Any GPZ turbo experts here?

martymoose

martymoose

Hero member
Location
Sydney, Australia
Problem with kwakasaki turbo, 1983, GPZ750E1. Rebuilt turbo, oil leaking from the delivery pipe, plenum chamber getting full of oil. New turbo. New seals. Same problem. If anyone has played with this setup, (Paul LC?), contact via PM would be appreciated. Cheers. Marty
 

Attachments

  • PXL_20230809_054324249.jpg
    PXL_20230809_054324249.jpg
    196.9 KB · Views: 22
Ha, Marty, I seem to remember THAT Triumph customer, bike Jurno, had a lot to do with those factory Turbos back in the day.
 
Not by any means an expert - but curious enough to do some googling. Looks like drainback into the plenum is a known problem.
There seems to be a fix available which invoves fitting a check valve in the oil line. Either modifying the OE line or an aftermarket replacement is available. GPZ Turbo forum is useful.
 
Hi Marty

on my 79 CBX turbo build what finally cured the turbo smoking was a 12 volt gear driven vacuum pump installed in the drain line, sucked the oil out on an ongoing basis. The reason for the problem was that the oil drain was installed to return the oil back into the crankcase by gravity. The crankcase pressure was so high under boost the oil was prevented from draining so had to be helped.....
 
Interesting solution. Am currently having the turbo rebuilt again, will keep you posted. Forum Greg pointed me to was taking about a one way valve in the return line, as the turbo sits lower than the oil level in the cases, am investigating this as well. Interesting project....
 
Hi Marty

known problem with properly draining turbo lubrication where the oil is circulated through the turbo to then go back into the crankcases, I rebuilt the turbo twice before I figured out what the real problem was, bloody hell. Under boost the crank case pressure below the pistons rises to the point where it pushes the draining oil back up into the turbo and then past the turbo seal. Even more of an issue if your turbo is below the level of oil in the engine.

Some turbo systems solve this by a self contained lubrication system for the turbo independent from the engine oil but then they have cooling issues with the oil lubricating the turbo.

Search ebay for 12 volt turbo scavenge pump, not sure if this link will work but here is something similar to what I used. Read the full description in the ebay listing and look at how many scavenge pumps have been sold. Solved all my turbo smoking problems. Was a bit of a plumbing pain in the ass, I had to mount it in the tail of the CBX and run lengthy oil lines but it solved the smoking issue. It was noisy but the CBX was so bloody loud the pump whine could not be heard once the engine was running. If I ever get around to turbocharging a Laverda triple I will include a scavenge pump in the layout.

www.ebay.com

Electric Oil Scavenge Pump for Remote Low Rear Mount Turbo Return Line 12v for sale online | eBay

Find many great new & used options and get the best deals for Electric Oil Scavenge Pump for Remote Low Rear Mount Turbo Return Line 12v at the best online prices at eBay! Free shipping for many products!
www.ebay.com
 
You must log in or register to reply here.
Back
Top