My Uncles Lotus. Now mine

[Pete]

So. Does anyone have experience with the gordini 807 cross flow engine?
It was running okay ish. As idling as I haven’t managed to get it road worthy yet. Then a tapping noise came which sounded like it was the valves maybe. Or the drive chain which I know it’s not now. But not sure. Found that number 4 spark plug wasn’t being used as when you disconnect and reconnect it doesn’t make a difference to the sound of the engine. Tested the spark and it sparks great. So figured the carb is the issue. Stripped the carb down. Cleared all channels put it back on and it doesn’t make a difference.
Ran a compression test. When engine was cold and it read 150. A few days ago.
Today ran the engine for a bit and the tapping noise went as the engine got warm. Then ran the compression test again. And it was around 100. Looking online it should be around the 130 with the cross flow engine.
So tried a leak test on it. And all fine there.
Think the next step is strip the engine down and either change the piston rings or re bore the engine and new selves?
Or any other suggestions? Thanks
Pete

[Richard48Y]

Why is No. 4 always the issue?

Have you removed the valve cover and turned the engine over to observe the valve train?
Perhaps a badly adjusted rocker? Might explain your tapping sound.

Fuel, Compression, and Spark. Your No. 4 is missing one of those.

You say you did a leak test, does this mean you fit a hose with a good supply of compressed air to each cylinder in turn, at TDC, and listened for escaping air? This works best with the valve cover on.
Can quickly tell you if rings, valves, or head gasket are at issue.
My own TS engined car is going to need rings, this is how I determined that.

[Pete]

Yeah removed the rocker cover. And checked the clearance of rocker arm at tdc of each piston. All the same.
Yes leak test done correctly. They all around 15%.

I just don’t know why it’s number 4. It has a spark. When I had the carbs off loaded with fuel they all squirted fine when I opened the throttle. So it can only be the compression. But it’s the same compression across all of them. Of just under 100.

[Richard48Y]

Humor me please.
Swap #4 plug with another and see if the issue moves with it.
Just because you have good spark TO the plug does not assure good spark AT the plug.

[jbcollier]

What brand and type of plug are you using.

Can you describe the noise it’s making in more detail.  The way you describe it, it seems constant.  Louder or quieter when cold or hot?  High tone or low.  “High” in the engine or “low”?  Pull each plug wire one at a time.  Does the noise change?

What is the oil pressure?  Cold?  Hot?

Crossflows come in a variety of compression ratios from 11:1 to 8.5:1 so 100 psi might be ok or completely worn depending on which you have.

[Pete]

Humor me please.
Swap #4 plug with another and see if the issue moves with it.
Just because you have good spark TO the plug does not assure good spark AT the plug.

I had already tried this. No didn’t make a difference

[Richard48Y]

Now I wonder about a vacuum leak at the manifold.
That might give a very weak mixture that does not ignite properly.
Car has sat so would not be a major surprise.
Do you have a "Colortune" spark plug available?
May be difficult to look at with a TS head but would show weak mixture.
May be simpler for you to fire up the car and spray around the intake at idle with some carby cleaner.
See if the RPM changes. If it does you have a leak.

[Pete]

We tried that. And it didn’t.

[Pete]

Also.
Does anyone use a quick release steering wheel hub? Just wondering if it’s a good option to go for to help getting in and out of the car? But I’m concerned how safe they are.

[EuropaTC]

I don't use one myself but they are very popular with Elise owners, esp. the S1 version because that's challenging if you've had one too many pies. Safety wise I'd say they are well proven and of course there's always the anti-theft feature if you take it with you !

I'm fine with a 13" wheel but the original owner of my car had a very small Astrali wheel on it when I bought the car. I can't recall if it was 10" or 11" off hand but it did clear the instruments.

Brian

[jbcollier]

I use one on mine.  I’m not sure why you would think they are unsafe.  They latch securely and require a deliberate action to remove.  Assuming you want to keep the stock switches and column, then there are only a few options.  I use a Lifeline adapter with a Moto Lita wheel.  Downsides?  It moves the wheel a further 2” out (like that myself but switches are now a bit of a reach) and there is a very, very slight amount of play (unnoticeable in use).  Upsides?  Pretty good theft deterrent and getting in and out is much, much easier.

[JR73]

I have one on mine too. Like jb has said, not sure why you would think they are unsafe? - have been used in motorsport for many years and you have to be quite deliberate in removing them.

I have the weld on spigot type by SPA Design which is identical to the one supplied on the Caterham and have never had any issue with either. - I don’t use the original column switchgear but I have seen the same installed with the original switches and covers in place. This version does require a good quality fabricator though for it to be attached correctly, the bolt on types are much easier to fit and easily up to the job.

They definitely give you more room when getting in or out along with the extra hurdle for any wannabe thieves to overcome…

[Pete]

I have never experienced one. And just had visions of me driving and it coming unattached whilst driving. Lol

[Pete]

Made some temporary suspension holders so I can take the engine out but still able to wheel the car back into the garage today.

I’m not going to drive it like that. It’s only so I can still move it about.

[BDA]

Being able to push the car around without a tranny is VERY handy! 

Did I miss the part that picks up the half shafts?