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N9T based Formula 2 engine?


Bean

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SAAB Turbo 16 valve cylinder heads were then fitted on top. This is where the team had a real revelation, made possible by the construction of the SAAB cylinder heads. If you pointed the heads the same way, so that timing gears were on the same side, it meant that one head would be positioned correctly but on the other side the exhaust ducts would face inward and the intake ducts outward. This, obviously, would not do. Instead of manufacturing a custom head, which could have made the production costs unsustainable, there turned out to be a simple solution. On the problem head intake ducts were converted to exhaust ducts and vice versa

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  • 1 month later...

Damnit - missed this discussion too!

Very interesting to see how close the Saab is, question fir V-M since he knows them both so well is how hard would it be?

(I don't even know off hand if Saab uses a timing chain)

Bolt holes look close enough to machine - only concern would be water jacket proximity, as well as coolant circulation assuming a timing chain could be sorted.

Sad part is this post is 6 years old and I'm still planning and not done anything. .. Soon though damnit. :)

Rabin

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They're disscussing some chrysler/simca 2L JRD-engine, whatever that means.

The JRD (Jicey Racing Developpement) engine was a 8v race version, looking stock but using two spark plugs per cylinder like in this 80' factory prototype head:

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The JRD was using a special block casting with siamese bores so when not competiting in the 2.0 class 2.5 was easy to reach and reliable.

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The Marelli ignitor isn't cheap like "a few Italian sport car" not cheap and on the wrong end so if you want to make your own dual plug head use wasted spark or a Nissan 720 distributor.

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SRDT - I'm truly amazed at your depth of knowledge as well as the documentation that you bring here - absolutely fantastic.

I had no idea they ran a dual plug design N9 head, so I'm quite curious if there was ever a reason given? Danielson never did it, even on the rumoured 550HP SuperProduction engines...

Ive got two Danielson heads now, and quite a few cracked core heads so I may need to start cutting up cores to see how easy it could be. Was going with VEMS running Bosch motorsports coils so the difference would just be to get the 8cylinder/4 coil set up - one for each cylinder.

Would also love one of those ally valve covers, but just can't justify cost since it's a cosmetic piece for the most part. (The Danielson ones were 400+ last I checked even if you could find one.)

Rabin

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I manage to impress even french people so as seen from america yes it's probably amazing :lol:

But I have to say that many of the cool technical things I learned along the years came from English language forums (as the Nissan twin spark distributor), and documentation is just asking google the right way to find things, things that people sometimes hosted online thinking the acces wasn't public :ph34r:

Dual plug heads was (and still is) a good way to improve ignition especially at that time when electronic ignition with knock sensor was just a dream.

Danielson was using heads left unmachined from the factory so it was in fact a cheap mod, for the race cars maybe heavily modifying the heads wasn't allowed or maybe the money was better spent elsewhere.

Another cheaper valve cover, this guy was JRD head of design.

http://www.maurelec.fr/catalog/product_info.php?manufacturers_id=16&products_id=92

Don't buy anything from Politecnic btw, the new owner will sell you parts from other professionals telling you they fit perfectly together but in fact they don't so you spend extra money for off the shelf parts with a crappy Politecnic sticker and you have to adapt them anyways. You may even end with parts more difficult to adapt.

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  • 3 months later...
16 hours ago, SRDT said:

The Lima block is the one that can use the Volvo head right?

Yes. Need also to follow that lead for BMW heads and see if there is closer ones. Would be nice to have selection of heads and lurk around with 505 turbo head gasget :)

Need to ask some disassemble stores if I can "shop" around next summer ;)

V-M

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  • 1 year later...

I had missed that link to the Lada Poch engines that V-M posted, but I came across it when searching something else.  Had no idea the Dakar Niva used the BA10, rear brake calipers, and the motor was a N9T block bored to 93mm and stroked to 90mm - with the ROC 4V head.  The engine was rated at 280HP and was used in the 87 Dakar race...  Cool stuff!

I found a couple e-mail contacts related to this new to me Lada engine, so we'll see if any more info comes up.

Any updates on the head similarities?

Rabin

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I have found another engine with a close design, this one is from... USSR.

The Moskvich 412 engine:

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Most claim it's a carbon copy of the BMW M10 engine but with a 104mm bore spacing and an aluminium block with wet liners it's really an engine on it's own.

During the many years of production they designed DOHC heads with 8v, 16v and even 20v!

http://forum.abarth-gmr.be/index.php?topic=4459.0

https://translate.google.fr/translate?hl=fr&sl=ru&tl=en&u=https%3A%2F%2Fforum.azlk-team.ru%2Findex.php%3Ftopic%3D77359.0

 

And bdw if you really, really want a ROC Head there is a brand new one for sale:

https://www.mikadoracing.com/index.php?action=DETAILLER&id_annonce=1759241

Indeed when you have an historic racecar as a toy you're used to spend big money...

 

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I admit the idea of a 4 valve turbo N9TE is very appealing,  but not at that price, and not to use an obviously rare part outside it's intended F2 race engine.

The reality is that even if they were readily available, the custom work needed to make it work on a turbo N9TE properlu would be as much or more again.  (Cams, exhaust manifold, intake, air box, tuning, etc etc...)

Instead I'm now leaning towards exploring the twin spark versions of the head and HOW they added the second plug from the intake side.

The 93mm bore with 90mm stroke for a 2443cc displacement is also appealing. :)

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If you want 2.5 out of a stock block you need a lot of machining and Darton style sleeves, that's why JRD used special blocks with siamese bores. It's probably the same for the head as you won't see many dual plug heads around.

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V-M did an experimental 96mm bore and mentioned the machinist said the block was very strong - no torque plate would likely have been needed during boring (although one was used).  Since this is essentially a closed deck iron block - quite sure Darton sleeves would be way overkill as long as there was decent material between bores.

92.5mm is a very common size to take these motors to, so 93mm should be no problem.  Costly part will be the offset ground crankshaft to get the 90mm stroke, and the custom rods. Forged flat top 93mm pistons should be fairly easy to source / spec out.

SRDT - Have you found much info on the JRD engines?  The best / most info Ive found has been the info you posted in this thread!  I have turned up the odd additional article on the Lada Poch Dakar motors - but technical details have been lacking.  

Most impressive was the Lada Poch engines were normally aspirated 2443cc motors that made 280HP!  (310 HP on Av gas was mentioned as well.)  Those were also twin plug heads from what I can see in pictures - but again - slim finding indepth technical details.

Really should just be content with the Danielson (2x) head I already have!  

Rabin

 

 

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In 1972 JRD is the engine builder for the Simca CG Proto MC: https://fr.wikipedia.org/wiki/Simca_CG_Proto_MC

In 1973 and 1974 the Coupe Simca-Shell cars must use Chrysler 2.0 engines, JRD is the best and almost unique engine builder.

In 1975 the JRD workshop is destroyed by arson and that's the end of JRD.

After that other engine builders will maintain the existing JRD engines and improve the designs under new names like MAURELEC.

In F2 those 8v JRD were quickly outdated by other engines with 16v heads and even worse pure racing engines like the Renault Gordini 2.0 V6.

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  • 1 month later...

I was looking information about BMW 16v 320is/M3 engines (s14b20-23) and did not find good pictures or information so I just deside to order headgasget for measure and see. :D

Compared on copper N9T head gasget. So its no go also. Bretty close but no.

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That's SO close!  I checked and the bore of the s14b25 is 94mm and it has even closer bore spacing than the N9TE.  Not turbo of course - but still interesting.

Nice work V-M!  Any updates on your motor?

Rabin

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  • 10 months later...

I've just joined  the site having picked up on these old discussions from 2009. If at all possible I want to try and build a ROC F2 spec engine so would be grateful if anyone can give me some information about the N9T engine and it's history (prior to finding this site I didn't even know what donor engine ROC had used In period which probably gives you an idea of where I am starting from.) The reason I want to 'source' an engine is because I have one of the ROC F2 cars from the 70's. 

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Welcome B29!

I assume your car didn't come with any engine spares?

The ONLY parts I've ever come across was the advert for the new head above, but it's marked sold now.

You could potentially get it running with an 8V head from the turbo N9T** engines and a custom NA cam - but I've got no idea what kinds of rules or restrictions vintage race cars have to follow.

In another thread I recently looked at twin plugging the stock head, but it would need holes bored into the head and machined spark tubes to be welded in to add the second plug.

Better idea is to copy what Danielson did and relocate the existing spark plug.  With a more modern/powerful ignition system firing spark more accurately - I suspect the advantage twin plugs had back then would either be eliminated or reduced to a very minor improvement at best.

Please feel free to start an engine thread though as I'd love to help any way I can.

Rabin

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b29, like in Chevron B29 I guess.

It is said that the ROC F2 engine was designed by Mario Illien and developed by Hans Funda.

The N9T bottom end is the last and best iteration of the Simca-Chrysler engine but not so special, you can find some N/A Tagora and Matra Murena with the "N9T" cast on the cylinder block.

Try the French Autodiva forum for more info about your car:
http://www.autodiva.fr/forum/viewforum.php?f=2

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1 hour ago, Bean said:

You could potentially get it running with an 8V head from the turbo N9T** engines and a custom NA cam - but I've got no idea what kinds of rules or restrictions vintage race cars have to follow.

Ford BDA, BMW M12/7 or Schnitzer 20-4 are more suited.

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44 minutes ago, SRDT said:

Ford BDA, BMW M12/7 or Schnitzer 20-4 are more suited.

Definitely more suited as a race motor if you're into competitive vintage racing, but if one is restoring it to be historically correct AND wants to run it in events you could built a decent 8V motor to Maurelec Lada-POC specs (240HP?) 

We'd need to know the intended purpose, budget, and race expectations to advise properly.

Rabin

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