24 replies to this topic

[Caddy]

Hello guys,

I havnt really used the forum to much in the past, so go easy on me please!
I've recently gained a 970 crankshaft.
I want to do something quite special with it, and was thinking possibly going down the turbo route, I was wondering if this has been done before at all or well it would work?
Cheers Dan

[Turbo Phil]

I don't know of anybody running a 970 Turbo, but there's no reason it can't be done.

Phil.

[mini13]

It could work really well, and would be exceptional for cirtain classes of racing, for example Will and Ben Hamer, have been running turbo'd 998 minis in hill climbs( about 140hp), the 998 with a turbo just falls into the 1400cc class iirc, your 970 with a +20 overbore would do the same, but you should beable to use a better head ( ugh will is now using a SC 7 port giving nigh on 180 hp), and spin the engine mugh higher,

 

you would need to do somithg a bit mad to make it worth while I think, you'd need to look at largish cam and turbo combinations to make the extra rpm potential of the head worth while, I'd say re13, with a gt17 or gt20 and spin the engine to 9k and see what it does.

Edited by mini13, 08 February 2014 - 12:39 PM.

[Leonrjohnson]

Check out this website:

http://project64mini.com/

 These Kiwis ran a 970 turbo to a world land speed record in its class.

[Caddy]

Thanks for the replies.
What kind of spec should I be looking at to get a decent power figure. I'm going to use a strong bottom end, with specialist components rods and omega forged pistons. What would you recommend on the piston cc size? And camshaft spec ect?
Thanks Dan

[Cooperman]

You really need a correct block and you definitely need the 970 rods to build a good 970 engine

 

It would be interesting for competition, but take care with the bore sizes that you stay within the rules.

 

The 970 has to rev really high in order to work well, so a light flywheel and a very low FDR is needed. I used a 4.1:1 in a 970 rally car I built.

 

You may need to lighten the valve gear as there can be problems due to valve train inertia.

 

Sounds an interesting, but very expensive, project and not really much good as a road car.

[Caddy]

This was a concern I had with the block as I would need to use a decked down 1275 block! I can get the correct length rods and already have an ultra lightweight flywheel and other bits from my current engine, and this engine would only be used on the road rarely as I'm going to use it for track days but also interested in hillclimbs and sprint racing. Also how would you lighten the valve train, carbon pushrods?
Dan

[Cooperman]

I've never trusted carbon pushrods. I machined down the cam followers and used a Cooper 'S' rocker shaft with the rockers modified, lightened and polished.

Lightened valve caps were also fitted with the correct rate double valve springs. It revved cleanly to 8500 rpm with a 286 cam, SC CR gearbox, twin HS4 carbs, 11:1 C.R., a really well-flowed head and a 4.1:1 FDR.

In its class it was competitive until it was up against a well-prepared Imp with a 998 engine and twin Webers, lightweight bodywork and a rev limit of c.10,000 rpm.

It was my son's car, but I drove it on a couple of events and, to be honest, I never really liked it. I guess I compared it to my 115 bhp Cooper 'S' 1293 which is seriously quick and an outright contender rather than just a class winner (sometimes).

Still, the 970 is an interesting engine and, of course, very rare.

[Caddy]

Yeah I've heard how the the carbon fibre rods are prone to breaking and it's hard to find a good set!
I've got titanium valve caps, I just need to get the correct sizes valves!

I've also had the idea of running my weber 45 with a turbo however you need a seal kit I'm told but can't find one anywhere ( or I'm just searching in the wrong places!)

[mini13]

I would look at using a non S block with 6" rods, I'm using the SC H beam rods and they are nicly made, and a resonable price.

 

blow through weber can be done, but I would look at using the 1275 Maestro manifold (long runners) and a normal turbo carb, and making up a long branch ex manifold and put the turbo over the clutch. (maybe cut up an LCB)

 

i think on a high rpm turbo engine manifold lengths become more of an issue, and also turbo size.... keem the turbo big so there is less turbine inlet pressure,

 

all a bit theoretical though!

[Cooperman]

Another interesting thread is this one with sensible and constructive comments.

[mini13]

I used some of the thick carbon pushrods, never had a breakage issue, but they were a nightmare to get clearance on, so pulled them out an ebayed them.

 

have you considered going for another head? K1100, 7 port, Punto,

 

I think the 8v punto/cinq head could work well, they are good for RPM and can be made to flow well.

[Caddy]

Yes I've heard good things about the sc rods and at a fraction of the price compared to other brands!

I've seen a few pictures of turbo set ups over the clutch, which would probably be the way forward!

I have also looked into other head possibilitys.
I loved the idea of a 16v k head and also 7 port.
I've heard of the punto head but never researched into this, I will have to investigate!

[mini13]

Punto head is an interesting one,

 

there is the choice of 8v or 16v, both use the same headgasket ( I can send a dxf of one if your interested) you need to plug and redrill head stud holes and water ways in a similar fassion to the K1100 conversion,  and put valve cutouts in for the 16v... for the 8v I think you can get away with no cutouts for the std cam, but might need them for the punto 75 cam due to the higher lift, although your probably ok oif your running dished pistons as the fiat lump has flat tops and only very small cutouts.

 

the conversion is easier than the K1100 as you dont need to do all the faffing about to convert the head to a cam belt, and I think you could get away without weldoing the head.

 

the 8v flows a similar amount to a 12G940, and basically has similar potential, but is OHC so there is more scope cam wise, and should have higher port flow speeds due to more efficient ports being 8 port, and is also easier to inject. The 16v although it flows really well is limited cam wise due to the hydraulic tappet arangement, not really worth looking at over about 7-7.5k rpm.

[Caddy]

Sounds very interesting, what kind of power outputs are people getting from this conversion?
I work for Fiat and Iveco so parts should be easy to source.

This is going to be an expensive build so It's going to take time! I've just got to figure out what route to take with it, I'm also very interested in how well the 970 would respond to a 7 port head, this would also probably be the cheapest option as it would all bolt straight on!