Martin’s PRV bone yard…

I can imagine, the ammount of work, but it is worth it! Great results.
I do not understand, why there should not be other parties interested. I think there would be a lot of interest for really high powered PRV's. Just think of all the undermotorised replicas, the Alpines wich will be more interesting the older they get and lot of other PRV powered car owners searching for
I think the one that puts effort into developing would surely be able to get it back and more.
Main problem i think is, that if there are others doing serious work and testing on these engines, they seem to keep their experience as a secret.
I think it's brilliant that you share your stuff, surely others out there around the world can profit, would be nice if they also add their experience, things like that will start the PRV development rolling!

To me, i'm really ready to throw in what i have, and what i'm able to do, im no engine engineer, but i can machine very precise parts, would be happy to reprofile valves, i have the perfect suit cnc-lathes and tools to do, unfortunately no 5 axis mill, in a couple of years maybe!!

[Alpineandy]

I don't think there would be any interested parties to put in any money

what type of money is necessary?

Martin

Had a talk to a cnc-chap, and they have a very nice newest technologie 3D scanning and converting machine, theoretically he could digitise your port work from a "positive model" (need no heads) of your ports without problems and very little outlay. So if your interestet in doing series

Hello Martin
I see my name mentioned here a pair of times
I'm not disappeared, just lot of works and things to do lately, and less time for cars
The engine is quite closed up, and i just got the car back from the painter, so in the next days i will have to put together engine and gearbox and put them in the frame. Then have to cable the wires, ducts etc... I think it will be still some times before testing



Now about my twin turbo: some weeks ago I suffered a big headgasket failure far from home :S here the gasket after dismount, what are your opinion about the problem ? This headgaskets are made from Glaser, and i bought them from Simon DE, for A610. The original ones in that point has just a pair of little holes, while this new ones has this big water passage, and so a thin cylinder side, where the cylinder wall failed in, and this point is the weakest of both headgaskets. Has anyone had problems? Or could be just a not good torqued head gave this ? After the change i cleaned better all the thread in the block and bolts, and borrowed a more professional torque wrench... now is already put together... I hope not to have again problems !

Hello Andrea,

Actually can you get a picture of the bottom left hand corner of the above frame?

There is more information here, the fire ring from what I can see has been "hammered" flat, certainly looks like it has ridged in it, if that isn't an oil trace or a camera flash shadow? I have seen this before, and similar to what you have experienced. If it is the above then its detonation and your gasket has done its job and saved your engine. Can you post a picture of the full 360 of the fire ring, with enough of the gasket features so I can see the orientation of the chamber - relation ship to the valves and plug. Some pictures of the remaining good fire rings would also be useful.

We're getting older Andrea, and I know I can't hear detonation any more as it's out side of my hearing range unless sever knock. My hearing keels over above 5.5kHz... so something to think about. The PRV chamber pings around 6.2 - 6.8KHz. I use a DSP signal processor now, gave up with amplified knock sensor signals, because I couldn’t hear it anyway! Old age got to love it...

I do like the engine cover in black, but why not paint the whole thing? Pity the 3ltr inlet manifold doesn’t look dressier than it does, functional, but not really pretty. What’s the pump housing on the front? By the way, still waiting answers to my previous asks:

Andrea, you had better put up some more spec details for the forum, such as:

- what valve springs are you using, rocker tubes (picture of the finished assembly would be good), rods, clutch assembly, looks like back-cut exhaust valves, inlet manifold is late 3ltr even-fire right, which cam chain adjusters are you using, and looks like you are blessed with being able to use the Volvo base plate with the wing sump (much better for oil control and surge)?

Martin

I don't think there would be any interested parties to put in any money

what type of money is necessary?

Hi Andy,

Are you thinking about your atmo project then?

I don't know, it's probably more about getting the cost on the CNC milling. I just find it a bit tedious these days doing the reproduction over multiple ports. I'm quite happy doing the detailed work and repeat tests etc, back and forth on the bench for one or two development ports, but once I've got what I need I lose interest, and find it harder these days to generate the enthusiasm to copy the same thing over and over again, just no more learning in it for me... I did a V12 not so long ago and it simply drove me nuts... so a big single really appeals )))

I'm currently trying to push myself to put the 24V heads up on the bench and put some numbers behind them, and then rework a cylinder or two, but the thought of effectively 24 inlet ports, and 48 if you add the exhausts is just not appealing these days.

What did you want to do?

Martin

Had a talk to a cnc-chap, and they have a very nice newest technologie 3D scanning and converting machine, theoretically he could digitise your port work from a "positive model" (need no heads) of your ports without problems and very little outlay. So if your interestet in doing series

Hi Chris,

Ok, great, yes I can port mould no problem, do them all the time, but you do get some shrinkage, and would still need to hand fettle after milling if done this way, depends how fussy you get about it really... fussy then laugh!

CNC turning the valves would be great though. I have just got some more valves of different fillet / back radius shapes and sizes to test and modify 47 - 51mm in 1mm steps, and a bunch of shapes in those sizes haha+

I need to make up some special guides as well... work has got me pretty tired out at the moment, but feel the need to be cutting metal and doing some tests for therapy

Martin

Ok... one thing at time for who have patience to read.

Atmo black engine:

stock valve and springs. just all cleaned and new.
on reassembly, i put a double washer under the springs.


rocker arms version is this one:


chamber is this one. Is not really a 3.0lt, but is a 2.85lt evenfiring Peugeot 505 version. Lot of work done on the ducts, cause they have the swirl restriction and bad exhaust. Nothing done to valve seat, they are new, just cleand.



Chain tensioner. here the photo of engine when i was disassembling it.
I dont remember now, i think they could be " D4 " ?


Stock rods, forged pistons. Side bolt block.



I have to keep the Delorean / Renault lower crankcase for using it in delorean. Here on reassembly.( PS you can barely see a GTA seats behind ^^ )


Also have to keep Delorean water pump for easy maintenance in future.
Is quite like A310, R30, volvo 260... this one is the press on pulley version.

Clutch would be a normal 2.5 turbo version, for this engine not big stress, would be quite roadly.


Now, my Twin Turbo 3.0lt

Here the photo of the two headgasket. Problem was just in one side, but I preferred to change both, and resurfacing a little the heads. This is quite all a Safrane Biturbo stock engine inside, just some heads and block works. Hope the photo can say something I still have them, i can make better photos next days.


Very interesting to know that the pinging is at 5-6Khz ! I did not know it
I think with my Megasquirt EFI i put on this winter i still need some tweaking... is really possible i had pinging and did not hear it. Stock Megasquirt dont have a pinging recognizing system, i think would be better for me to implement it. I have the two OEM pinging sensor on the engine, just not connect to Megasquirt efi. Problem occurred in higway, I was doing around 5200rpm, full turbo boost, very hot out, and 215 Km/h... for some time ^^' When suddely went to 5 cylinder and growth temperature, and smoke out exhaust. Classic So if something was little out, i surely found it, that was the right way !!
Clutch: I'm still using the GTA turbo clutch, wich is surely inadeguate, but just when driving to limit of rpm.
After the head problem i think i cooked also the rear main seal, so maybe end of summer i will change it and clutch time would be. I would like to use the AP racing single disc i found on their website, should be CP2346-42 disc and CP2345 cover assembly. Or maybe I will buy the expansive A610 clutch from Simon De...or anyone which has a better price

[Alpineandy]

I don't think there would be any interested parties to put in any money

what type of money is necessary?

Are you thinking about your atmo project then?

I don't have anything to 'modify' at the moment (and no money to change that!)

I just thought that if the figure was known, the interest could be gauged.

To digitise a chamber will be about 750 I think .

Nice post Andrea.

Glad it has the earlier valve spring setup, I think a much better spring than the later 3ltr even-fire n/a engines – higher spring rate and the max lift they can accommodate. I'm guessing the later springs were actually cheaper in main production; it does what it needs to do with the OE components and allows no more. The earlier single spring can be played with far more, installed height, accommodate high lift and hit around 180lb on full lift, max you will get out of the later spring before bind is about 165lb. The double washer is essential in my book, and will have you into the 65 lb mark, than the weedy 56-ish OE installed provide your seat work hasn't recessed the valve too much.

Did you put a back cut on the inlet valve? Gives a little more flow through the lift curve with no other work, so worth doing.

I presume the picture of the cams is prior to having them reground, right?

What is the nice oil filter you are using, do you have a description and part number? I had a few similar size, but gone now, and I can’t find any details where they came from; larger filtration area is always better.

Head gaskets, looks like you have some distortion starting in cylinder 3 as well, just not as bad. It’s not surprising the two front chambers are the hottest, so this will be where detonation starts. The gasket fails, as the sudden transient pressure pulse lifts the head and reduces the clamping pressure on the gasket… the rest is QED. There is not much you can do about it practically, one of those limitations of the package we have, so it comes down to tune / ecu setup and keeping your intake charge temperature down.

Martin

Hi Martin,

no works or back cut done on the valves, head was assembled before i found this info in the forum ^^' I will make a reason for it, Maybe next engine...

Sure the 3,0lt springs are POOR ! compared to the earlier evenfiring. In the past time, on my 3.0lt PRV, i found little valve signs on pistons on dismantling, for an over-rpm break, i think 7500rpm ? I was at the time not sure if it was springs faults or something other, but now you say me you noticed the same, i will try to not use never the 3.0lt springs

The oil filter is a PURFLUX LS520 , for Peugeot 505 V6. I dont remember now if it's a 3/4" or M20.

Yes, photo of the cams is prior cutting, here instead some shot after grinding:

The oil filter is a PURFLUX LS520 , for Peugeot 505 V6. I don't remember if it's a 3/4" or M20.

Is it like the following perhaps? http://r.ebay.com/dGdw8p

Hi Andrea, thanks for that, I will order one up and see
... 7500 rpm I think that was definitely asking for it

Thanks for posting the flowbench results Martin, very interesting numbers, nice to see it listed that way to compare!
So i think it's not too bad to take the 2.5l heads as a base!

Hi Chris

Yes I agree a good base, just the atomisation issue. Are you still able / prepared to modify some inlet valves for me? It would be a great help to get them consistent, something I will struggle.


Bi-turbo engine got picked up on Saturday, so that one has gone, hopefully get some photos soon of it installed.