]

https://m.facebook.com/Thunderboltpigs/ 

[biddie_fiddler]

Wow some awesome work so far mate! Is this something you'd ever consider doing as a service?

Seems like something people would pay for to have done. Especially given the quality of the results over hand-ported solutions offered by other places. 

 

Keen to see the finished result!!! 😄 

[hjtrbo]

Thanks.

 

What's the going rate for a port job?

 

 

Based on what I've learned in the last day and a bit, then with streamlining of a few things I.e. bunch of flappers CNC'd somewhere else, I can see around the $400 mark being about right. Like I said, no idea what it's worth. 

 

Record time delivery from Melbourne to regional Vic. Bonus, got to spend this afternoon playing in the shed again. 

 

Time to bore the hole out. I mentioned earlier about centering over the existing bore hole, but after some measuring, the existing hole is not centred across the casting. It was roughly 2.8mm off. After a little back and forward I worked out where it needed to be and got into it. Bored it out close enough to 38mm.

 

With the hole finally bored out you can see the OEM land is a fair way off. The important thing here is that the hole is now centred correctly across the casting.

 

I decked the flapper sealing face down into the casting to get a new surface for it to seal to. What you can’t quite see in the photo is the surface finish is pretty sh!t. Spoke to a Machinist mate of mine about it and he said to turn my boring head into a fly cutter and go at it that way. Single point at high rpm / light cut should give a good finish he said. Then from there I can lap it in with paste if I want the last 10%.  

 

Close enough to CGC’s port job. I just don’t have the flashy lighting to make it look good. The dimensions are the same. And the main point of difference is they are using a genuine Garret housing whereas mine is a Pulsar copy housing.

 

Important part is the sealing face. As mentioned above, I’m going to go at it again to improve the surface finish. But as far as the contact face and concentricity is concerned, she’s right on. Bearing blue to verify.

 

Tomorrow I'll start working on brushing the dust off the TIG, find some 316 to have a refresher on and put everything back together. Cheers all 

Edited 29/09/22 12:54 PM by hjtrbo
speeellingg

[hjtrbo]

It doesn't sound like much, but here is 32mm compared to 38mm. A basic calc has the flow rate with 26psi inlet pressure and assuming 1 psi outlet pressure and 900°C at 19m³/min for the 32mm port and 26m³/min for the 38mm port.  A back of the napkin flow increase of 37%.