Based on your
past posts, that motor has given you a lot of grief and no wonder. LPG, pushing the performance envelope of an engine that has proven not to be receptive to it, sleeving a non-sleevable block, etc. Sorry to say, but that thing is cursed and spoiled goods, mate.
I tend to agree with most of the above..Yes it is an all aluminium engine and it's had a short production time and its had a fairly hard life.
The gas has been on for over 2 years and it could be this increasing the combustion temperature, that will then explain the worn valve stems as the valves must be getting a bit warmer than what there used to.
Also back to the gas it's only been fitted on the last head and not the other 2 , the valves on the other hand have just been changed out between the bare heads as there has been no signs of damage.
Bobby Singh has mapped it with another van with the same engine but I'm not blaming the map as it still returned good power and torque even with the damage in the engine. I've stripped the engine due to a broken rear engine mount as the engine torque has pulled the threads from the block so I thought I would strip and look at the starting issue which had only been a recent thing.
Since I altered the injector fixing for the injectors they have shown no visible wear in the top of there bores, and even though I'm not using stretch bolts on these they are not over tightened.
The camshaft had signs of stepping on the number one inlet along with the worn follower on the same lobe and could be signs off reduced oil flow as most of the remaining 9 followers are showing signs of wear.
The bore for number 5 has thrown a bit of a curve ball as I had thought it was just a worn bore and rings on a compression test. This is not really the case as on a kerosene test on the bores the plasma coated bores lost its fluid quicker than the steel lining so this then brings me onto the question of " is the +50 nozzles bore washing the plasma coating?" I don't know as there seems not to be many higher powered r5 engines that do 20k+ mileage a year , most are just weekend and show stuff.
The head has jumped and I can see movement on the crank bolts with wear marks up the side of the bolts, I have found a set of 12.9 grade bolts that I'm going to install but ARP don't have anything suitable.
The only difference I can see apart for a bore missing on the 4 pot is they don't have a gear driven top end and it's a cam belt,it's not cross flow, I still have a 492cc per bore similar to the 8v pd and inlet/exhaust valves the same size .
As I said in one of my passed threads on coolant whether it's just all getting to hot and possibly needs a bit more cooling for the top end ?
For the future this is going to be the last for this engine as I have other plans, but just seeing what it's capable of as an everyday driver and the diesel over this side of the pond is on borrowed time with the government.
