Section view or cut away drawing of TC head

[Certified Lotus]

Does anyone have a section view or cut away drawing of the twin cam head? I am interested in the water ways and oil ways.

[rgh0]

These were posted here sometime ago by Avro

These are a couple of sections that were scanned on a photocopier that i have also posted before

Hope they show what your looking for
cheers
Rohan

[Certified Lotus]

Thanks Rohan! Those head cut aways are very impressive. You can clearly see the water jacket, but im not sure I can tell where the oil jacket is. Your photocopy cross section seems to show the voids where the oil flows. Is that a correct assumption?

[rgh0]

I am not sure what you mean by "oil jacket"

There are 3 oil drillings at the front for the cam feed and one at the rear for draining from the exhaust across to the inlet cam shaft valleys. There is also the breather oil disengaging chamber at the right rear, my second last cross section shows that.

cheers
Rohan

[Certified Lotus]

I'm probably using the wrong terminology. I'm trying to see if the oil in the head flows horizontally, not just vertically. Oil Gallery?

In the cutaway pictures there is a void in the block (blue circle area) what is this for?

[attachment=0]Lotus Twin Cam Cutaway

[rgh0]

It is part of the water jacket around the exhaust port. You see it also in my section scan through the ports.

cheers
Rohan

[el-saturn]

DRAWINGS where are they????..........................that's exactly what I'm constantly asking for: no replies! many many moons ago I'd be drawing this stuff: every 100mm a new cross section A:A, B:B, C:C, D:D, E:E ----------- then we'd use axis X,Y,Z sections to make sure: NO QUESTIONS LEFT - that's when pattern makers tell you HOW GOOD YOUR DRAWINGS ARE ---------------- they're sooooo 3 dimensional??? luv u guys sandy

[rgh0]

Sandy

I am sure SAS and Dave Bean must have drawings of their replacement heads and of the original Lotus Head done when the replacement patterns and machining was developed. QED who say they use the original Lotus patterns may also have the original drawings. However your chances of getting access to any of these is not great I think

There must be many scrap heads around that are too soft or too badly corroded for use that someone with a good band saw can section and produce a complete set of drawings and photos

cheers
Rohan

[Certified Lotus]

It is part of the water jacket around the exhaust port. You see it also in my section scan through the ports.

cheers
Rohan

Thanks!

If anyone has a weber head that is no longer usable, but intact, I have access to a machine shop that can cut the head into sections and then I can photograph everything in high resolution. Must be shipped to US.

[avro]

I do have a number of scrap heads and would be more than happy to part with one to anybody that would like to section it. I would happily do it myself having done the one above, but time at the moment is a little tight and it could be a good few weeks before I could complete it.

Interesting to compare my pictures of the sectioned head and the photocopies that Rohan has posted. The reason for the failure of what was a brand new casting is that in the very final stages of machining and porting it broke through into the water jacket on number three inlet port.

Comparing the photo of the new casting and that of the photocopy head where both have been sectioned through the centre line of the valve, it's clear to see that the water jacket on the new aftermarket casting is huge in comparison . Hence it being turned first into a door stop and later sectioned and put on a plinth to remind me of what a pain in the backside these Lotus engines can be. ( but I still can't get enough of them)

Nick Stagg (avro)

[Certified Lotus]

Nick, if your willing to box ithe weber head and ship it to the US, I'll pay for the postage. Let me know. Glen

By the way, I was very surprised at the volume of the water jacket in your section cutaway. Now I know why, it was a new design head.

[avro]

Hi

I'll dig one out over the next day or two and enquire on the shipping costs

Send me a PM with your details

Cheers

Nick

[Certified Lotus]

Thanks Nick. PM sent.