Mclaren M8b replica (visual)

Howard Jones

Supporter
One of the things that occurs to me is that when using a reverse lower wishbone and trailing arms the rear upright is more complicated than a twin A arm/toe link layout would otherwise be.

The different pickup point widths at the top and bottom make the construction process more complicated it seams.

I do like the ring locating system you used for the caliper mount. Good innovative construction method. Most people don't realize just how much time goes into the "how". I know for me, once I have figured out "how" the do is usually pretty easy.

So what have you settled on for the bearing hub tube optimum wall thickness? How are you going to locate the bearing inside the housing? Are you using a spacer between the bearing internally? Or am I wrong about how that works?

Trying to learn something here, forgive my lack of detailed knowledge.
 
Nice Job Russell, I was going to fab up rights from steel and only chose casting for the look. The weight difference is negligible and my solid casting would definitely be heavier, If I go again I think I would still cast but hollow core as I already have the pattern but would rethink my hubs and watching your build and others really shows me the better/easier/economic options out there. At the time I used what I already had.

Thanks and keep up the good image our American friends seem to have of us Anzac's

Cheers Leon.
 

Terry Oxandale

Skinny Man
Supporter
One of the things that occurs to me is that when using a reverse lower wishbone and trailing arms the rear upright is more complicated than a twin A arm/toe link layout would otherwise be.
Yep. The Corvette C5/C6 is a perfect example in which the same piece is used as an upright for the front as well as the rear. Instead of a steering arm, its a toe-link arm.
 
Howard
If I was going to make a mk3 version, I would try and buy some 84mm dia bar or possibly some 80mm. I used 90mm bar for these ones, bored them 50mm at a friendly workshop and then turned them out on my lathe at home.
Bearings and hubs drives are Subaru Impreza fronts and the bearing is a nice fat wide one piece center ring construction. There is an outer oil seal landing at 72mm + and that sits against a 2mm x 3mm ring. The main bearing is a one piece inner section that is pressed in from the inside and that is an interference fit 72mm dia. This is then further retained by a circlip with the inner 72mm + oil seal pushed up against that circlip. The drive hub is normally pressed thru the `outer` oil seal and outer roller bearing to meet the inner roller bearing and oil seal with their inner bearing faces butting together for the correct clearnce. When the axel nut is torqued up, the bearing is then set / held correctly. In my case I very carefully cut the Subaru housing and removed the bearing assembly and installed them in my hubs as they were almost brand new.
Mk3`s would have the thinner center boss in which I would probably still turn the outer oil seal landing and true up the inside (but leave undersize). Once the attachments are welded, the bearing area can then be turned out to fit. I might ? make the uprights a little shorter...I might make them out of 2mm sheet, how ever you would be struggling to save 1kg in weight so would question that. The big thing to allow for is that there is at least 10mm of steel boss protruding so that you can swing the fabricated assembly in a decent sized lathe to turn out the bearing area...that`s one thing I can not do. The cutting off ring on the lazer cut brake mount was a mk2 development to save weight apart from accurate location. Other than that, it was a simple exercise. If you want some better photos of the mk1 and mk2`s, I can do.
Next fun job is to make mk2 inlet manifolds for the down draft Del Orto`s.
Cheers
Russell
 
Great work bro
With fabrications such as your rear up rights --it would be good practice to have them normalised or at least stress relieved prior to machining
The advantage of this treatment is for close tolerance sizing, roundness, etc and reduced fatigue cracking during service.

(forty + years of precision machining exp. at your service) :D
 
Hi Russel,
Have you tried to get a heavy wall hollow bar that would save you lots of machining.
Am enjoying your build thread.
Cheers Ali
 
Ali - Grey
Yes i have but my scotch background figured that free boring was cheaper than hollow bar at twice the price.
Russell
 

Howard Jones

Supporter
Russell, spend your valuable time working on your car, but when you do find yourself with a spare moment more pictures would always be appreciated. I suspect by more people than you might think! Once your information is here on this site it will always be of use in the future. Really fabulous work!

Howard
 

Terry Oxandale

Skinny Man
Supporter
Russell, spend your valuable time working on your car, but when you do find yourself with a spare moment more pictures would always be appreciated. I suspect by more people than you might think! Once your information is here on this site it will always be of use in the future. Really fabulous work!

Howard
X2 - always looking forward to your photo progress.
 
Well big day today, been round the chassis a dozen times looking for any missed welds and prepping it ready for paint. I think i have everything covered and will attach the body work via light weight sub frames as I have not built the body yet so do not know heights etc. The removable roll bar has been welded to its base plates and will have the back braces fitted later. I plan on having the immediate rear body work area surrounding the motor to the width of the roll back stay braces fixed to the chassis so I can have a tilt up rear clip. Last car was a two man op to check the oil or anything else.
I am using POR 15 to paint it this time so its really been cleaned and sanded with any sharp bits rounded off. Lessons from last time learned are using different colored undercoat so you can see where the top coat is going...it was really hard with black undercoat a black top coat!
I shall post some more pics once its got some colour and as I re assemble it. My last shock and spring arrives tomorrow from Mr Summit. I have also just drawn up the inlet manifold and Del Orto carb plates ready for lazer cutting as that is the next major dirty task, between 10 and 15 hours work involved.
Its been extremely hot here the last few days, only cool place has been my shed...cool.
Cheers
Russell
 

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You certainly build a nice chassis Russell, I imagine you refine the detail with each build and by the time you get to full production it will be perfection, Watch out RCR.
Looks awsome.

Cheers Leon

PS, what method of construction are you going to use for the body and why aren't you using the same molds as your first car. I thought that was quite a nice body??
 
Leon,
You learn from all your previous mistakes and end up making bigger ones..sometimes. Not sure that I would want to build one for a wage as I doubt you could afford the time it takes.
As for the body, biggest mistake was not making a mould for the first car.
This time I will make the mould from custom wood and some American poystyrene which should make shaping easy!. I have a plan showing cross section shapes and will cut out profiles and set them up just like building a boat hull. The shape will then be developed with two or three layers of 3mm MDF panel which has a good surface once sealed and sanded. Then its a case of sanding off the corners which can be done with a profiled sanding board. With most of the Mclaren being flat surfaces, I have been convincing myself that it will be easy having built it many times in my dreams! I will get the mould up to a reasonable surface and spend my time perfecting the ensuing body as I don`t plan on a production run. I will do the mould as a one piece and cut it up once its cured. Making the mould will be my winter task. This time I will get my air scoops in the right place so that when critiqued by `the trust` they will have to look harder for faults.
Regards
Russell
 
That sounds pretty much the same as what I'm doing, using MDF sheet and Ply.
I have now made both doors and both front fenders and have started the right rear 1/4 with the tail fin. Because I don't want to make a buck then a mold and then the actual body I'm going to glass over what will actually be the buck as such, I will use a weave glass cloth so I get a pretty good surface and then just smooth it with a filler spay putty, If it is strong enough I will extract most of the timber buck from it and then give it more glass on the inside. The other thing I have decided is vynil wrap and not paint this will also help with a better finish. Another thing, have you ever really looked at the original cars, The finish is not great, most if not all replica bodys are usually a better finish than the originals ever were. Well it will be good to compare notes as it looks like we will be doing our bodies at the same time.

Cheers Leon.
 
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Russell,
In case you haven't seen it there is a Gemco body for sale on TradeMe, (Competion cars) at the moment. Could save you some time.
Regards Steve
 
Hi Russell,
something I have noticed with both of your Uprights and is really obvious in photo 2 post #75 is that the lower and upper bushes don't seem to be parallel in post #75 you have a peice of alloy sitting on the top bush running forward to the chassis which I'm thinking looks pretty much where the trailing link will go and the top bush appears to point down quite a bit, is this just an optical allution or is there a specific reason for this, not critisizing, just curious.

Cheers Leon
 
Leon
Yes your correct, that picture does look worse than actual, once set up the bottom wishbone is parallel to the ground the top bush is slightly lower at the front. This is generally called a design element! in this case its just how it happened. I looked at cutting the top fabrication to weld the upper bush tube in parallel but considered that it was not going to effect anything. Time will tell. That piece of alloy was also sitting on top of the chassis rail and was just to give me an indication of the trailing arm positions / angles.
Off for a couple of weeks in Ohiwa.
Cheers
 
Cool, Enjoy your holiday, Ohiwa is a nice spot as are all those eastern BOP beaches. I'm from Whakatane originaly and have had lots of holidays arund that area, Opotiki and Te Kaha are also great spots.

Cheers Leon.
 
Well life can be a surprise...that holiday has been postponed. Son in law, 48 went to sleep and forgot to wake up so sadly we put him to rest tomorrow. Did not see that coming.
Have made some progress over the last week or so with the chassis now painted and soon to be off the rotisserie after the floors are riveted on. Had a major issue with the paint splitting and reacting with the stripper i had used to clean the chassis so had to strip all the paint off and repeat the cleaning process again. Got stuck in and made the inlet manifolds for the 4 x 40mm Del Orto carbs, that means approx 20 hours including making the jig so that they are both the same. I have the lazer drawings if anyone wants some Rover inlet to 40mm Del Orto`s cut. Now I can start to re assemble the car and think about doing some engine work. I plan on doing a mild port and polish along with tidying the flow path on the heads and increasing the capacity of the sump along with some surge baffles. I have attached some pictures of how I fabricated the inlets and have written a how to description (not att.) if anyone is interested. Basically i made up a jig that held my two plates in position and fabricated 1 5/8 u bend tube to fit. There was some forming over a round mandrel with a small hammer and the secret is to cut very small bits off as you work the shape to fit. Total cost was $98.00 for the lazer and $60.00 for the u bends plus 20 hours of sweat....works of art surely.
 

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My thoughts are with you and your family at this time, far to young, makes you thankful and appreciate the time we have.
I would have to agree, Truely works of art !! and getting them matching exactly is important as you would see if the carbs were at different angles, you have that perfect from what I see in the photos. Looking forward to seeing that body grow.

Cheers Leon
 
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