Lotus Elan

My first engine rebuild

PostPost by: Concrete-crusher » Sat Oct 28, 2017 3:08 pm

I'm starting my first engine rebuild mainly to fix the oil leaks of which there are quite a few but also with the hope of achieving a more smoothly running and reliable engine so I can venture further with some confidence that my elan won't let me down.

First job was getting the engine out , which I did leaving the gearbox in place. I know its a topic of debate but I think putting it back will be easier with the gearbox attached.

my first surprise is that the clutch plate looks better than I expected , its just over 7mm thick and has a clearance over the rivets of 1mm. do people think I need to replace this.

my second observation is a crack in the ring gear , so I'm sure this will need replacing , I don't want to race the car and to achieve smooth running , I'm thinking of keeping the flywheel and just having new ring gear and getting it balanced. does that sound right.

dsc04552.jpg and


I will keep adding to the thread , I expect it will take me well into next spring time and budget permitting

Steve
Concrete-crusher
Third Gear
Third Gear
 
Posts: 386
Joined: 09 Jun 2013
Location: UK

PostPost by: nmauduit » Sat Oct 28, 2017 4:31 pm

Depending on the budget, I would consider at least a clutch disk change in most cases, possibly with the pressure bearing (i.e. not the pressure plate if in good condition and you want to save). The rationale being if all goes well, the clutch disk would likely be the first reason (or pressure bearing next) for pulling the engine again.

Regarding the starter ring, are you sure there is a crack? how would it hold in place if so, is it welded on various spots around?
S4SE 36/8198
User avatar
nmauduit
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1528
Joined: 02 Sep 2013
Location: France

PostPost by: Panda » Sun Oct 29, 2017 5:38 am

Hi Steve, Fit a new clutch plate and release bearing and check the spigot bearing carefully.
Replace the ring gear if cracked or worn, but don't worry about rebalancing. I agree crack can't have fully developed or ring gear would be spinning on flywheel, but don't take any chances.
You may need specialist help to heat and fit new ring gear.
good luck Alan P.
Panda
Second Gear
Second Gear
 
Posts: 153
Joined: 05 Mar 2011
Location: Sydney, Australia

PostPost by: miked » Sun Oct 29, 2017 9:09 am

Steve be careful that the new thrust bearing is a snug fit on the carrier. I have encountered slack fits even when trying new carriers. The bearing only sits on a shoulder by a small amount.
Regarding putting back in one piece, I only tried it once with a plus two and had to abandon. Not sure what you car is but on that I had the sandwich plate near the clutch slave cylinder catching the engine mounting. Right PITA. This was a Lotus chassis.
I usually work on my own and can manage to get out single handed but only need a hand by another going back in when coupling the motor to the gearbox. Spanner on crank and me under to guide. Also no silly angles with engine gearbox combinations and risk to paint.
I know this is a matter of opinion but I find this way less stressful. I suspect chassis type plays a part.

Mike
Mike

Elan S4 Zetec
BSA B33
Suzuki Hustler T250
BMW rninet scrambler
Suzuki TC120R trailcat
Suzuki TC120 trailcat
Suzuki K11 super sport
User avatar
miked
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1185
Joined: 29 Sep 2003
Location: Northwest UK

PostPost by: promotor » Sun Oct 29, 2017 12:54 pm

Concrete-crusher wrote:
my second observation is a crack in the ring gear , so I'm sure this will need replacing , I don't want to race the car and to achieve smooth running , I'm thinking of keeping the flywheel and just having new ring gear and getting it balanced. does that sound right.

DSC04552.JPG




Ring gears are made from one piece that is joined/welded together - I believe what you are seeing is the join point. If the ring gear hasn't been spinning then it's unlikely cracked. If you try to fit another you will find it a headache of a job - even proper shops manage to mash the ring gear when fitting them. You'll need a gas torch, and some hammers/punches, and good/quick hand/eye co-ordination to knock it on as the cold flywheel quenches the ring gear and shrinks it quicker than you'd think BEFORE it's gone over the retaining lip, which is bigger diameter than the flywheel ring gear seating face - this is why you have to heat the ring gear to get it over this lip.

I would get a magnifying glass and inspect the suspected area closely.
User avatar
promotor
Fourth Gear
Fourth Gear
 
Posts: 529
Joined: 16 Mar 2012
Location: Derbyshire, U.K.

PostPost by: Chancer » Sun Oct 29, 2017 2:04 pm

There is no doubt that a gas torch is the way to go (an oxy-acetylene/propane not a blowlamp) but I did several X/flow ring gears plus other Ford engines when I was young just using a gas oven, we didn't even have a freezer to put the flywheel in which also helps.
Chancer
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1391
Joined: 20 Mar 2012
Location: Northern France/ Sussex UK

PostPost by: alan.barker » Sun Oct 29, 2017 4:35 pm

I fitted a new starter ring by heating it in an oven 230? and putting the flywheel in the freezer.
You need to have everything prepared and be very very quick. Big hammer and drift ready.
I suggest you get the flywheel surfaced also + you need to change the spigot bearing regardless of condition.
Fit new clutch kit with new release bearing.
If you do that at least you won't have clutch vibration just rotoflex wind up :mrgreen: to deal with.
Alan
Alan.b Brittany 1972 elan sprint fhc Lagoon Blue 0460E
alan.barker
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 2435
Joined: 06 Dec 2008
Location: BRITTANY FRANCE

PostPost by: Concrete-crusher » Thu Nov 02, 2017 4:51 pm

Thanks for the comments , on closer inspection I agree that what I thought was a crack is most likely the join as suggested so thanks again.

I have now stripped the head and can see oil was getting past the guides , also looking at the seats there is a ridge so I think they also need changing , so new guides , seats and valves on order from Sue Miller who's ever so helpful and I,m off to the local machine shop Saunders in copythorne to get them pressed in. Fingers crossed.

I have attached a picture of the head , looks ok in my view , does anyone know what the numbers mean.

They are cast WM9403 , 26 E 311 and stamped no 2879 , DTB 735
img_0882.jpg and
Concrete-crusher
Third Gear
Third Gear
 
Posts: 386
Joined: 09 Jun 2013
Location: UK

PostPost by: alan.barker » Thu Nov 02, 2017 5:18 pm

Are you sure the seats cannot be saved. There are lots of horror stories about valve seat replacement.
Imho i would change the guides and see if seats can be saved.
Guides need to be removed very very carefully or you will tear out alloy from the head if just pressed out :shock:
When fitting new guides slowly heat up head in oven and put guides in the deep freeze. If possible it's best to freeze guides with liquid nitrogen.
IF SEATS NEED replacement the head MUST be heated and seats MUST be frozen with liquid nitrogen.
If you get the seats changed please be very sure of the machine you use or you will cry :roll:
Alan
Alan.b Brittany 1972 elan sprint fhc Lagoon Blue 0460E
alan.barker
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 2435
Joined: 06 Dec 2008
Location: BRITTANY FRANCE

PostPost by: RichC » Thu Nov 02, 2017 6:04 pm

Ah, your FIRST engine rebuild ! as they say , it's much easier the second time ... :D
User avatar
RichC
Fourth Gear
Fourth Gear
 
Posts: 855
Joined: 28 Apr 2009
Location: Tendring Essex

PostPost by: alan.barker » Thu Nov 02, 2017 6:27 pm

That's true but you don't want to rebuild the first rebuild a second time too soon :cry:
Alan
Alan.b Brittany 1972 elan sprint fhc Lagoon Blue 0460E
alan.barker
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 2435
Joined: 06 Dec 2008
Location: BRITTANY FRANCE

PostPost by: Concrete-crusher » Fri Nov 03, 2017 6:10 pm

Today I took the gearbox out. The thrust bearing feels quite sloppy and the input shaft has a lot of play around 3mm I'd say , I also cant see any where the bush that's shown in the manual between the clutch plate and the flywheel is this essential as I don't seem to have it ?

img_0888.jpg and


thanks steve
Concrete-crusher
Third Gear
Third Gear
 
Posts: 386
Joined: 09 Jun 2013
Location: UK

PostPost by: alan.barker » Fri Nov 03, 2017 6:31 pm

The bush is the spigot bearing which is pressed into the crankshaft on early 4 bolt crankshafts or on later 6 bolt crankshafts it's a needle roller bearing pressed into the crankshaft.
If you fit a complet clutch kit get the flywheel surfaced to be sure of no vibration.
Alan
Alan.b Brittany 1972 elan sprint fhc Lagoon Blue 0460E
alan.barker
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 2435
Joined: 06 Dec 2008
Location: BRITTANY FRANCE

PostPost by: Concrete-crusher » Fri Nov 03, 2017 11:55 pm

Ok yes I have found it , thanks Steve
Concrete-crusher
Third Gear
Third Gear
 
Posts: 386
Joined: 09 Jun 2013
Location: UK

PostPost by: Chancer » Sat Nov 04, 2017 11:23 am

The input shaft play is normal (I assume you mean that you can lift the end of the shaft up and down 3mm total) as the with the box removed the shaft is supported by one bearing at one end only when the engine and box are bolted together the input shaft will engage in the spigot bearing and there will be no movement.

Check the bearing visually and spin it up when degreased to assess its condition, check also the spigot bearing or bush, the absence of this is quite common and will result in gearbox damage and clutch vibration.
Chancer
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1391
Joined: 20 Mar 2012
Location: Northern France/ Sussex UK
Next

Total Online:

Users browsing this forum: Dave-M and 10 guests