Martin’s PRV bone yard…

That is indeed a thing of beauty. Beige Formica 1970's era old kitched cupboard on the left. Class in a glass! Just like I have in my garage.

More pics of the Motor!

Ok here you go... creeping up on it to not scare it away... lol... I think the induction noise is going to get a bit tiring, but hey ho!



Soon to be running on a Renix 3A ecu, will keep you posted.

Martin

Hey ho, update time, Houston we have go! This is for Eddie really, I will get a better video for you when we go to Peter's dyno, welcome to come if you can... this has been a real collaborative project in terms of getting Chris up and running with his P4 after a long history. The car is simply stunning, and it has been achieved with ingenuity by Chris; it hasn't been a 20k budget spend on an engine upgrade either, substantially less... Chris had originally contacted Stunned Monkey for a tripple weber setup to replace the constant injection setup he had on his R30 PRV unit. Stunned put Chris on to me very kindly, and I talked with Chris regarding potential options, suggested going even-fire PRV engine swap, cams, fuel injection, and throttle bodies... intention was to achieve the same costs approximately as the webers and inlet manifold for the tripples. It was agreed, and off we went, I then put Chris in touch with Eddie to get the throttle bodies, manifold, and linkage setup. CLee and I sorted a donar 3ltr engine, received a cam upgrade, and I then had the OE Fenix 3A ecu to sort blah blah... both Chris and I have had various bits to do here and there, and last year I was pretty time depleted, so progress was slow, and each visit I made was really fixing bugs one at a time around the engine, as it had all been sat for 20 years... and you simply find things, Chris dilgently fixed and we moved forward.. I've obviously got to know Chris very well through the process, and it has been a pleasure to walk this journey with him.. he's already talking about his next dream project... and ummm it would be nice, especially when you look at his work and attention to detail... Ok, back to the plot - yesterday got Chris up and running with a Mot trip map, real tuning to be finished off on a session later... but here you go, first spin of the wheels for 20 years...

http://www.youtube.com/watch?v=pUJeM6rRlho

Enjoy,
Martin

Hi all,

I know, total thread neglect... well, all my stuff is on facebook instead these days. Anyway, wanted to get some input on this one, had it on the dyno yesterday, not the best of days as it turned out... stuff such as my emulator not wanting to play, trying a different system and struggling with the software, and didn't quite establish if it was me or the kit. So I guess I'll have to return to this one, but for now it is 238bhp @ 6000 rpm, and 224 ft-lb @ 3700 rpm, and I have no clue whether this good, bad, or indifferent?? What is folks experience, be good to get peoples input, as don't know whether I'm leaving food on the table, or I should be happy, at the moment, think I'm just grumpy...

Cheers,
Martin

[stephendell]

Sounds OK to me for an Atmo

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Thanks, for the feedback Stephen. On the face of it though, roughly 80hp / litre, is not hugely exciting though is it... I need to think about this more, and hence the ask; how does this compare with what is out there, what ever the degree of development from mild to wild... Just so can get some comparison of where this sits, understand the differences, and rationlise it. If I was doing these all the time, then I would know and wouldn't bother me if you see what I mean..

Thanks,
Martin

What was the spec on the GTA Production? https://www.youtube.com/watch?v=_Xgd8r52qdE

Does that give any hints, mechanical injection and lots of head work?

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Talking chalk and cheese though there, Darren yes know of it obviously, but this isn't a nut and bolt built engine, to a spec and setup for race with that intension. This is a secondhand engine with bolt-ons only, no head work, just OE seats recut as the valves weren't sealing, so I'm looking more comparison with street builds, and the carb conversion boys, as a Holley will suck up a small child just as well as the throttle bodies.. but I can't see any data... what rpm does the torque (more importantly) and power roll off, where are the peak rpm points for same parameters etc, what sort of setup... static compression, and what sort of cam spec... Bit like thd old Fast Car (late 1980s, early 90s version of the magazine...), where they took a car, bogo milesge, and chucked a cam, air filter and a bunch of bananas at it, and dyno the before and after and made 10hp laugh This kinda thing, take your motor, bolt on, and spin it for a Saturday night special... There must be tons of data out there, or the results are all less than 80hp/liter, but I'm not inclined to believe that, I'm just curious... Given the numbers of engines out there, cam suppliers, and all the different profiles, carb setups etc etc... there must be data... Be great to pull it into a graph, get a trend line of complexity of build, and could then compare other engines, as this data does exist for other makes in broad terms...

Cheers,
Martin

[mettersl]

I can't comment on other NA PRV builds apart from production cars, and for these what you are achieving is quite impressive. You probably know all this already but...a quick internet look up found lots of dead links (tuners have moved on clearly) but this is what I could glean:-

Early odd fire, smaller capacity instals on carbs were 120-145 as was the DeLorean on Bosch K mechanical injection.
For example
The delorean 130hp
the Peugeot 604, mechanical PI, 2.6 144hp.
Tha Talbot Tagora, two triple choke carbs on a 2.66 NA engine produced 166 HP
The 2.9 Alpine atmo is notionally 160,
The 3.0 in the Laguna or Espace is 167
The 3.0 24v engine in a Citroen 197HP, I think Rupert is getting something like this out of his 24v (Rupert, care to comment?)

This page claims 240-280 is possible NA with more head work than you have done, so again maybe you should be happy

http://www.projectvixen.com/dmcnews-archive/msg43318.html

You will probably like this thread too, if you haven't seen it already.

http://alpinerenault.free.fr/outils/forum/viewtopic.php?f=9&t=28109

This one claims the factory got 295 out of the 310 in NA form, so there may be a bit more available with a lot more work, or it might be bar talk.
http://www.aussiefrogs.com/forum/technical-performance/15361-prv-v6-dyno-shootout-charts-facts-3.html

All of which says that 236 from a 3.0 NA 12V engine with just cams, throttle bodies and PI seems pretty good to me, I'd be happy...

I reckon you've done very well with those numbers but I think it proves what I've been thinking you've injected it and you can sort out all the timing on the Ecu and head work. I've put the holly on mine it did improve it but haven't done anything else. Now I've ported it and done some more work on the exhaust It is a hell of a lot better but I haven't had time to dino it, but I know it will be let down by the timing. I am hoping for about 175 /180 with old ignition, I think to get more like you've done it would be cam and larger valves and ignition

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Hi both,

Thanks for your replies, much appreciated, it was a tough day at various levels, and may have coloured my feeling, but I didn't really come away with a sense of achievement. But that does include other aspects that sit outside a pure power number. I will look up the threads, thanks, I'm really surprised there isn't more empirical information... everything seems quite vague..

As to the timing, actually what I have ended up with on power (WOT) than part throttle, isn't impossible to achieve mechanically with weights and springs... I used to tune the Fiat SOHC distributors with spring rate and length changes to change the response "curves", well, more accurately, break points and rates... I break at 1400, and then again at 2560 rpm if that helps. I can't remember what the OE curve looks like?

Best regards,
Martin

The OE curve is pretty bad it's in the book, The main reason being was that the fuel-air is fully vaporised as the manifold and the base of the carb is heated direct of the cylinder head.
So when you put the holly on all that's disconnected and it's back to a more standard engine so you have a much denser volume going in which obviously isn't suited to the timeing, so if you set maximum advance to get the best power it's not that good for the low and medium range.
The other power restriction is actually the old modified manifold because once you've ported and opened up the inlet port, the diameter of the old manifold is smaller it is such an odd shape you can't Open it up, so a new evenly spaced and larger inlet manifold needs to be made and I reckon it needs to be a juel plain as well.

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Yes aware of the curve details in the book, simply can't remember it, and would have to look back, will do out of interest at some point. But by the sounds of it, looks like you need to make the weaker of the two control springs stronger to reduce the initial centrifugal advance a tad...

Inlet manifold, yes take your point, may be this is an opportunity for a few club members to club together, invest in the tooling costs splitting it between you, and get some OE inlet manifolds extrude honed... now that would be a game changer... or the "club" could invest in it for the benefit of the members, now that would be forward looking...

I would be happy to perform the before and after flow bench testing...

Cheers,
Martin

[mettersl]

Hmm, new manifolds.....it's a shame that the Atmo and even fire engines need different shapes for best performance....but I was thinking about this when looking at the manifolds on the evenfire you were working on last week.

[Alpineandy]

Martin, those sound like very good numbers to me if it's got stock heads.
You know better than me, but I gather the standard inlet throats are the main restriction.

That would be good however there are different combinations that people would want to do like throttle bodies Holly carb or triple carbs depending on their budget. Probably the best way would be to have like a stock universal part that goes on the heads and then different designs that then fit onto it if that is possible.

Hey all ,

Need some tuning help. Got the beast running but would like to know (confirm) the idle setting advance (believe it is 12-14deg)
see vid:
https://www.youtube.com/watch?v=WPLaNYjItnA

I would like to know what the jet and cam pump settings are for the Holly Carb set up. Overall good. I have one remaining oil leak at the back of the engine. From the video the deceleration is slow. Not quite there but making progress. Opinions requested.

BTW Martin... yes your were right. The "shim" seems to be working.

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Hi Brian

Great you have it running... on to the real fun now

What ignition settings and carb jet setup are you on now? Save folk writing out what they have, and not necessarily being right either... what advice were you given for your setup? Sounds a bit dull at the moment, so loads of improvement to be had

As I recall, and correct where I have it wrong, you are 2.9ltr(?), increased compression, and 290 / 300 cam was it? So cam and compression... you should need less timing than stock, but think you will need a proper dyno session to get the best compromise on settings. Given a good wideband, the jetting you should be able to do yourself, I would run 12.8 -13 afr on power, and she will run sweet..

Regards,
Martin