Cat crossflow tank in a Lotus Seven?

[jbcollier]

Will the below tank fit in a Lotus Seven (S3)?

 

https://caterhamparts.co.uk/tanks/575-fuel-tank-carb-ford-and-vauxhall-engines-alloy.html?search_query=Fuel+tank&results=212

[OldAndrewE]

I guess either Chris at Redline or Arch Motors will know the answer

[jbcollier]

Unfortunately it's radio silence from Redline.  I'll try Arch.

[Tony P]

If you haven't solved this in the meantime, I'll measure my tank tomorrow and post here.

I think the width might ultimately be the critical thing - Weale suggests that over the years width was increased to increase the capacity, though I think that pre-dated S3. I know that earlier cars had a notably shallower boot, but whether that was solely due the allowance for movement of the live-axle diff, or whether a taller and slimmer tank was required too - I cannot remember... oh, and inlet neck on a current tank would be on the right, is that ok?

Did you solve the conundrum of whether or not later Caterham sidescreens would or wouldn't fit?
Nobody offered as reason as why they wouldn't, and anecdotal evidence offered here suggested they probably would.
The later 'increased visibility' ones had taller window sections - which has implications for the hood - but it's hard to see what else would be different. Unless someone can tell us...

[rkeywood]

I have a card template for the section of the tank Caterham supplied a while back and can post the measurements if that helps. The tank was a few centimetres different from than the '86 steel tank it replaced but fitted OK with a bit of adjustment to the securing straps. The fuel gauge sender holes may be different - I think the current tanks are 6 holes and the earlier gauge senders 5 holes.

[jbcollier]

The consensus from the experts was "no" to the side screens fitting.  They would be too long.  It was also pointed out that the early style screens with their vents are actually quite useful.  Something I confirmed on my first road trip -- the same trip that led to the plugged filter from debris in my original but freshly steamed and lined tank.   The top they were fuzzier on but if the screens won't fit then the top must be a miss as well.  Mike Brotherwood is having new screens and tops made up and I have my name down for a set.

 

The filler is on the right on S3 Sevens so all good there.  Any dimensions would be gratefully received.  Looking for them from a carburetted crossflow vehicle, which should preclude wide chassis and other later shinnagons.

 

 

[rkeywood]

Here's the dim's for the ends - I can copy onto card and send to you if you want. I'll check the length in the car tomorrow. I've fitted in both an '86 live axle crossflow and my '89 car.

[jbcollier]

Thanks, much appreciated.

[rkeywood]

And further to #7 800mm long

[jbcollier]

Just heard back, Arch says a Caterham crossflow tank will fit!

[jbcollier]

Big shout out to Caterham.  After my enquiry, they have added a photo with dimensions to to the listing.

[jbcollier]

I'm ordering one and will report back.

[jbcollier]

Well, it “fits”.

I have to redesign the axle brace as it extends too far into the tank’s space.  It was actually rubbing against the original tank and had worn through the 1/8” wall brace !!!!

 

[jbcollier]

The new tank requires a 3/4” spacer at the front lower edge to lift the tank slightly, and significant bending of the fuel sender’s lever (make it shorter to reduce total travel).  It will all work though you couldn’t call it drop in.

[ECR]

Not seen that design of axle brace before, is it standard fit?

[jbcollier]

Not enough experience to say, sorry.

[jbcollier]

Better:

[jbcollier]

The sender just bolts up.  You have to make a thicker cork gasket as the thread inserts sit a little proud.  The tank itself is slightly lower but the rubber elbow still reaches.