Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Walnut Blasting GDI Engine

https://www.delphiautoparts.com/en-gb/resource-center/article/common-gdi-service-issues#:~:text=Understanding%20common%20service%20issues%20for%20GDi&text=This%20can%20cause%20issues%20such,engines%20can%20accelerate%20oil%20vaporization.

Not sure if the link above to the delphi site will work, but it gives more detail on additional issues that can arise with GDI engines and it appears that simply diverting the crank case fumes is not the total solution. Also suggests why oil pools are found in the manifolds, early oil degradation and premature bore wear, etc.

Interesting article Doug Have taken the liberty of condensing it into a hyperlink here.

It does seem the negatives outweigh the positives, specifically that oil vaporisation due to higher temperatures increases the presence of droplets on valves in the first place, not so much that they are not washed away by upstream fuel. I read during the development of the Ford Cyclone engine direct injection was considered and even used on a prototype but their engineers eventually chose port injection.

Thanks Richard.
Despite googling on my ipad, I cant get my head around how to incorporate a link like that. Perhaps you could educate me, either via this page or by means of a PM?
Thanks.

As someone who has little knowledge (or interest 🙂) in 'new-fangled' engines ... is the problem 'direct-injection' or 'dumping crap out of the crankcase down the inlet'?? .... would venting the motor to a catch-can in the first place, leaving the inlet to breathe fresh filtered air, have avoided the issue from scratch!

K

If you read the Delphi article referred to above, it suggests that crankcase fume injection is not the only long term issue.

A question about preparing the engine before walnut blasting the inlet tract:
How do you turn the engine as required in order to make sure the valves are fully closed?
And how do you assess they are fully closed?

Can't you just turn engine in direction of normal running using a suitable socket on crank nut/bolt Robert, with second person observing visually when inlet valves close plus say a further quarter turn to be sure. Then repeat for other cylinders after blasting and clean up.

PM waiting.

What I did (informed from what I'd seen elsewhere online, mostly in a You Tube video guide) was turn the crank with a socket on the front pulley bolt and knowing when each piston was at TDC by removing the spark plugs and having a long screwdriver carefully poked down the plughole, resting on the relevant piston crown - making sure it wasn't getting jammed at any point, which it never felt like it would.

I did likewise to find TDC but instead used a long straight softwood stick, about 4mm dia, purloined from SWMBO’s garden shed. Not mega accurate, but good enough to make sure the inlet valves are closed.