Damn the PRV V6

davemcbean

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I've just spent a few hours working on a PRV V6. I couldn't believe how ridiculously silly they are to work on. Even though it was out of the car and hanging from a chain block, removing the starter motor and the heater hoses (just so we could remove the transmission) was not a simple job. I shudder to think what they are like to work on when they're in the car.

On top of this they have a silly rocker design, a lengthy single row timing chain (which is difficult, if not impossible to replace with a duplex chain) and they have way too many bolts in them. Apart from the fact that they are larger in capacity than other Peugeot engines, I fail to see any other advantage in having one.

The 505 turbo engine (Simca 2.2 litre) seems to be much better laid out than the V6 or the GTi motor and the turbo can easily produce way more power than either of them. It's a great pity that they never sold them here (they never made one for our side of the road).

Dave
 
Dave,

I noticed one at a wreckers in Melbourne
and checked it out.
The sheer size of it will put you off
I think a v8 conversion would be neater.
Dont know much about them and ill leave it at that
Wow but it sure is big :eek:

Murat
 
Dave and Murat,
With all bullshit extras removed from the engine and the engine bay (505) it is as easy to work on as a 404 and the size of the engine itself is quite small. The 604 engine (English delivered) that I have just removed has done 26 years of service without any internal repairs, I have the receipts, I can't imagine a better record than this. Mind you in Australian delivered 604 form it is far less impressive!
I have fitted the B280 motor and will let know how it goes after I get it running, some work to be done to get the Autronic injection working.
The B280 motor has different rockers and the aluminium parts inside the rocker cover are gold anodised!

Regards, Graham
 
Graham,

I agree, a bare bones V6 in a bare bones 505 seems like the way to go for competition, but a V6 with any extras (including heater) in a 504 or 604 engine bay is a real bastard.

That's interesting to know that the even-fire engine has a different rocker design. Do they have better exhaust manifolds? Are you getting extractors made and a wilder camshaft?

I'd really like to have some pictures of your rally car and engine bay on my website, if you're interested.

Regards,
Dave
 
I was never impressed by the water pump mountings, which break off either the block, the timing cover or the pump at sufficient points to make getting belt tension difficult on some cars.

But the basic engine is good, and access not bad apart from that hose that goes under the manifold...

Now, if your beef was about the way the fuel pump drips petrol onto the water hose that joins the back of the heads and rots that hose out prematurely, I'd say you were onto something. It was for this reason, and also the projected conversion to dual fuel, that I fitted a cheapy Repco electric pump on mine.

I also agree that it's hard to get at the starter... and you didn't mention the oil filter or engine number!
 
There's also the fact that the distributor is at the back and sits below and behind the standard aircleaner, and the fuel pump is at the back also. In addition the alternator is below one bank (almost unavoidable on a V engine) and the 13mm bolt heads for the engine mounts are hard to get at. The bolts that hold the transmission to the engine are not all that easy to get at when the engine is in the car either.

It's the absolute antithesis of the 4 cylinder pushrod engine, where everything is childsplay and very easy to access.

The more engines I work on, the more I appreciate simple 4 cylinder inline engines. I think the 2.2 litre 4 cylinder side valve "Go-Devil" engine as fitted to the WWII Jeep has to be one of the ultimate engines as far as simplicity goes.

Dave
 
Ray,

Whatever happened to the 604 that you had?

The 604 that I just stripped looked very similar. It had been off the road for quite a few years and had a Holley (Weber DGV copy) on it. It was lying in a Paddock at Kellyville.

Dave
 
Graham,

I have heard good things regarding the reliability of the prv v6 and just put off by the sheer size of everything.
Infact i found out porsche were thinking about using it on the 944 but desided late to go with the lighter 4 cylinder.
So it must be a good design if the german
engineers were thingking of using it.
Goodluck with your car

Murat
 
David,
I have just discovered that the B 280 motor has smaller inlet ports - 36 mm.
This ties in with what you were saying about the earlier versions having too large a port.
For the moment I will be running the motor internally standard. Really, the 604 motor had almost enough power and a lot of torque in 3rd and 4th gear.
I'll try to organise some photos soon.
Do you know of a source for 403 valve guides?

Regards, Graham
 
Graham,

I don't know of a source for 403 valve guides. You can always have the old ones bronze sleeved.

I'm going to get some rally retreads cut soon. What sort of pattern would you recommend for 50% gravel 50% asphalt? I've been looking at the kind of patterns used on new rally tyres and some of them are fairly complex. Some of the asymmetric ones have a fairly simple diagonal square block pattern though. Maybe I'll just get a simple diagonal square block pattern cut (non-assymetric) with about 10-15mm wide grooves in between the blocks. I plan to use some Michelin tyre cases which I have (195/65 14").

Dave
 
Originally posted by davemcbean:
<STRONG>The more engines I work on, the more I appreciate simple 4 cylinder inline engines. I think the 2.2 litre 4 cylinder side valve "Go-Devil" engine as fitted to the WWII Jeep has to be one of the ultimate engines as far as simplicity goes.</STRONG>

Ah... simplicity... flip up the tensioner and the generator (what's an alternator, luv?) slips in, the belt stops turning the water pump and you can ford the creek without getting ignition wet...

Nothing simple about them except what's obvious... behind it all was a lot of clever scheming to make them seem simple.

Like driving lights that turn back around so you can work on the engine in the dark...

And the other perfect example of that kind of thought was the 404. The gearlinkages, master cylinder, clutch linkage and steering column nicely exposed and accessible, nothing in the way of the exhaust or likely to be overheated by it...

Oh, that's right, we had to have right hand drive!

Whatever happened to the 604 that you had?

The 604 that I just stripped looked very similar. It had been off the road for quite a few years and had a Holley (Weber DGV copy) on it. It was lying in a Paddock at Kellyville.


It's on a vacant block of land in Petrie, devoid of almost everything except that auto trans. Gave up on it, but I would love to have been able to fit it out with dual fuel... remind me to tell you about that plot one day.

Involved using that 305 carby I still have... and which bolts straight on.
 
Dave,

What's up with the valve timing problem you speak of on your site? I'd like to know more about this and if you know what the situation is like on the even-fire balance-shaft version (like the 505).

I drove an '87 505 V6 5 speed a few weeks ago for the first time. The engine had really nice "tip-in"--very immediately delivery of power. It also sounds beautiful and seemed very smooth. Doesn't have the guts of a late model 505 Turbo though--especially at high speed. Felt like it would possibly outrun a 405 Mi16 though--especially off-the-line.

-Joe
 
Joe,

The valve timing problem is due to the fact that the rockers, etc, are a mirror image of each other on each bank, but the camshafts both turn in the same direction. This would not be a problem with roller cam followers, but with flat (or slightly curved) followers it means that the cam lobe on one bank begins and finishes lifting the follower at slightly different points than on the opposite bank. With the standard camshafts the discrepancy is only a few degrees, but the wilder the cams you fit to them, the greater the discrepancy becomes. So with a 280 degree cam (off seat figures) the discrepancy in duration can be 20 degrees or more. It is possible to grind each cam differently to allow for this discrepancy, but you need to find a cam grinder who really knows their stuff.

By the sounds of one of Graham's above posts, the even-fire V6 has redesigned rockers, and so may not have this problem.

Dave
 
Dave,
What is your planned use for the tyres? Sounds interesting, what is the cost per tyre?
You can't get K liners in 8.5 mm, however I discovered yesterday that 504 diesel guides may fit and there are plenty available.
 
Originally posted by GRAHAM WALLIS:
<STRONG>Dave,
What is your planned use for the tyres? Sounds interesting, what is the cost per tyre?
You can't get K liners in 8.5 mm, however I discovered yesterday that 504 diesel guides may fit and there are plenty available.</STRONG>

Graham,

I plan to use the tyres for the odd historic rally that I go in. I went in one in the Hunter Valley a year ago, which was great fun.

Flex Treads at Moss Vale hand cuts rally treads for $13.75 per inch of width of tread. My 195/65 14" tyres are 7.5-8" in width, so the cost will be about $103-$110 per tyre. It's not cheap, but I haven't been able to find a cheaper alternative. There used to be second-hand 14" rally tyres (ex Japan) for sale for less than $100 each, but the supply seems to have dried up, because I can't find anyone who sells them anymore.

Dave
 
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