Weird Cylinder Head

Post by: **AlfaLofa** » Sat Nov 23, 2013 2:40 pm

Is it me ??

What's with this head ??

It's on Ebay here:

http://www.ebay.co.uk/itm/Lotus-Twin-Ca ... 4acc7198ac

Post by: **vernon.taylor** » Sat Nov 23, 2013 2:59 pm

Salut AlfaLofa

Just noticed that, too. I suppose there could be bodge to repair a broken manifold and some clever thermostat surgery to make more room on the right - but still. I hope there's a more interesting explanation.

@+

Vernon

Post by: **bitsobrits** » Sat Nov 23, 2013 10:59 pm

Interesting. There are a few differences in the casting from a typical twin cam head in that there is no "bridge" piece at the rear or the center of the spark plug valley. In the center of the valley the wide raised section is unusual as well. Though resolution is lost when magnified, it certainly appears to me the thermostat housing is cast integrally with the two center runners. And there clearly was never a cast-in breather box at the right rear of the head. If it's not a Lotus development piece, it could be an aftermarket pattern head to suit a particular installation. Was the Kent engine ever used in a front wheel drive installation?

Post by: **pharriso** » Sat Nov 23, 2013 11:14 pm

Wow, I thought my cylinder head was a bit of a mystery...

>> Was the Kent engine ever used in a front wheel drive installation?

Yes on Fiestas, but I don't see the connection.

Post by: **bitsobrits** » Sat Nov 23, 2013 11:34 pm

The connection to front drive is that perhaps the head is an aftermarket design intended for a front drive application. A transverse engine placement could explain the thermostat relocation as well as what appears to be removable carb mounts on the inlet tract.

Of course that is only one possible explanation.

Post by: **rgh0** » Sat Nov 23, 2013 11:54 pm

My bet would be on an early Lotus prototype development cylinder head. The lack of the oil catch chamber, the lack of the webs on the top at centre and rear that were added during development to try to solve head gasket failures point to it being a very early prototype. They also played with the inlet tract lengths also which this design seems to be setup to facilitate. it is interesting that i have never seen any comment about moving the thermostat housing from the inlet to the exhaust side in any of the write ups on the early engine development as you would have thought a change like that would have been worth commenting on.

Probably not a very usable head for today but i suspect an important part of twin cam history that should be preserved and on show in a museum - maybe Lotus themselves should buy it

If I was advertising it - I would be claiming it as the first twin cam engine from a Jim Clarke 23 as it could very well be :lol:

cheers
Rohan.

Post by: **twincamman** » Sun Nov 24, 2013 12:30 am

May be an Atlantic head from F.A. Series in North America

Post by: **Deans Sprint** » Sun Nov 24, 2013 12:35 am

Hi all i enjoyed reading this post and I would like to ask a question.

I have a Sprint with about 40k miles after a rebuild. I run a breather tube from the cam cover to a home made catch tank and run a rubber tube from in place of the tube to the air box which is now blanked off.

Over the weekend i removed the Airbox off as I was going to reduce the chokes from 33 to 30mm as I'm chasing a bit more bottom end.

In the Airbox and on the bottom of the ram tubes was a drop of engine oil on each of them and oil in the Weber body?

The car does not blow smoke on start-up and still goes like stink!

Any advice appreciated
Attachments
100_2681.JPG and

Post by: **Elan45** » Sun Nov 24, 2013 1:18 pm

This is a very early development head. I have very few books down here in Florida, but some of the early Elan/ Lotus books have photos of these. I remember one photo of such a head installed in a car with a water tube that ran around behind the head and then forward on the left side of the engine.

There was one of these for sale on the internet (this side of Atlantic) back in the early 90s that had droped a valve and needed severe repair. Some even earlier versions of the TC head only had 4 cam bearings per cam. This one though looks like it is in decent shape with some race history. I wonder what happened to the crankshaft?

Roger

Post by: **billwill** » Sun Nov 24, 2013 7:33 pm

Deans Sprint wrote:
100_2681.JPG
Hi all i enjoyed reading this post and I would like to ask a question.

I have a Sprint with about 40k miles after a rebuild. I run a breather tube from the cam cover to a home made catch tank and run a rubber tube from in place of the tube to the air box which is now blanked off.

Over the weekend i removed the Airbox off as I was going to reduce the chokes from 33 to 30mm as I'm chasing a bit more bottom end.

In the Airbox and on the bottom of the ram tubes was a drop of engine oil on each of them and oil in the Weber body?

The car does not blow smoke on start-up and still goes like stink!

Any advice appreciated
Attachments
100_2681.JPG and

It would be best if you reposted this in a new topic.

It is off-topic and will get lost in here.

Post by: **john.p.clegg** » Sun Nov 24, 2013 9:19 pm

Roger

"Some even earlier versions of the TC head only had 4 cam bearings per cam."

This one has only four bearings per cam...

John :wink:

Post by: **Quart Meg Miles** » Sun Nov 24, 2013 9:48 pm

john.p.clegg wrote:Roger

"Some even earlier versions of the TC head only had 4 cam bearings per cam."

This one has only four bearings per cam...

John

"I wondered who'd spot that first"!

I never realised that the front inlet side head stud was out of line. I had to check my own photos.

Post by: **Elanintheforest** » Thu Nov 28, 2013 3:58 pm

Such a fascinating find that I just had to go and have a look.

The guy selling the head knows what he's got...he deals in / maintains / repairs classic race cars which were quite distracting whilst I was trying to photograph the head. Maserati Birdcage, Lotus 16, Ferrari F40, Dino 206, McLaren M10....and they were the tip of the iceberg!

He acquired the head some years ago in a Lotus 23 package, and it has been used. It looks like quite an early prototype, without the bridge casting in the plug well (as per the photo below of the Twincam in the Lotus 23, from Autocar June '62).

Here are some pictures of the head...a very important piece of Twincam history I think.

The seller of the head says he has had countless emails and daft offers to buy the engine / bits, so there is a lot of awareness out there of exactly what this cylinder head really is. Unfortunately it will probably go into a private collection and not be seen again.

A great bit of history for our cars though!

Here's the website for the seller so you can have another drool....

http://www.legendsracing.co.uk/

Mark