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[knighty]

my 1.7 8v boxer is making a tapping noise when crusing at a set speed, it doesnt make it when accelerating, only when crusing when the engine is under very small load at a set speed.........the engine is from a 1990 G-plate, so its a hydraulic head version, was told it had done about 90,000 miles when purchased........I'm thinking it needs a new set of tappets - or do you think it could be something else?.......what sort of wedge should I expect to pay for 8 tappets?

[Admin]

Hi

Would not expect all to go at once, and would expect most failures to be obvious at idle.

A ticking noise at about 3000rpm on my P4 turned out to be the big end shells just starting to fail. Got away with just new shells.

All the best

Keith
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[knighty]

big end shells..........dont say that!.......shizer.......

[Admin]

Hi

To be honest, if you can get away with shells alone then it is a far easier job than changing the hydraulic tappets. It can be done from below just taking the sump plate off the access the big end bolts.

All the best

Keith
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[Ben_nz]

The tapping noise could be anything as far as we can tell over the net, maybe not even coming from the engine. If you have wear on the faces of your tappets then you'll probably have corresponding wear on the cam lobes, but this is the kind of thing I'd expect you could hear at a range of rpm, with or without the engine under load.
Maybe there's a problem with the fuel mixture in one cylinder under those circumstances, maybe the noise is from your gearbox etc.

Does the frequency of the noise relate to engine rpm? Does it occur at no load? When you say 'cruising at a set speed', do you mean engine speed? If so is the noise present in different gears?
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[Oggie]

Is your car using 2 twin webbers , if so they can generally be quit noisy at low rpm , especially when not using the standard air filter box. Has the car been tuned recently or any engine work done, if so try back tracking to whats been done.
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PHAT 33

[Eddie_W]

Just to really make your day, a similar noise on one of my series 1s turned out to be that some clever clogs, be it at the factory or subsequent, had on two pistons fitted the gudgeon circlips both on one side with none on the other. End result was two lovely square grooves in each bore and one stuffed block. Motor didn't have much blowby and ran really well. At first I suspected bigends which as already stated are quite easy to check but alas they were fine and further investigation revealed the gudgeon damage.
However it may be possible to pinpoint the source of your noise with the airfilter off and a large screwdriveras a resonator. Plastic end in your ear and the blade against the block in different areas will often narrow it down and the position where it is loudest will indicate the source. This includes the sump but bigends usually knock under load , not so much on cruise.
Good luck
Eddie
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[knighty]

excellent ideas guys, thanks very much, yes I will try the screw driver trick.......am sure its not the gearbox or carbs.......I'm convinced its something cam related.....possibly the big ends, I will probably let it rattle all through summer, then fix it during winter, so I'm not going to rush into it.

another question.......what sort of coolant temperature should a 1.7 8v maintain?

[Admin]

Hi

Temp should basically be 80~90ish. Stats get a bit lazy with age.

In the (pretty unlikely) event it is the big ends then I would do them. Leaving them will trash the crack, yet on the 33 a set of shells is cheap and they are easy to fit.

All the best

Keith
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[knighty]

ok, I will do that at the end of summer, where is the best place to get a set of shells from?........Alfa main dealer of my local motor spares shop?

80-90 sounds good to me.......my alfa powered buggy is running around 90.

[RBL]

knighty, I got mine form an motor engineer in Poole who polished, checked and measured the crank before ordering the correct shells for me.

My engine runs at about 88-90. A bit more in hot weather. I've just calibrated my water temp gauge using a spare temp sender unit and a home brew thermometer in a kettle!
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Porsche 550 spyder replica with Alfa Sprint 1.7 engine

[RBL]

ps - are there any pictures of your buggy? I'd love to see it and how you fitted the engine.
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Porsche 550 spyder replica with Alfa Sprint 1.7 engine

[RBL]

D & R James Engineering Services Ltd
16, Benson Rd, Nuffield Industrial Estate, Poole, Dorset BH17 0GB
Tel: 01202 678679

This is who I used, though I know they're not in your area, perhaps could give advice.
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Porsche 550 spyder replica with Alfa Sprint 1.7 engine

[knighty]

thanks for the contact details much appreciated, to be honest I certainly wont be removing the crank, but I will be able to put a micrometer over the journals before I order to right ones......while laying under the buggy of course!

but I still need to do the screw-driver test on the heads

funny you should mention the kettle test, I did exactly the same thing the other day using the sender from my 1.5 engine!.......said 50DegC on the buggy gauge, kettle reading said 90DegC!!!!.....I'm preying the 1.7 sender will give bettrer results but I doubt it will - but you never know!.......the pleb that originally built the car just plugged an aftermarket gauge into an alfa sender and expected it to work - plonker.........its taken me over 4 years to do a roling restoratiobn to de-bug all his cock-ups.......its a completley different car now

will post some pictures very soon