Advice on Rust and Rear Suspension Mount Mods please

[Steve Strain]

Hi Guys

Whilst modifying my HF2000 chassis for the Alfa QV I noticed (with the rear struts off), that the inside of both top chassis rails are badly rusted!
As my car has been on the road for 11 years now, I can only assume that every time I drove it in the rain that water spray has been forced into the top chassis rails around the 4 bolt holes and from underneath the strut mounting plate. This is despite using a rubber plug over the bolt holes. In fact I believe that due to the use of the plugs I have made the chassis sweat more by not allowing the water to evaporate!
On my chassis there is quite a large opening under the strut mounting plate big enough to get fingers into and bits of rust out. Why is this opening there!!!
I know how to stop future rust by filling the hole and using cavity wax, but does anyone have a quick way of getting the flaky stuff out and neutralising whats there?

I have noticed from the many gallery photos etc that many of you convert the 4 bolt arrangement to look like original cars top strut mount. I am thinking of doing this in order to get rid of the need for the beta mounting block and perhaps dealing to the rust.
The old beta block has deteriorated with age allowing a lot of undampened jiggling which means lost traction. If I do this and use a top and bottom nolathane bush will I encounter any problems? This seems to be what the original cars have.
I note however that some of you still retain, the 4 bolts (eg Colin Artus circuit racer), others have 2 bolts combined with the original cars dish arrangement. Is there some reason for this?

If remove the bolt up plate, make up a dish mount that looks like the original and then slot the hole, will this give me good (and safe) camber adjustment?

Any opinions and pictures would be very greatly appreciated.

Regards

Steve

[chris.richard]

I think the different top mounts you describe are on different models, ie Haxk or Litto/Allora/Corse, and are not aftermarket modifications.

[guy mayers]

hi, I the top mounts on my Transformer/Hawk were modified by Geoff Turton in Widnes but still reain the original Beta top mounts. The reason was to eliminate some of the rust, strengthen the chassis slightly but mostly to make the rear of the chassis closer to the original Stratos. Closing off the open sections and filling with cavity wax should certainly help stop the problem but I can't think of any method of effectively removing the flaky bits other than with compressed air and/or a thin tube and a hoover!
Guy

[Steve Strain]

Hi Guy

Yes tried the hoover with a section of small plastic pipe taped to the end. A great idea, it worked well thanks. Also used some hooked shaped wire to scrape the worst out. I have also since sprayed a rust kill product in. and once this has dried I will try flushing out with air or perhaps or hot water.

I think I will go ahead with the mods just so that I can open up the area to prepare it better and reinforce it such is the amount of rust.

This makes me wonder what is going on in the rest of the car especially the main folded structure chassis around the floor.

regards

Steve

[guy mayers]

Hi Steve, if the box sections are sealed they should be fine inside. When I did some work on Gerrys' Alitalia car I had to fit a plumbed in fire system and this entailed drilling a rivet hole or two in one of the diagonal sections in the rear bulkhead area. As soon as I punched through there was a flood of water from within onto the floorpan but it was all clean, no sign of rust staining! Didn't stop me spraying it with waxoyl though just in case! The steel is so thick I'm sure it'll outlast most of us but a little preventative maintenance is a good idea. Try looking at the right lower section of the engine cage, where the wishbone bolts to. I'll bet that the holes for the original Beta engine mounting block are still there and open - another place to rustproof! I'm not sure about using a cavity wax down the sides of the sills though. I'd speak to a fibreglass expert as it may soak into the fiblres and cause damage. What does everyone else think?
Guy

[Steve Strain]

I hadn't thought of the possibility of damaging the fibreglass.
I will await a few comments from others.

On the subject of the side sills and the bulk head diagonal box sections etc, what do you think about filling them with foam to improve sound proofing? Does anyone have any opinions as to whether this a good idea or not could it perhaps cause problems with moisture retention etc?

David was talking about flame resistant expandable foam, I would be interested in a brand name to track down over here in NZ.

Steve

[chris.richard]

I found these with a search engine. There must be equivalents down under.
http://www.avrfixings.co.uk/sanda.htm#PU%20FOAMS

http://www.kincora.net/html/kinc2.htm

http://www.absealantsltd.com/Technical_data_soudafoam.htm

[B]Your question: How much is Soudafoam FR? Do you have stockist in the Scottish Borders? Do you supply mail order?


Thank you for email.

We do not have a stockist in the Scottish Borders, however you can order from us direct.

The Souda Foam FR is £7.95 per can, plus VAT = £9.34.

Carriage is free if you order Souda Foam FR in box (12) quantities, if not carriage will be charged at £2.50 per can.

If you would like any additional information please do not hesitate in contacting me, on (01264) 359984[\B]

I doubt if filling the chassis with foam will make any difference to the noise. The sound waves will be transmitted in the metal, not through the air inside.

How small a hole can cavity wax be injected through?

[Steve Strain]

Does any one know why the beta strut top mounting position is offset from the centre line of the top chassis rail when compared to the original cars?

Having cured the rust problem (only pitted inside the top chassis rail, which I have sprayed, scraped and wire brushed) I now intend cutting off the 4 bolt plates (as I no longer use the beta hats - I use race coils over a fabricated strut with Bilstein inserts and nolathane top bushes), and mounting the strut so that it looks closer to the original.

However if the top of the strut was located in the centre of the chassis rail the result would be a massive camber angle.

My guess at the reason for this is (assuming the wish bone size and location is the same) that it must be due to the inherent camber angle of the beta strut compared to the original or something to do with the wheel hub manufacture.

Has anyone looked at this? I note that mods to most club cars leave the top mount location offset.

thanks

Steve

[chris.richard]

Is the chassis rail in the same position as in the original? It could be the top of the strut is in the right place, but the rail is different. Probably Colin Artus would know.

[Steve Strain]

Hi Chris

Well thats a good point. I can only go by photos.
I agree with you that only Colin would know.

Steve

[colin artus]

The rear chassis rail is in the same position as the original. The reason that the strut mount is not as the original, is that it is for the Beta strut. Remember that the car was originally designed to take the complete Beta subframe assembly and so these upper mounts duplicate the position and angle of the original Beta; thus retaining the geometry of the Beta.
Over the years people have been using less and less of the Beta to the point where its only the hubs and bearings in the carrier that remain. If Gerry thought that it was justified he could incoporate the Stratos upper mountings, redesign the hubcarrier and use a custom strut. I doubt that current sales would justify this though.


Colin