Alfa Pages

[knighty]

I have a 1.7 8v hydraulic head boxer in my beach buggy and its been making a tapping noise for a while now and its now really pissing me off as I cant seem to trace or fix it, the noise seems more pronounced when the engine is crusing or under light load, not so much under acelleration, so far I have:

1) dropped the sump off, inspected the con-rod shell bearings, and they looked like new, if they are good, I assume the crank mains are also good, as they feed the con-rods with oil.

2) removed the fuel pump drive pin, as I use an electri fuel pump, as I thought it might be the noisy culprit

3) just changed the hydrailic tappets for new ones

all of the above have not worked.....fook

I'm thinking its still related to the hydraulic tappets, perhaps low oil pressure is not pumping them up enough and causing the tapping noise.......where is the best place to measure oil pressure, and what sort of figures should it be?.........if its low, whats the normal cause?....worn oil pump innards perhaps?

my worst fear is a con-rod small end piston or gudgeon pin is badly worn and its slapping about, but when I inspected the big-ends via dropping the sump off, I didnt really feel any play........do the small ends ever let go on boxers??

I have just bought an engine off ebay for a fiver, so now have a spare block which I shall rape for spares........no carbs though!

[RBL]

A friend of mine once gave me a tip for silencing noisy hydraulic tappets.

Change some of the engine oil for diesel (not sure what ratio, I can find out - may be 50:50!) Run it up to temperature for a while, then change the oil. The thinner mixture will penetrate the tappets, loosen them up and reduce the noise.

However, I've never tried it myself!
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Porsche 550 spyder replica with Alfa Sprint 1.7 engine

[JeremyC]

Or use a flushing oil.
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'93 Black 33 1.7 16v