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Author Topic: UK Lakester build G/GL  (Read 3173 times)
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Lemming Motors
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« Reply #30 on: January 15, 2018, 07:45:45 AM »

Haven't done any punching yet - I hope I can live up to the other K one W one's. (KIWI's). I don't know the named individuals.

This build has 3 distinct but related time phases: 1. the excuses 2. the build 3. growing appendages of suitable size to drive at ca. 200mph.

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A Bonneville Lakester please barman.
Certainly sir; a lick of salt, a sip of gas and a twist of Lemming. More Lemming sir?
Just a squeeze.

A Squeeze of Lemming it is sir.
Lemming Motors
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« Reply #31 on: January 15, 2018, 08:13:59 AM »

Front end discussion time. I know there is a parallel Lakester front end thread but I'd like to propose my thoughts here.

Working my frontal area from my engine choice: the only body (fuselage) area I could save is perhaps in a future iteration going to dry sump. For now though the body shape will more or less mimic the engine outline. That gave me some depth and I realised in early sketches that I could find some space under my legs (reference LeMans and F1 driving position). It is extremely comfortable and I can (so far) egress with helmet and extra clothing layers but will not harm any steel until I have done this with driving suit etc. so its time to move on and finalise other debatable things.

To business: the original (Ford) solid axle was located by the buggy spring at the front and a trailing wishbone at the rear that terminated in a large ball joint somewhere below the gearbox-ish.

http://www.hotrod.com/articles/0810rc-old-ford-wishbones/#0810rc_04_z-wish_list-model_a_wishbone

If my research is correct then early hot rods dropped the wishbone because the 'look' meant the wishbone clashed with the engine and gearbox new lowered position. So they split the wishbone and had two more or less parallel training arms but retained the axle attachment. This meant there is a torsional moment on the axle in single wheel bump. To sex things up they went to hairpin trailing arms but still had torsional moments. Someone changed this to 4 bars and I assume this eliminates the torsion on the axle (I always thought 4 bars were to control castor but perhaps that is a coincidental benefit).

If my front suspension components (on a straight axle) are mounted inboard what, if any, advantage do 4 bars have over said wishbone? My axle will then pivot (single wheel bump) between the sliding bush at the front (previously discussed) and the ball joint of the wishbone. I don't see that the wishbone needs to be all that long as the axle attachment ends of the wishbone will be quite close together. On that basis there is no torsional load on the axle(?).

Does anyone have a feel for single wheel bump - should I be containing an inch and half (more, or less)? I also feel that the shocks need to be geared (bell cranks, pushrods, levers) as mounting them to the axle a few inches apart in the centre would only be 1/2" - 3/4" travel and to my mind that's pretty much running without a shock - I would think 1.1/2" to 2" of shock travel would be desirable(?).
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A Bonneville Lakester please barman.
Certainly sir; a lick of salt, a sip of gas and a twist of Lemming. More Lemming sir?
Just a squeeze.

A Squeeze of Lemming it is sir.
Interested Observer
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« Reply #32 on: January 15, 2018, 08:28:14 AM »

Back to the chassis for a moment..
An area you might want to consider is the longitudinal tube above the steering wheel.  It is not clear what sort of structure might be in front of the front bulkhead, but assuming that would be mostly bodywork, in any sort of frontal impact you probably donít want that tube coming at you.  Triangulating that would stiffen it considerably, especially since the tube is only held by the curved bars which would bend at their bases rather easily.
Another thing would be to run a direct cross-member across in the cowl/instrument panel area to help keep the two sides of the upper chassis rails from ballooning out sideways.
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Interested Observer
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« Reply #33 on: January 15, 2018, 09:18:55 AM »

It is a matter of degree, but adding up clearances, compliances, and geometry, a short narrow based wishbone would accentuate the possibility of the front axle steering itself as a whole.
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ggl205
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« Reply #34 on: January 15, 2018, 10:17:43 AM »

"I also feel that the shocks need to be geared (bell cranks, pushrods, levers) as mounting them to the axle a few inches apart in the centre would only be 1/2" - 3/4" travel and to my mind that's pretty much running without a shock - I would think 1.1/2" to 2" of shock travel would be desirable(?)."

LM, I am at this point now with my front suspension. I tried mounting front dampers in a 1:1 position and that restricts damper travel when you are shooting for a maximum .500" of total bump. I have 1:2 bell cranks left over from an old FC car and will be looking for a way of grafting them into the car. Good fortune with your new lakester. I will add my comments to those of Stainless and welcome you to G/GL and G/FL. I can't think of anything better than having three or more cars duking it out for top honors.

John
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Rex Schimmer
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« Reply #35 on: January 15, 2018, 02:44:54 PM »

John,
As I discussed in an earlier post, might have been on Skip's thread regarding front suspension, if you run wish bones, split radius rods, or 4 bar all of them try to twist the axle on a one wheel vertical displacement. If you happen to look at midget or sprint car front locating set ups you will see that they run parallel rods on one side, usually the left, of the axle and a single locating rod on the other. This arrangement eliminates the attempted twisting of the axle on one wheel vertical displacement situations, i.e. bumps. One of the challenges for this type of setup if you are mounting the steering rack to the axle, is that the steering link can be in the way of the single locating rod. This can be over come with some inventive design. I agree with your desire to have 1.5-2 inches of travel and as ggl205 (the other John) said having the shocks/springs located close to the center line does reduce shock travel in the one wheel travel situation, but not in the total front travel, both wheels.

Rex
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Lemming Motors
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« Reply #36 on: January 17, 2018, 05:12:51 AM »

IO - thank you for the comments especially re the top longitudinal (over the legs) - I had overlooked that. In principle this is where my shocks will mount (longitudinally) so I will tie bracing in with the needs of the shock mounts.

All: many thanks for your comments and advice so far. As commented by a number of people egress is best assessed suited and booted. Ideally I will get the suit from the US (they're charging £ for $ here) so may be a wee delay until I can arrange a trip or a mule.

Question: pros and cons of a one piece vs. a two piece SFI 20 suit? At this stage I am looking at Impact and Simpson - is another brand more applicable (mobility, weight etc.)?
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A Bonneville Lakester please barman.
Certainly sir; a lick of salt, a sip of gas and a twist of Lemming. More Lemming sir?
Just a squeeze.

A Squeeze of Lemming it is sir.
NathanStewart
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« Reply #37 on: January 18, 2018, 05:54:46 PM »

Any rough sketches of the overall body design?
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El Mirage 200 MPH Club Member
Lemming Motors
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« Reply #38 on: January 19, 2018, 04:24:43 AM »

No sketches I'm afraid. The ply formers were scaled up to roughly determine the nose shape and the cross section at the widest point (firewall). These shapes in turn came from scale model plans for a P38 Lightning, which, after all, is where the belly tank came from.

For nostalgic reasons I would like the nose section to allude to the P38 (without the guns) but for practical reasons the windscreen and cockpit will have to be more flared. I'd love to do a flat screen and then from there to the back of the cage in curved Lexan so it really looks like a cockpit but I suspect a drag car style screen is more efficient. I am hoping the rear can taper like the booms on the P38 and unless there is a strong aero reason not to (that's a question) a tail fin that could be mistaken for P38 at a distance. Form will have to follow function though.

Painted in invasion colours (silver fuselage with white and black stripes) so probably not enough contrast for Bonneville - I guess yellow or red wheel discs alluding to prop spinners should fix that.

In plan it should look like a trout as the widest point starts around my knees and continues till just before the diff then gently tapers to the rear.
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A Bonneville Lakester please barman.
Certainly sir; a lick of salt, a sip of gas and a twist of Lemming. More Lemming sir?
Just a squeeze.

A Squeeze of Lemming it is sir.
Rex Schimmer
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« Reply #39 on: January 19, 2018, 01:42:35 PM »

John, I happen to have an original Lockheed blue print of the P-38 , titled " Three View Model Plans for Lockheed Interceptor" dated around 1936-7. I will take a couple of pics and put them on the thread. Nice drawings of the plan, side and frontal views of the P-38 even before it was designated P-38.

Rex
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Lemming Motors
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« Reply #40 on: January 19, 2018, 04:25:39 PM »

Rex
Iíd be happy to send my address and cover the postage smiley, save you the inconvenience of scanning.
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A Bonneville Lakester please barman.
Certainly sir; a lick of salt, a sip of gas and a twist of Lemming. More Lemming sir?
Just a squeeze.

A Squeeze of Lemming it is sir.
Rex Schimmer
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Only time and money prevent completion!




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« Reply #41 on: January 19, 2018, 06:34:05 PM »

First let me see if my local blue printing co can do a drawing that is this large, 34" x 54". Or I can take a photo. Let me check.

Rex
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wobblywalrus
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« Reply #42 on: January 19, 2018, 09:51:22 PM »

As per your earlier post about slipping of to B'ville while on vacation...  My wife Rose went with me last year.  It seemed like an idea that would not work beforehand.  She did the full thing, like getting up at 4:30 and being out on the salt at sunrise with the racers, listening to the pre-race briefing, drinking funky coffee from the truck stop, etc.  Even more bizarre was that she liked the goofy places we stay at on the trip there and back, like the Malheur Field Station, the campground at Angel Creek, and others.  It is quite an adventure to race on the salt flats and the ladies like it, too.  Tracey might have a good time.

   
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« Reply #43 on: January 19, 2018, 10:09:51 PM »


Question: pros and cons of a one piece vs. a two piece SFI 20 suit? At this stage I am looking at Impact and Simpson - is another brand more applicable (mobility, weight etc.)?

With a two piece you can take your jacket off when it's hot. Personally Id prefer a one piece.

Having said that I had a disappointing experience with Simpson lately, they stopped calling as soon as they realised I wasn't in the US. I went with HMS  in NC and got a Schroth harness, certified on the day it was shipped and happily sent to an intermediary in the US no B/S. It was a recommendation from Andy Welker, his suggestions are pretty much gospel.....
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Few understand what I'm trying to do but they vastly outnumber those who understand why...................

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« Reply #44 on: January 19, 2018, 10:38:10 PM »

My choice is the two piece suit its easier to get into and after a run much easier to cool off. Also consider the SFI 15 suit your rear engine so the 15 suit would be legal this adds to the benefit since the 20 suit is much heavier making exiting the car a bit more difficult.
 Ronnieroadster
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Working in the shop I use the 'F' word a lot. No not that word these words Focus and Finish go Fast and Flathead Ford!
 ECTA  XF/BGRMR Record 179.8561
 LTA    XF/BGRMR  Record 186.946
 SCTA  XF/BGRMR Record 192.448
 SCTA  XXF/BGRMR Record 216.131 plus a Red Had
"Life Memeber of the Bonneville 200 MPH Club"
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