Mad new cam cover - bulk buy?

[scooby dooby doo]

jj - I'm going to need something to fill in the gaps in my engine upgrade. Whilst DVA will upgrade the engine i need help and a garage to get it out of the car and then back in again. including a rough mapping and fitting the dry sump bits...

 

Do you have an official email address i can talk to you on or is it just the normal one 🤔

 

HOOPY Membership Number 4136 R706KGU

[Johnty Lyons]

David get me at usuall one ring me if you want 07774672338 I'll do anything i can to help now that air travel has become so cheap i'm 2ing and frowing a lot.

 

jj

N.I. L7C AO.

Membership No.3927.

[clive]

Julian

 

Have been reading through the post's concerning breather holes, correct me if I'm wrong, but the general concensus seems to be if you have a dry sump then go for at least one small breather hole even though they are blocked off on the VHPD cover, by Caterham as mine is,(excuse me if I'm missing the point but I'm not too hot on the mechanical side of 7 ownership)

If the above is right please ignore my last email & take this as my confirmed order.

Cam cover £100.00

Bag bolts £3.93

Anodisation in Red with linished fins £15.00

One breather outlet channel £15.00

 

Once you have confirmed the additional items are OK, I will whip my chq in the post.

 

Cheers

 

Clive

 

 

Edited by - clive on 30 Oct 2002 14:53:16

[Fred]

i was wondering why you all want the vents in the cover. when minister block the vents off.

with the dry sump .why do you you feel this is necessary. 🤔

i also notice the last time i saw peters he did not have one in the cover either .

is there a reason for this .

[V7 SLR]

From here Peter describes the following:

Opening up a breather in the head improves the drainage considerably for dry sumped applications.

... and then

Any breather in the head will mostly inhale. This is good news. You can either put a filter on the breather or you can tee it from the catch tank. The difference is this:

 

Filter:

Catch tank exhales copiously, with significant oil mist coating the underside of the car etc. Full evacuation of acidic condensate from combustion products, so oil stays in better condition. More frequent oil checks are required because quite a lot disappears as mist.

 

Tee:

Catch tank vent exhales the volume of blowby fumes only. Acidic fumes are recirculated through the head and crankcase, contaminating the oil particularly when run from cold. Engine loses less oil.

 

I run with a filtered breather.

---

... and then this

Factory decision comes down to:

 

1. Industry myth that a crankcase vacuum gives more power

2. Industry myth that a vacuum helps scavenging (in fact exactly the opposite)

3. Ease of implementation.

4. Some race teams with properly designed dry sump systems do it.

 

Even Neil at Pace gave me a story about alternative laws of physics that apparently apply. The symptoms of a vacuum in the crankcase can be as a result of good scavenging. A vacuum in the crankcase does not of itself mean that good scavenging is going on.

 

The only thing that gets the oil out of the engine and into the scavenge pump inlet side is a pressure gradient. If the pressure in the crank case is reduced then the pressure gradient to the entry of the scavenge pump is also reduced. If the cam cover is sealed, the only net matter being introduced into the engine cavities is piston blow-by gas. Blow-by gas introduced in the crankcase prevents the oil draining from the head at a faster rate than the oil is being pumped into the head.

 

Opening up a breather causes a draught to blow from the top of the engine down to the pickup. This assists oil drainage from the head.

---

Not sure when you last saw PC's engine, but at "The Clash" at Curborough, he had a filtered breather then. That was in May IIRC.

 

Worcs L7 club joint AO.//Membership No. 4379//Azure Blue SLR No. 0077//Se7ens List Tours

 

[Julian Thompson]

OK!

 

I'm back.

 

Order status.

 

000D Me (-dry sump prototype-)

 

PAID, SENT 1/11/02, 000W Simon Hayward (-wet sump prototype-BOLT KIT) £153.93

 

PAID, WAITING, 001D Hoopy (RED, BOLT KIT, 1 SMALL BREATHER) £143.93

 

PAID, WAITING, 002D Nige V7 (BOLT KIT, 1 SMALL BREATHER) £128.93

 

003D Count (RED/SILVER, BOLT KIT, 1 SMALL BREATHER) £143.93

 

004D John Howe (BOLT KIT, 1 SMALL BREATHER) £128.93

 

005D TopHose (BLUE/SILVER, BOLT KIT, 1 SMALL BREATHER) £143.93

 

006D David Ward (BLACK/SILVER, BOLT KIT, 1 SMALL BREATHER, APOLLO RETURN) £158.93

 

007D Clive (RED/SILVER, BOLT KIT, 1 SMALL BREATHER) £143.93

 

008D Mark Durrant (BOLT KIT) £113.93

 

009D Johnty Lyons (RED/SILVER, 1 SMALL BREATHER, BOLT KIT) £143.93

 

010D Lawrence Hoy (RED, BOLT KIT) £128.93

 

011D Mark Boardman (BLACK/SILVER, BOLT KIT, TIMING ACCESS, 1 SMALL BREATHER) £203.93

 

Please note that I've done my best to keep this list updated but it is YOUR resposibility to check it and ensure your cover will be to the correct specification.

 

Thanks Jue.

 

Now please read the next post.....

[Julian Thompson]

The standard breathers in the cam cover are on the exhaust manifold side. This is where the wet sump prototype had them, so it would be a direct replacement for the standard cover.

 

Is there any mileage in repositioning the single breather to the other side on the dry sump ones?

 

 

[Fred]

Thanks V 7SLR understand now.

[V7 SLR]

Ju,

 

Both the breathers on mine are on the inlet side so I'd assumed they'd be on that side too. I absolutely need them on that side pretty please.

 

Good reason is so the breather can be plumbed into the airbox backplate.

 

Worcs L7 club joint AO.//Membership No. 4379//Azure Blue SLR No. 0077//Se7ens List Tours

 

[David Ward]

Julian

Both my breathers are on the inlet side, and this was a std. Caterham cover . I need my single breather to be on this side please. However as previously explained the Apollo pipe enters on the manifold side. I'll try and get a pic to you with the cheque this weekend.

David

[Lawrence_Z]

cheque on it's way Julian

 

many thanks

Lawrence

[Lawrence_Z]

V7

 

I also saw PC's engine at Curborough and his cam cover did not have a vent in it.....

 

he did however have the head venting through a non return valve and mini filter.

 

Will your design operate in the same way? and will connecting your vent to an air box not create a whole new batch of problems?

 

Lawrence (just interested)

[V7 SLR]

Symantics.... the point being his head was vented to facillitate oil drainage from the head to the sump. I don't want to drill the head, so a vent in the cam cover does the same job.

 

I'm not 100% convinced about the airbox yet. The intention was to utilise the general air filter, to prevent my having to purchase a specially-designed one. I need to determine if the air pressure in the airbox is greater at all times than that generated by the scavenge pump. If at any time the air pressure is lower then the cam area will push oil into the airbox and it all gets messy. Don't fancy that.

 

Not sure how I will measure air pressure in the airbox. I would guess that sudden large throttle openings would be the cause of negative breathing WRT to the cam cover. This might be where a valve should be used. Perhaps I can use this valve to indicate the direction of negative air pressure. Obviously that would need a visible flap... Hmm... anyone got any suggestions?

 

Worcs L7 club joint AO.//Membership No. 4379//Azure Blue SLR No. 0077//Se7ens List Tours

 

[Lawrence_Z]

Another question prompts a new thread

 

Surely all breathers must be connected to a catch tank

 

Lawrence

[Julian Thompson]

OK guys, breathers to be on the inlet side unless otherwise requested.

 

I think the point about the breather thing lawrence was that the one in the cam cover sucks in, rather than blows out!

 

I'd like someone to pop a vac meter on it and go for a blat to see the sort of pressures we are talking and to clear up PC's only ambiguous bit where he states that the cambox breather "mostly" is in vaccuum.

 

We could actually tap the airbox backplate and run the same test simultaneously to measure Nige's question about the differences between the 2 vaccuums.

 

As I see it, trying to be logical, the vaccuum in the cambox must be created by the pressure differential in the drysump system between the head area and the lower tank? This can't be much (can it?) and surely is less than the main induction vaccuum, which would wreck Nige's plan to use the backplate as an air tap?

 

Hmmmmmmmn. Anyone got 2 vac meters or a couple of old turbo guages that have a vac section?

[John Howe]

Cheque posted... breather on inlet side please

 

JH

Deliveries by Saffron, the 222bhp yellow Sausage delivery machine

[philwaters]

Julian, if you need any Cad modelling done for the light project, let me know. I have modelled a replica, much more hollow and it has a material volume of around 26100 cubic mm. Ali is about 2700kg/m3 so a rough caluculation gives about 70grams per unit. I weighted the normal one at about 260-280g each on the kitchen scales. (waiting for everyoneto correct my figures!!)

I can't afford to buy if it goes ahead, but would enjoy being involved - can e-mail cad models that he might be able to use to program, etc....

 

p.s. can you tell I'm bored at work?

 

Phil Waters

You mean you can drive these?

I thought it was just there to polish 😬

[Graham Perry]

I know Julian threatened to shoot us if we discussed this, but (dons body armour) would it still need a rubber seal of some kind to be incorporated into the design ? I suspect it probably would. I was looking at mine the other day and thought that they are surprisingly complex shapes so CAD sounds a great idea.

[scooby dooby doo]

i have a spare (disposable as its covered in gaffer tape gunge) light block if its needed for comparisons.

 

HOOPY 500 kg R706KGU

[philwaters]

Regarding the rubber sealing... I looked at this and whilst I think it would be a good idea - the current ones are rubbish and I intend to hollow out my current ones and use grommets in the rear wing hole anyway. That leaves the seal between the lens and body. Any ideas? Custom rubber seals will be hugly expensive - personally I'd run a small bead of clear silicone and bolt it up - then run round with a wet rag to clean it up...

As for the shape, I intend to do a 1:1 side plot that I can cut out and hold up to the car... (would also measure it properly - sometimes helps )

 

P.S. Where do I stand to be shot? 😳

 

P.P.S I personaly think they will be far too expensive as the amount of waste material alone is huge, and of course that takes a long time to machine out!!!

 

p.p.p.s - simple picture added to the pages below.

 

Phil Waters

You mean you can drive these?

I thought it was just there to polish 😬

 

Trying to learn how to spell.

 

 

Edited by - philwaters on 5 Nov 2002 14:11:47

[scooby dooby doo]

you could change the shape of the light block a bit so that its not as think. so instead of being 10mm at the bottom and 25mm on the top (or whatever it is) when viewed from the side it'd be 16mm on the top and 1mm on the bottom. even lighter then

 

HOOPY 500 kg R706KGU

[philwaters]

Already done Hoopy, it is 3mm at the bottom face, instead of 12mm... with a similar reduction at the top.

The curve of the arch is the biggest worry, hence the cut out trial idea. Of course, the rubber ones also give a bit as you tigthen them up, so don't have to be that close anyway... could end up with unsightly gaps ☹️

 

Phil Waters

You mean you can drive these?

I thought it was just there to polish 😬

[scooby dooby doo]

Good man ❗

 

re the possibility of a gap - thats why we have an expert like you on the case with the CAD software ❗

 

HOOPY 500 kg R706KGU

[philwaters]

Maybe me saying something was not a good idea afterall 😳

How good and consitent are Caterham rear wings? Not very I think...

 

Phil Waters

You mean you can drive these?

I thought it was just there to polish 😬

[scooby dooby doo]

surely there must be sort of trim that would fill the gap nicely - like the stuff between the wing and side of the car..

 

HOOPY 500 kg R706KGU