Lotus Elan

Engine Mounts & tilting twink

PostPost by: nico » Mon Jan 01, 2007 1:34 pm

Hi - Happy New Year to all listers

I know this has been mentioned before and after having looked through som previous threads on the above matter- the details expereinced previously did not meet my enquiry.


I have just fitted new standard stock engine mounts to my engine and installed in the car and before bolting everthing back on- I trial fitted the bonnet and noted that the clearance was insufficent from the cam cover to the underside of the bonnet.

My question is :

What is average clearance between the underside of the carb manaifold studs and to the top of the footwell - mine is in the order of 50mm.?

Does any one know if they have had to swop the heater valve over with the temp sender unit as I have had to swop these over as this clashes with the passenger footwell. I am of the view that this makes no real difference to the efficency of the water circulation to & from the head to the heater matrix.(Unless Lotus water is holier than thou!!!!)?

Does the above mean that I have fitted the exhaust side mount the wrong way round with the 'u' shape bracket in the 'n' position. Meaning that if it fails the engine will drop rather than catch in the inverted 'u' position. I had it the other way originally and the cam cover was level!??? :x

I am getting frustrated as there is no text in the manual that tells me what is correct and having looked at Brian Buckland's book the mounts used are those fitted to a spyder spaceframe chassis where the mounts are fitted to the chassis back to front and utilising the bespoke brackets from engine to mounts.

I have a spyder chassis but the sheet metal version that utilise the ford mounts purchased and fitted.

Some photos showing the correct positioning of mounts and extent of 'tilt'.would be useful

Secondly as I have installed a tubular 4-2-1 steel exhaust onto the engine while in situ and this was a real challenge as the tolerance between exhaust downpipe and top lip of chassis is at the moment about 3-5mm at a guess. I have not cut the top lip of the chassis for clearance as I note that has been done on Gordon Lund's Lotus book and not mentioned in Brian Buckland's book.

I know each Elan that came out the factory were never identical in fitment compared to modern day cars- but I would be grateful of some advice on the above as I am now nervous about completing my rebuild until the above points have been ironed out /corrected.

Thanks in advance for help and assistance.

Nick
nico
Second Gear
Second Gear
 
Posts: 115
Joined: 12 Sep 2003
Location: Leicestershire

PostPost by: ppnelan » Mon Jan 01, 2007 9:00 pm

Nick,

The mountings should both have the flat steel section facing UPWARDS, i.e. the part that attached to the engine looks like an 'n'. This WILL enable the engine to sit on the chassis part of the mounting if (when!) the rubber fails.

There should be spacers between the exhaust side mounting & the engine block to 'centralise' the engine in the chassis, and give some clearance between the exhaust manifold & chassis.

If the cambox hits the bonnet, check that the gearbox mounting is OK, and that the correct spacers are fitted between the mounting and mounting bracket (bolted to the chassis).

:arrow: Matthew
ppnelan
Fourth Gear
Fourth Gear
 
Posts: 734
Joined: 16 Sep 2003
Location: Norfolk, UK

PostPost by: bcmc33 » Tue Jan 02, 2007 12:43 am

Nick,

To measure the height of the engine was a little difficult the way you described.
On my baby Elan I took a line across the wings (fenders) and measured the gap to the length and width centre of the rocker box - 55mm. Plenty of space for the bonnet (hood).


Brian Clarke
User avatar
bcmc33
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1847
Joined: 10 Apr 2006
Location: Aldridge, West Midlands, UK.

PostPost by: elansprint71 » Tue Jan 02, 2007 11:00 pm

Nick,
Engine height is a well known problem with the Elan because there are so many variables, engine mountings being only one!
Prior to pulling mine apart to fit a new (Spyder) chassis I checked the relationship between the top of the cam cover and the body- I put a long, straight (important!) piece of timber across the car between the top of the front wings (fenders?) over the part of the cam cover where the timing chain runs, in my case this is where it sats "Big Valve Twin Cam". This piece of timber was just (maybe 3mm) clear of the cam cover; the curvature of the bonnet (hood) provides the rest of the clearance. As there was slight evidence of the cam cover touching the underside of the bonnet I decided that when it all went back together I would aim for 8mm clearance.
When we sat the body on the chassis it was obvious that the cam cover would not clear the bonnet as the length of timber was "balancing" on the cam cover; I guessed that the engine mountings would "relax in use" by maybe 3mm and packed up the body/chassis to gain the starting clearance of 5mm, this seems to have worked out OK.
I suggest that you check your starting point with a length of 4x2 and go from there (don't forget to flip the timber over by 180 degrees to check that it is straight!).

Apologies for length of post but you need to get this clearance correct or risk cracking the bonnet.

Cheers,
Pete.
User avatar
elansprint71
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 4142
Joined: 16 Sep 2003
Location: Cheshire, UK.

PostPost by: john.p.clegg » Wed Jan 03, 2007 7:01 am

The other way is to get a short length of thinwall pipe (in my case 15mm copper) and flatten the last three inches then bend at 90 degrees,this gives one a feeler guage which can be left dangling ,first ex side then inlet side,off the front of the rocker box cover down to near the sump.
Just close the bonnet (hood) and grab the "feeler guage" under the car and you then have a good judge of the cam/bonnet glearance by the amount of up/down movement.....

John :wink:
User avatar
john.p.clegg
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 5754
Joined: 21 Sep 2003
Location: Manchester

PostPost by: ElliottN » Wed Jan 03, 2007 1:35 pm

Nick,

The heater valve? Ranks with the clutch slave cylinder as a design location masterpiece. To be correct it IS located in the rear hole in the thermostat housing but you have to lift the engine (i.e. undo engine mounts and jack engine up) to install/remove it as you've found out. I have seen it in the forward location a few times and I can't imagine it matters if you swap the valve and the temp bulb. A trick I would stress with the capillary tube for the bulb is to put a bend in it coming out from the thermostat housing and "fix" it to the heater valve - with 2-3 coils of tube between that fixing and the entry through the firewall. Reason for this is the failure point is almost always the soldered joint between the capillary tube and the bulb, caused by vibration. If you make the tube captive on the heater valve then the vibration will be taken mostly at that point and the tube is infinitely stronger than the soldered joint. All those words..... just see picture attached.

Photo of standard engine mounts also attached. Viewed as you would see them looking horizontally at the block (mounted as an 'n' not a 'u'). Exhaust side is on left, inlet side on right. When you get your head around the difference in the relative location of the plate (bonded into the mount) which bolts to the chassis, you can see that the inlet side mount will actually hold the engine higher (by approx. 15mm - though I have seen the location of the chassis bolt plate bonded into either mount vary by +/- 3 mm on occasions) to ensure the carb's clear the footwell. Note that all this is different if you have a 1600 block (but I assume you don't). Finally when all that is said, I have a Lotus chassis - so maybe your Spyder chassis is different?

As for offset of the inlet manifold studs - a quick measurement shows the top studs on my engine are offset from the footwell approx 100 mm and (with the carbs - webers - and airbox on) I can just comfortably slide my fingers (large male variety) along between the airbox and footwell. My bonnet clears the front of the valve cover on my car by at least 10 mm's (and I have strengthening tubes bonded into the underside of the bonnet, one of which is right over the front of the valve cover).

As for your exhaust there are a number of variables but it is not uncommon (e.g. big bore exhaust fitted or messing with engine mounts and/or spacers on the exhaust side) to have to remove a few mm's off the chassis to allow #3 exhaust header to clear the frame. I have the standard fabricated exhaust manifold (4-2-1) and when I last renewed my engine mounts I had to relieve the chassis of a few mm's which I put it down to variations in the geometry of the new mounts.

Take care.
Attachments
DSC01799.JPG and
Mounting capillary tube on heater valve.
Engine Mounts 1.JPG and
Exhaust Side on left - Inlet Side on right. Viewed as mounted on block.
Elliott - 70 S4 dhc
User avatar
ElliottN
Second Gear
Second Gear
 
Posts: 189
Joined: 19 Apr 2004
Location: Sydney, Australia

PostPost by: bcmc33 » Wed Jan 03, 2007 3:42 pm

Pete,

I've just checked my Sprint in the same way as you and found the mid point to be exactly 5mm.
However, it is clear that the engine is not vertical as one end gap of the "Big Valve" pad is 2mm and the other end 8mm, and the straightedge across the wings shows the body to be perfectly horizontal. The chassis (Spyder original type) legs either side of the engine are exactly vertical in-line with the body.
There is no visual evidence of sag on what would be the offending near side engine mount, or contact with the bonnet. Therefore, my question - is the engine meant to be vertical?

So now noticing, for the first time, that the engine is not horizontal in the ?Y? axis (width), I checked to see what it is in the ?X? axis (length), and found that the engine sloped down from front to rear by 15mm.
Now I have no real idea if these alignment figures are meaningful or not ? but I am sure someone out there will know.


Brian Clarke
User avatar
bcmc33
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1847
Joined: 10 Apr 2006
Location: Aldridge, West Midlands, UK.

PostPost by: elansprint71 » Thu Jan 04, 2007 5:19 pm

Brian,
It is normal for the carb side of the engine to be higher than the exhaust side, this allows the carb/airbox to clear the footwell; also the engine slopes down to the rear. Your dimensions sound OK, assuming that it is the carb side which is high!

When you fit the bonnet, is the front edge at the correct hight? If it is lower than the surrounding fibreglass this could be your problem; check that the curved "hinge" area of the bonnet has the metal runners fitted and that these runners ride on raised plastic "thingies" (despite being an engineer I can't think what to call these!), some of mine were missing, so I used the lower half of those plastic covers which one uses to hide the screws on your number plate, a sort of cup shape. These raise the bonnet to the correct height. Also check that the bonnet is at the correct ehight at the rear. :lol:

Cheers,
Pete.
User avatar
elansprint71
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 4142
Joined: 16 Sep 2003
Location: Cheshire, UK.

PostPost by: sparkey » Fri Jan 05, 2007 8:44 pm

I've just had the same problem with my +2. As time was running out I adjusted the bonnet catches so that the bonnet sat a bit high until I thought of a solution. I've driven it for a few weekends now and the engine has settled so that I can now put the bonnet back to normal and have some ( a little ! ) clearance. Don't know if that's relevant to your situation, but hope it helps.

Steve
User avatar
sparkey
Second Gear
Second Gear
 
Posts: 68
Joined: 07 Jan 2006
Location: High Peak

PostPost by: Bruce Crowthorne » Mon Jan 08, 2007 10:05 am

I guess I may have a problem.
I have two identical mountings - both the type from the exhaust side (so no "dropped" version.

Now I have never had my car in one piece, so I don't know if I have clearance problems or not.
I have a Spider non spaceframe chassis (apparently Spider built sheet stell ones for a while in the seventies until Lotus objected and Spider moved to the spaceframe version)
Does anyone know if this Spider chassis uses the same mountings?

Thanks
Bruce
User avatar
Bruce Crowthorne
Third Gear
Third Gear
 
Posts: 264
Joined: 30 Aug 2005
Location: Emsworth, Hants

PostPost by: bcmc33 » Mon Jan 08, 2007 12:00 pm

My Sprint has an original Spyder chassis, and the engine mount metals are the same as shown in Nick's pictures.
I think you will certainly have a height problem with the exhaust mount on the carb side to an extent that it may not fit at all.
In the Paul Matty parts book there are two variants of the RH mount which is carb related. I guess that the engine has to be a little higher for the Webber/Dellorto carb variants compared to the Stromberg carbs in order to miss the top of the footwell.


Brian Clarke
User avatar
bcmc33
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1847
Joined: 10 Apr 2006
Location: Aldridge, West Midlands, UK.

PostPost by: jkolb » Mon Jan 08, 2007 6:20 pm

Buckland's book shows 2 spacers between the transmission crossmember and the transmission mount. These are about 1 cm thick and will have the effect of lowering the front of the engine respective to the hood. I did not have these on my car and am very happy that I found the reference in Buckland's book, as I changed to the BRM repro cover (TTR) and had interferance.

Jerry
jkolb
Second Gear
Second Gear
 
Posts: 137
Joined: 13 Sep 2004

PostPost by: nico » Mon Jan 08, 2007 8:35 pm

Thanks everyone for their help on this - this feedback has really helped
me look and resolve solved the problem- i now have two exhaust side mounts(new) which explained why I could'nt get the engine to tilt correctly and ordered new part from SMiller, the comments relating to the gearbox spaceers are correct in that I have not fitted these when installing the gearbox mount- does any one know the reference number or detail of the parts needed- i presume they are two small tubular spacers.

Any one after an exhaust mount (1) only free - only postage to pay!!!!!

This forum is so useful and really is worth its weight in gold and more!!!!
:D

Nico
nico
Second Gear
Second Gear
 
Posts: 115
Joined: 12 Sep 2003
Location: Leicestershire

PostPost by: bcmc33 » Tue Jan 09, 2007 12:59 am

Paul Matty parts list has two gearbox mounts S1/2 & S3/4. It may be worth asking what the difference is. And also ask about the need for or availableity of spacers.


Brian Clarke
User avatar
bcmc33
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1847
Joined: 10 Apr 2006
Location: Aldridge, West Midlands, UK.

PostPost by: hatman » Tue Jan 09, 2007 9:14 am

nico wrote:
Any one after an exhaust mount (1) only free - only postage to pay!!!!!



Nico


I'd stick it away in your toolbox if I were you Nico - they don't last too long - the heat from the exhaust manifold cooks the rubber pretty quickly and they de-laminate. You may need to replace the one fitted rather quicker than you'd expected! :?
hatman
Third Gear
Third Gear
 
Posts: 407
Joined: 05 Oct 2004
Next

Total Online:

Users browsing this forum: rgh0 and 10 guests