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Discussion Starter #1
Lotus Friends:

I am working with a local machinist to fabricate liner clamps for the Lotus 910 engine. These are based on a design by Travis (Vulcan Grey). The set will consist of the two clamps as you see in the attached photo. You will have to provide the necessary tubes to slide over the head studs (see the photo). These tubes can be made of any rigid material. Travis's illustration shows copper, but you can also use PVC, aluminum tubing, etc. Just be certain the wall thickness is sufficient to withstand the torque applied. I have used heavy-wall PVC in working on my own engine with a set of improvised clamps. As the illustration shows these clamps accommodate the locator pins on the block deck, and have sufficient clearance to permit the pistons to easily slide in and out of the liners. I am currently waiting for a quote from the machinist, so I am just trying to gauge how many people may be interested. The more that ordered, the lower the cost per unit. A set of clamps consists of two, as shown in the photo. They are placed between cylinder #1 and #2 and #3 and #4 to lock the liners down after the head is removed.

Expressing an interest of course does not commit you to anything. This is just to get an idea of how many out there may like to have a set for their toolbox. If you have any other questions you can PM through the forum or on the TurboEsprit listserv, or directly to me a [email protected].
 

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Is this to prevent the liners from being dislodged (sealant failure) during disassembly or reassembly of the short block? Will tapping out the pistons/rods dislodge the liners otherwise?
 

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Discussion Starter #3
Liner Clamps

Yes, that's correct. If you look in the service manual there is a picture of the clamps that I guess were once available from Lotus. It you remove the head nothing is holding the liners against any upward thrust, so turning the crankshaft, pushing out the pistons, etc. can dislodge the liners. Since you can only get the pistons out through the top, it is prudent to lock the liners down with something. I have used improvised aluminum stock to do this in the past but if you need to get the pistons out it is necessary that the clamps retain the liners only along their edge in order to refit the pistons and accommodate a ring compressor. Having now rebuilt a few of these engines I am of the opinion that they make the process easier and more secure.

:)
 

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Discussion Starter #4
Too much $$$

Got the quote back from the machine shop and the cost will likely be in excess of $150 for a set of two clamps.

-eek-

Too much money in my opinion so I am not going to go forward with this project.
 

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My nephew has a CNC plasma cutter, if you can send me a CAD file I can get a quote from him. He could probably do a nice version of the Lotus type for not much money.
 

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I'm surprised about the price. The water pump seal tool seemed about right. I realize there of two of these (but from a large sheet of aluminum the cost for each is minimal) and they need a little more complicated milling vs turning on the lathe for the water pump tool, but I figured I'd throw my order in at $50-60 or less. If Travis' suggestion for water cutting or Sanj's nephew produces a better price point, I'll be in.
 

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Discussion Starter #8
Agreed

Yeah, I was guessing $50-$60 for a pair. I didn't talk to Brian about the cost but I don't think he would be using plasma cutting so I think from his perspective it's a lot of mill type work. I don't think they do any sort of heat-based cutting. Shop's too small.

:sad:

Sanj - it would be great to see what it might cost to have this done on a CNC plasma machine - with Travis's permission I can send you the file. At $50 or $60 I'd definitely get a pair.
 

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It looks like a good idea.

The water jet may have a better finish than the plasma.
Filing the Alu plasma cut is like filing on a spark plug insulation.

Alternatively you could probably scribe them out and use a 1/2 round file to get them done with ~15 minutes of work. Or just tape the template to the part and cut and file. That makes more sense (to me) than a big set up fee for mass production.
 
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