Liner clamps

[Mike6]

Starting to put my engine back together after a rather lengthy rebuild and realised that it is going to be risky getting the liners and pistons back in without using liner clamps which I believe are now unobtainable.

I don't really have the facilities to make them up and wonder if some kind person out there might lend them to me if I pay postage and perhaps a small hire fee.

Hoping that someone might be able to help me!.

[andydclements]

Do you need to clamp the liners in place for long, or just a short while between fitting the liners, pistons and getting the head on?

If it's the latter then don't worry, just do it in the space of a few hours and take care to not push the pistons up the bores.

[Vulcan Grey]

I'm going to need mine soon

But in case you find someone to help you make some simple ones...

Here's my design

https://picasaweb.google.com/lotusse/LotusEngineRebuild#5446017287384695218

then I used copper pipe from Home Depot, and the head nuts

https://picasaweb.google.com/lotusse/LotusEngineRebuild#5446017518579990690

my CAD drawing here

https://docs.google.com/open?id=0B2nifoCpaFSfNTAwM2Y0N2ItODRhNC00NTM0LWJkZjUtMTc3OWNhMzA0ODZk

[910Esprit]

Assuming you are using something like Loctite 572 to seal the liners, no clamps are required for rebuild or subsequent maintenance. (as the bond is much greater than the original goo) This procedure was given to me by a 907 specialist and it certainly works.

Fit the liners with 572. Then temporarily fit the head using an old gasket, torque the head down at a moderate load e.g. 50ft lbs and leave overnight. Remove head and continue rebuild. 'voila' no clamps needed and the bond is good enough to secure the liners even if turning engine over.

[CHANGES]

That is much the way i do it too. ( as in the news feature part 3 )

[Mike6]

Thank you for advice. Have the Loctite on order

[Vulcan Grey]

Not to be a downer, but the Loctite 572 was the formulation that Lotus changed to in the 93-97 manual, and also the sealant that Lotus used on the early Esprit V8, which apparently had some leaking issues.... And was later changed back to the Hylomar...

I don't think the Loctite 572 is bad, or wrong for the job, but it is an anaerobic and cures, where the hylomar doesn't cure and is not as susceptible to being disturbed. I think the 572 would be ok if it is fully assembled and head torqued within the 4 hr window.

The use of it in the 4cyl cars might actually be better since the block and cylinders are aluminum, so there won't be a differential in their thermal expansion!

Here's something written by my friend Tim Engel

[quote

]- cylinder liners to block Hylomar PL32 Universal Blue, Medium – original Lotus spec for 907 thru 910

(I’ve had great results with Hylomar on iron liners, and I still use it in

the 9XX 4-cylinder engines.)

- cylinder liners to block Loctite 572 – REPLACED Hylomar PL32 beginning with 1993-97 manual

- cylinder liners to block Hylomar 3400 – REPLACED Loctite 572 after problem with V8 cyl-liner leaks.

[Mike6]

Thanks Travis. However, for my money if Dave Lisle has used Loctite 572 on his 400 plus BHP car then I cannot see any problems for my old car turbo.

[910Esprit]

I'm not aware that Hylomar 3400 was retrospectively specified for the 4 cyl engines. (although I prepare to stand corrected) 572 is excellent and I cannot personally see any reason to even consider using the inferior PL32 as that definitely does need liner clamps!

Agree that you must seat the liners within 4 hours.

NB I think the main reason for the 918 moving from 572 to 3400 may have been a reduced curing time. In practice both sealants have still been known to fail in overheating conditions on the 918.

Edited November 2, 2011 by 910Esprit

[Vulcan Grey]

It wasn't as far as I know either.

I should restate one thing I said above. The Hylomar 3400 does cure, it is an anaerobic, so it will cure in the absence of oxygen, and it'll cure pretty fast once assembled. While the Hylomar 3400 is less stiff than the Loctite 572, they both can be disturbed if the pistons are moved when the head is off, so don't do that!

The original sealant was a Hylomar PL32M, which is a non-setting sealant similar to the Hylomar Universal Blue Medium today. Lotus' reasoning for the change seemed to be to go to a setting adhesive to help hold the liners in place a bit while work was being performed on the engine at a later time...

Cylinder Liner Adhesive

The sealant used between the base of the cylinder liners and the block (formerly Hylomar) has been changed to Loctite 572 adhesive sealant (A912E7030V) in order to: reduce fretting and noise; improve sealing durability; reduce the risk of liner disturbance with the cylinder head removed. The use of Loctite 572 has been Introduced together with the new block and head castings, but may be used on all Lotus 900 series engines. <

On my 89SE (with the original Hylomar sealant) my liners were extremely easy to slide out once the head was off.

But the downside is a short working time on both of the anearobics. The Hylomar 3400 also has a short working tiime ~45min.

For my rebuild I went with Hylomar HPF by Permatex (same as the Hylomar Universal Blue Racing or Hylomar AF depending on year +/-2008). it never sets up and has unlimited working time and reassembly. it is also immune to thermal expansion effects.

http://www.hylomarse...l/products.html

I recently blew a head gasket on the race track, probably due to a defective pressure cap! I lost over a gallon of coolant, got very hot, but no coolant in the oil!

[Vulcan Grey]

The Hylomar Universal Blue, AF, Racing, HPF, are all designed to seal wet cylinder liners in the block. So that would be keeping the coolant out of the oil.

I also recommend using liner clamps to seat the liners, and if you need to move the crank with the head off. Even Loctite 572 or Hylomar 3400 could be disturbed. And the movement of the pistons could push a liner out if it was sealed with the non-setting Hylomar (AF, UB, HPF...). Thought theoretically the UB, AF, Racing, HPF stuff can be disassembled and reassembled without needing to be cleaned and sealant reapplied.... Though I wouldn't do it with oil all over the place... maybe in a race car.

[Sir Paolo]

I made some liner clamps out of old gudgeon pins (perfect length), shaped some plating and secure them with head nuts.

I also adhere to the 4 hour head-torquing rule, even though opinion is divided. It seems that if the head isn't torqued down within that time, the sealant can go off (albeit partly) and won't compress properly when final torquing is carried out.

[Mike6]

Thanks for the advice. Used Loctite 572 and bolted down head using old gasket. Left it for a week and its stuck firm.

[910Esprit]

You can certainly turn the engine without liner clamps with 572. Its one of the reasons specified for moving from the earlier Hylomar to an anaerobic sealant. I've done it a numbe of times and have never suffered either a head gasket failure or a liner failure. (I'm not anti liner clamps either - I would probably use them if I owned any....).

[Mike6]

May seem like belt and braces but I intend to insert piston one, replace head and torque down on old gasket. Then connect to crankshaft, remove head and repeat for each piston in turn. That way it seems there should not be any disturbance to liners and I will be a lot fitter at the end of the day

[lotus4s]

That's a lot of unnecessary stretching on the head bolts. The liners won't move with fresh 572 that has cured for a week but if you're that concerned, clamp a piece of bar stock on top of each liner after you insert the piston, you could even use a piece of hardwood with holes drilled in.

[Mike6]

Hadnt thought about the stretching issue so will make up a few simble clamps

[Sir Paolo]

Not sure if head-studs get stretched that much. Lotus themselves don't recommend changing them in the course of a rebuild.

What is generally understood is that the head needs to be torqued down whilst liner sealant cures.

[mjcarter73]

Hi- just wondered if you have the cad files of the liner clamps. I was going to get some cut but they tell me that they would need a  dxf or dwg file format. Are these available perhaps- personally I cnat see why they cant read the data off the pdf but there you are!

 

Thanks a lot for the diags

Mike