Engine to Bonnet Clearance

[RichardHawkins]

I am approaching the stage in my restoration when I will soon need to fit the body. The engine/gearbox assembly is in the chassis. I have taken measurements from chassis to the top front of the cam cover, and from the chassis to body front mounts (by the steering rack) to the underside of the bonnet. The engine appears to be too high by about half an inch.

My engine number is D16856B stamped on block and D1L8568 on registration document. The block, on the exhaust side, has 3020 stamped on and E6015 cast in. According to Brian Buckland this identifies it as an early mark 2 engine, the car was first registered in 1968. I think the engine is original despite the numbers being different as the two numbers could almost be incorrectly written.

I have had the car a long time. I bought it in 1979 as a non runner with the intention of restoring, I bought a Lotus replacement chassis in 1980, but life got in the way until retirement. I think this chassis is a genuine Lotus pre galvanised version.

When viewed from above the axis of the engine/gearbox assembly does not align with that of the chassis. The tail of the gearbox is close to the left hand side of the chassis. In effect the engine/gearbox appears to be rotated clockwise (still viewed from above). I have fitted a 4mm spacer between the right hand engine mount and the chassis, this has brought the gearbox tail into the centre line of the chassis, which is where I presume it should be.

I think I have the engine mountings the correct way up and on the correct sides, that is with the carburettor side higher than the exhaust side, and both mounted so that if the rubber fails the engine cannot drop out. The engine mount spacers are on the exhaust side and are 1.125" long, as stated in Brian Bucklands book.

When I dismantled the car it had no air box and the wrong mounting on the carburettor side. I thought a previous owner had made a mistake, now I am concerned that it was necessary to get the bonnet to close.

I could install packers between the body and chassis, but if I pack the body upwards I expect the air box will clash with the footwell.

What clearance should there be between cam cover and bonnet?

Has anyone else had a similar problem, and what is the solution?

Richard Hawkins

[rgh0]

My car is the same 1868 Elan S4 FHC Weber with Stromberg bonnet and there is plenty of clearance.

Do you have the spacers under the gearbox that lift its tail and thus lower the nose of the engine ?

cheers
Rohan

[RichardHawkins]

Rohan,

I have the gearbox as high as it will go at the rear without touching the chassis. I did not want want to fit the body to the chassis to check my measurements, but may have to.

Richard

[rgh0]

If the gear box is as high as it will go and the carbs as low as they will go versus the footwell then it should fit unless the engine is to far forward or the bonnet or its surrounding support is the wrong shape.

You may need to assemble the body on the chassis to work out what exactly the problem is as you say.

cheers
Rohan

[RichardHawkins]

Rohan,

Thanks for the help, I have been searching through the manual and parts book hoping to find any drawings that may help, and noticed that in section BA drawing B1 there are some spacer washers shown (part number BA.16.AO6W 1207) between the chassis and the mounting points I front of the rack, which is where I am measuring from. Of course I do not remember if there were spacers installed when I took the body off.

What should the clearance be between the chassis and the front of the sump? I have just got enough room for a 9.5mm drill

It looks horribly like I will have to test fit the body to check clearances. I really did not want to fit the body more than once.

[rgh0]

Yes there is only a small gap between the chassis and front of the sump. My Elan is stored elsewhere currently as i am driving my Esprit and working on my Plus 2 so i cant easily check the actual measurement but 9.5 mm does sound about right. If I recall correctly I can just get my fingers up into the gap to clean

cheers
Rohan

[Davidb]

I just measured my Elan-new engine mounts fitted yesterday and I have 12 mm clearance.

[RichardHawkins]

Rohan and David,

Thanks for confirming sump to chassis clearance.

Richard Hawkins

[stugilmour]

Richard, we had a similar issue putting my restored Plus 2 body on to a Spyder chassis.

I would have to look, but think I needed two or three packing washers to get the Plus 2 bonnet to fit. I also required packing washers at some of the backbone bolts, presumably to take up imperfections in the moulded body. As my Plus 2 Federal had a Stromberg head we were constrained only with the cam cover. Ended up very tight on top of the carbs though, which the PO had changed to SU's that may be a bit taller than Stromberg's? Of course with the Stromberg head clearance to the fender was no issue.

I thought this was a standard issue for all models, at least after we had our fitment issues having never done the job before? i.e. Drop the body into place with engine installed to get correct clearance with the new chassis, paying particular attention to the carbs and cam cover. Pack as required. Mark the front tower holes to suit clearance with a transfer punch the correct diameter for the bobbin hole. Lift body to allow access to drill and tap towers. Lower back in to place and button things up with fingers crossed.

http://www.warco.co.uk/punches/333-tran ... -sets.html

I think the Plus 2 cam cover front clearance is tighter than the Elan. Having some plasticine to hand can help with checking the actual bodies clearance. We actually screwed up a bit when drilling the chassis towers and had to finess the body upwards to fit the bonnet by slightly ovalling the bobbins. We had initially seated the body fully down at the nose, and then discovered the bonnet issue with everything in place. The bitch was using an angle drill with the engine in place to open up the body holes slightly.

Anacdotally I recall my friend (was the Lotus dealer back in the day) mentioning having issues with some Europa bodies cracking quickly as stress had been placed in the body by trying to bolt the front down too tight relative to the tower bolts.

Best of luck. Let us know how it works out. Usual cautions of ' might be different for Plus 2' etc.

HTH

Stu

PS. Will be going through a similar issue again when we try to install a Tall Block Weber shortly. Thinking I may have to oval the engine mounts a bit to tighten up the pan clearance.