Lotus Elan

69 Stromberg bodywork clearance

PostPost by: kfbrinton » Thu Jul 04, 2019 2:17 pm

I have noted contact between the bottom of the rear Stromberg carburetor and the body work. The motor mounts appear to be okay. Is this a normally close fit on these cars? In the event it is a motor mount issue has anyone been successful in replacing the exhaust side motor mount with the headers in place.

Also getting engine vibration transmitted to the body to the point that the outside mirror rattles. Not sure this is due to contact between rear carb and the bodly. The engine has just been assembled and installed after 20 years in a box. While I have not really noticed the vibration so much in the past the engine does have a lightened flywheel.
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PostPost by: 69S4 » Thu Jul 04, 2019 3:28 pm

There's two components to the bodywork clearance issue - firstly do you have the correct carb side mount and, secondly, is it any good if you do. The Stromberg engine uses the same engine mount on both sides whereas the other versions use a different one on the carb side. From memory the correct mount lowers that side of the engine to stop the carb tops hitting the bonnet / hood. And that, of course, results in the carb bottoms hitting the footwell.

I tried a number of mount changes and couldn't find one that stopped the carbs hitting something. In the end I gave up and slotted the engine mount holes on the chassis side. That way I could raise or lower the engine mm by mm until it stopped hitting. Making sure the bonnet mounting bolts at the front were correctly set up and likewise with the catches at the rear gave the bonnet a bit more clearance.

Re the vibration - mine has a lightened flywheel and I don't get mirror shake. Carb balance is tough with the Strombergs - it's hard to get an even idle. Maybe it's that.
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PostPost by: SENC » Thu Jul 04, 2019 11:53 pm

Share a few pics of the mounts and the carb mounting and we might have some better ideas for you, but the base of the carbs should have good clearance at the bottom if all is set up correctly. I had the same problem as you as a result of a failing motor mount - replacing them gave me the expected clearance. I did the replacement with the headers on so it can be done - but fiddly and I sure wish I had smaller hands when I did!

If the motor mounts are, in fact, good, I'd next wonder if you installed the carbs without the adaptor - the extra extension from the engine would give the carbs a little more lift.
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PostPost by: rgh0 » Fri Jul 05, 2019 10:38 am

There are two engine mount types as far as I am aware

standard - i believe from an Anglia
high lift - a Lotus special

The Weber elan used a high lift mount on the carb side and standard on the exhaust side to achieve clearance at the bottom of the Weber ( and Delortos ) to the foot well. The engine was not level and was raised on the carb side

The Stromberg Elan used two standard mounts as Strombergs did not need to be lifted for clearance with the foot well and the engine was horizontal

The Plus 2 foot well provided greater clearance and used the standard mount on both sides in both the Weber and Stromberg versions.

If you have Strombergs hitting the foot well in an Elan then the engine mounts may have failed ( probable as current engine mounts are poor quality and can fail in a few weeks). Perhaps you have a Lotus high lift mount on the exhaust and standard on the inlet which would tilt the engine the other way and may cause the Stromberg to hit. Or perhaps something else is wrong such as the body to high versus the sub frame.

cheers
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PostPost by: oldelanman » Fri Jul 05, 2019 4:52 pm

Do you have the correct spacers under the gearbox mount? If they are not present the rear of the engine will be slightly lower than it should be and the clearance under the rear carb reduced.

I don't know if mine is typical but I have only around 6mm static clearance below the rear carb jet cover and it does just tap the footbox sometimes when pulling away from rest .. never happens during normal driving so I haven't ever bothered to rectify it. Maybe I'll get around to it eventually.
rear-carb-clearance-to-footbox-003.jpg and
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PostPost by: kfbrinton » Sat Jul 06, 2019 1:56 pm

Thanks. Carb mounts are correct. Will check the motor mounts. Am considering modifying the footwell to provide more clearance.
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PostPost by: jaman » Fri Sep 20, 2019 5:54 am

A bit OFF TOPIC …

Noticed your Intake Filters .. Very Neat installation. What are they and where did you get them?
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PostPost by: kfbrinton » Fri Sep 20, 2019 6:00 pm

I have had those air cleaners for over 20 years. I cannot remember where I got them... probably r.d.enterprises.
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PostPost by: kfbrinton » Fri Sep 20, 2019 6:02 pm

I have since replaced the motor mounts... problem solved.
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