Friday, 19 September 2014

Engine Support Systems

I've been "guilted" into publishing this post seeing it's been a while.........
So here you go (Jim).

Now that the engine has finally found its home (well, at least I thought it had - read on), I could concentrate on the various support systems required such as coolant, oil lines and oil cooler, running the loom, power-steering pump and lines, alternator and , charging, throttle linkages, clutch lines, etc.

Firstly, I built some templates for mounting the power-steering and alternator "combo" - and you can see the results in the photo below. This is achieved by initially pressing cardboard against the heads to locate the pattern of threaded bolt holes and then tracing this out on a sheet of 2mm aluminium plate. You can see the multi-groove drive pulley on the crank for the serpentine belt system I'm building. There will be a smooth-faced idler pulley between the steering pump and alternator pulleys, that the back of the serpentine belt runs on. The Alternator is the unit that can swing out on its upper mount to provide tension for the belt.



 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
After cutting out the cardboard to the initial estimated shape, I then trace that onto the thin aluminium sheet and cut that out for a "test fit". Using this thin alloy sheet is a balance between being easy to cut, drill and modify as needed, versus being just strong enough to hold its shape to give me a reasonable final result. Once happy (after plenty of tweaks!), this plate is simply placed on a photocopier and scanned into a CAM/CAM package - SolidWorks where all curves, straight-edges and bolt holes can be accurately drawn-up and designed. The results of that are shown below.
 


From the computer designed drawing above, I then had some scrap steel plate laser cut to this design (to be used as a rock-solid dummy template for a final test-fit). This proved successful and allowed me to estimate a serpentine belt length - so I hit the "go" button to produce the final alloy mounting plates.
 
As can be seen below, these plates were completed nicely and look great.

 
 
 
 
 













The sequence with which the plates are mounted is as shown in the "exploded" view earlier. The power steering pump bolts directly to the small plate and this plate is then sandwiched (via spacer dowels) directly up against the back of the front plate. The three larger holes in the front plate are the recesses inside of which the mounting bolts for the pump reside. The rear plate includes a recessed section that engine coolant passes through.
The rear plate is 16mm thick while the others are 12mm thick. This design would be good for any 429/460 engine running TrickFlow A460 heads. And I suspect the mounting holes drilled into these heads mimics stock bolt-hole locations, so the plate design is probably ok for any 429/460 engine.
Belt alignment (for/aft) is achieved by setting the correct length of the spacer dowels between these plates. The best way to measure his of course is to "index" off the crank drive pulley by placing a straight-edge on it and rotating it back and forth to sweep across areas where the other pulleys would be positioned.

Lastly, by having the engine installed and running it occasionally, it has showed that I need to make some more room for the rear of the induction (at the firewall) - if i am to have any chance of fabricating a "cold air box". So..... out came the engine yet again (which takes about 2 hours working solo) and I have scalloped out a 14 inch central section of the custom brace that runs across the firewall - all good.
The other tricky area has been for the pressure lines that enter/exit the power steering rack. The standard fittings point straight out from the rack via AN-6 male fittings and occupy and area that I need for the big-block extractors. The result (as expected) is that the hydraulic lines (braided hose) get too close to the extractors and risks significant heat soak issues. My solution is to replace these original AN fittings with suitable "banjo" fittings - so the lines exit sideways and run along the rack. This has resulted in a nice low-profile solution to give me much more room. The photo below shows the final setup.



















The nice thing about banjo fittings is that you can swivel them in any direction (except where they bump into each other). This provides the range of adjustment i need for this engine/chassis combo.