'95 910 Engine Rebuild

[surypap3]

I have a locked up engine and am weighing rebuild options. My engine is a '95 but I also have a good '93 engine. So one option is to swap in the ' 93 which has the bottom and top ends assembled and ready to go. However, it would make better sense to have the '95 engine remain with the car. Is there help on the forum from persons who have rebuilt this motor? Are the liners difficult to swap out? Do they center-up on installation? Are they pressed in or fitted some other way? Do they require decking? Does the rebuild require someone with a good deal of 910 experience. These questions are why using the '93 long block remains as an option. Thank you

[tomcattom]

Based on your profile saying your have an S4s, I'm presuming that is what the '95 engine is from. That being the case the head's are certainly different between the '93 and '95 engine, so you would lose some performance gains by just dropping in the '93 engine.

If you're not fussy about "numbers matching" then you could use the block from you '93 engine with the '95 head because I believe the bottom ends are the same, but I'm sure someone more knowledgeable will be along and correct me if I'm wrong with that. Without knowing why the engine is locked up and what damage was caused this all assumes that the '95 head is okay. But even if not, if its repairable I would suggest you want to save that S4s head if you can.

 

[Barrykearley]

Liners need a tool to fit and ensure the nip is correct - all simple stuff though.

It’s very well documented in the engine section of the workshop manual. Like Tom has mentioned the S4s head is different with valves being changed on the one tower. Definitely rebuild the engine.

[Chillidoggy]

You may find some helpful information in my refurb thread from here - https://www.thelotusforums.com/forums/topic/71107-ians-s4s-refurb/?page=75

 

 

[surypap3]

Thank you for the replies! Correct .... the '95 engine is from my S4S. The damage (or lockup) is from a water logged engine. I had pulled the spark plugs and closed the hood while it was outside. I learned later (a very long time later) that while sitting outside rain was able to fill the engine. When I was ready to work on it (after 3 household moves), the engine would not turn. I have not explored why the person I sent the car to could not get it apart. He was able to strip it down to the short block. I do believe you are right in suggesting I marry the '95 engine back to the car. Is there a superduper crank pulley removal tool I should start with. I am guessing if I can get that off then I can make an attempt at getting the crank out. From the pictures attached you might wonder why there is any issue at all with disassembly. Thoughts?

[Barrykearley]

I’d be inclined to fill the liners full of diesel and leave to soak for an extended period.

[910Esprit]

Im suprised its seized.  I've brought much worse back into service.   I cant see any reason why you could not soak the pistons, as Barry suggests, and then tap them out from below as usual.  The worst that is likely to happen is that you would drive out the liners & pistons as a single assembly, which could then be addressed on the bench. 

[surypap3]

This makes sense to me. I'll give it a try! Thx

[EXCEL V8]

Just warm the crank pulley up (hair drier/fan heater) - it should come off easily.  I've made a shrink-fit pulley for mine that doesn't go on 'till it's above 60*C!

Pete

[drdoom]

Hi Jack,

A couple of points worth bearing in mind while having a go at rebuild of your engine, in case you feel unfamiliar with the lump. Devotion to care of threads in the alloy castings is invaluable in sparing yourself avoidable grief and expense. Upon reassembly, beyond all the basics you will need to come to terms with the finer points of sealants where critical on these engines. Take time to thoroughly study reference material such as that of @Chillidoggy. Put together right, these are great engines.

Cheers

[surypap3]

2 hours ago, drdoom said:

Hi Jack,

A couple of points worth bearing in mind while having a go at rebuild of your engine, in case you feel unfamiliar with the lump. Devotion to care of threads in the alloy castings is invaluable in sparing yourself avoidable grief and expense. Upon reassembly, beyond all the basics you will need to come to terms with the finer points of sealants where critical on these engines. Take time to thoroughly study reference material such as that of @Chillidoggy. Put together right, these are great engines.

Cheers

First, thx for idea of the heat gun. Always happy to pull that out of its box! Secondly, drdoom ....... what is the "lump"? Also, any further detail on the "threads" comment? To that end, should I replace all studs attaching the head to the block? I had a big block Chevy where a bolt began to stretch (I think) as I reused it. Sold the car before I removed the head to see what was happening for sure. Thank you

[Chillidoggy]

He original Lotus head studs are high-quality items, with rolled threads. There’s no reason to replace them as long as they’re undamaged.

[surypap3]

Good news on the studs. Thx

[surypap3]

All, Check this out. I got the crank to move albiet #4 brought the sleeve with it. I stopped to collect my thoughts about what to do next. Do I keep turning the crank until #4 is all the way up, then stop to remove #4 plus sleeve. Then remove pistons one at a time when they reach top? Thanks in advance!

[drdoom]

Jack, you really must get caught up on your studies before plowing forward, as the above photo indicates. There, we see one liner having been pushed loose of its home in the block, no big deal but one of the aspects one must be on top of in dealing with the engine series. "Lump" is a term for engine which our Brit friends find amusing, works for me. On threads I meant to be wary of torque values, care in extraction of stubbornly stuck fasteners, etc. There are so many valuable points of reference to be had in reading through postings within this forum, also true of the forums hosted in the U.S. Check in with the folks at <  https://groups.io/g/TurboEsprit/topics > as well.

Cheers

[surypap3]

More good news

[surypap3]

4 minutes ago, drdoom said:

Jack, you really must get caught up on your studies before plowing forward, as the above photo indicates. There, we see one liner having been pushed loose of its home in the block, no big deal but one of the aspects one must be on top of in dealing with the engine series. "Lump" is a term for engine which our Brit friends find amusing, works for me. On threads I meant to be wary of torque values, care in extraction of stubbornly stuck fasteners, etc. There are so many valuable points of reference to be had in reading through postings within this forum, also true of the forums hosted in the U.S. Check in with the folks at <  https://groups.io/g/TurboEsprit/topics > as well.

Cheers

Well, you will probably have head in hands when you see the crank pulley pics I just sent. At this point, I will slow up to take in the good information provided. I guess I just had to see for myself just how stuck the crank and pistons were (lay of the land). Also, the engine was already taken down to the bare block by the fella I previously entrusted the engine rebuild, the one who said the engine was trash. So I have been doing inventory on what I have, will need and advice from the forum. There are a number of good videos I have been watching, plus lotus esprit world, Dermot's and the parts/service manual. Since I am new at this forum, I am trying to digest additional info. I will take your suggestion to heart and thank you kindly!

[Chillidoggy]

Now the No.4 liner seal has been broken, I’d keep going, take the piston and corn rod out with it. It took me a lot or force to even dislodge my liners, so you’ve already done 25% of that work. Once it’s out, it’ll be easier to disassemble.

If the other pistons are moving in the bores, then they can be removed in the normal manner.

Congratulations on pulley removal. Mine was so tight I was doubtful it could be removed intact.

[surypap3]

Thank you Chillidoggy ..... Today I am planning to place it on the engine stand and soak for awhile. Reading up on getting liners out and running thru the links drdoom sent. What has your experience been on pulling liners and the tool you used? You said getting them out took a lot of force. Did you reuse/coat your liners? Did you send them (piston, rods and liners) out to a shop (Lesco and JAE in USA) for rework?  Do they need the block? Thx

[Chillidoggy]

You could of course use the liner puller tool as shown in the Lotus Service Notes. Or make one.

I used a piece of suitably long softwood and a small club hammer to break the liner seal first. Once they started moving, I then tapped them out gently on opposite sides of the liner. Depending on how much sealant was originally used is dependent upon how much grief they are to remove. Mine were liberally coated with sealant, and a pig to move. Removing the old sealant is best achieved by using Frost Strip Gel, or some other paint stripper that hasn't been emasculated over the years. Nothing else touched it.

 

Pretty sure the rest of your questions are answered in my refurb thread. Go read!

[surypap3]

Got it. Thx

 

[surypap3]

Made some progress. Got the pistons out. Once the #4 was out, everything rotated much easier. I do not have a liner puller yet so once I pick one out, I will pull the liners. Been reading the forum posts and glad for the drdoom and cdoggy mentions to get up to speed on these. Lots of info and some interesting experiences suggesting care and planning. Thx to all. Here's some pics.

[drdoom]

Remarkable rust on that crank. I'd look for a shop competent in shot-peening if it checks out otherwise. Lots to check on this engine, it's not been kept in the best state.

Cheers

[snowrx]

For my engine (iron liners) it did not take much to get the liners out. I made a puller out of some threaded rod, but probably could of just driven them out from below with a hammer and a stepped pilot.

Top plate has dimples underneath to stay on studs

[surypap3]

I have been asking advice on who to go to that is experienced with these motors. I have 3 names within my driving range. One name I heard twice and that nice to hear. I like the puller by snowrx. Looks like some machining would be necessary. I am also looking at any tool loaner programs. But at the same time that option as diminished since tools were not returned despite hefty loaner fees.

Since I am going thru this I should look at performance builds that may have been referenced by members. Please shout if you know of these references. As always, thank you!