Lotus Europa Community
Lotus Europa Forums => Garage => Topic started by: LeftAngle on Thursday,August 13, 2015, 06:29:37 PM
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Has anyone come across badly measured component mountings? The front lower wishbone on my S2 is angled rearward. The upper wishbone is dead-on aligned with the one on the right. There's no trauma to the frame, no repairs or welds (unless brilliantly executed and poorly measured) Measuring across the front from the center, the left bearing is 3/16" to 1/4" further out, but measured in from the end, it's the same as all the others.
When I picked the car up, the lower left bearing was trashed, but not sloppy. The alignment was dead-on and the car tracked OK. The left wheel sets about 1/4" further back in the wheel opening, but I marked that down as a difference in the body mould. No one noticed the slight angle of the vertical link after pulling the body off or when the entire brake system was re-done. I know I'll have to cut the bearing out and re-weld it in the proper position, but I'm also disbelieving this defect has been there unnoticed for 45 years. I can't mount the tubular and adjustable wishbones until I get it straightened out.
If anyone has another theory as to how the bearing holes could be so far off, I'd like to hear it. Here are some marked up photos of what I discovered, plus a couple for my ego:
The body, in a pre-gelcoated state and the other things finished... I'm hoping I can time the frame and mechanics with the fiberglass guru's work. There's a ton of carbon fiber work he has to do yet at the engine end and a concours I'm signed up for on Hilton Head the end of October. Tick-tock, tick-tock.
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End of October, tick tock indeed.
Complete a-arm dimensions are in the manual. Manuals at lotus-europa.com, click on documentation.
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Since you intend to replace the front suspension with adjustable tubular pieces, I'm not sure where your concern is. From your pictures, the frame looks straight but if you're concerned about it, you can do some diagonal measurements to satisfy yourself that it is straight. However I would advise you to keep the stock lower A-arm setup as they are designed to protect the frame in the event of an accident so in that case, you would need to satisfy yourself that the lower pieces are straight. I don't remember how my front suspension went together, but it wouldn't surprise me if there was a little misalignment here or there. I know I used shims at the lower shock mount.
I presume when you mention 'bearing' you're talking about the suspension bushings on the inner end of the a-arm pieces. They do get beat up. You might want to review this discussion: http://www.lotuseuropa.org/LotusForum/index.php?topic=1127.0
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The first thing to do would be to measure the wishbone dimensions per the factory specs in the manual. I would also measure the after market tubular wishbones and see how they compare to the factory specs. You might try trial fitting the tubular wishbones to see if they solve the misalignment issue.
"If anyone has another theory as to how the bearing holes could be so far off, I'd like to hear it"
I'm not sure if you're referring to the mounting point on the frame or the wishbone in the above quote.
It's hard to tell from your description if you're facing the same issue that Peter and I have in our measurements with bent arms.
I just spoke to Ray at RDE this morning to see if he had stock replacement lower wishbones. Nada, he hasn't seen good lower wishbones come through his business in years. His aftermarket replacements are $525 per set. I'll call JAE and DBE later on this morning.
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Dude, your car looks KILLER!!!!! I can't wait to see it finished!! Where all are you putting the CF?
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In the past parts like suspension arms would go in and out of availability - obviously, we're in an 'out' period. Certainly the small run would make the tooling to produce reproductions of the stock pieces very expensive so it may end up that the only option is tubular pieces. I would expect that most vendors of tubular replacements would produce good pieces. Richard at Banks has a set that I would trust implicitly but it's always a good idea to verify everything is right.
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Wow... Where do I start? First off, thank every one of you for taking the time to address my situation. And Grumblebuns is dead on correct about my sad attempt at describing it all.
I spent my career designing stuff and writing patents for it and I have the habit of using retentive definitions of things that no one but patent attorneys can relate to. I apologize and will try again.
I think where I went off the tracks is when I used the word "bearings". I wasn't trying to describe the bushings or anything wrong with the wishbones themselves, but was referring to the holes that go through the frame, where the bolts pass through to secure the inside ends of the wishbones (and bushings) to the frame. Those holes have short tubes welded to them.
Those tubes turn the holes into "bearings". And I know they don't look like the bearings, but that's what describes their function. In a court of law, that's what they'd be to referred as.
Anyway, the left side, lower holes that run through the frame on my car were drilled at an angle. The bolt that passes through them is also at an angle. And the wishbone that's held in place between them is at an angle as well. The angle is toward the rear. And because the upper frame holes are straight, and the wishbone goes straight, the vertical link gets twisted. The upper end pointing at 11:30 and the lower at 5:30. The lower hole through the front of the frame needs to be moved toward the center of the car 3/16 to 1/4". That will straighten the bolt and rotate the wishbone to make the vertical link face 12:00/6:00.
Oddly, if I were to bend the front bar of the wishbone to shorten it by 3/16-1/4" that would straighten things out as well... Hmmmmm... Nah, that'd be cheating.
When all the parts were worn, there was enough slop to hide the mis-alignment. But with new Spax shocks, new bushings and shortened spring, it became impossible to fit it all together.
Now, I have to re-install the old parts so the frame can be rolled onto the trailer and taken to the shop.
There, I'll cut out the front lower hole and move it to where it's supposed to be. And then everything should fall right into place.
I'm looking forward to getting those tubular parts installed (got them via Ray, btw) The yellow Spax and chrome springs were hidden behind the OEM parts, so that's my rationalization for getting them.
This next bit's for Chuck:
I can't tell you how great your comment made me feel. I designed the changes to please my own aesthetics and my fiberglass guru has been killing himself making moulds and hand forming everything to please me. The project has been hidden away so not too many people have seen it in its final form. You're the first one to comment on it. (actually, the second... My wife says it looks orange. Everyone else says bright red).
Everything's been formed by hand. He makes his own moulds so no off-the-shelf body parts are being used. This is no exaggeration. The only parts that haven't been modified are the doors.
You asked about the carbon fiber:
A yacht designer named Nathanael Herreshoff once said the inside of a fiberglass boat looks like frozen snot. Years later, Colin Chapman had a fit when one of his designers drew up a car with double fiberglass panels to hide the embarrassing goop. Evidently he wasn't familiar with Chapman's philosophy on weight.
Well, I side with Herreshoff on this. I think the Europa's back end, under the lid, is horrific.
Anywhere that single layered fiberglass can be seen, will be covered in patterned carbon fiber. My racing days are over And don't forget this will be a show car. Performance isn't a priority.
Speaking of weight and fiberglass, I'm convinced the boxy, shortest line between two points shape of the Europa's body was done for weight saving as much as it was for drag coefficiency.
If you were to match the profile of the Europa S2 with that of a Lola Mk 6 GT, you'd be surprised to see they're the same. The difference comes when matching the Lola's beautiful curves against the Europa's minimalistic form. Bulging fenders add fiberglass and the weight that comes with it. My fenders don't bulge and they were moulded with some special kind of thin, light cloth & resin, so maybe it evens out.
:lotus:
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I now understand the issue. Sloppy work from 70s era British auto workers? :beerchug: Also suspect that the US auto workers were just as bad back then.
Your pictures now make sense and you have a good plan for the fix.
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The upper a-arm mounts and lower a-arm mounts are not symmetrical. They are offset to create three degrees of castor.
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... not to say that your a-arms might not also be bent: very common problem. My obviously bent frame also had mismatched a-arms. I'm not fond of the aftermarket tubular replacement a-arms. They are strong where they shouldn't be and weak where they should be strong. If you are patient, originals turn up on eBay.
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I agree about using the stock A-arms, but where are the tubular ones weak where they should be strong?
Hopefully some become available on ebay soon since he wants to have the car together for October! Yikes!
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The upper a-arm mounts and lower a-arm mounts are not symmetrical. They are offset to create three degrees of castor.
John,
Does the chassis drawing show the non symmetry of the wishbone mounting points? I can see in dimension 10 that the mounting points are at an angle in relation to the bottom and top of the chassis but it also looks to me that both the top and bottom mounting points are parallel to each other.
Joji Tokumoto
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Looking at the chassis drawings everything looks aligned because the 3 degrees of castor is attained by attaching the front beam 3 degrees off vertical. However, with the body mounted, everything looks to be tilted/crooked/off-centre.
(Edited to make sense!)
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I agree about using the stock A-arms, but where are the tubular ones weak where they should be strong?
Hopefully some become available on ebay soon since he wants to have the car together for October! Yikes!
Well, the show isn't until the very end of October... And it doesn't have to be running for me to take it over there. A lot of "trailer queens" that haven't run for years'll show up. It's a great way to keep a car pristine. That's not what I want, but putting the body on, adding hardware and throwing the interior in might be doable. Signing myself up for the event was a way to keep me on track and have ammunition to hurry up my fiberglass guru, who's become a great friend. If it doesn't happen this year, it'll get done by next. My arms are in great shape and not bent, but the tubular ones definitely show better. When the project's done, the originals will probably turn up on eBay along with the other bits that won't be going back on.
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The tubular a-arms are very strong in their length but are reduced to simple flat plate where the ball joint/trunion attaches. The originals are very strong there and are designed to bend first in the middle to help protect the chassis.
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I see your point, John. The ones that Richard sells seem to carry the tube past where the shock mounts but ends just before where the trunnion mounts. I can see this is a potential weak point. Not diminishing your point, I expect Richard's to be as reliable as everything else he sells. The Spyder units do not appear to be quite as stout in that area as Richard's but the picture isn't as good so I can't tell for sure. It's interesting that both of them have curved lower A-arms rather than straight. Any ideas why that might be? Could that be to help save the frame in the case of an accident? Are they built by the same guys?!
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Richard makes a lot of the Europa stuff that others then sell; not necessarily Spyder but certainly SJS.
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Yep, I know some places on this side of the pond sell some of his stuff. Looking at their page, r.d. enterprises, appears to sell his front A-arm sets and I'm sure they sell other stuff of his, too.
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Lefty, I appreciate the thoughtful response! I am absolutely blown away by the look of your car. Keep it up!!!