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Dropped valve?

caterhamnut

By caterhamnut
in TechTalk

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caterhamnut

caterhamnut

Posted
Posted

🙆🏻feck and poo.

Driving last night, overtaking along a duel carriageway and a noise, followed by stuttering running/missing and a bit of metalic clunking! Pulled over, engine idles and starts/runs but roughly with the odd metallic thud on the cam cover (dropped valve being pushed up by piston?) - oops!

Had just fitted DTB's and the engine was running sooo nicely. Lovely idle and smooth, but was waiting to go to Steves RR for a map check - the map was the one we ran with the big single TB - Peter C did a great job at scaling the fueling etc, but wanted to check it.

 

I'm hoping it isn't a self-inflicted accident, where something I haven't done up properly on the DTB and air box set up has come off and been ingested!

Engine sits at Marks awaiting inspection.....

 

Still, on a brighter note, before this it was running very very quietly - those Scouse air boxes (thanks Dave J *thumbup* *smile*) work well, and it had a very smooth idle, with a nice booming noise at higher revs. Hopefully the problem won't be too great. Hoping for about 200bhp on the RR (simply from bolting the DTB's onto the 184bhp engine) but much more concerned at having a nice drivable engine. The single TB was great on track when flooring it, but a bit lumpy and rough around town (as predicted) and it is true what others have said - if the car is arubbish to drive at slow speeds, you certainly don't use it as much as before....

 

Was hoping to get the car up to the 50th for the Arch stand, so lucky it blew last night and not whilst Tony P was driving it up.... 🙆🏻

 

www.mycaterham.com

here

Videos

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101,000 miles car

Jason Plato

Jason Plato

Posted
Posted

☹️ buggar !

 

VHPD head next then ? *smile*

 

I hope it hasnt injested a clip off the airbox 😔

 

I had them bonded on with gooe following similar stories.

 

 

 

Taffia rear gunner

 

oilyhands

oilyhands

Posted
Posted

The latest Autoteknix airbxoes have no internal clips or appendages, everything is external so there is zero chance of ingesting a clip. If the fasteners are correctly done up with loctite then there are no issues, however it is easy to forget the loctite.... make sure that the trumpet studs and nuts are loctited too. This is in common with *any* induction system.

 

Oily

caterhamnut

caterhamnut

Posted
  • Author
Posted

*thumbup* cheers guys. Hoping it isn't going to be too bad - I have faith in the lack of too much noise! *gulp*

As you say Dave, any clips where all bonded in nicely, so I have no fears its anything to do with the air box *thumbup* - if it is it will be user error on my behalf and not using loctite (the usual ' I'll do them all up now, make sure it all works, then go back and do 'em properly..... 😔 excuse!)

I shall report back when I know...

 

www.mycaterham.com

here

Videos

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101,000 miles car

Mick Day

Mick Day

Posted
Posted

Sorry to hear the news Angus, however shouldn't be too difficult to fix.

Was hoping to get the car up to the 50th for the Arch stand, so lucky it blew last night and not whilst Tony P was driving it up....
Tony drove my car back from Spa & managed 34mpg on the Autoroute. Pretty outstanding for a 227BHP DVA engine with mapping by the 2 Steves!

 

 

caterhamnut

caterhamnut

Posted
  • Author
Posted

*thumbup* Just goes to show that a k-series, built and maintained properly, is still a very good, reliable, economical engine (present problems excepted, but I still come out on the engines side bearing in mind the mileage and use we have got out of them!!)

I suspect Tony was also being pretty careful!

Although Peter C is getting similar figures with his aswell...

 

www.mycaterham.com

here

Videos

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101,000 miles car

rj

rj

Posted
Posted

Angus,

 

Sorry to hear this.

 

Suppose it coulden't be a valve spring that has given up?

 

What are the specs of your head?

 

/regin

F355GTS

F355GTS

Posted
Posted

Looks like one of the bolts holding No2 trumpet came loose and whilst the bolt is rolling about the airbox the washer appears to have gone in *eek*

 

Mark

caterhamnut

caterhamnut

Posted
  • Author
Posted

Stole my thunder... *smile*

I haven't seen it yet, but as Mark says! - so entirely my fault, as predicted above - loctite should have been used...will await to see what damage has been done.

 

www.mycaterham.com

here

Videos

here

101,000 miles car

Alex Wong1697456877

Alex Wong1697456877

Posted
Posted

What a nightmare. Saw a similar thing happen to a Vx and suprisingly not much damage - hope the same is true for you.

 

Have just bought a pair of locking wire pliers and some wire as this kind of thing has always worried me. Bought them on E-bay.

 

Good luck Angus.

rj

rj

Posted
Posted

Angus,

 

As you know I'm a bit of a collector. If you reckon I've got something which will help you getting the engine back in working order please feel free to give me a shout.

 

 

/regin

Unclefester

Unclefester

Posted
Posted

*eek* *eek* *eek* Oh dear.

 

Sorry to hear this....we are all, after all, allegedly human and thus prone to the occasional error. I find mine are ALWAYS blameable on someone else.

 

I'm sure you will recall (nudge nudge) being INTERRUPTED while putting that airbox back on, eh?

 

Meanwhile.....I think I'd feel safer if I took my airbox off and checked those dratted little trumpet fixings....... 😳 *eek* ☹️

 

Lucy in the Sky with Diamonds..ooooh hooo hooo!!...

😬 😬Abbey Road Time-Machine *eek* *eek*

 

dannylt

dannylt

Posted
Posted

Sorry to hear that. Ammo & Fauldsport were paranoid enough to lockwire my trumpet fixings which certainly gives piece of mind on an expensive head!

 

caterhamnut

caterhamnut

Posted
  • Author
Posted

Thanks guys - Regin and Mav, many thanks for your offers *thumbup* *smile* - most kind.

Looks like we have been reasonably lucky.

Taking the sparks plugs out showed signs of damge on one:

here

 

Looking through the exhaust ports before disassembly we could see that the valves on one cylinder were not seated and therefore showed damage.

Taking the head off showed the damage. The good news was that the washer was still sitting on the piston, and looks to be whole. Piston is obviously marked, but not excessively so and not cracked (I hope!) Spot the washer sitting centrally.

here

 

Here is a before and after shot of the washer. Pretty well hammered I'd say!!

here

 

The damage to the head will require a little work - new valves obviously and some cleaning up of the surface, along with re-seating of the valves in the head.

here

 

All in all, could have been worst, as others have found out, so consider ourselves very lucky! Re-assembly will involve loctite, lockwire as danny suggests and also soem blobs of silicon on the bolt heads! *smile*

 

Once fixed its off to The Steves to tweak the map - as you can see it is a little sooty right now...

 

Thinking about it UF, I am sure that someone didask me something whilst I fitted the trumpets.....

...alas I was actually on my own when I put them on, so entirely me 😔

 

www.mycaterham.com

here

Videos

here

101,000 miles car

 

Edited by - angus&tessa on 17 Sep 2007 21:36:28

rj

rj

Posted
Posted

Well,

 

 

At least there is less soot to remove from cylinder 2 *smokin*

 

It looks like youve been fairly blessed *thumbup*

 

/r-)

Tony C

Tony C

Posted
Posted

Sorry to hear about this Angus, but as you say, it could have been a lot worse. When I had my K-Series I fitted studs to the TB's with a nylock nuts on the back of the TB's and then secured the trumpets with nylock nuts - bit overkill, but reasonably secure *cool*

 

BRG Brooklands SV 😬 It seems that perfection is achieved not when there is nothing more to add, but when there is nothing more to take away. (Antoine de Saint-Exupery)

caterhamnut

caterhamnut

Posted
  • Author
Posted

Thats right Peter - I had only just fitted the DTB's (it was single VVC plenum) so the map hasn't been sorted just yet - probably running rich with bigger injectors etc - idles beautifully though *smile*

 

www.mycaterham.com

here

Videos

here

101,000 miles car

rj

rj

Posted
Posted

Angus,

 

 

I managed to get my map within 1% with my wideband lambda thingy.

 

Of course if you want to borrow it you're welcome.

 

/r

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