My K series education continues ....

[ECR]

I was a little suprised to find that the (gold) dry sump pulley is not keyed onto the pump shaft in any way. Is this some clever sort of fail safe design where the pulley slips if the pump ingests something solid or just the way it is ?

[6speedmanual]

.....just that for a low torque application the clamping force of the fixing is often sufficient. Keying is most useful when positional location is required, eg a camshaft. Better to keep engineering simple and cost effective for the job it is required to do.

 

If your pump ingests something... well you'll have more to worry about than whether the pully slips enough to save the pump ❗ ❗ *eek* ... like what lump of metal just escaped from the moving parts of the engine 😳

 

6SpeedManual

*tongue*There's no such thing as too much BHP per Ton 😬

[ECR]

I see your point, thanks

 

A slipage of that pulley could well be fatal though .....

[ncm]

Changed the cambelt on the runaround a few weeks ago. You may be interested to learn that the Fiesta zetec(1250) engine has no keys or pins etc for any of the belt pulleys. It relys soley on the bolt clamping pressure to transfer the drive, so I guess Ford have no issues with this way of doing things.

 

Brian.

[Peter Carmichael]

In practice, the slippage can assist in tightening a loose bolt. Don't loctite the bolt otherwise you'll never get it undone without jamming something in the pump.

 

Copaslip on the bolt.

[Slipper man]

I was going to make the same point as ncm: on a Duratec the Cam belt pulley is also not keyed unless modified (as it always is in a 7 I believe)

 

Great engines, eh?

 

Yes, I know about the wheels before you say it

[oilyhands]

I hope you mean the *timing chain* pulley 😬

 

oily

[Rob Walker]

Slipper man,

 

Your info is out of date, The cosworth CSR engine has no keyway mod nor does the C/R 400 engine. The crank gear wheel that drives the chain that drives the oil pump and cams is clamped by a massive bolt with a special diamond encrusted washer. The clamping force is huge and any keying deemed not necessary. Its also very easy to time up the engine.

 

ECR,

 

If you look at the oil pump shaft it has a slight taper machined on it, the allen bolt pulls the pulley onto this taper. However I have seen several come loose including my own which came off completely. Fortunately I always ran with a micro switch on the belt tensioner that tiggered a warning light on my dash so was able to shut her down before running out of oil.

 

Rob

[Alex Wong1697456877]

OT - Slipperman - Heard about your little wheel problem (!) Glad you're ok. Didn't a similar thing happen to you in an AC?

[ECR]

I wondered if it had a taper. That makes me feel happier.

Slippage should indeed tighten the bolt Peter, and that adds confidence.Thanks for the loctite comment, I would have probably used it ...

 

Rob

The pump I am fitting (s/h) has a microswith attached and in view of your experience I will certainly suggest to the owner that it should be wired in.

 

Slipperman

Undoubtedley a great engine (but only up to a point :))

[Englishmaninwales]

However I have seen several come loose including my own which came off completely

Rob, so far so good ❗ *thumbup*But I did do it up with loctite, but I didn't know any better then(see PC's entry above) but I guess I'll never get it undone, now 😳. It is however set up with your microswitch

 

Malcolm

[Rob Walker]

I think a better solution to holding the scavenge pump pulley would be a short length of threaded studding loctited into the tapped hole in the pumps shaft then secure the pulley with its washer and a nylock nut or wired nut.