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First time posting here, Ive been told that the AUB cylinder head can be used to build the popular AFH/AVY hybrid, I understand the cams and pulleys are different, I have built the engine and tried to turn it over, my lupo sport originally had an AUB unit but the engine seized so I used the head to build my hybrid which is AUB/AVY as I was told it would run with a map. The engine turns over but struggles on the compression stroke, as if the starter is weak but I checked it and it is fine.

I am wondering if anyone has built a hybrid either using the AUB or AFK successfully and if I could ask them some questions to sort some teething issues I am currently experiencing myself. 




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I dont know much about those engines but would have checked piston to valve clearance to make sure they clear. Also compression ratio may have changed.

Take plugs out and rotate, if it has tight spots take the cams off and rotate again, if the tight spots have now gone then it is valve train or piston to valve contact.

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No evidence for this hybrid anywhere so that suggests it's not viable, however that's part of the fun, as sausage says you need to get basic engineering sorted, do water and oil feeds all line up properly? and will it work mechanically. From doing this in the past a couple of pointers

1/ use a used head gasket so you dont have to orques the bolts.

2/ use plastigague glued to the valve base to check clearances, assemble torque to 50% rotate disassemble measure the plastigague

3/ When looking for clearennces allow for heat expansion and the  stretch that happens at high rpms.

4/ you need to map the cam timimg relative to the crank rotation and piston pisition, it may be that you have clearance and that the CAMS need re-timing for the hybrid.

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So ive made an inspection to the oil feeds and water galleries and they all line up, also replaced the tensioner and it seems to be turning over a lot better.

Thank you for the replies, always appreciate help, and yes it is fun ahaha.

I am now down to one fault stopping spark and thats G28, Engine speed sensor, Implausible signal, I had to refit the trigger wheel on the crank as it had been removed by the previous owner,, I used tool T10017 to fit it, but its still throwing up this fault so I am going to look at realigning it again. 

I based my conversation on a Turbo'd AVY/AFK that was flaoting around local to me before the owner moved to australia



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