I'm on with building a Nasp 5 cylinder Focus RS / ST / Volvo engine at the moment and I'm wondering what is the best route to take regarding stroke.


I will use the 83mm block and bore it to 84mm as I have two of these in my garage awaiting attention.

Problem is do I use the 77mm stroke crank and go for a high reving (9500rpm) engine?

Or do I use the 90mm stroke and go for a more torquey engine that may produce more power?

The BTCC Volvos produced over 300bhp out of the 2 litre 5 cylinder using a 83mm bore and 73mm stroke

The good thing about the 77mm stroke route is the extra revs and the good rod length of 152mm giving a rod ratio of 2

It will give a capacity of just over 2.1

The bad thing about the 90mm stroke is the lower rev limit and the rod length of 140mm which gives a bad rod ratio of 1.5

What do you guys suggest I should do?

Head will be reworked using larger valves with smaller stems, hydraulic tappets will be replaced for solids and I already have the throttle bodies and manifold sorted for a 10 injector setup which was developed for a touring car team in Belgium.

Also have sourced some cam blanks for some wild profile cams too.


Cheers

Austen

 

I guess not many people know much about this engine then

 

Austen, try www.passionvolvo.com

 

I’m a Master Tech at Volvo but what your doing doesn’t really crop up in my day to day job!!

If you need any info on the engine like torque settings, assembly instructions I may be able to help as I have rebuilt a fair few in my time.

 

ooh isnt that a nice looking motors

 

What are the main faults with this engine you have come across?

 

To be honest there pretty reliable and well designed/built. The weak point is the connecting rods and I have rebuilt a couple that have slightly bent rods due to increased boost (been chipped). When this happens the small end catches on the crank web resulting in a bottom end knock.

Rear main failures were fairly common on the early engines but we don’t get too many failing now.

Thermostats can sometimes stick and cause overheating and if not noticed in time will lead to head gasket failure.

Very rarely the aluminium castings can go pourus and lead to an oil leak.

 

Got a few bits for this engine already

Managed to get a lightweight steel flywheel made for a 7.25" clutch



Also managed to get hold of a throttle body injection manifold system too

Looking at getting a Pace dry sump system,

If I can get around 5 people interested they will do all the castings etc for the volvo 5 cylinder engine as in the Focus ST225

 

Details of the engine spec are:
S60 base engine

35mm inlet valve 6mm stem
31mm exhaust valve 6mm stem
double valve springs
titanium retainers
32mm solid buckets
Cat cams 310 deg inlet 13.5mm lift
Cat Cams 300 deg exh 13 mm lift
Larger seats
Extensive head porting to suit

13:1 high compression pistons made to my spec from CP 83mm bore

2.0l 77mm steel crank

152mm h section rods,, give rod ratio of almost 2:1

3 stage Dry Sump system

Using Jenvey inlet system, inc Individual throttle bodies

KMS Management system

The engine will be a 2.1L screamer

 

the guy you need to speak to is Don off teh focus st oc site, Don Kalmar Union - he is very keyed up on these engines... http://www.kalmar-union.com/

 

I've spoken to Don a few times, nice bloke

In his words he admitted to be clueless when it came to this

 

 

Here are some pics of the sump pan before welding

I had spare made just incase, if interested in it PM me

The base plate is 3/4 inch 6082 alloy to keep the rigidity of the block

The channel and bottom are 1/4 inch 6082

The Oil take off's are screened fittings made by Pace Products in the UK.

Hope you like?

 

77mm and 9500rpm isnt particuarly working hard so im sure that would be good but I would be inclined to go for the 90mm stroke and still go to 8500rpm though

Loads of XE engines out there at 86mm making monster power at way beyond 9000rpm, so 8500rpm on a 90mm doesnt seem a big ask at all.

Depends on how bad those rod angles end up though of course!
Can you not gain a few more mm for longer rods by moving the pin up in the piston, espicially if you are going high comp which you obviously will be?

 

Rod ratio is already 1.97

77mm stroke 152mm c/c rods

 

So the 140 and 90 is coming out at 1.55

Can see why that would bother you!

And to get it back to nearer to a ratio of 2, is going to need the pin moving up 40mm, so blatantly not going to happen!


I think you have answered your own question then mate, on rod ratio alone it looks like it needs to be the 77mm crank!

 

I decided to keep it 2.1 with a 77mm stroke as I spoke to a few guys who seriously race westfields and the concensious was that the 2.0L will be more controlable and faster on track, more revs and less torque are better in these type of cars, esp mid corner

Managed to get the head flow tested as well

 

After over a year of waiting I finally got my head and cams back from QEP / Cat Cams

Just need to get some pistons made and I can start bolting the engine together.

Need to redress the inlet valve seat area and skim the head also

 

2.0l crank

 

Nice to see this still progressing

 

Love it!

 

Just getting the head ceramic coated on the inlet and exhaust ports and combustion chamber.

Once that is back its going to JWT @ Stanwood Engineering for a dummy build to make up some dummy pistons with the right height and valve cutouts so the pistons can be ordered from CP in the USA

Using the old pistons as a template, building them up with chemical metal then machining them to suit.

Once completed then sending them as a template for CP to copy

 

Christ thats some serious work, what sort of cost is in a completely custom set of pistons?

 

Nice work Austen !

I did see the sump pans on ebay, did you put some velocity stacks on there as well or were they not yours ?

 

Yes i made some velocity stacks up for the Jenvey plenum, but got an extra 4 made as spares and sold them on ebay

 

Stacks went a lot cheaper than I expected tbh

Got some tb spacers if you ever need some :

 

Looks nice

 

Here are some pics of the sump all welded up top and bottom

The screened scavenge takeoffs are designed and manufactured by Pace Products in the UK who make alot of dry sump systems so they are a proven design

Note the main bolt reliefs machined into the base

 

this is very cool! i bet the engine will sound fantastic when its built. never heard a 5cylinder on throttle bodies :O

 

It should sound like this

This is capped at 8500rpm due to regs

Mine should hit 9500rpm plus

http://www.youtube.com/watch?v=zvcv3gtYFp4

 

Just updated a few pics

 

the volvo cars in the WTCC are all atmo 5 cylinders.

there destroked to 2 litres, run a single throttle-body and a beutifull 5-1 exhaust manifold

they sound like formula 1 cars on the back strait at brands hatch lol

 

I must admit they do sound one of the best engines

That was one of my main reasons for doing a high reving nasp 5 cyl

 

i might have some pictures/videos to post.. not sure how much use they will be but i'll post anyway

 

did you find those pics?

 

I've managed to get hold of the cam belt idler pully as pictured below

I managed to get one from one of the touring car race teams in Sweden

 

 

that s40 in the clip sounds fucking awesome....i dont think i should have watched that

 

what an engine youve built mate.Any more pics of the build?i love these engines.

 

No new pics as yet, its coming together slowly