Peugeot 505 GTI - V6 conversion

driven said:
May want to consider that a drive belt needs 120 deg wrap to work correctly.
The power steering pulley does not have this and will slip.
One of many
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The higher the load the more angle of contact is required
One tensioner per belt otherwise the belt will oscillate badly on two
View attachment 238877
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Well observed. The early photos above were missing the later idler pulley addition, at that time I was mainly concerned about getting the alignment correct.

I'm yet to build the tensioner (it will be higher up, underneath the air conditioning compressor), but the angles of the belt shown in this photo will be pretty close.

My biggest concern is a fairly long stretch of unsupported belt between the crank and the air conditioning compressor. If it flaps, I may have to add an additional idler.

belt routing.jpg
 
I would love to do this one day.

Out of interest, how would a Toyota gr series v6 would go in a 505? Must be similar weight to a prv but I'd imagine it revs a little nicer.
 
lowpugV2 said:
I would love to do this one day.

Out of interest, how would a Toyota gr series v6 would go in a 505? Must be similar weight to a prv but I'd imagine it revs a little nicer.
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Anything is possible if your pockets are deep enough. I believe that the GR series of engines are physically quite large, so it could be a bit of a challenge. And if you're going to the effort of customising bell housings or gearbox adapters, as well as engine mounts etc, I would say there are better engines out there to spend your money and effort on.
 
So, onto the second of the amazing coincidences that I've encountered in this build.

The 605 water pump is very difficult to find replacements for, so ideally I would like to be able to use the earlier Volvo style, which are still readily available, and I even have a couple of new ones on the shelf. However, I would need to find a way to keep it working with the serpentine belt system.

Once again, a 406 power steering pulley saves the day. Flipped over once again, and mounted to the face of the Volvo water pump, it is (nearly) perfectly in line with the crankshaft and alternator pulleys. I will have to shim it ever so slightly.

I made a small boss to act as a centering ring for the pulley (inside diameter of the pulley is 30mm, diameter of shaft is 15mm).
water pump boss.jpg


I then drilled the holes in the pulley out by 1mm as the holes didn't quite line up, and then fitted the pulley.
water pump belt.jpg


This whole system can be tensioned using the alternator adjustment. I am a little concerned about the lack of the wrap of the belt around the alternator pulley, but I think I'll leave it be and see if it slips. If it does, I will add an idler pulley between the crankshaft and alternator.
 
Would an idler pulley between water pump and alternator be more effective as creating more wrap on alternator with less direct load on idler and full crank load on alternator pulley? Jim
 
dacia4x4 said:
Would an idler pulley between water pump and alternator be more effective as creating more wrap on alternator with less direct load on idler and full crank load on alternator pulley? Jim
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I actually think the weak link might be the wrap around the crank pulley. Totally happy with the water pump, thats quite a large area of belt contact for a fairly light load.

My understanding is that the bearing load in a serpentine belt arrangement is spread evenly across all elements. I think it might be affected by the diameter of each pulley element and the angles to the adjacent pulleys. Can't remember that class!

The belt sits a good 80mm from the front of the timing belt cover, so any idler would have to be on a fairly sturdy bracket. Another reason I'm hoping I can get away without it.
 
Yeah thinking about it the laguna v6 has an idler pulley between crank pulley and alternator,obviously to achieve more wrap around crank pulley.
 
Demannu said:
My understanding is that the bearing load in a serpentine belt arrangement is spread evenly across all elements. I think it might be affected by the diameter of each pulley element and the angles to the adjacent pulleys. Can't remember that class!
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From my understanding of statics and loads the pully diameter is not relevant and the forces equal. Angle of force vector would bisect the on and off points of the belt on the relevant pulley. Agree or not?
 
You haven't allowed for belt friction, so that on and off belt forces differ, ie one side is the slack side. I have long forgotten the differential equations for this stuff. They could be looked up.
 
Simple Elec eng not Mech eng. I had enough of differential and partial differential equations to last a lifetime. Simple analysis and throws it out as you say not allowing for the friction etc. Hats off, you made me think. He will be fine. That PDF is far too much like Uni, ME30x!
 
Wowsers, this is getting more complicated than I was expecting. To simplify things, I'm going to run with my 'suck it and see' approach. If it slips, I'll add an idler between the crankshaft and alternator.

I changed directions in this evening's tasks. I removed the exhaust manifolds, knowing that I had at least one broken stud to deal with (it was missing when I bought the engine). Unfortunately, two more decided that they would rather stay, so I had a total of three broken studs to remove.


broken stud.jpg


As you can see, they were all recessed well below the surface of the cylinder head.

I opted for the 'weld a washer then a nut to it' trick to remove them:
stud removal 1.jpg


Success! Three out of three:
stud removal 2.jpg

stud removal 3.jpg


The rest of the evening was spent contemplating how I am going to move the distributor from the back of the head to the front of the head. I have a plan - watch this space.
 
On to moving the distributor from the back of the head to the front of the head!

Phase 1 - the drive boss.

balance shaft drive before.jpg

This is where I need to add the drive boss. This photo was taken to remind me of the timing of the balance shaft! Two straight lines line up with the dot....

drive sprockets.jpg

First thing to do was to add a dowel on the opposite side of the drive sprocket, to drive and correctly time the new boss. Conveniently, there was already a punched hole in exactly the right spot. Then pressed in a piece of 7mm mild steel round bar and presto!

socket centraliser.jpg

There is a recess on the drive cog that is exactly the same diameter as the original boss on the end of the camshaft, and a matching recess on the distributor drive boss, so I went to my usual go-to for specific diameter bits of round steel - a box of assorted old crappy sockets. This old 5/8 spark plug socket was the perfect diameter to make a centralising ring for the distributor drive boss.

socket centraliser 2.jpg

Perfect fit in both sides!

centraliser ready.jpg

Trimmed down, squared off (surprisingly the socket didn't actually have a square end, it had about a 0.8mm wonkiness to it.

centraliser protrusion.jpg

Perfect protrusion, I don't want to 'squash' this part in between the drive boss and the sprocket, so there is about 0.5mm room to move in there.

boss assembled.jpg

All fitted together!

boss assembled with rotor button boss.jpg

And another with the distributor rotor button drive head installed. And in focus.

All that is left to do now is to track down a slightly (18mm-ish) longer bolt. The bolt I'm using at the moment is from a Volvo with the camshaft on the front of the head, but the balance shaft sprocket adds additional width that I need to account for to make sure that there is enough thread engagement in the camshaft to torque it up properly.

Coming soon - Phase 2 - modification of the timing chain cover to support the distributor!
 
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No time like the present! On to phase 2.

Basically, my template was a Volvo B280 timing chain cover (which is the same as a 505 ZN3J item - factory 505 V6), which secures the distributor to the front of the timing chain cover on the LH cylinder bank, like this:
B280 timing chain cover.jpg


I started by removing the 605 timing chain cover and cleaning it to a point where I was happy to put it into the sandblasting cabinet (nothing ruins blasting medium like oil and grease):
timing chain cover before.jpg


I sandblasted the area around the location that the distributor was going to be installed to make the best surface for adhesion for the next step.....
sandblasted tc.jpg


Next step invoved a product that I have used before with great success... it is a metal-reinforced 2-part epoxy that when mixed up has the consistency of play-dough. It is called Knead-It and is available at most hardware or auto stores #NotAnAd. I used to keep a tube in my glovebox, and I've used it for emergency repairs on everything from radiators to interior parts.
knead it.jpg


I pressed it firmly into the recesses in the timing chain cover to build up all of the areas that were too low. Once it had cured (supposed to be a few hours, but realistically about 20 minutes), I started filing it flat, then cut a hole for the distributor drive to go through, and drilled and tapped the holes to hold the distributor to the cover. The seal presses in place.
tc assembled.jpg


It doesn't look pretty, but it doesn't have to. You won't be able to see it once the distributor is installed.

I used longer bolts than usual to hold the distributor on, which total 30mm of thread engagement, including about 7mm through the original alumnium, the remained through the epoxy. They just protrude into the timing chain housing:
tc rear.jpg


Et voila!
distributor installed.jpg


Bonus image: Twin-spark PRV?
twin spark.jpg


I did have to cut a small tab off of the front of the rocker cover to clear the distributor.

Some bonus thoughts:

1. I did have access to a TIG welder, and considered using this to add the necessary material. However, I didn't want to risk warping the timing chain cover, and in my experience, the aluminium used in these doesn't weld very well. Given that the epoxy is basically just filling space, I had no hesitations going this route.

2. Obviously the firing order on the distributor will be reversed. I had access to a complete spare distributor assembly, so I have left the original distributor and leads in place as a template for which cylinder is firing at a given point, and I can then replug the ignition leads onto the new distributor in the correct order.
 
This evening I circled back to make the rear bracket for the power steering pump. This actually took a couple of goes, I wasn't happy with the first attempt, so much so that I won't even document it here.

This is the second attempt. It's a single piece that supports the pump both vertically and horizontally.

I should probably note however, that the pump was already extremely rigid with just the front bracket. This pump installation I now feel is quite heavily over-engineered - just the way I like it.

Here is the bracket:
ps pump rear bracket 3.jpg

ps pump rear bracket 2.jpg


And here is how it all fits together:
ps pump rear bracket 1.jpg


It has come over all rainy and foggy here now, so I'll wait until it dries out a bit (hopefully tomorrow) before sandblasting and painting the bracket.

Eagle-eyed viewers will recognise the bolt holding the bracket to the block as a cut-down camshaft sprocket pulley bolt from a 604 V6. There was a random, unused threaded hole in the block in a convenient location, but it is an M12x1.00 thread - extremely fine for that size. The only thing I could find in that thread, with thread all the way to the head of the bolt, was the camshaft sprocket bolt.

I suspect that the threaded hole was originally designed to allow the use of an engine stand at the factory. The modular/split style of block means that conventional engine stands aren't particularly useful during assembly. On this engine, it was packed full of mud, so it wasn't used in the 605 configuration.
 
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